- developers - lists.mariadb.org

Re: [Maria-developers] d8e3cfacebc: MDEV-14616: WSREP has not yet prepared node for application use error
by Sergei Golubchik 15 Mar '18

15 Mar '18

Hi, Jan! On Feb 13, jan wrote: > revision-id: d8e3cfacebc47849532ef3e7bbf18f9da53bab88 (mariadb-10.1.31-20-gd8e3cfacebc) > parent(s): 474f3df092cc73342b2da03aa03ba5c66930f596 > author: Jan Lindström > committer: Jan Lindström > timestamp: 2018-02-13 10:04:48 +0200 > message: > > MDEV-14616: WSREP has not yet prepared node for application use error > > Contains following Galera fixes: > > MW-405 Make sure wsrep is ready in wait_until_connected_again.inc What is "MW-405", can I see the original bug report somewhere? > wait_until_connected_again issues 'SHOW STATUS' query repeatedly > until mysqld replies without errors. However, SHOW STATUS is > treated specially by wsrep in that it is allowed to proceed > even if wsrep is not yet in ready state. As a consequence, > after returning from wait_until_connected_again, wsrep may > not be ready yet and subsequent queries may fail with error > "1047 WSREP has not yet prepared node for application use". > To avoid those errors, the patch includes > wait_wsrep_ready.inc at the end of the wait_until_connected_again.inc I don't quite understand the issue. Old code did wait_wsrep_ready.inc after wait_until_connected_again.inc. Now wait_wsrep_ready.inc is included in wait_until_connected_again.inc. This seems to imply that the bug was "there were some cases where wait_wsrep_ready.inc was not included after wait_until_connected_again.inc". There are, of course, two ways to fix such a bug. Either include wait_wsrep_ready.inc after wait_until_connected_again.inc, or include wait_wsrep_ready.inc in wait_until_connected_again.inc. The latter fix implies that there are no possible cases when one would want to wait for a server to be connected, but before wsrep is ready. Are there? For the purpose of testing, that could be useful, could it not? > kill_galera.inc can no longer rely on wait_until_connected_again.inc. > This is because wait_until_connected_again now tries to make sure > that the server it is connected eventually transition to ready state. > Whereas some tests may need to kill galera while the server is in a > non-primary view. Which means that there are cases when a test needs the server connected, but before wsrep is ready, right? > MW-408 Fix 'WSREP error while trying to determine node state' > > mysql-test-run.pl sporadically reports 'WSREP error while > trying to determine node state' right after starting servers > for test execution. This happens because we try to execute a > SELECT statement that queries the current value of status variable > wsrep_ready. If this statement fails, the above message is reported. > The failure is due to fact that wsrep may return error > ER_LOCK_WAIT_TIMEOUT (on any SELECT statement) if it is not ready > and wsrep_sync_wait enabled for SELECTs. The fix is to disable > wsrep_sync_wait for the session that issues those SELECT statements. 1. Could you put this fix in a separate commit please? 2. Sorry, I don't understand. Where do "we try to execute a SELECT statement that queries the current value of status variable wsrep_ready" ? > --- > mysql-test/include/restart_mysqld.inc | 3 - > mysql-test/include/start_mysqld.inc | 3 - > mysql-test/include/wait_until_connected_again.inc | 11 ++- > mysql-test/mysql-test-run.pl | 104 ++++++++++++++++++++++ > mysql-test/suite/galera/include/kill_galera.inc | 1 - > 5 files changed, 111 insertions(+), 11 deletions(-) > > diff --git a/mysql-test/include/restart_mysqld.inc b/mysql-test/include/restart_mysqld.inc > index a0447280ff5..940e081c431 100644 > --- a/mysql-test/include/restart_mysqld.inc > +++ b/mysql-test/include/restart_mysqld.inc > @@ -50,9 +50,6 @@ if (!$restart_parameters) > # Call script that will poll the server waiting for it to be back online again > --source include/wait_until_connected_again.inc > > -# Wait for wsrep > ---source include/wait_wsrep_ready.inc > - > # Turn off reconnect again > --disable_reconnect > > diff --git a/mysql-test/include/start_mysqld.inc b/mysql-test/include/start_mysqld.inc > index 04dff714d49..e31f26aad8c 100644 > --- a/mysql-test/include/start_mysqld.inc > +++ b/mysql-test/include/start_mysqld.inc > @@ -16,9 +16,6 @@ if (!