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[Maria-developers] MDEV-17399: JSON_TABLE: Code cleanup
by Sergey Petrunia 04 Mar '21

04 Mar '21

Hi Alexey, Please check out this patch: http://lists.askmonty.org/pipermail/commits/2021-March/014492.html Any objections to it? BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://petrunia.net

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[Maria-developers] MDEV-17399: JSON_TABLE: Crash with nested path
by Sergey Petrunia 01 Mar '21

01 Mar '21

Hi Alexey, I was looking at Json_table_nested_path::set_position(), wondering why does it have an assignment np->m_null= TRUE; but doesn't clear the NULL values and trying to come up with an example of this going wrong when I've hit this crash: select * from json_table( '[ {"name": "X", "colors":["blue"], "sizes": [1,2,3,4], "prices" : [10,20]}, {"name": "Y", "colors":["red"], "sizes": [10,11], "prices" : [100,200,300]} ]', '$[*]' columns ( seq0 for ordinality, name varchar(4) path '$.name', nested path '$.colors[*]' columns ( seq1 for ordinality, color text path '$' ), nested path '$.sizes[*]' columns ( seq2 for ordinality, size int path '$' ), nested path '$.prices[*]' columns ( seq3 for ordinality, price int path '$' ) ) ) as T order by seq0, name; Note this==NULL: (gdb) wher #0 0x00005555560edf72 in Json_table_nested_path::set_position (this=0x0, j_start=0x7ffeb0016e68 "[ \n {\"name\": \"X\", \n \"colors\":[\"blue\"], \"sizes\": [1,2,3,4], \"prices\" : [10,20]},\n {\"name\": \"Y\", \n \"colors\":[\"red\"], \"sizes\": [10,11], \"prices\" : [100,200,300]}\n]", j_end=0x7ffeb0016f12 "", pos=0x7ffeb0035e51 "\245\245\245\245\245\245\245\245\006") at /home/psergey/dev-git2/10.6-hf-review6/sql/table_function.cc:239 #1 0x00005555560ee12f in Json_table_nested_path::set_position (this=0x7ffeb0017060, j_start=0x7ffeb0016e68 "[ \n {\"name\": \"X\", \n \"colors\":[\"blue\"], \"sizes\": [1,2,3,4], \"prices\" : [10,20]},\n {\"name\": \"Y\", \n \"colors\":[\"red\"], \"sizes\": [10,11], \"prices\" : [100,200,300]}\n]", j_end=0x7ffeb0016f12 "", pos=0x7ffeb0035e48 "") at /home/psergey/dev-git2/10.6-hf-review6/sql/table_function.cc:262 #2 0x00005555560ee9f0 in ha_json_table::rnd_pos (this=0x7ffeb0014f00, buf=0x7ffeb0025570 "\377", pos=0x7ffeb0035e48 "") at /home/psergey/dev-git2/10.6-hf-review6/sql/table_function.cc:434 #3 0x00005555561ca6a4 in handler::ha_rnd_pos (this=0x7ffeb0014f00, buf=0x7ffeb0025570 "\377", pos=0x7ffeb0035e48 "") at /home/psergey/dev-git2/10.6-hf-review6/sql/handler.cc:3101 #4 0x00005555563852e3 in rr_from_pointers (info=0x7ffeb001f9e0) at /home/psergey/dev-git2/10.6-hf-review6/sql/records.cc:615 #5 0x0000555555da4a75 in READ_RECORD::read_record (this=0x7ffeb001f9e0) at /home/psergey/dev-git2/10.6-hf-review6/sql/records.h:81 #6 0x0000555555ee1876 in join_init_read_record (tab=0x7ffeb001f918) at /home/psergey/dev-git2/10.6-hf-review6/sql/sql_select.cc:21644 #7 0x0000555555edf35a in sub_select (join=0x7ffeb001d948, join_tab=0x7ffeb001f918, end_of_records=false) at /home/psergey/dev-git2/10.6-hf-review6/sql/sql_select.cc:20666 #8 0x0000555555ede8e6 in do_select (join=0x7ffeb001d948, procedure=0x0) at /home/psergey/dev-git2/10.6-hf-review6/sql/sql_select.cc:20216 #9 0x0000555555eb24e7 in JOIN::exec_inner (this=0x7ffeb001d948) at /home/psergey/dev-git2/10.6-hf-review6/sql/sql_select.cc:4484 #10 0x0000555555eb1613 in JOIN::exec (this=0x7ffeb001d948) at /home/psergey/dev-git2/10.6-hf-review6/sql/sql_select.cc:4264 Please fix. BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://petrunia.net

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Re: [Maria-developers] ee538938345: MDEV-21117: refine the server binlog-based recovery for semisync
by Sergei Golubchik 26 Feb '21

26 Feb '21

Hi, Sujatha! The main comment - the logic is so complex, I wasn't able to understand it, unfortunately. I've reviewed almost everything, see comments below. But not the Recovery_context methods. Please explain how it works and how all these truncate_validated, truncate_reset_done, truncate_set_in_1st, etc all work together. On Feb 26, Sujatha wrote: > revision-id: ee538938345 (mariadb-10.3.26-68-gee538938345) > parent(s): 7d04ce6a2d4 > author: Sujatha <sujatha.sivakumar(a)mariadb.com> > committer: Andrei Elkin <andrei.elkin(a)mariadb.com> > timestamp: 2021-02-08 17:58:03 +0200 > message: > > MDEV-21117: refine the server binlog-based recovery for semisync > this should be MDEV subject. But if you like this better you can rename the MDEV instead > > Problem: > ======= > When the semisync master is crashed and restarted as slave it could > recover transactions that former slaves may never have seen. > A known method existed to clear out all prepared transactions > with --tc-heuristic-recover=rollback does not care to adjust > binlog accordingly. > > Fix: > === > The binlog-based recovery is made to concern of the slave semisync role of > post-crash restarted server. > No changes in behaviour is done to the "normal" binloggging server > and the semisync master. > > When the restarted server is configured with > --rpl-semi-sync-slave-enabled=1 > the refined recovery attempts to roll back prepared transactions > and truncate binlog accordingly. > In case of a partically committed (that is committed at least > partially > > in one of the engine participants) such transaction gets committed. > It's guaranteed no (partially as well) committed transactions > exist beyond the truncate position. > In case there exists a non-transactional replication event > (being in a way a committed transaction) past the > computed truncate position the recovery ends with an error. > > To facilite the failover on the slave side facilitate > conditions to accept own events (having been discarded by the above recovery) > are relaxed to let so for the semisync slave that connects to master > in gtid mode. gtid_strict_mode is further recommended to secure > from inadvertent re-applying out of order gtids in general. > Non-gtid mode connected semisync slave would require > --replicate-same-server-id (mind --log-slave-updates must be OFF then). Sorry, I failed to understand this paragraph :( > > diff --git a/mysql-test/suite/binlog/t/binlog_truncate_active_log.test b/mysql-test/suite/binlog/t/binlog_truncate_active_log.test > new file mode 100644 > index 00000000000..cf89525dcac > --- /dev/null > +++ b/mysql-test/suite/binlog/t/binlog_truncate_active_log.test > @@ -0,0 +1,76 @@ > +# ==== Purpose ==== > +# > +# Test verifies the truncation of single binary log file. > +# > +# ==== Implementation ==== > +# > +# Steps: > +# 0 - Create table t1 and insert/commit a row. > +# 1 - Insert an another row such that it gets written to binlog but commit > +# in engine fails as server crashed at this point. > +# 2 - Restart server with --rpl-semi-sync-slave-enabled=1 > +# 3 - Upon server start 'master-bin.000001' will be truncated to contain > +# only the first insert > +# > +# ==== References ==== > +# > +# MDEV-21117: recovery for --rpl-semi-sync-slave-enabled server > + > +--source include/have_innodb.inc > +--source include/have_aria.inc > +--source include/have_log_bin.inc > +--source include/have_debug.inc > +--source include/have_binlog_format_statement.inc have_binlog_format_statement obviously implies have_log_bin. it's redundant to specify it explicitly. and you don't need have_debug here > + > +call mtr.add_suppression("Can.t init tc log"); > +call mtr.add_suppression("Aborting"); > + > +# The following cases are tested: > +# A. 2pc transaction is followed by a blank "zero-engines" one > +# B. 2pc transaction follows the blank one > +# C. Similarly to A, with the XA blank transaction > + > +--connection default it's connection default by default (not surprisingly) :) > +RESET MASTER; > +CREATE TABLE t ( f INT ) ENGINE=INNODB; > +CREATE TABLE t2 ( f INT ) ENGINE=INNODB; > +CREATE TABLE tm ( f INT ) ENGINE=Aria; Why Aria? I mean, the default "standard" non-transactional engine is MyISAM. If you use Aria, it means you thought about it and decided to deviate intentionally from the default. What were your considerations? > + > +--echo # Case A. > +# Both are doomed into truncation. > +--let $this_search_pattern = Successfully truncated.*to remove transactions starting from GTID 0-1-6 why not simply --let SEARCH_PATTERN = Successfully truncated...etc... > +--let $query1 = INSERT INTO t VALUES (20) > +--let $query2 = DELETE FROM t2 WHERE f = 666 /* no such record */ > +--source binlog_truncate_active_log.inc > + > +--echo # Case B. > +# The inverted sequence ends up to truncate only $query2 > +--let $this_search_pattern = Successfully truncated.*to remove transactions starting from GTID 0-1-10 > +--let $query1 = DELETE FROM t2 WHERE f = 0 why not `= 666 /* no such record */` ? is `= 0` important here? > +--let $query2 = INSERT INTO t VALUES (20) > +--source binlog_truncate_active_log.inc > + > + > +delimiter |; > +CREATE PROCEDURE sp_blank_xa() > +BEGIN > + XA START 'blank'; > + DELETE FROM t2 WHERE f = 666 /* no such record */; > + XA END 'blank'; > + XA PREPARE 'blank'; > +END| > +delimiter ;| > + > + > +--echo # Case C. > +--let $this_search_pattern = Successfully truncated.*to remove transactions starting from GTID 0-1-13 > +--let $query1 = INSERT INTO t VALUES (20) > +--let $pre_q2 = CALL sp_blank_xa > +--let $query2 = XA COMMIT 'blank' > +--source binlog_truncate_active_log.inc > +DROP PROCEDURE sp_blank_xa; > + > +--echo # Cleanup > +DROP TABLE t,t2,tm; > + > +--echo # End of the tests > diff --git a/mysql-test/suite/binlog/t/binlog_truncate_active_log.inc b/mysql-test/suite/binlog/t/binlog_truncate_active_log.inc > new file mode 100644 > index 00000000000..b1ffaf18268 > --- /dev/null > +++ b/mysql-test/suite/binlog/t/binlog_truncate_active_log.inc > @@ -0,0 +1,70 @@ you need source include/have_debug_sync.inc here, as this file uses DEBUG_SYNC > +connect(master1,localhost,root,,); > +connect(master2,localhost,root,,); > +connect(master3,localhost,root,,); just FYI (no need to change anything), you know that parentheses and extra commas are optional, right? that is, it could be written as connect master1,localhost,root; connect master2,localhost,root; connect master3,localhost,root; > + > +--connection default > + > +# First to commit few transactions > +INSERT INTO t VALUES (10); > +INSERT INTO tm VALUES (10); > + > +--connection master1 > +# Hold insert after write to binlog and before "run_commit_ordered" in engine > +SET DEBUG_SYNC= "commit_before_get_LOCK_commit_ordered SIGNAL master1_ready WAIT_FOR signal_never_arrives"; > +--send_eval $query1 > + > +--connection master2 > +SET DEBUG_SYNC= "now WAIT_FOR master1_ready"; > +if ($pre_q2) is $pre_q2 a flag or a query string? it's used as a flag, it's set as a query string. > +{ > + CALL sp_blank_xa; > +} > +SET DEBUG_SYNC= "commit_before_get_LOCK_after_binlog_sync SIGNAL master2_ready"; > +# To binlog non-xid transactional group which will be truncated all right > +--send_eval $query2 > + > + > +--connection master3 > +SET DEBUG_SYNC= "now WAIT_FOR master2_ready"; > +SELECT @@global.gtid_binlog_pos as 'Before the crash'; > + > +--write_file $MYSQLTEST_VARDIR/tmp/mysqld.1.expect > +wait > +EOF > + > +--source include/kill_mysqld.inc > +--source include/wait_until_disconnected.inc you know that kill_mysqld both writes 'wait' to the expect file and includes wait_until_disconnected ? > +# > +# Server restart > +# > +--append_file $MYSQLTEST_VARDIR/tmp/mysqld.1.expect > +restart: --rpl-semi-sync-slave-enabled=1 > +EOF why "append_file" and not "write_file" ? and why wait, you could've written restart right away, couldn't you? > + > +connection default; > +--enable_reconnect > +--source include/wait_until_connected_again.inc > + > +# Check error log for a successful truncate message. > +let $log_error_= `SELECT @@GLOBAL.log_error`; > +if(!$log_error_) > +{ > + # MySQL Server on windows is started with --console and thus > + # does not know the location of its .err log, use default location > + let $log_error_ = $MYSQLTEST_VARDIR/log/mysqld.1.err; isn't it always $MYSQLTEST_VARDIR/log/mysqld.1.err? other tests don't do it conditionally > +} > +--let SEARCH_FILE=$log_error_ > +--let SEARCH_RANGE=-50000 if you're searching in the error log - and you are - it's best not to set the SEARCH_RANGE at all. Then it'll search from the last CURRENT_TEST: label. That is, it'll search in all error log entries generated by the current test and not in the error log that came from earlier tests. > +--let SEARCH_PATTERN=$this_search_pattern > +--replace_regex /FOUND [0-9]+/FOUND #/ can it be found multiple times? Why would binlog be truncated more than once? > +--source include/search_pattern_in_file.inc > + > +SELECT @@global.gtid_binlog_pos as 'After the crash'; > +--echo "One row should be present in table 't'" > +SELECT COUNT(*) as 'One' FROM t; Do you know which one? If yes, why not `SELECT * FROM t` ? > + > +# Local cleanup > +DELETE FROM t; > +--disconnect master1 > +--disconnect master2 > +--disconnect master3 > diff --git a/mysql-test/suite/binlog/t/binlog_truncate_multi_engine.test b/mysql-test/suite/binlog/t/binlog_truncate_multi_engine.test > new file mode 100644 > index 00000000000..fe153e5703c > --- /dev/null > +++ b/mysql-test/suite/binlog/t/binlog_truncate_multi_engine.test > @@ -0,0 +1,78 @@ > +# ==== Purpose ==== > +# > +# Test verifies truncation of multiple binary logs. and "with multiple transactional storage engines" ? > +# > +# ==== Implementation ==== > +# > +# Steps: > +# 0 - Create two tables in innodb and rocksdb engines, > +# > +# In loop for A,B,C cases (below) do 1-5: there's no loop now (which is good, don't add it please :) > +# 1 - execute FLUSH LOGS command to generate a new binary log. > +# Start a transaction inserting rows of sufficient sizes > +# so binary log gets rotated at commit > +# 2 - Using debug simulation make the server crash at a point where > +# the transaction is written to binary log *and* either of > +# A. neither of them commits > +# B. only one commits > +# C. both commit > +# 3 - print the # of binlog files before the transaction starts and after its > +# commit is submitted > +# 4 - Restart server with --tc-heuristic-recover=BINLOG_TRUNCATE outdated comment? > +# 5 - Restart normally to print post recovery status. > +# > +# ==== References ==== > +# > +# MDEV-21117: recovery for --rpl-semi-sync-slave-enabled server > + > + > +--source include/have_innodb.inc > +--source include/have_rocksdb.inc > +--source include/have_log_bin.inc this is redundant > +--source include/have_debug.inc > +--source include/have_debug_sync.inc > +--source include/have_binlog_format_row.inc > + > +--let $old_max_binlog_size= `select @@global.max_binlog_size` > +call mtr.add_suppression("Can.t init tc log"); > +call mtr.add_suppression("Aborting"); > +--let $MYSQLD_DATADIR= `SELECT @@datadir` > + > +CREATE TABLE t1 (a INT PRIMARY KEY, b MEDIUMTEXT) ENGINE=Innodb; > +CREATE TABLE t2 (a INT PRIMARY KEY, b MEDIUMTEXT) ENGINE=rocksdb; > + > +--let $case = A: neither engine committed => rollback & binlog truncate > +# Hold off engine commits after write to binlog and its rotation. > +# The transaction is killed along with the server after that. > +--let $kill_server=1 > +--let $debug_sync_action = "commit_after_release_LOCK_log SIGNAL con1_ready WAIT_FOR signal_no_signal" > +--let $restart_parameters = --rpl-semi-sync-slave-enabled=1 > +--let $test_outcome= 1 row should be present in both tables; binlog is truncated; number of binlogs at reconnect - 3 > + --source binlog_truncate_multi_engine.inc > +--echo Proof of the truncated binlog file is readable (two transactions must be seen): > +--let $MYSQLD_DATADIR = `select @@datadir` no need to set the $MYSQLD_DATADIR twice > +--exec $MYSQL_BINLOG --short-form --skip-annotate-row-events $MYSQLD_DATADIR/master-bin.000002 > + > +--let $case = B: one engine has committed its transaction branch > +# Hold off after one engine has committed. > +--let $kill_server=1 > +--let $debug_sync_action = "commit_after_run_commit_ordered SIGNAL con1_ready WAIT_FOR signal_no_signal" > +--let $restart_simulate_partial_commit = 1 this variable seems to be unused > +--let $restart_parameters = --rpl-semi-sync-slave-enabled=1 --debug-dbug=d,binlog_truncate_partial_commit this seems to be a rather crude way of faking a partially committed transaction. better to crash after the first engine has committed, that'd be much more natural. > +--let $test_outcome= 2 rows should be present in both tables; no binlog truncation; one extra binlog file compare with A; number of binlogs at reconnect - 4 > + --source binlog_truncate_multi_engine.inc > + > +--let $case = C: both engines have committed its transaction branch you didn't do --let $debug_sync_action = "reset", so the old value is used. Intentional? > +# Hold off after both engines have committed. The server is shut down. > +--let $kill_server=0 > +--let $restart_parameters = --rpl-semi-sync-slave-enabled=1 > +--let $test_outcome= 2 rows should be present in both tables; no binlog truncation; the same # of binlog files as in B; number of binlogs at reconnect - 4 > + --source binlog_truncate_multi_engine.inc > + > + > + > +DROP TABLE t1, t2; > +--replace_result $old_max_binlog_size VALUE_AT_START > +--eval SET @@global.max_binlog_size = $old_max_binlog_size better use evalp instead of eval, then you won't need replace_result but really I think you don't need to save/restore max_binlog_size at all, because you restart the server anyway. > + > +--echo # End of the tests > diff --git a/mysql-test/suite/binlog/t/binlog_truncate_multi_engine.inc b/mysql-test/suite/binlog/t/binlog_truncate_multi_engine.inc > new file mode 100644 > index 00000000000..c260a7987e2 > --- /dev/null > +++ b/mysql-test/suite/binlog/t/binlog_truncate_multi_engine.inc > @@ -0,0 +1,64 @@ > +# > +# Loop body of binlog_truncate_multi_engine.test > +# Parameters: > +# $debug_sync_action describes debug-sync actions > +# $kill_server 1 when to crash, 0 for regular restart > +# $restart_parameters the caller may simulate partial commit at recovery > +# $test_outcome summary of extected results > +# $MYSQLD_DATADIR > + > +--echo # > +--echo # > +--echo # Case $case > +--echo # > +RESET MASTER; > +FLUSH LOGS; > +SET GLOBAL max_binlog_size= 4096; > + > +connect(con1,localhost,root,,); > +#--connection con1 > +--echo List of binary logs before rotation > +--source include/show_binary_logs.inc > +INSERT INTO t1 VALUES (1, REPEAT("x", 1)); > +INSERT INTO t2 VALUES (1, REPEAT("x", 1)); > +BEGIN; > + INSERT INTO t1 VALUES (2, REPEAT("x", 4100)); > + INSERT INTO t2 VALUES (2, REPEAT("x", 4100)); > + > +--eval SET DEBUG_SYNC= $debug_sync_action > +send COMMIT; > + > +--connection default > +SET DEBUG_SYNC= "now WAIT_FOR con1_ready"; > +--echo List of binary logs after rotation > +--source include/show_binary_logs.inc > + > +--echo # restart the server with $restart_parameters > +if ($kill_server) > +{ > + --echo # the server is crashed > + --source include/kill_mysqld.inc > + --source include/start_mysqld.inc > +} > +if (!