$restart_parameters) > # Call script that will poll the server waiting for it to be back online again > --source include/wait_until_connected_again.inc > > -# Wait for wsrep > ---source include/wait_wsrep_ready.inc > - > # Turn off reconnect again > --disable_reconnect > > diff --git a/mysql-test/include/wait_until_connected_again.inc b/mysql-test/include/wait_until_connected_again.inc > index 6f64ef45440..4958d276ebd 100644 > --- a/mysql-test/include/wait_until_connected_again.inc > +++ b/mysql-test/include/wait_until_connected_again.inc > @@ -11,10 +11,7 @@ let $counter= 5000; > let $mysql_errno= 9999; > while ($mysql_errno) > { > - # Strangely enough, the server might return "Too many connections" > - # while being shutdown, thus 1040 is an "allowed" error > - # See BUG#36228 > - --error 0,1040,1053,2002,2003,2005,2006,2013,1927 > + --error 0,ER_SERVER_SHUTDOWN,ER_CONNECTION_KILLED,2002,2003,2006,2013 > show status; > > dec $counter; > @@ -26,3 +23,9 @@ while ($mysql_errno) > } > --enable_query_log > --enable_result_log > + > +# WSREP: SHOW STATUS queries are allowed even if wsrep > +# is not ready. Make sure wsrep is ready before > +# returning from this script > + > +--source include/wait_wsrep_ready.inc > diff --git a/mysql-test/mysql-test-run.pl b/mysql-test/mysql-test-run.pl > index eaec51b82b4..324f2e98ebd 100755 > --- a/mysql-test/mysql-test-run.pl > +++ b/mysql-test/mysql-test-run.pl > @@ -2883,6 +2883,49 @@ sub mysql_server_wait { > $warn_seconds); > } > > +sub have_wsrep() { > + my $wsrep_on= $mysqld_variables{'wsrep-on'}; > + return defined $wsrep_on > +} > + > + > +sub check_wsrep_support() { > + if (have_wsrep()) > + { > + mtr_report(" - binaries built with wsrep patch"); > + > + # ADD scripts to $PATH to that wsrep_sst_* can be found > + my ($path) = grep { -f "$_/wsrep_sst_rsync"; } "$::bindir/scripts", $::path_client_bindir; > + mtr_error("No SST scripts") unless $path; > + $ENV{PATH}="$path:$ENV{PATH}"; > + > + # Check whether WSREP_PROVIDER environment variable is set. > + if (defined $ENV{'WSREP_PROVIDER'}) { > + if ((mtr_file_exists($ENV{'WSREP_PROVIDER'}) eq "") && > + ($ENV{'WSREP_PROVIDER'} ne "none")) { > + mtr_error("WSREP_PROVIDER env set to an invalid path"); > + } > + # WSREP_PROVIDER is valid; set to a valid path or "none"). > + mtr_verbose("WSREP_PROVIDER env set to $ENV{'WSREP_PROVIDER'}"); > + } else { > + # WSREP_PROVIDER env not defined. Lets try to locate the wsrep provider > + # library. > + my $file_wsrep_provider= > + mtr_file_exists("/usr/lib/galera/libgalera_smm.so", > + "/usr/lib64/galera/libgalera_smm.so"); > + > + if ($file_wsrep_provider ne "") { > + # wsrep provider library found ! > + mtr_verbose("wsrep provider library found : $file_wsrep_provider"); > + $ENV{'WSREP_PROVIDER'}= $file_wsrep_provider; > + } else { > + mtr_verbose("Could not find wsrep provider library, setting it to 'none'"); > + $ENV{'WSREP_PROVIDER'}= "none"; > + } > + } > + } > +} > + > sub create_config_file_for_extern { > my %opts= > ( > @@ -3341,6 +3384,62 @@ sub run_query { > return $res > } > > +sub run_query_output { > + my ($mysqld, $query, $outfile)= @_; > + > + my $args; > + mtr_init_args(\$args); > + mtr_add_arg($args, "--defaults-file=%s", $path_config_file); > + mtr_add_arg($args, "--defaults-group-suffix=%s", $mysqld->after('mysqld')); > + > + mtr_add_arg($args, "--silent"); > + mtr_add_arg($args, "--execute=%s", $query); > + > + my $res= My::SafeProcess->run > + ( > + name => "run_query_output -> ".$mysqld->name(), > + path => $exe_mysql, > + args => \$args, > + output => $outfile, > + error => $outfile > + ); > + > + return $res > +} > + > +sub wait_wsrep_ready($$) { > + my ($tinfo, $mysqld)= @_; > + > + my $sleeptime= 100; # Milliseconds > + my $loops= ($opt_start_timeout * 1000) / $sleeptime; > + > + my $name= $mysqld->name(); > + my $outfile= "$opt_vardir/tmp/$name.wsrep_ready"; > + my $query= "SET SESSION wsrep_sync_wait = 0; > + SELECT VARIABLE_VALUE > + FROM INFORMATION_SCHEMA.GLOBAL_STATUS > + WHERE VARIABLE_NAME = 'wsrep_ready'"; > + > + for (my $loop= 1; $loop <= $loops; $loop++) > + { > + if (run_query_output($mysqld, $query, $outfile) != 0) > + { > + $tinfo->{logfile}= "WSREP error while trying to determine node state"; > + return 0; > + } > + > + if (mtr_grab_file($outfile) =~ /^ON/) > + { > + unlink($outfile); > + return 1; > + } > + > + mtr_milli_sleep($sleeptime); > + } > + > + $tinfo->{logfile}= "WSREP did not transition to state READY"; > + return 0; > +} > > sub do_before_run_mysqltest($) > { > @@ -5380,6 +5479,11 @@ sub start_servers($) { > $tinfo->{comment}= "Failed to start ".$_->name() . "\n"; > return 1; > } > + > + if (have_wsrep() && !wait_wsrep_ready($tinfo, $_)) > + { > + return 1; > + } > } > return 0; > } > diff --git a/mysql-test/suite/galera/include/kill_galera.inc b/mysql-test/suite/galera/include/kill_galera.inc > index c61bad8e19d..f95dccf2185 100644 > --- a/mysql-test/suite/galera/include/kill_galera.inc > +++ b/mysql-test/suite/galera/include/kill_galera.inc > @@ -18,4 +18,3 @@ > exit(0); > EOF > > ---source include/wait_until_disconnected.inc > _______________________________________________ > commits mailing list > commits(a)mariadb.org > https://lists.askmonty.org/cgi-bin/mailman/listinfo/commits Regards, Sergei Chief Architect MariaDB and security(a)mariadb.org