$kill_server) > +{ > + --echo # the server is restarted > + --source include/restart_mysqld.inc it'd be simpler not to use $kill_server at all. And instead write let $shutdown_timeout=0; instead of $kill_server=1; and let $shutdown_timeout=; instead of $kill_server=0; and above you won't need two if's, you can just do source include/restart_mysqld.inc; > +} > + > +--connection default > +--echo # > +--echo # *** Summary: $test_outcome: > +--echo # > +SELECT COUNT(*) FROM t1; > +SELECT COUNT(*) FROM t2; > +SELECT @@GLOBAL.gtid_binlog_state; > +SELECT @@GLOBAL.gtid_binlog_pos; > +--echo List of binary logs at the end of the tests > +--source include/show_binary_logs.inc > +--echo # *** > +# cleanup > +DELETE FROM t1; > +DELETE FROM t2; > +--disconnect con1 > +--echo # > diff --git a/mysql-test/suite/binlog/t/binlog_truncate_multi_log.test b/mysql-test/suite/binlog/t/binlog_truncate_multi_log.test > new file mode 100644 > index 00000000000..231e90dbdc9 > --- /dev/null > +++ b/mysql-test/suite/binlog/t/binlog_truncate_multi_log.test > @@ -0,0 +1,105 @@ > +# ==== Purpose ==== > +# > +# Test verifies truncation of multiple binary logs. > +# > +# ==== Implementation ==== > +# > +# Steps: > +# 1 - Set max_binlog_size= 4096, to help a series of inserts into a > +# transaction table 'ti' get binlog rotated so many time while the > +# transactions won't be committed, being stopped at > +# a prior to commit debug_sync point > +# 2 - kill and restart the server as semisync slave successfully to > +# end with an expected first binlog and the gtid state. > +# > +# ==== References ==== > +# MDEV-21117: recovery for --rpl-semi-sync-slave-enabled server > + > +--source include/have_innodb.inc > +--source include/have_log_bin.inc > +--source include/have_debug.inc > +--source include/have_debug_sync.inc > +--source include/have_binlog_format_row.inc > + > +call mtr.add_suppression("Can.t init tc log"); > +call mtr.add_suppression("Aborting"); > + > +--let $old_max_binlog_size= `select @@global.max_binlog_size` > +SET @@global.max_binlog_size= 4096; > + > +RESET MASTER; > +FLUSH LOGS; > +CREATE TABLE ti (a INT PRIMARY KEY, b MEDIUMTEXT) ENGINE=Innodb; > +CREATE TABLE tm (a INT PRIMARY KEY, b MEDIUMTEXT) ENGINE=MyISAM; > + > +connect(master1,localhost,root,,); > +--echo "List of binary logs before rotation" > +--source include/show_binary_logs.inc > + > +# Some load to either non- and transactional egines > +# that should not affect the following recovery: > +INSERT INTO ti VALUES(1,"I am gonna survive"); > +INSERT INTO tm VALUES(1,"me too!"); > + > +# hold on near engine commit > +SET DEBUG_SYNC= "commit_after_release_LOCK_after_binlog_sync SIGNAL master1_ready WAIT_FOR con1_go"; > +--send_eval INSERT INTO ti VALUES (2, REPEAT("x", 4100)) > + > +connect(master2,localhost,root,,); > +# The 2nd trx for recovery, it does not rotate binlog > +SET DEBUG_SYNC= "now WAIT_FOR master1_ready"; > +SET DEBUG_SYNC= "commit_before_get_LOCK_commit_ordered SIGNAL master2_ready WAIT_FOR master2_go"; > +--send_eval INSERT INTO ti VALUES (3, "not gonna survive") > + > +--connection default > +SET DEBUG_SYNC= "now WAIT_FOR master2_ready"; > +--echo "List of binary logs before crash" > +--source include/show_binary_logs.inc > +--echo # The gtid binlog state prior the crash will be truncated at the end of the test > +SELECT @@global.gtid_binlog_state; > +--write_file $MYSQLTEST_VARDIR/tmp/mysqld.1.expect > +wait > +EOF > + > +--source include/kill_mysqld.inc > +--source include/wait_until_disconnected.inc > + > +# > +# Server restart > +# > +--append_file $MYSQLTEST_VARDIR/tmp/mysqld.1.expect > +restart: --rpl-semi-sync-slave-enabled=1 > +EOF > + > +connection default; > +--enable_reconnect > +--source include/wait_until_connected_again.inc > + > +# Check error log for a successful truncate message. > +let $log_error_= `SELECT @@GLOBAL.log_error`; > +if(!$log_error_) > +{ > + # MySQL Server on windows is started with --console and thus > + # does not know the location of its .err log, use default location > + let $log_error_ = $MYSQLTEST_VARDIR/log/mysqld.1.err; > +} > +--let SEARCH_FILE=$log_error_ > +--let SEARCH_RANGE=-50000 > +--let SEARCH_PATTERN=truncated binlog file:.*master.*000002 > +--replace_regex /FOUND [0-9]+/FOUND #/ > +--source include/search_pattern_in_file.inc > + > + > +--echo "One record should be present in table" > +SELECT count(*) FROM ti; > + > +--echo # The truncated gtid binlog state > +SELECT @@global.gtid_binlog_state; > +SELECT @@global.gtid_binlog_pos; > + > +--echo # Cleanup > +--replace_result $old_max_binlog_size VALUE_AT_START > +--eval SET @@global.max_binlog_size = $old_max_binlog_size > +DROP TABLE ti; > + many of my comments above apply to this test too > +--echo # End of the tests > diff --git a/mysql-test/suite/binlog/t/binlog_truncate_multi_log_unsafe.test b/mysql-test/suite/binlog/t/binlog_truncate_multi_log_unsafe.test > new file mode 100644 > index 00000000000..6aba2935fde > --- /dev/null > +++ b/mysql-test/suite/binlog/t/binlog_truncate_multi_log_unsafe.test > @@ -0,0 +1,142 @@ > +# ==== Purpose ==== > +# The test verifies attempt to recover by the semisync slave server whose > +# binlog is unsafe for truncation. > +# > +# ==== Implementation ==== > +# 2 binlog files are created with the 1st one destined to be the binlog > +# checkpoint file for recovery. > +# The final group of events is replication unsafe (myisam INSERT). > +# Therefore the semisync slave recovery may not. > +# > +# Steps: > +# 0 - Set max_binlog_size= 4096, to help an insert into a > +# transaction table 'ti' get binlog rotated while the > +# transaction won't be committed, being stopped at > +# a prior to commit debug_sync point > +# 1 - insert into a non-transactional 'tm' table completes with > +# binary logging as well > +# 2 - kill and attempt to restart the server as semisync slave that > +# must produce an expected unsafe-to-recover error > +# 3 - complete the test with a normal restart that successfully finds and > +# commits the transaction in doubt. > +# > +# ==== References ==== > +# MDEV-21117: recovery for --rpl-semi-sync-slave-enabled server > + > + > +--source include/have_innodb.inc > +--source include/have_log_bin.inc > +--source include/have_debug.inc > +--source include/have_debug_sync.inc > +--source include/have_binlog_format_row.inc > + > +--let $old_max_binlog_size= `select @@global.max_binlog_size` > +SET @@global.max_binlog_size= 4096; > + > +call mtr.add_suppression("Table '.*tm' is marked as crashed and should be repaired"); > +call mtr.add_suppression("Got an error from unknown thread"); > +call mtr.add_suppression("Checking table: '.*tm'"); > +call mtr.add_suppression("Recovering table: '.*tm'"); > +call mtr.add_suppression("Cannot trim the binary log to file"); > +call mtr.add_suppression("Crash recovery failed"); > +call mtr.add_suppression("Can.t init tc log"); > +call mtr.add_suppression("Aborting"); > +call mtr.add_suppression("Found 1 prepared transactions"); > +call mtr.add_suppression("mysqld: Table.*tm.*is marked as crashed"); > +call mtr.add_suppression("Checking table.*tm"); > + > +RESET MASTER; > +FLUSH LOGS; > +CREATE TABLE ti (a INT PRIMARY KEY, b MEDIUMTEXT) ENGINE=Innodb; > +CREATE TABLE tm (f INT) ENGINE=MYISAM; > + > +--let $row_count = 5 > +--let $i = 3 > +--disable_query_log > +while ($i) > +{ > + --eval INSERT INTO ti VALUES ($i, REPEAT("x", 1)) > +--dec $i > +} > +--enable_query_log > +INSERT INTO tm VALUES(1); > + > +connect(master1,localhost,root,,); > +connect(master2,localhost,root,,); > +connect(master3,localhost,root,,); > + > +--connection master1 > + > +# The 1st trx binlogs, rotate binlog and hold on before committing at engine > +SET DEBUG_SYNC= "commit_after_release_LOCK_after_binlog_sync SIGNAL master1_ready WAIT_FOR master1_go"; you don't wait for master1_ready anywhere. intentional? > +--send_eval INSERT INTO ti VALUES ($row_count - 1, REPEAT("x", 4100)) if you plan to insert rows 1,2,3,4,5 then your $i=3 and $row_count=5 are not independent, you should use $i=$row_count-2. (probably $i=`select $row_count-2`) or don't pretent this test is tunable and use literals instead of variables. > + > +--connection master2 > + > +# The 2nd trx for recovery, it does not rotate binlog > +SET DEBUG_SYNC= "commit_before_get_LOCK_commit_ordered SIGNAL master2_ready WAIT_FOR master2_go"; > +--send_eval INSERT INTO ti VALUES ($row_count, REPEAT("x", 1)) > + > +--connection master3 > +SET DEBUG_SYNC= "now WAIT_FOR master2_ready"; > +SET DEBUG_SYNC= "commit_before_get_LOCK_after_binlog_sync SIGNAL master3_ready"; > +--send INSERT INTO tm VALUES (2) > + > +--connection default > +SET DEBUG_SYNC= "now WAIT_FOR master3_ready"; > +--echo # The gtid binlog state prior the crash must be restored at the end of the testSELECT @@global.gtid_binlog_state; eh? Was this SELECT supposed to be on a separate line? > + > +--write_file $MYSQLTEST_VARDIR/tmp/mysqld.1.expect > +wait > +EOF > + > +SELECT @@global.gtid_binlog_state; > +--source include/kill_mysqld.inc > +--source include/wait_until_disconnected.inc > + > +# > +# Server restarts > +# > +--echo # Failed restart as the semisync slave > +--error 1 > +--exec $MYSQLD_LAST_CMD --rpl-semi-sync-slave-enabled=1 >> $MYSQLTEST_VARDIR/log/mysqld.1.err 2>&1 > + > +--echo # Normal restart > +--append_file $MYSQLTEST_VARDIR/tmp/mysqld.1.expect > +restart: Okay. *this* is a reasonable use of wait/restart in the expect file. In other cases, I think, you can just restart, no need to wait, as you don't do anything while the server is down. still, here you don't need to write 'wait' to the expect file and don't need to wait_until_disconnected (kill_mysqld is doing both) > +EOF > + > +connection default; > +--enable_reconnect > +--source include/wait_until_connected_again.inc > + > +# Check error log for correct messages. > +let $log_error_= `SELECT @@GLOBAL.log_error`; > +if(!$log_error_) > +{ > + # MySQL Server on windows is started with --console and thus > + # does not know the location of its .err log, use default location > + let $log_error_ = $MYSQLTEST_VARDIR/log/mysqld.1.err; > +} > +--let SEARCH_FILE=$log_error_ > +--let SEARCH_RANGE=-50000 > +--let SEARCH_PATTERN=Cannot trim the binary log to file > +--replace_regex /FOUND [0-9]+/FOUND #/ > +--source include/search_pattern_in_file.inc > + > +--echo # Proof that the in-doubt transactions are recovered by the 2nd normal server restart > +--eval SELECT COUNT(*) = $row_count as 'True' FROM ti > +# myisam table may require repair (which is not tested here) > +--disable_warnings > +SELECT COUNT(*) <= 1 FROM tm; > +--enable_warnings > + > +--echo # The gtid binlog state prior the crash is restored now > +SELECT @@GLOBAL.gtid_binlog_state; > +SELECT @@GLOBAL.gtid_binlog_pos; > + > +--echo # Cleanup > +--replace_result $old_max_binlog_size VALUE_AT_START > +--eval SET @@global.max_binlog_size = $old_max_binlog_size see comments elsewhere about $old_max_binlog_size, -50000, $log_error_, etc > +DROP TABLE ti, tm; > +--echo End of test > diff --git a/mysql-test/suite/rpl/t/rpl_semi_sync_fail_over.cnf b/mysql-test/suite/rpl/t/rpl_semi_sync_fail_over.cnf > new file mode 100644 > index 00000000000..3518eb95b67 > --- /dev/null > +++ b/mysql-test/suite/rpl/t/rpl_semi_sync_fail_over.cnf > @@ -0,0 +1,13 @@ > +!include suite/rpl/rpl_1slave_base.cnf > +!include include/default_client.cnf > + > + > +[mysqld.1] > +log-slave-updates > +gtid-strict-mode=1 > +max_binlog_size= 4096 > + > +[mysqld.2] > +log-slave-updates > +gtid-strict-mode=1 > +max_binlog_size= 4096 why not an .opt file? why max_binlog_size here and not at run-time like in other tests? > diff --git a/mysql-test/suite/rpl/t/rpl_semi_sync_fail_over.test b/mysql-test/suite/rpl/t/rpl_semi_sync_fail_over.test > new file mode 100644 > index 00000000000..972aaf2c8b4 > --- /dev/null > +++ b/mysql-test/suite/rpl/t/rpl_semi_sync_fail_over.test > @@ -0,0 +1,144 @@ > +# ==== Purpose ==== > +# > +# Test verifies replication failover scenario. > +# > +# ==== Implementation ==== > +# > +# Steps: > +# 0 - Having two servers 1 and 2 enable semi-sync replication with > +# with the master wait 'after_sync'. > +# 1 - Insert a row. While inserting second row simulate > +# a server crash at once the transaction is written to binlog, flushed > +# and synced but the binlog position is not updated. > +# 2 - Post crash-recovery on the old master execute there CHANGE MASTER > +# TO command to connect to server id 2. > +# 3 - The old master new slave server 1 must connect to the new > +# master server 2. > +# 4 - repeat the above to crash the new master and restore in role the old one > +# > +# ==== References ==== > +# > +# MDEV-21117: recovery for --rpl-semi-sync-slave-enabled server > + > + > +--source include/have_innodb.inc > +--source include/have_log_bin.inc > +--source include/have_debug.inc > +--source include/have_debug_sync.inc > +--source include/have_binlog_format_row.inc > +--let $rpl_topology=1->2 > +--source include/rpl_init.inc isn't this a normal master-slave.inc topology? > + > +--connection server_2 > +--source include/stop_slave.inc > + > +--connection server_1 > +RESET MASTER; > + > +--connection server_2 > +RESET MASTER; > +set @@global.rpl_semi_sync_slave_enabled = 1; > +set @@global.gtid_slave_pos = ""; > +CHANGE MASTER TO master_use_gtid= slave_pos; > +--source include/start_slave.inc > + > + > +--connection server_1 > +ALTER TABLE mysql.gtid_slave_pos ENGINE=InnoDB; why? > +set @@global.rpl_semi_sync_master_enabled = 1; > +set @@global.rpl_semi_sync_master_wait_point=AFTER_SYNC; > + > +call mtr.add_suppression("Can.t init tc log"); > +call mtr.add_suppression("Aborting"); > +call mtr.add_suppression("1 client is using or hasn.t closed the table properly"); > +call mtr.add_suppression("Table './mtr/test_suppressions' is marked as crashed and should be repaired"); > + > +CREATE TABLE t1 (a INT PRIMARY KEY, b MEDIUMTEXT) ENGINE=Innodb; > +INSERT INTO t1 VALUES (1, 'dummy1'); > + > +# > +# CRASH the original master, and FAILOVER to the new > +# > + > +# value 1 for server id 1 -> 2 failover > +--let $failover_to_slave=1 > +--let $query_to_crash= INSERT INTO t1 VALUES (2, REPEAT("x", 4100)) > +--let $log_search_pattern=truncated binlog file:.*master.*000001 > +--source rpl_semi_sync_crash.inc > + > +--connection server_2 > +--let $rows_so_far=3 > +--eval INSERT INTO t1 VALUES ($rows_so_far, 'dummy3') > +--save_master_pos > +--echo # The gtid state on current master must be equal to ... > +SHOW VARIABLES LIKE 'gtid_binlog_pos'; > + > +--connection server_1 > +--sync_with_master > +--eval SELECT COUNT(*) = $rows_so_far as 'true' FROM t1 > +--echo # ... the gtid states on the slave: > +SHOW VARIABLES LIKE 'gtid_slave_pos'; > +SHOW VARIABLES LIKE 'gtid_binlog_pos'; > + > +--connection server_2 > +# > +# CRASH the new master and FAILOVER back to the original > +# > + > +# value 0 for the reverse server id 2 -> 1 failover > +--let $failover_to_slave=0 > +--let $query_to_crash = INSERT INTO t1 VALUES (4, REPEAT("x", 4100)) > +--let $query2_to_crash= INSERT INTO t1 VALUES (5, REPEAT("x", 4100)) > +--let $log_search_pattern=truncated binlog file:.*slave.*000001 > +--source rpl_semi_sync_crash.inc > + > +--connection server_1 > +--let $rows_so_far=6 > +--eval INSERT INTO t1 VALUES ($rows_so_far, 'Done') > +--save_master_pos > +--echo # The gtid state on current master must be equal to ... > +SHOW VARIABLES LIKE 'gtid_binlog_pos'; > + > +--connection server_2 > +--sync_with_master > +--eval SELECT COUNT(*) = $rows_so_far as 'true' FROM t1 > +--echo # ... the gtid states on the slave: > +SHOW VARIABLES LIKE 'gtid_slave_pos'; > +SHOW VARIABLES LIKE 'gtid_binlog_pos'; > + > + > +--let $diff_tables=server_1:t1, server_2:t1 > +--source include/diff_tables.inc > + > +# > +--echo # Cleanup > +# > +--connection server_1 > +DROP TABLE t1; > +--save_master_pos > + > +--connection server_2 > +--sync_with_master > +--source include/stop_slave.inc > + > +--connection server_1 > +set @@global.rpl_semi_sync_master_enabled = 0; > +set @@global.rpl_semi_sync_slave_enabled = 0; > +set @@global.rpl_semi_sync_master_wait_point=default; > +RESET SLAVE; > +RESET MASTER; > + > +--connection server_2 > +set @@global.rpl_semi_sync_master_enabled = 0; > +set @@global.rpl_semi_sync_slave_enabled = 0; > +set @@global.rpl_semi_sync_master_wait_point=default; > + > +--replace_result $SERVER_MYPORT_1 SERVER_MYPORT_1 > +eval CHANGE MASTER TO master_host='127.0.0.1', master_port=$SERVER_MYPORT_1, master_user='root', master_use_gtid=no; evalp > +--source include/start_slave.inc > + > +connection default; > +--enable_reconnect > +--source include/wait_until_connected_again.inc > + > +--source include/rpl_end.inc > diff --git a/mysql-test/suite/rpl/t/rpl_semi_sync_crash.inc b/mysql-test/suite/rpl/t/rpl_semi_sync_crash.inc > new file mode 100644 > index 00000000000..4289df9155f > --- /dev/null > +++ b/mysql-test/suite/rpl/t/rpl_semi_sync_crash.inc > @@ -0,0 +1,87 @@ > +if ($failover_to_slave) > +{ > + --let $server_to_crash=1 > + --let $server_to_promote=2 > + --let $new_master_port=$SERVER_MYPORT_2 > + --let $client_port=$SERVER_MYPORT_1 > + > + --connect (conn_client,127.0.0.1,root,,test,$SERVER_MYPORT_1,) > +} > +if (!$failover_to_slave) > +{ > + --let $server_to_crash=2 > + --let $server_to_promote=1 > + --let $new_master_port=$SERVER_MYPORT_1 > + --let $client_port=$SERVER_MYPORT_2 > + > + --connect (conn_client,127.0.0.1,root,,test,$SERVER_MYPORT_2,) > +} > + > + > +# Hold insert after write to binlog and before "run_commit_ordered" in engine > + > +SET DEBUG_SYNC= "commit_after_release_LOCK_after_binlog_sync SIGNAL con1_ready WAIT_FOR con1_go"; > +--send_eval $query_to_crash > + > +# complicate recovery with an extra binlog file > +if (!$failover_to_slave) > +{ > + --connect (conn_client_2,127.0.0.1,root,,test,$SERVER_MYPORT_2,) > + # use the same signal with $query_to_crash > + SET DEBUG_SYNC= "now WAIT_FOR con1_ready"; > + SET DEBUG_SYNC= "commit_after_release_LOCK_lock SIGNAL con1_ready WAIT_FOR con2_go"; both signal con1_ready? which one will you be waiting below then? > + --send_eval $query2_to_crash > +} > + > +--connection server_$server_to_crash > +SET DEBUG_SYNC= "now WAIT_FOR con1_ready"; > +--source include/kill_mysqld.inc > +--source include/wait_until_disconnected.inc > + > +--connection server_$server_to_promote > +--error 2003 > +--source include/stop_slave.inc > +SELECT @@GLOBAL.gtid_current_pos; > + > +--let $_expect_file_name=$MYSQLTEST_VARDIR/tmp/mysqld.$server_to_crash.expect wasn't $_expect_file_name already set above? > +--let $restart_parameters=--rpl-semi-sync-slave-enabled=1 > +--let $allow_rpl_inited=1 > +--source include/start_mysqld.inc > + > +--connection server_$server_to_crash > +--enable_reconnect > +--source include/wait_until_connected_again.inc > + > +# Check error log for correct messages. > +let $log_error_= `SELECT @@GLOBAL.log_error`; > +if(!$log_error_) > +{ > + # MySQL Server on windows is started with --console and thus > + # does not know the location of its .err log, use default location > + let $log_error_ = $MYSQLTEST_VARDIR/log/mysqld.$server_to_crash.err; > +} > +--let SEARCH_FILE=$log_error_ > +--let SEARCH_RANGE=-50000 > +--let SEARCH_PATTERN=$log_search_pattern > +--source include/search_pattern_in_file.inc > + > +--disconnect conn_client > + > +# > +# FAIL OVER now to new master > +# > +--connection server_$server_to_promote > +set global rpl_semi_sync_master_enabled = 1; > +set global rpl_semi_sync_master_wait_point=AFTER_SYNC; > + > +--connection server_$server_to_crash > +--let $master_port=$SERVER_MYPORT_2 > +if (`select $server_to_crash = 2`) > +{ > + --let $master_port=$SERVER_MYPORT_1 > +} > +--replace_result $SERVER_MYPORT_1 SERVER_MYPORT_1 $SERVER_MYPORT_2 SERVER_MYPORT_2 > +eval CHANGE MASTER TO master_host='127.0.0.1', master_port=$new_master_port, master_user='root', master_use_gtid=SLAVE_POS; > +set global rpl_semi_sync_slave_enabled = 1; > +set @@global.gtid_slave_pos=@@global.gtid_binlog_pos; > +--source include/start_slave.inc see comments about -50000, $log_error_, wait_until_disconnected, evalp, etc > diff --git a/sql/sql_class.h b/sql/sql_class.h > index 140394fefc1..87fa88d4c89 100644 > --- a/sql/sql_class.h > +++ b/sql/sql_class.h > @@ -4632,7 +4632,7 @@ class THD :public Statement, > LF_PINS *tdc_hash_pins; > LF_PINS *xid_hash_pins; > bool fix_xid_hash_pins(); > - > + bool is_1pc_ro_trans; I don't like how it looks, it's in THD (for every single connection and more) and it's only used in some exotic cases. It's set in two places around ha_commit_one_phase(), when it would be better to set it inside ha_commit_one_phase(), in one place only. But I cannot suggest how to get rid of it yet as I don't understand what it's for, I've asked a question about it below, in Gtid_log_event::Gtid_log_event > /* Members related to temporary tables. */ > public: > /* Opened table states. */ > diff --git a/sql/handler.h b/sql/handler.h > index 2a346e8d9d1..bd39f46bf1f 100644 > --- a/sql/handler.h > +++ b/sql/handler.h > @@ -873,6 +873,14 @@ typedef struct xid_t XID; > /* The 'buf' has to have space for at least SQL_XIDSIZE bytes. */ > uint get_sql_xid(XID *xid, char *buf); > > +/* struct for heuristic binlog truncate recovery */ it's not "heuristic binlog truncate recovery" anymore, please don't call it that, it's confusing > +struct xid_recovery_member > +{ > + my_xid xid; > + uint in_engine_prepare; // number of engines that have xid prepared > + bool decided_to_commit; > +}; > + > /* for recover() handlerton call */ > #define MIN_XID_LIST_SIZE 128 > #define MAX_XID_LIST_SIZE (1024*128) > diff --git a/sql/slave.cc b/sql/slave.cc > index 28e08e32346..9b3f73e5341 100644 > --- a/sql/slave.cc > +++ b/sql/slave.cc > @@ -6944,7 +6945,9 @@ static int queue_event(Master_info* mi,const char* buf, ulong event_len) > } > else > if ((s_id == global_system_variables.server_id && > - !mi->rli.replicate_same_server_id) || > + (!mi->rli.replicate_same_server_id && > + !(semisync_recovery= (rpl_semi_sync_slave_enabled && > + mi->using_gtid != Master_info::USE_GTID_NO)))) || How can "semisync recovery" code path reach queue_event()? > event_that_should_be_ignored(buf) || > /* > the following conjunction deals with IGNORE_SERVER_IDS, if set > diff --git a/sql/log_event.h b/sql/log_event.h > index 8a342cb5cd3..1588ab85104 100644 > --- a/sql/log_event.h > +++ b/sql/log_event.h > @@ -482,6 +482,16 @@ class String; > */ > #define LOG_EVENT_IGNORABLE_F 0x80 > > +/** > + @def LOG_EVENT_ACCEPT_OWN_F > + > + Flag sets by the gtid-mode connected semisync slave for > + the same server_id ("own") events which the slave must not have > + in its state. Typically such events were never committed by > + their originator (this server) and discared at its crash recovery sorry, I failed to understand that > +*/ > +#define LOG_EVENT_ACCEPT_OWN_F 0x4000 > + > /** > @def LOG_EVENT_SKIP_REPLICATION_F > > diff --git a/sql/log_event.cc b/sql/log_event.cc > index e344fc8894f..a593db10d16 100644 > --- a/sql/log_event.cc > +++ b/sql/log_event.cc > @@ -7918,6 +7924,7 @@ Gtid_log_event::Gtid_log_event(const char *buf, uint event_len, > domain_id= uint4korr(buf); > buf+= 4; > flags2= *buf; > + ++buf; I'd written flags2= *buf++; :) > if (flags2 & FL_GROUP_COMMIT_ID) > { > if (event_len < (uint)header_size + GTID_HEADER_LEN + 2) > @@ -7925,9 +7932,31 @@ Gtid_log_event::Gtid_log_event(const char *buf, uint event_len, > seq_no= 0; // So is_valid() returns false > return; > } > - ++buf; > commit_id= uint8korr(buf); > + buf+= 8; > + } > + /* the extra flags check and actions */ > + if (static_cast<uint>(buf - buf_0) < event_len) > + { > + flags_extra= *buf; > + ++buf; > + /* extra flags presence is identifed by non-zero byte value at this point */ "extra engines" > + if (flags_extra & FL_EXTRA_MULTI_ENGINE) > + { safety, check that buf+4-buf_0 <= event_len > + extra_engines= uint4korr(buf); > + buf += 4; four bytes for the number of engines participating in a transaction is very generous... and optimistic. I'd say one byte is more than enough. > + > + DBUG_ASSERT(extra_engines > 0); > + } > } > + /* > + the strict '<' part of the assert corresponds to extra zero-padded > + trailing bytes, > + */ > + DBUG_ASSERT(static_cast<uint>(buf - buf_0) <= event_len); > + /* and the last of them is tested. */ > + DBUG_ASSERT(static_cast<uint>(buf - buf_0) == event_len || > + buf_0[event_len - 1] == 0); > } > > > @@ -7958,6 +7990,22 @@ Gtid_log_event::Gtid_log_event(THD *thd_arg, uint64 seq_no_arg, > /* Preserve any DDL or WAITED flag in the slave's binlog. */ > if (thd_arg->rgi_slave) > flags2|= (thd_arg->rgi_slave->gtid_ev_flags2 & (FL_DDL|FL_WAITED)); > + /* count non-zero extra recoverable engines; total = extra + 1 */ > + if (is_transactional) > + { > + if (has_xid) > + { > + extra_engines= > + max<uint>(1, ha_count_rw(thd, thd_arg->in_multi_stmt_transaction_mode())) 1. a bit confusing to use both thd and thd_arg in the same line 2. max() is strange. it means the result is 1, when ha_count_rw() is 0. can ha_count_rw() here even be 0? 3. also it's somewhat an unfounded assumption that only r/w engines will have the transaction prepared. But we can make it a fact, if we won't prepare r/o engines at all (in ha_prepare). > + - 1; > + } > + else if (unlikely(thd_arg->is_1pc_ro_trans)) > + { > + extra_engines= UINT_MAX; // neither extra nor base engine why is that? > + } > + if (extra_engines > 0) > + flags_extra|= FL_EXTRA_MULTI_ENGINE; > + } > } > > > diff --git a/sql/handler.cc b/sql/handler.cc > index 6792e80b8fe..247ab7267bf 100644 > --- a/sql/handler.cc > +++ b/sql/handler.cc > @@ -1245,6 +1245,24 @@ int ha_prepare(THD *thd) > DBUG_RETURN(error); > } > > +/* > + Returns counted number of > + read-write recoverable transaction participants. > +*/ > +uint ha_count_rw(THD *thd, bool all) the name doesn't match the implementation, please, rename > +{ > + unsigned rw_ha_count= 0; > + THD_TRANS *trans=all ? &thd->transaction.all : &thd->transaction.stmt; > + > + for (Ha_trx_info * ha_info= trans->ha_list; ha_info; > + ha_info= ha_info->next()) > + { > + if (ha_info->is_trx_read_write() && ha_info->ht()->recover) > + ++rw_ha_count; > + } > + return rw_ha_count; > +} > + > /** > Check if we can skip the two-phase commit. > > @@ -1960,8 +1982,122 @@ struct xarecover_st > XID *list; > HASH *commit_list; > bool dry_run; > + MEM_ROOT *mem_root; > + bool error; > }; > > +/** > + Inserts a new hash member. > + > + returns a successfully created and inserted @c xid_recovery_member > + into hash @c hash_arg, > + or NULL. > +*/ > +static xid_recovery_member* > +xid_member_insert(HASH *hash_arg, my_xid xid_arg, MEM_ROOT *ptr_mem_root) > +{ > + xid_recovery_member *member= (xid_recovery_member*) > + alloc_root(ptr_mem_root, sizeof(xid_recovery_member)); > + if (!member) > + return NULL; > + > + member->xid= xid_arg; > + member->in_engine_prepare= 1; > + member->decided_to_commit= false; > + > + return my_hash_insert(hash_arg, (uchar*) member) ? NULL : member; > +} > + > +/* > + Inserts a new or updates an existing hash member to increment > + the member's prepare counter. > + > + returns false on success, > + true otherwise. > +*/ > +static bool xid_member_replace(HASH *hash_arg, my_xid xid_arg, > + MEM_ROOT *ptr_mem_root) > +{ > + xid_recovery_member* member; > + if ((member= (xid_recovery_member *) > + my_hash_search(hash_arg, (uchar *)& xid_arg, sizeof(xid_arg)))) > + member->in_engine_prepare++; > + else > + member= xid_member_insert(hash_arg, xid_arg, ptr_mem_root); > + > + return member == NULL; > +} > + > +/* > + Hash iterate function to complete with commit or rollback as decided > + (typically at binlog recovery processing) in member->in_engine_prepare. > +*/ > +static my_bool xarecover_do_commit_or_rollback(void *member_arg, > + void *hton_arg) > +{ > + xid_recovery_member *member= (xid_recovery_member*) member_arg; > + handlerton *hton= (handlerton*) hton_arg; > + xid_t x; > + my_bool rc; > + > + x.set(member->xid); > + rc= member->decided_to_commit ? hton->commit_by_xid(hton, &x) : > + hton->rollback_by_xid(hton, &x); > + > + DBUG_ASSERT(rc || member->in_engine_prepare > 0); > + > + if (!rc) > + { I don't think you can trust rc on that. if it's non-zero, it's an error all right. but it's a bit of a stretch to presume that nonexisting xid is always an error. also commit_by_xid returns int, not my_bool. > + member->in_engine_prepare--; > + if (global_system_variables.log_warnings > 2) > + sql_print_warning("%s transaction with xid %llu", > + member->decided_to_commit ? > + "Committed" : "Rolled back", (ulonglong) member->xid); > + } > + > + return false; > +} > + > +static my_bool xarecover_do_count_in_prepare(void *member_arg, > + void *ptr_count) > +{ > + xid_recovery_member *member= (xid_recovery_member*) member_arg; > + if (member->in_engine_prepare) > + { > + *(uint*) ptr_count += member->in_engine_prepare; This is a rather weird semantics. it's kind of a number of transactions times number of engines. if one transaction wasn't committed in two engines and another transaction wasn't rolled back in one engine, the counter will be 3. how are you going to explain this to users? > + if (global_system_variables.log_warnings > 2) > + sql_print_warning("Found prepared transaction with xid %llu", > + (ulonglong) member->xid); > + } > + > + return false; > +} > + > +static my_bool xarecover_binlog_truncate_handlerton(THD *unused, > + plugin_ref plugin, > + void *arg) > +{ > + handlerton *hton= plugin_hton(plugin); > + > + if (hton->state == SHOW_OPTION_YES && hton->recover) > + { > + my_hash_iterate((HASH*) arg, xarecover_do_commit_or_rollback, hton); Why is the function called xarecover_binlog_truncate_handlerton if it doesn't truncate anything? > + } > + > + return FALSE; > +} > + > +uint ha_recover_complete(HASH *commit_list) > +{ > + uint count= 0; > + > + plugin_foreach(NULL, xarecover_binlog_truncate_handlerton, > + MYSQL_STORAGE_ENGINE_PLUGIN, commit_list); > + my_hash_iterate(commit_list, xarecover_do_count_in_prepare, &count); > + > + return count; > +} > + > static my_bool xarecover_handlerton(THD *unused, plugin_ref plugin, > void *arg) > { > @@ -1969,6 +2105,9 @@ static my_bool xarecover_handlerton(THD *unused, plugin_ref plugin, > struct xarecover_st *info= (struct xarecover_st *) arg; > int got; > > + if (info->error) > + return TRUE; plugin_foreach() aborts as soon as the callback returns true. so, remove info->error, and return TRUE from xarecover_handlerton on error instead. > + > if (hton->state == SHOW_OPTION_YES && hton->recover) > { > while ((got= hton->recover(hton, info->list, info->len)) > 0 ) > @@ -1988,7 +2127,7 @@ static my_bool xarecover_handlerton(THD *unused, plugin_ref plugin, > } > #endif /* WITH_WSREP */ > > - for (int i=0; i < got; i ++) > + for (int i=0; i < got && !info->error; i ++) eh? how can info->error ever be true above? you break out of the loop when setting info->error= true, > { > my_xid x= IF_WSREP(WSREP_ON && wsrep_is_wsrep_xid(&info->list[i]) ? > wsrep_xid_seqno(info->list[i]) : > @@ -2013,7 +2152,20 @@ static my_bool xarecover_handlerton(THD *unused, plugin_ref plugin, > info->found_my_xids++; > continue; > } > - // recovery mode > + > + /* > + Regular and semisync slave server recovery only collects > + xids to make decisions on them later by the caller. > + */ > + if (info->mem_root) > + { > + if (xid_member_replace(info->commit_list, x, info->mem_root)) > + { > + info->error= true; > + sql_print_error("Error in memory allocation at xarecover_handlerton"); > + break; > + } > + } else add into the else branch something like /* this branch is only for the legacy TC_LOG_MMAP */ compile_time_assert(sizeof(TC_LOG_MMAP) > 1 ); > if (IF_WSREP((wsrep_emulate_bin_log && > wsrep_is_wsrep_xid(info->list + i) && > x <= wsrep_limit), false) || > diff --git a/sql/log.cc b/sql/log.cc > index 8073f09ab88..a9808ed8823 100644 > --- a/sql/log.cc > +++ b/sql/log.cc > @@ -7977,6 +7982,7 @@ MYSQL_BIN_LOG::trx_group_commit_leader(group_commit_entry *leader) > #endif > } > > + DEBUG_SYNC(leader->thd, "commit_before_update_end_pos"); this isn't used in any tests > /* > update binlog_end_pos so it can be read by dump thread > Note: must be _after_ the RUN_HOOK(after_flush) or else > @@ -9609,6 +9618,180 @@ int TC_LOG::using_heuristic_recover() > /****** transaction coordinator log for 2pc - binlog() based solution ******/ > #define TC_LOG_BINLOG MYSQL_BIN_LOG > > +/** > + Truncates the current binlog to specified position. Removes the rest of binlogs > + which are present after this binlog file. > + > + @param truncate_file Holds the binlog name to be truncated > + @param truncate_pos Position within binlog from where it needs to > + truncated. > + > + @retval true ok > + @retval false error > + > +*/ > +bool MYSQL_BIN_LOG::truncate_and_remove_binlogs(const char *file_name, > + my_off_t pos, > + rpl_gtid *ptr_gtid, > + enum_binlog_checksum_alg cs_alg) > +{ > + int error= 0; > +#ifdef HAVE_REPLICATION > + LOG_INFO log_info; > + THD *thd= current_thd; > + my_off_t index_file_offset= 0; > + File file= -1; > + IO_CACHE cache; > + MY_STAT s; > + > + if ((error= find_log_pos(&log_info, file_name, 1))) > + { > + sql_print_error("Failed to locate binary log file:%s." > + "Error:%d", file_name, error); > + goto end; > + } > + > + while (!(error= find_next_log(&log_info, 1))) > + { > + if (!index_file_offset) > + { > + index_file_offset= log_info.index_file_start_offset; > + if ((error= open_purge_index_file(TRUE))) > + { > + sql_print_error("Failed to open purge index " > + "file:%s. Error:%d", purge_index_file_name, error); > + goto end; > + } > + } > + if ((error= register_purge_index_entry(log_info.log_file_name))) > + { > + sql_print_error("Failed to copy %s to purge index" > + " file. Error:%d", log_info.log_file_name, error); > + goto end; > + } > + } > + > + if (error != LOG_INFO_EOF) > + { > + sql_print_error("Failed to find the next binlog to " > + "add to purge index register. Error:%d", error); > + goto end; > + } > + > + if (is_inited_purge_index_file()) > + { > + if (!index_file_offset) > + index_file_offset= log_info.index_file_start_offset; > + > + if ((error= sync_purge_index_file())) > + { > + sql_print_error("Failed to flush purge index " > + "file. Error:%d", error); > + goto end; > + } > + > + // Trim index file > + if ((error= > + mysql_file_chsize(index_file.file, index_file_offset, '\n', > + MYF(MY_WME))) || > + (error= > + mysql_file_sync(index_file.file, MYF(MY_WME|MY_SYNC_FILESIZE)))) > + { > + sql_print_error("Failed to trim binlog index " > + "file:%s to offset:%llu. Error:%d", index_file_name, > + index_file_offset, error); > + goto end; > + } > + > + /* Reset data in old index cache */ > + if ((error= reinit_io_cache(&index_file, READ_CACHE, (my_off_t) 0, 0, 1))) > + { > + sql_print_error("Failed to reinit binlog index " > + "file. Error:%d", error); > + goto end; > + } > + > + /* Read each entry from purge_index_file and delete the file. */ > + if ((error= purge_index_entry(thd, NULL, TRUE))) > + { > + sql_print_error("Failed to process registered " > + "files that would be purged."); > + goto end; > + } > + } > + > + DBUG_ASSERT(pos); > + > + if ((file= mysql_file_open(key_file_binlog, file_name, > + O_RDWR | O_BINARY, MYF(MY_WME))) < 0) > + { > + error= 1; > + sql_print_error("Failed to open binlog file:%s for " > + "truncation.", file_name); > + goto end; > + } > + my_stat(file_name, &s, MYF(0)); > + > + /* Change binlog file size to truncate_pos */ > + if ((error= > + mysql_file_chsize(file, pos, 0, MYF(MY_WME))) || > + (error= mysql_file_sync(file, MYF(MY_WME|MY_SYNC_FILESIZE)))) > + { > + sql_print_error("Failed to trim the " > + "binlog file:%s to size:%llu. Error:%d", > + file_name, pos, error); > + goto end; > + } > + else > + { > + char buf[21]; > + > + longlong10_to_str(ptr_gtid->seq_no, buf, 10); > + sql_print_information("Successfully truncated binlog file:%s " > + "to pos:%llu to remove transactions starting from " > + "GTID %u-%u-%s", file_name, pos, > + ptr_gtid->domain_id, ptr_gtid->server_id, buf); > + } > + if (!(error= init_io_cache(&cache, file, IO_SIZE, WRITE_CACHE, > + (my_off_t) pos, 0, MYF(MY_WME|MY_NABP)))) > + { > + /* > + Write Stop_log_event to ensure clean end point for the binary log being > + truncated. > + */ I'm not sure about it. The less you touch the corrupted binlog the better. simply truncating it would be enough, wouldn't it? > + Stop_log_event se; > + se.checksum_alg= cs_alg; > + if ((error= write_event(&se, NULL, &cache))) > + { > + sql_print_error("Failed to write stop event to " > + "binary log. Errno:%d", > + (cache.error == -1) ? my_errno : error); > + goto end; > + } > + clear_inuse_flag_when_closing(cache.file); > + if ((error= flush_io_cache(&cache)) || > + (error= mysql_file_sync(file, MYF(MY_WME|MY_SYNC_FILESIZE)))) > + { > + sql_print_error("Faild to write stop event to " > + "binary log. Errno:%d", > + (cache.error == -1) ? my_errno : error); > + } > + } > + else > + sql_print_error("Failed to initialize binary log " > + "cache for writing stop event. Errno:%d", > + (cache.error == -1) ? my_errno : error); 1. I don't see why you need to sync after every operation. 2. you should clear inuse flag just before closing, otherwise flush_io_cache can overwrite it again if it'll happen to have it in the cache. > + > +end: > + if (file >= 0) > + { > + end_io_cache(&cache); > + mysql_file_close(file, MYF(MY_WME)); > + } > + error= error || close_purge_index_file(); > +#endif > + return error > 0; > +} > int TC_LOG_BINLOG::open(const char *opt_name) > { > int error= 1; > @@ -10040,26 +10223,515 @@ start_binlog_background_thread() > > return 0; > } > +#ifdef HAVE_REPLICATION > +class Recovery_context > +{ > +public: > + my_off_t prev_event_pos; > + rpl_gtid last_gtid; > + bool last_gtid_standalone; > + bool last_gtid_valid; > + bool last_gtid_no2pc; // true when the group does not end with Xid event > + uint last_gtid_engines; > + std::pair<uint, my_off_t> last_gtid_coord; may be a comment at the end // <binlog id, binlog offset> ? > + /* > + When true, it's semisync slave recovery mode > + rolls back transactions in doubt and wipes them off from binlog. > + The rest of declarations deal with this type of recovery. > + */ > + bool do_truncate; > + rpl_gtid binlog_unsafe_gtid, truncate_gtid; > + char binlog_truncate_file_name[FN_REFLEN] ; > + char binlog_unsafe_file_name[FN_REFLEN] ; > + /* > + When do_truncate is true, the truncate position may not be > + found in one round when recovered transactions are multi-engine > + or just on different engines. > + In the single recoverable engine case `truncate_reset_done` and > + therefore `truncate_validated` remain `false' when the last > + binlog is the binlog-checkpoint one. > + The meaning of `truncate_reset_done` is according to the following example: > + Let round = 1, Binlog contains the sequence of replication event groups: > + [g1, G2, g3] > + where `G` (in capital) stands for committed, `g` for prepared. > + g1 is first set as truncation candidate, then G2 reset it to indicate > + the actual truncation is behind (to the right of) it. > + `truncate_validated` is set to true when `binlog_truncate_pos` (as of g3) > + won't change. > + Observe last_gtid_valid is affected, so in the above example g1 > + would have to be discarded from the 1st round binlog state estimate which > + is handled by the 2nd round (see below). I failed to understand that either :( > + */ > + bool truncate_validated; // trued when the truncate position settled > + bool truncate_reset_done; // trued when the position is to reevaluate Nor that :( > + /* Flags the fact of truncate position estimation is done the 1st round */ > + bool truncate_set_in_1st; > + /* > + Monotonically indexes binlog files in the recovery list. > + When the list is "likely" singleton the value is UINT_MAX. > + Otherwise enumeration starts with zero for the first file, increments > + by one for any next file except for the last file in the list, which > + is also the initial binlog file for recovery, > + that is enumberated with UINT_MAX. > + */ > + uint id_binlog; > + enum_binlog_checksum_alg cs_alg; // for Stop_event with do_truncate rename to checksum_alg, please. "charset algorithm" looks very puzzling and "cs" almost everywhere means CHARSET_INFO. > + bool single_binlog; > + std::pair<uint, my_off_t> binlog_truncate_coord; > + std::pair<uint, my_off_t> binlog_unsafe_coord; > + > + Recovery_context(); > + bool decide_or_assess(xid_recovery_member *member, int round, > + Format_description_log_event *fdle, > + LOG_INFO *linfo, my_off_t pos); > + void process_gtid(int round, Gtid_log_event *gev, LOG_INFO *linfo); > + int next_binlog_or_round(int& round, > + const char *last_log_name, > + const char *binlog_checkpoint_name, > + LOG_INFO *linfo, MYSQL_BIN_LOG *log); > + bool is_safe() what do you mean "safe" ? > + { > + return !do_truncate ? true : > + (truncate_gtid.seq_no == 0 || // no truncate > + binlog_unsafe_coord < binlog_truncate_coord); // or unsafe is earlier > + } > + bool complete(MYSQL_BIN_LOG *log, HASH &xids); > + void update_binlog_unsafe_coord_if_needed(LOG_INFO *linfo); > + void reset_truncate_coord(my_off_t pos); > + void set_truncate_coord(LOG_INFO *linfo, int round, > + enum_binlog_checksum_alg fd_cs_alg); > +}; > comments about what every method does? > +bool Recovery_context::complete(MYSQL_BIN_LOG *log, HASH &xids) > +{ > + if (!do_truncate || is_safe()) > + { > + uint count_in_prepare= ha_recover_complete(&xids); > + if (count_in_prepare > 0 && global_system_variables.log_warnings > 2) > + { > + sql_print_warning("Could not complete %u number of transactions in " > + "engines.", count_in_prepare); > + return false; // there's later dry run ha_recover() to error out > + } > + } > + > + /* Truncation is not done when there's no transaction to roll back */ > + if (do_truncate && truncate_gtid.seq_no > 0) > + { > + if (is_safe()) > + { > + if (log->truncate_and_remove_binlogs(binlog_truncate_file_name, > + binlog_truncate_coord.second, > + &truncate_gtid, > + cs_alg)) > + { > + sql_print_error("Failed to trim the binary log to " > + "file:%s pos:%llu.", binlog_truncate_file_name, > + binlog_truncate_coord.second); > + return true; > + } > + } > + else > + { > + sql_print_error("Cannot trim the binary log to file:%s " > + "pos:%llu as unsafe statement " > + "is found at file:%s pos:%llu which is " > + "beyond the truncation position " > + "(the farest in binlog order only is reported); " "farest" doesn't look like a word > + "all transactions in doubt are left intact. ", > + binlog_truncate_file_name, binlog_truncate_coord.second, > + binlog_unsafe_file_name, binlog_unsafe_coord.second); > + return true; will this abort server startup? > + } > + } > + > + return false; > +} > + > +Recovery_context::Recovery_context() : > + prev_event_pos(0), > + last_gtid_standalone(false), last_gtid_valid(false), last_gtid_no2pc(false), > + last_gtid_engines(0), > + do_truncate(rpl_semi_sync_slave_enabled), > + truncate_validated(false), truncate_reset_done(false), > + truncate_set_in_1st(false), id_binlog(UINT_MAX), > + cs_alg(BINLOG_CHECKSUM_ALG_UNDEF), single_binlog(false) > +{ > + last_gtid_coord= std::pair<uint,my_off_t>(0,0); > + binlog_truncate_coord= std::pair<uint,my_off_t>(0,0); > + binlog_unsafe_coord= std::pair<uint,my_off_t>(0,0); > + binlog_truncate_file_name[0]= 0; > + binlog_unsafe_file_name [0]= 0; > + binlog_unsafe_gtid= truncate_gtid= rpl_gtid(); > +} > + > +/** > + Is called when a committed or to-be-committed transaction is detected. > + @c truncate_gtid is set to "nil" with its @c rpl_gtid::seq_no := 0. > + @c truncate_reset_done remembers the fact of that has been done at least > + once in the current round; > + @c binlog_truncate_coord is "suggested" to a next group start to indicate > + the actual settled value must be at most as the last suggested one. > +*/ > +void Recovery_context::reset_truncate_coord(my_off_t pos) > +{ > + DBUG_ASSERT(binlog_truncate_coord.second == 0 || > + last_gtid_coord >= binlog_truncate_coord || > + truncate_set_in_1st); > + > + binlog_truncate_coord= std::pair<uint,my_off_t>(id_binlog, pos); > + truncate_gtid= rpl_gtid(); > + truncate_reset_done= true; > +} > + > + > +/* > + Sets binlog_truncate_pos to the value of the current transaction's gtid. > + In multi-engine case that might be just an assessment to be exacted > + in the current round and confirmed in a next one. > +*/ > +void Recovery_context::set_truncate_coord(LOG_INFO *linfo, int round, > + enum_binlog_checksum_alg fd_cs_alg) > +{ > + binlog_truncate_coord= last_gtid_coord; > + strmake_buf(binlog_truncate_file_name, linfo->log_file_name); > + > + truncate_gtid= last_gtid; > + cs_alg= fd_cs_alg; > + truncate_set_in_1st= (round == 1); > +} > + > +bool Recovery_context::decide_or_assess(xid_recovery_member *member, int round, > + Format_description_log_event *fdle, > + LOG_INFO *linfo, my_off_t pos) > +{ > + if (member) > + { > + DBUG_EXECUTE_IF("binlog_truncate_partial_commit", > + if (last_gtid_engines == 2) > + { > + DBUG_ASSERT(member->in_engine_prepare > 0); > + member->in_engine_prepare= 1; > + }); > + /* > + xid in doubt are resolved as follows: > + in_engine_prepare is compared agaist binlogged info to > + yield the commit-or-rollback decision in the normal case. > + In the semisync-slave recovery the decision may be > + approximate to change in later rounds. > + */ > + if (member->in_engine_prepare > last_gtid_engines) > + { > + char buf[21]; > + longlong10_to_str(last_gtid.seq_no, buf, 10); > + sql_print_error("Error to recovery multi-engine transaction: " > + "the number of engines prepared %u exceeds the " > + "respective number %u in its GTID %u-%u-%s " > + "located at file:%s pos:%llu", > + member->in_engine_prepare, last_gtid_engines, > + last_gtid.domain_id, last_gtid.server_id, buf, > + linfo->log_file_name, last_gtid_coord.second); > + return true; > + } > + else if (member->in_engine_prepare < last_gtid_engines) > + { > + DBUG_EXECUTE_IF("binlog_truncate_partial_commit", > + member->in_engine_prepare= 2;); > + DBUG_ASSERT(member->in_engine_prepare > 0); > + /* > + This is an "unlikely" branch of two or more engines in transaction > + that is partially committed, so to complete. > + */ > + member->decided_to_commit= true; > + if (do_truncate) > + { > + /* > + A validated truncate pos may not change later. > + Any "unlikely" (two or more engines in transaction) reset > + to not-validated yet position ensues correcting early > + estimates in the following round(s). > + */ > + if (!truncate_validated) > + reset_truncate_coord(pos); > + } > + } > + else // member->in_engine_prepare == last_gtid_engines > + { > + if (!do_truncate) // "normal" recovery > + { > + member->decided_to_commit= true; > + } > + else > + { > + /* > + The first time or further estimate the truncate position > + until validation. Already set not validated yet postion > + may change only through previous reset > + unless this xid in doubt is the first in the 2nd round. > + */ > + if (!truncate_validated) > + { > + DBUG_ASSERT(round <= 2); > + /* > + Either truncate was not set or was reset, else > + it gets incremented, otherwise it may only set to an earlier > + offset only at the turn out of the 1st round. sorry, I cannot parse that :( > + */ > + DBUG_ASSERT(truncate_gtid.seq_no == 0 || > + last_gtid_coord >= binlog_truncate_coord || > + (round == 2 && truncate_set_in_1st)); > + > + last_gtid_valid= false; // may still (see gtid) flip later > + if (truncate_gtid.seq_no == 0 /* was reset or never set */ || > + (truncate_set_in_1st && round == 2 /* reevaluted at round turn */)) > + set_truncate_coord(linfo, round, fdle->checksum_alg); > + > + DBUG_ASSERT(member->decided_to_commit == false); // may flip later > + } > + else > + { > + DBUG_ASSERT(!truncate_reset_done); // the position was settled > + /* > + Correct earlier decisions of 1st and/or 2nd round to > + rollback and invalidate last_gtid in binlog state. > + */ > + if (!(member->decided_to_commit= > + last_gtid_coord < binlog_truncate_coord)) > + { > + last_gtid_valid= false; // settled > + if (truncate_gtid.seq_no == 0) > + truncate_gtid= last_gtid; > + } > + } > + } > + } > + } > + else if (do_truncate) // "0" < last_gtid_engines > + { > + /* > + Similar to the multi-engine partial commit of "then" branch above. > + The 2nd condition economizes away an extra (3rd) round in I don't think "economizes" is a word > + expected cases of first xid:s in the binlog checkpoint file > + are actually of committed transactions. So fully committed > + xid sequence is passed in this branch without any action. > + */ > + if (!truncate_validated) > + reset_truncate_coord(pos); > + } > + > + return false; > +} > + > +/* > + Is invoked when a standalone or non-2pc group is detected. > + Both are unsafe to truncate in the semisync-slave recovery so > + the maximum unsafe coordinate may be updated. > + In the non-2pc group case though, *exeptionally*, > + the no-engine group is considered safe, to be invalidated > + to not contribute to binlog state. > +*/ > +void Recovery_context::update_binlog_unsafe_coord_if_needed(LOG_INFO *linfo) > +{ > + if (!do_truncate) > + return; > + > + if (truncate_gtid.seq_no > 0 && // g1,U2, *not* G1,U2 > + last_gtid_coord > binlog_truncate_coord) > + { > + DBUG_ASSERT(binlog_truncate_coord.second > 0); > + /* > + Potentially unsafe when the truncate coordinate is not determined, > + just detected as unsafe when behind the latter. > + */ > + if (last_gtid_engines == 0) > + { > + last_gtid_valid= false; > + } > + else > + { > + binlog_unsafe_gtid= last_gtid; > + binlog_unsafe_coord= last_gtid_coord; > + strmake_buf(binlog_unsafe_file_name, linfo->log_file_name); > + } > + } > +} > + > +/* > + Assigns last_gtid and assesses the maximum (in the binlog offset term) > + unsafe gtid (group of events). > +*/ > +void Recovery_context::process_gtid(int round, Gtid_log_event *gev, > + LOG_INFO *linfo) > +{ > + last_gtid.domain_id= gev->domain_id; > + last_gtid.server_id= gev->server_id; > + last_gtid.seq_no= gev->seq_no; > + last_gtid_engines= gev->extra_engines != UINT_MAX ? > + gev->extra_engines + 1 : 0; > + last_gtid_coord= std::pair<uint,my_off_t>(id_binlog, prev_event_pos); > + if (round == 1 || do_truncate) > + { > + DBUG_ASSERT(!last_gtid_valid); > + > + last_gtid_no2pc= false; > + last_gtid_standalone= > + (gev->flags2 & Gtid_log_event::FL_STANDALONE) ? true : false; > + if (do_truncate && last_gtid_standalone) > + update_binlog_unsafe_coord_if_needed(linfo); > + /* Update the binlog state with any 'valid' GTID logged after Gtid_list. */ > + last_gtid_valid= true; // may flip at Xid when falls to truncate > + } > +} > + > +/* > + At the end of processing of the current binlog compute next action. > + When round increments in the semisync-slave recovery > + truncate_validated, truncate_reset_done > + gets reset/set for the next round, > + as well as id_binlog gets reset either to zero or UINT_MAX > + when recovery deals with the only binlog file. > + > + @param[in,out] round the current round that may increment here > + @param last_log_name the recovery starting binlog file > + @param binlog_checkpoint_name > + binlog checkpoint file > + @param linfo binlog file list struct for next file > + @param log pointer to mysql_bin_log instance > + @return 0 when rounds continue, maybe the current one remains > + 1 when all rounds are done > + -1 on error > +*/ > +int Recovery_context::next_binlog_or_round(int& round, > + const char *last_log_name, > + const char *binlog_checkpoint_name, > + LOG_INFO *linfo, > + MYSQL_BIN_LOG *log) > +{ > + if (!strcmp(linfo->log_file_name, last_log_name)) > + { > + /* Either exit the loop now, or increment round */ > + DBUG_ASSERT(round <= 3); > + > + if ((round <= 2 && likely(!truncate_reset_done)) || round == 3) > + { > + // Exit now as the 1st round ends up with the binlog-checkpoint file > + // is the same as the initial binlog file, so already parsed; or > + // the 2nd round has not made own truncate_reset_done; or > + // at the end of the 3rd "truncate" round. > + DBUG_ASSERT(do_truncate || round == 1); > + // The 3rd round is done only when the 2nd trued truncate_reset_done > + // and consequently truncate_validated. > + // No instances of truncate_reset_done in first 2 rounds allows > + // for exiting now. our (unwritten) coding style says that multi-line comments should use /*...*/ > + DBUG_ASSERT(round < 3 || truncate_validated); > + > + return true; > + } > + else > + { > + DBUG_ASSERT(do_truncate); > + /* > + the last binlog file, having truncate_reset_done to indicate > + needed correction to member->decided_to_commit to reflect > + changed binlog_truncate_pos. > + */ > + truncate_reset_done= false; > + truncate_validated= true; > + rpl_global_gtid_binlog_state.reset_nolock(); > + > + if (round > 1 && > + log->find_log_pos(linfo, binlog_checkpoint_name, 1)) > + { > + sql_print_error("Binlog file '%s' not found in binlog index, needed " > + "for recovery. Aborting.", binlog_checkpoint_name); > + return -1; > + } > + id_binlog= (single_binlog= !strcmp(linfo->log_file_name, last_log_name)) ? > + UINT_MAX : 0; > + round++; > + } > + } > + else if (round == 1) > + { > + if (do_truncate) > + { > + truncate_validated= truncate_reset_done; > + rpl_global_gtid_binlog_state.reset_nolock(); > + truncate_reset_done= false; > + id_binlog= 0; > + > + DBUG_ASSERT(!single_binlog); > + } > + round++; > + } > + else > + { > + /* > + NOTE: reading other binlog's FD is necessary for finding out > + the checksum status of the respective binlog file. > + Round remains in this branch. > + */ > + if (log->find_next_log(linfo, 1)) > + { > + sql_print_error("Error reading binlog files during recovery. " > + "Aborting."); > + return -1; > + } > + if (!strcmp(linfo->log_file_name, last_log_name)) > + { > + if (do_truncate) > + { > + DBUG_ASSERT(!single_binlog); > + id_binlog= UINT_MAX; > + } > + else > + return 1; // regular recovery exit > + } > + else if (do_truncate) > + id_binlog++; > + > + DBUG_ASSERT(id_binlog <= UINT_MAX); // the assert is "practical" > + } > + > + DBUG_ASSERT(!single_binlog || > + !strcmp(linfo->log_file_name, binlog_checkpoint_name)); > + > + return 0; > +} > +#endif > > int TC_LOG_BINLOG::recover(LOG_INFO *linfo, const char *last_log_name, > IO_CACHE *first_log, > - Format_description_log_event *fdle, bool do_xa) > + Format_description_log_event *fdle_arg, bool do_xa) > { > Log_event *ev= NULL; > HASH xids; > MEM_ROOT mem_root; > char binlog_checkpoint_name[FN_REFLEN]; > bool binlog_checkpoint_found; > - bool first_round; > IO_CACHE log; > File file= -1; > const char *errmsg; > + Format_description_log_event *fdle= fdle_arg; > #ifdef HAVE_REPLICATION > - rpl_gtid last_gtid; > - bool last_gtid_standalone= false; > - bool last_gtid_valid= false; > + Recovery_context ctx; > #endif > + /* > + The for-loop variable is updated by the following rule set: > + Initially set to 1. > + After the initial binlog file is processed to identify > + the Binlog-checkpoint file it is incremented when the latter file > + is different from the initial one. Otherwise the only log has been > + fully parsed and the loop exits. > + The 2nd starts with the Binlog-checkpoint file and ends when the initial > + binlog file is reached. It is excluded from yet another processing > + in the "normal" non-semisync-slave configuration, and then the loop is > + done at this point. Otherwise in the semisync slave case it may be parsed > + over again. The 2nd round may turn to a third in "unlikely" condition of the > + semisync-slave is being recovered having multi- or different engine > + transactions in doubt. > + */ I don't understand that. Why semisync-slave case is special? > + int round; > > if (! fdle->is_valid() || > (do_xa && my_hash_init(&xids, &my_charset_bin, TC_LOG_PAGE_SIZE/3, 0, > @@ -10072,39 +10744,63 @@ int TC_LOG_BINLOG::recover(LOG_INFO *linfo, const char *last_log_name, > > fdle->flags&= ~LOG_EVENT_BINLOG_IN_USE_F; // abort on the first error > > + /* finds xids when root is not NULL */ > + if (do_xa && ha_recover(&xids, &mem_root)) > + goto err1; > + > /* > Scan the binlog for XIDs that need to be committed if still in the > prepared stage. > > Start with the latest binlog file, then continue with any other binlog > files if the last found binlog checkpoint indicates it is needed. > + > + In case the semisync slave recovery the 2nd round may include > + the initial file as well as cause a 3rd round when transactions > + with multiple engines are discovered. > + Additionally to find and decide on transactions in doubt that > + the semisync slave may need to roll back, the binlog can be truncated > + in the end to reflect the rolled back decisions. > */ > > binlog_checkpoint_found= false; > - first_round= true; > - for (;;) > + for (round= 1;;) > { > - while ((ev= Log_event::read_log_event(first_round ? first_log : &log, > + while ((ev= Log_event::read_log_event(round == 1 ? first_log : &log, > fdle, opt_master_verify_checksum)) > && ev->is_valid()) > { > enum Log_event_type typ= ev->get_type_code(); > switch (typ) > { > + case FORMAT_DESCRIPTION_EVENT: > + if (round > 1) > + { > + if (fdle != fdle_arg) > + delete fdle; > + fdle= (Format_description_log_event*) ev; why is it needed? all binlog files should have the same Format_description_log_event anyway. > + } > + break; > case XID_EVENT: > + if (do_xa) > { > - if (do_xa) > + xid_recovery_member *member= > + (xid_recovery_member*) > + my_hash_search(&xids, (uchar*) &static_cast<Xid_log_event*>(ev)->xid, > + sizeof(my_xid)); > +#ifndef HAVE_REPLICATION > { > - Xid_log_event *xev=(Xid_log_event *)ev; > - uchar *x= (uchar *) memdup_root(&mem_root, (uchar*) &xev->xid, > - sizeof(xev->xid)); > - if (!x || my_hash_insert(&xids, x)) > - goto err2; > + if (member) > + member->decided_to_commit= true; > } > - break; > +#else > + if (ctx.decide_or_assess(member, round, fdle, linfo, ev->log_pos)) > + goto err2; > +#endif > } > + break; > case BINLOG_CHECKPOINT_EVENT: > - if (first_round && do_xa) > + if (round == 1 && do_xa) > { > size_t dir_len; > Binlog_checkpoint_log_event *cev= (Binlog_checkpoint_log_event *)ev; > @@ -10124,9 +10820,18 @@ int TC_LOG_BINLOG::recover(LOG_INFO *linfo, const char *last_log_name, > } > } > break; > +#ifdef HAVE_REPLICATION > case GTID_LIST_EVENT: > - if (first_round) > + if (round == 1 || (ctx.do_truncate && > + (ctx.id_binlog == 0 || ctx.single_binlog))) > { > + /* > + Unlike the normal case, in do_truncate the initial state is > + in the first binlog file of the recovery list. > + */ don't understand that either :( > + DBUG_ASSERT(!ctx.do_truncate || !ctx.single_binlog || > + ctx.id_binlog == UINT_MAX); > + > Gtid_list_log_event *glev= (Gtid_list_log_event *)ev; > > /* Initialise the binlog state from the Gtid_list event. */ > @@ -10135,19 +10840,16 @@ int TC_LOG_BINLOG::recover(LOG_INFO *linfo, const char *last_log_name, > } > break; > > -#ifdef HAVE_REPLICATION > case GTID_EVENT: > - if (first_round) > + ctx.process_gtid(round, (Gtid_log_event *)ev, linfo); > + break; > + > + case QUERY_EVENT: > + if (((Query_log_event *)ev)->is_commit() || > + ((Query_log_event *)ev)->is_rollback()) > { > - Gtid_log_event *gev= (Gtid_log_event *)ev; > - > - /* Update the binlog state with any GTID logged after Gtid_list. */ > - last_gtid.domain_id= gev->domain_id; > - last_gtid.server_id= gev->server_id; > - last_gtid.seq_no= gev->seq_no; > - last_gtid_standalone= > - ((gev->flags2 & Gtid_log_event::FL_STANDALONE) ? true : false); > - last_gtid_valid= true; > + ctx.last_gtid_no2pc= true; > + ctx.update_binlog_unsafe_coord_if_needed(linfo); what about DML on non-transactonal tables? it won't have COMMIT/ROLLBACK will it? > } > break; > #endif > @@ -10217,35 +10923,43 @@ int TC_LOG_BINLOG::recover(LOG_INFO *linfo, const char *last_log_name, > file= -1; > } > > - if (!strcmp(linfo->log_file_name, last_log_name)) > - break; // No more files to do > +#ifdef HAVE_REPLICATION > + int rc= ctx.next_binlog_or_round(round, last_log_name, > + binlog_checkpoint_name, linfo, this); > + if (rc == -1) > + goto err2; > + else if (rc == 1) > + break; // all rounds done > +#else > + if (!strcmp(linfo->log_file_name, last_log_name)) > + break; // No more files to do indentation > +#endif > + > if ((file= open_binlog(&log, linfo->log_file_name, &errmsg)) < 0) > { > sql_print_error("%s", errmsg); > goto err2; > } > - /* > - We do not need to read the Format_description_log_event of other binlog > - files. It is not possible for a binlog checkpoint to span multiple > - binlog files written by different versions of the server. So we can use > - the first one read for reading from all binlog files. > - */ > - if (find_next_log(linfo, 1)) > - { > - sql_print_error("Error reading binlog files during recovery. Aborting."); > - goto err2; > - } > fdle->reset_crypto(); > - } > + } // end of for > > if (do_xa) > { > - if (ha_recover(&xids)) > - goto err2; > - > + if (binlog_checkpoint_found) > + { > +#ifndef HAVE_REPLICATION > + if (ha_recover_complete(&xids)) > +#else > + if (ctx.complete(this, xids)) > +#endif > + goto err2; > + } > free_root(&mem_root, MYF(0)); > my_hash_free(&xids); > } > + if (fdle != fdle_arg) > + delete fdle; > + > return 0; > > err2: Regards, Sergei VP of MariaDB Server Engineering and security(a)mariadb.org

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[Maria-developers] Systems Integration and Raising of the Abstraction Level
by Alejandro Sánchez 26 Feb '21

26 Feb '21

We have highly evolved systems such as SQL, HTTP, HTML, file formats or high level programming languages such as Java or PHP that allow us to program many things with little code. Even so a lot of effort is invested in the integration of these systems. To try to reduce this problem libraries and frameworks that help in some ways are created but the integration is not complete. It is well known that most of the time when you try to create something to integrate several incompatible systems what you get in the end is to have another incompatible system :). Still I think the integration between the systems mentioned above is something very important that can mean a great step in the evolution of computing and worth a try. To explore how this integration can be I have created a framework that I have called NextTypes and that its main objective is the integration of data types. For me it is something very illogical that something as basic as a 16 bits integer receives a different name in each of the systems ("smallint", "short", "number") and can also be signed or unsigned. In any moment, due to a mistake from the programmer, the number of the programming language does not fit in the database column. Besides these names are little indicative of its characteristics, it would be clearer for example to use "int16". Whatever names are chosen the most important thing is to use in all systems the same names for types of the same characteristics. Also there is no standard system for defining composite data types of primitive types and other composite types. From an HTML form to a SQL table or from one application to another are required multiple transformations of the data. Lack of integration also lowers the level of abstraction, making it necessary to do lots of low level stuff for systems to fit. NextTypes at this moment is nothing more than another incompatible system with the others. It simply integrates them quite a bit and raises the level of abstraction. But what I would like is that the things that compose NextTypes were included in the systems it integrates. Finally I would like to list some examples of improvements in database managers, SQL, HTTP, HTML, browsers and programming languages that would help the integration and elevation of the level of abstraction. Some of these enhancements are already included in NextTypes and other frameworks. SQL --- - Custom metadata in tables and columns. - Date of creation and modification of the rows. - Date of creation and modification of the definition of the tables. - Use of table and column names in prepared statements. Example: select # from # where # = ?; - Use of arrays in prepared statements. Example: select # from article where id in (?); # = author,title ? = 10,24,45 - Standardization of ranges of valid values and resolution for date, time and datetime types in database managers an HTML time element. PostgreSQL ---------- - Facilitate access to the definition of full text search indexes with a function to parse "pg_index.indexprs" column. Other database managers ----------------------- - Allow transactional DDL, deferrable constraints and composite types. JDBC ---- - High level methods that allow queries with the execution of a single method. Example: Tuple [] tuples = query("select author,title from article where id in (?), ids); - Integration with java.time data types. HTTP - Servers -------------- - Processing of arrays of elements composed of several parameters. fields:0:type = string fields:0:name = title fields:0:parameters = 250 fields:0:not_null = true fields:1:type = string fields:1:name = author fields:1:parameters = 250 fields:1:not_null = true Another possibility is to generate in the browser arrays of JSON objects from the forms. "fields": [ { "type": "string", "name": "title", "parameters": 250, "not_null": true }, { "type": "string", "name": "author", "parameters": 250, "not_null": true } ] XML/HTML - BROWSER ------------------ - Input elements for different types of numbers with min and max values: 16 bits integer, 32 bits integer, 32 bits float and 64 bits float. - Input elements for images, audios and videos with preview. - Timezone input element. - Boolean input element with "true" and "false" values. - Null value in file inputs. - Clear button in file inputs like in date and time inputs. - Show size in file inputs. - Extension of the DOM API with high level and chainable methods. Example: paragraph.appendElement("a").setAttribute("href", "/article"); - Change of the "action" parameter of the forms to "target" to indicate the URL where to execute the action. The "action" parameter is moved to the different buttons on the form and allows executing a different action with each of the the buttons. Example: <form target="/article"> <button action="delete">Delete</button> <button action="export">Export</button> </form> - "select" elements that change a parameter of the current URL. Example: <select url-parameter="lang"/> <option>en</option> <option>es</option> URL = https://demo.nexttypes.com/?lang=en - "content-type" attribute in links and context menu in the browser to open links with external applications using WEBDAV, similar to a file manager. Example: <a href="" content- type="application/vnd.oasis.opendocument.text"> ------------------------------ | Open link with ... | | Open link with LibreOffice | - Background submission of forms without using XMLHttpRequest, display of result in dialog window or file download, and execution of a Javascript function for subsequent actions. Example: <form background show-progress callback=function()> - Dialog with progress indicator of form submission. Must show total size, transmitted data and average speed. Possibility to pause or cancel the submission. - Dynamic datalist with searchable JSON source. Over data source URL is added a "search" parameter with input value. Example: <input list="article-list" name="article" type="text" /> <datalist id="article-list" src="/article?lang=en&view=json&names" /> Example query URL: "/article?lang=en&view=json&names&search=Ne" - Same appearance and operation of inputs with dynamic datalist in all browsers. - Option tags with icons. Example: <option icon="/icons/save.svg">Save</option> - Tabs, Tree, etc widgets - Mechanism to close HTTPS sessions initiated with client certificate authentication. JAVA ---- - Subclasses of String or some system of variants of String that allows assigning a regular expression or class that limits its valid values to avoid code injection or values that will crash the system. Example: String:Type = "[a-z0-9 _] +"; Or String:Type = TypeChecks; String:Type type = "article_language"; -> correct String:Type type = "Article-Language"; -> error We can talk about the characteristics of each system in its mailing list or group. For the general topic of system integration I have created a discussion in the github project. https://github.com/alejsanc/nexttypes/discussions/6 This email has been sent to the following mailing lists and groups: pgsql-hackers(a)lists.postgresql.org pgsql-jdbc(a)lists.postgresql.org mozilla.dev.platform(a)googlegroups.com public-html(a)w3.org jdbc-spec-discuss(a)openjdk.java.net jdk-dev(a)openjdk.java.net maria-developers(a)lists.launchpad.net chromium-dev(a)chromium.org https://mysqlcommunity.slack.com/archives/C8R1336M7 Best regards. Alejandro Sánchez.

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[Maria-developers] Re MDEV-7317: Ignored indexes
by Sergey Petrunia 25 Feb '21

25 Feb '21

Hi Varun, The code for the task is mostly fine. But I would like to question the user experience. == Ignoring an index causes InnoDB table rebuild == First (and foremost), making an index ignored (or not ignored) in an InnoDB table rebuilds the table: MariaDB [test]> set session alter_algorithm='instant'; alter table t1 alter index c ignore; Query OK, 0 rows affected (0.001 sec) ERROR 1845 (0A000): ALGORITHM=INSTANT is not supported for this operation. Try ALGORITHM=COPY This misses the point of the feature. If one needs to rebuild the table anyway, they can just drop (or recreate) the index. Curiously, it works with MyISAM. I think, the ideal solution would be to make ignoring/not ignoring the index an SQL layer change that doesn't concern the storage engine. If this is not possible, lets make InnoDB aware that it doesn't need to rebuild the table in this case. == Backward compatibility for SHOW CREATE TABLE == SHOW CREATE TABLE will show something like: KEY `a` (`a`) IGNORE, MySQL here is more backward-compatible and shows: KEY `a` (`a`) /*!80000 INVISIBLE */, Do we need to do this as well? I have no strong opinion here. == Use of Ignored index in hints == I can use Ignored index in FORCE/IGNORE index hints: MariaDB [test]> explain select * from t1 force index(a) where a<3 and b<3; +------+-------------+-------+------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+-------+------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | t1 | ALL | NULL | NULL | NULL | NULL | 1000 | Using where | +------+-------------+-------+------+---------------+------+---------+------+------+-------------+ This is allowed. I think, this misses the point of the feature. The point of this feature is to check "what will happen if one drops the index". For this particular query, the effect will be like this: MariaDB [test]> explain select * from t1 force index(no_such_index) where a<3 and b<3; ERROR 1176 (42000): Key 'no_such_index' doesn't exist in table 't1' and MySQL agrees with me here (below index a is present but is invisible) : mysql> explain select * from t1 force index(a) where a<3 and b<3; ERROR 1176 (42000): Key 'a' doesn't exist in table 't1' == optimizer_switch flag == Seeing "ignore_indexes=on" in optimizer_switch looks scary. I would say, we don't need an @@optimizer_switch flag. Maybe, Serg disagrees. If we have to have a switch flag, and its name should be short (my opinion), I would use the noun form: ignored_indexes=ON|OFF I'm not 100% happy with this, but ignoreD is much better here than ignore. (Before acting on this review point, lets check with others). BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://petrunia.net

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Re: [Maria-developers] MDEV-17399: JSON_TABLE, commit 85757ecbef44484270e385a8d52998c67f72d11a
by Sergey Petrunia 24 Feb '21

24 Feb '21

Hi Alexey, First reactions to the JSON_TABLE patch: == CI Build is failing == Please check http://buildbot.askmonty.org/buildbot/grid?category=main&branch=bb-10.6-mde… the JSON_TABLE tests are failing. == On testcases == I see now the patch has tests in 3 files: 1. mysql-test/main/json_table_mysql.test 2. mysql-test/main/json_table_mysql2.test 3. mysql-test/suite/json/t/json_table.test #1 and #2 are both fixed copies of MySQL's test. Please remove one of them (the one that has less coverage). Then, can we have both files in the same testsuite? == On Table_function_json_table::ready_for_lookup() == Now that we have end_lateral_table, do we need to use Table_function_json_table::ready_for_lookup? This looks like two solutions for [almost] the same problem? I see that this example from json_table_mysql.test still uses the code path with ready_for_lookup() : --error ER_BAD_FIELD_ERROR UPDATE t1, JSON_TABLE(t1.c1,'$[*]' COLUMNS (a INT PATH '$.a')) AS jt1 SET jt1.a=1; Here, the name resolution for "jt1.a" is done without adjustment for end_lateral_table. Do we need the ready_for_lookup() trick here? (If we do, are we fine with m_setup_done to be set to true but never reset back to false? How will this work with PS?) == On opt_sum.cc == The diff has this: diff --git a/sql/opt_sum.cc b/sql/opt_sum.cc index af2d9ddc2e7..d021c651196 100644 --- a/sql/opt_sum.cc +++ b/sql/opt_sum.cc @@ -299,6 +299,7 @@ int opt_sum_query(THD *thd, tl->schema_table) { maybe_exact_count&= MY_TEST(!tl->schema_table && +//mdev-17399 !tl->table_function && (tl->table->file->ha_table_flags() & HA_HAS_RECORDS)); is_exact_count= FALSE; Please remove this if it is no longer needed. == On table dependencies: table elimination == create table t20 (a int not null); create table t21 (a int not null primary key, js varchar(100)); insert into t20 values (1),(2); insert into t21 values (1, '{"a":100}'); explain select t20.a, jt1.ab from t20 left join t21 on t20.a=t21.a join JSON_TABLE(t21.js,'$' COLUMNS (ab INT PATH '$.a')) AS jt1; +------+-------------+-------+------+---------------+------+---------+------+------+----------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+-------+------+---------------+------+---------+------+------+----------------------------+ | 1 | SIMPLE | t20 | ALL | NULL | NULL | NULL | NULL | 2 | | | 1 | SIMPLE | jt1 | ALL | NULL | NULL | NULL | NULL | 40 | Table function: json_table | +------+-------------+-------+------+---------------+------+---------+------+------+----------------------------+ Here we can see an apparently invalid query plan: table t21 was eleminated even if JSON_TABLE uses it. == On table dependencies: regular subqueries == But it doesn't work for regular subqueries either (and this is unexpected): insert into t21 values (3, '{"a":300}'); explain select a, (select jt1.ab from JSON_TABLE(t21.js,'$' COLUMNS (ab INT PATH '$.a')) as jt1 ) from t21; +------+-------------+-------+------+---------------+------+---------+------+------+----------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+-------+------+---------------+------+---------+------+------+----------------------------+ | 1 | PRIMARY | t21 | ALL | NULL | NULL | NULL | NULL | 2 | | | 2 | SUBQUERY | jt1 | ALL | NULL | NULL | NULL | NULL | 40 | Table function: json_table | +------+-------------+-------+------+---------------+------+---------+------+------+----------------------------+ Note the 'SUBQUERY', that is, the subquery is considered uncorrelated? This needs to be investigated. BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://petrunia.net

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Re: [Maria-developers] MDEV-17399: Columns of JSON datatype?
by Sergey Petrunia 17 Feb '21

17 Feb '21

On Sun, Feb 14, 2021 at 05:14:10PM +0400, Alexey Botchkov wrote: > One question left about the json_table_mysql.text. > > --error ER_WRONG_OUTER_JOIN > SELECT * FROM t1 RIGHT JOIN > (SELECT o FROM t2, JSON_TABLE(j, '$[*]' COLUMNS (o FOR ORDINALITY)) AS jt) > AS t3 > ON (t3.o = t1.x); > > What is exactly wrong with the above join? It should work. The reason it doesn't work was described by me in the email with subject "MDEV-17399: JSON_TABLE's dependencies are not updated after derived merge" dated Feb, 8th. What happens here is: Thread 14 "mysqld" hit Breakpoint 1, Table_function_json_table::setup() (gdb) list 1091 } 1092 } 1093 > 1094 m_dep_tables= m_json->used_tables(); 1095 (gdb) p m_dep_tables $44 = 1 If you go one frame up, you will see that we are in select#2. tables are: (gdb) p join->select_lex->leaf_tables.elem(0)->alias.str $56 = 0x7ffeb0016550 "t2" (gdb) p join->select_lex->leaf_tables.elem(0)->table->map $58 = 1 (gdb) p join->select_lex->leaf_tables.elem(1)->alias.str $60 = 0x7ffeb0017d70 "jt" (gdb) p join->select_lex->leaf_tables.elem(1)->table->map $62 = 2 Ok, jt depends on t2. Then: Thread 14 "mysqld" hit Breakpoint 2, simplify_joins (gdb) p join->select_lex->leaf_tables.elements $65 = 3 (gdb) p join->select_lex->leaf_tables.elem(0)->alias.str $66 = 0x7ffeb0015870 "t1" (gdb) p join->select_lex->leaf_tables.elem(0)->table->map $67 = 1 (gdb) p join->select_lex->leaf_tables.elem(1)->alias.str $68 = 0x7ffeb0016550 "t2" (gdb) p join->select_lex->leaf_tables.elem(1)->table->map $69 = 2 (gdb) p join->select_lex->leaf_tables.elem(2)->alias.str $70 = 0x7ffeb0017d70 "jt" (gdb) p join->select_lex->leaf_tables.elem(2)->table->map $71 = 4 But the m_dep_tables still has the old value: (gdb) p join->select_lex->leaf_tables.elem(2)->table_function->m_dep_tables $72 = 1 BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://petrunia.net

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[Maria-developers] MDEV-8306: EXPLAIN JSON output is not JSON-ish
by Sergey Petrunia 15 Feb '21

15 Feb '21

Hi Varun, (This email is not the complete input, and not the most important part of the input. More to follow. I think it's better to split input into multiple smaller pieces, it's easier to track, and you get to see the first portions of the input sooner) EXPLAIN EXTENDED SELECT t3.b, t2.a, t1.b, t1.a FROM t1,t2,t3 WHERE t1.b=t3.b ORDER BY t1.b DESC, t2.a DESC LIMIT 3; +------+-------------+-------------+------+---------------+------+---------+------+------+----------+------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | filtered | Extra | +------+-------------+-------------+------+---------------+------+---------+------+------+----------+------------------------------------+ | 1 | SIMPLE | t2 | ALL | NULL | NULL | NULL | NULL | 10 | 100.00 | | | 1 | SIMPLE | t1 | ALL | NULL | NULL | NULL | NULL | 20 | 100.00 | Using join buffer (flat, BNL join) | | 1 | SIMPLE | <sort-nest> | ALL | NULL | NULL | NULL | NULL | 3 | 100.00 | Using filesort | | 1 | SIMPLE | t3 | ALL | NULL | NULL | NULL | NULL | 100 | 5.00 | Using where | +------+-------------+-------------+------+---------------+------+---------+------+------+----------+------------------------------------+ So, here <sort-nest> includes t2 and t1, and then t3 is joined with it. However in EXPLAIN FORMAT=JSON output they all look like peers: { "query_block": { "select_id": 1, "table": { "table_name": "t2", "access_type": "ALL", "rows": 10, "filtered": 100 }, "block-nl-join": { "table": { "table_name": "t1", "access_type": "ALL", "rows": 20, "filtered": 100 }, "buffer_type": "flat", "buffer_size": "65", "join_type": "BNL" }, "read_sorted_file": { "filesort": { "sort_key": "`sort-nest`.b desc, `sort-nest`.a desc", "table": { "table_name": "<sort-nest>", "access_type": "ALL", "rows": 3, "filtered": 100 } } }, "table": { "table_name": "t3", "access_type": "ALL", "rows": 100, "filtered": 5, "attached_condition": "t3.b = `sort-nest`.b" } } } which is counter-intuitive. Also, `sort-nest` is quoted. I assume it is because of the '-' in it? Maybe we should change the name to avoid the quoting? BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://petrunia.net

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Re: [Maria-developers] MDEV-17399 New patch for JSON_TABLE
by Sergey Petrunia 14 Feb '21

14 Feb '21

Hi Alexey, Input on the latest patch for MDEV-17399. It's good to see the patch taking shape, but have you tried running MySQL's tests for JSON_TABLE on it? I did, and it has caught several crashes, as well as error-no-error discrepancies and different query results. Some of these were expected, but some show that something needs to be fixed. Please find the first few cases below. It seems there is something odd going odd with the name resolution, both in MariaDB and MySQL - I don't have explanation for some of the errors. I intend to study the issue more and elaborate in a later email. Meanwhile, first obvious cases: === Crash in Name resolution == CREATE TABLE t1 (a INT, b INT); CREATE VIEW v2 AS SELECT * FROM t1 LIMIT 2; SELECT b FROM (SELECT * FROM v2) vq1, JSON_TABLE(CONCAT(vq1.b,'[{\"a\":\"3\"}]'), '$[*]' COLUMNS (id FOR ORDINALITY, jpath VARCHAR(100) PATH '$.a', JEXST INT EXISTS PATH '$.b') ) AS dt; === Crash in error reporting === select * from json_table( '[{"a":"3"},{"a":2},{"b":1},{"a":0}]', "!@#$!@#$" columns (id for ordinality, jpath varchar(100) path '$.a', jexst int exists path '$.b') ) as tt; === Item print misses quotes === CREATE VIEW v2 AS SELECT * FROM JSON_TABLE('{}', '$' COLUMNS ( x VARCHAR(10) PATH '$.a' DEFAULT '"isn''t here"' ON EMPTY) ) t; SHOW CREATE VIEW v2; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 't here"' ON EMPTY)) `t`' at line 1 === Error for outer reference == # JSON_TABLE referring outer scope CREATE TABLE t1(id int, jd JSON); INSERT INTO t1 values (1, '[1,3,5]'),(2,'[2,4,6]'); SELECT * FROM t1 WHERE id IN (SELECT * FROM JSON_TABLE(t1.jd, '$[*]' COLUMNS (id INT PATH '$')) AS jt); Produces: ERROR 1054 (42S22): Unknown column 't1.jd' in 'JSON_TABLE argument' Should not produce it (Note that for some other kinds of outer references it seemed to work) BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://s.petrunia.net/blog

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[Maria-developers] MDEV-17399: Name resolution and handling dependencies
by Sergey Petrunia 14 Feb '21

14 Feb '21

Hi Alexey, At the moment, name resolution of JSON_TABLE's first argument is done "like in the WHERE clause" - one can refer to any table that is defined in the WHERE clause. This allows one to write queries where JSON_TABLE tables have incorrect dependencies - circular - dependency that contradicts the dependency imposed by OUTER JOIN - dependency that contradicts STRAIGHT_JOIN (WRONG-DEPS) the patch checks for these cases but I've reported cases where it fails. I haven't been find any statement in the SQL Standard about this, but it makes a statement about similar constructs, table functions and LATERAL subqueries: https://jira.mariadb.org/browse/MDEV-17399?focusedCommentId=179327&page=com… Other databases seem to apply the same limitation to JSON_TABLE's argument. When they do it, this automatically fixes all the wrong-dependency issues - a query with (WRONG-DEPS) is rejected at the name resolution phase. I think we should follow this and modify name resolution process to work in the same way. The way MySQL did it is described here: https://dev.mysql.com/worklog/task/?id=8867, LLD, grep for end_lateral_table. I'm not fond of having implicit parameters (end_lateral_table) which change they way name resolution works, but I think it is an acceptable solution (and we already have other such parameters). (An alternative option would be to have items in JSON_TABLE's first argument to use their own Name_resolution_context object that would specify the correct first/last table they should look at. This seems to be much harder to do). What do you think? BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://petrunia.net

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