1 0

Re: [Maria-developers] [Commits] dc3d6c9edb3: MDEV-15477: SESSION_SYSVARS_TRACKER does not track last_gtid
by Sergei Golubchik 09 Mar '18

09 Mar '18

Hi, Oleksandr! On Mar 09, Oleksandr Byelkin wrote: > revision-id: dc3d6c9edb3536e5f0c87ac1e9c04891d50fc420 (mariadb-10.2.13-32-gdc3d6c9edb3) > parent(s): 6cf25e5eb76923550173a0059036d80c80a053d6 > author: Oleksandr Byelkin > committer: Oleksandr Byelkin > timestamp: 2018-03-09 14:39:40 +0100 > message: > > MDEV-15477: SESSION_SYSVARS_TRACKER does not track last_gtid > > register changes of last_gtid > > diff --git a/mysql-test/t/session_tracker_last_gtid.test b/mysql-test/t/session_tracker_last_gtid.test > --- /dev/null > +++ b/mysql-test/t/session_tracker_last_gtid.test > @@ -0,0 +1,18 @@ > + > +--source include/have_innodb.inc > +--source include/have_binlog_format_mixed_or_statement.inc Why "mixed or statement"? > diff --git a/sql/log.cc b/sql/log.cc > --- a/sql/log.cc > +++ b/sql/log.cc > @@ -5945,7 +5945,20 @@ MYSQL_BIN_LOG::write_gtid_event(THD *thd, bool standalone, > } > if (err) > DBUG_RETURN(true); > + bool changed_gtid= (thd->last_commit_gtid.seq_no != gtid.seq_no); > thd->last_commit_gtid= gtid; > + if (changed_gtid && > + thd->session_tracker.get_tracker(SESSION_SYSVARS_TRACKER)->is_enabled()) > + { > + sys_var *svar; > + mysql_mutex_lock(&LOCK_plugin); > + if ((svar= find_sys_var_ex(thd, "last_gtid", > + sizeof("last_gtid") - 1, > + false, true))) > + thd->session_tracker.get_tracker(SESSION_SYSVARS_TRACKER)-> > + mark_as_changed(thd, (LEX_CSTRING*)svar); > + mysql_mutex_unlock(&LOCK_plugin); > + } No, please. You svar will always be Sys_last_gtid. There is no need to search for it on every write_gtid_event(), under a mutex. See in sys_vars.cc around Sys_autocommit how to do it easier. Also, perhaps it'd be safer to rename last_commit_gtid to m_last_commit_gtid, make it private and provide a setter and a getter. The setter will update the tracker. I'll make sure that last_commit_gtid is not changed anywhere else bypassing the tracker. Regards, Sergei Chief Architect MariaDB and security(a)mariadb.org

1 0

Re: [Maria-developers] 6cf25e5eb76: Session tracking info support in mysqltest
by Sergei Golubchik 09 Mar '18

09 Mar '18

Hi, Oleksandr! On Mar 09, Oleksandr Byelkin wrote: > revision-id: 6cf25e5eb76923550173a0059036d80c80a053d6 (mariadb-10.2.13-31-g6cf25e5eb76) > parent(s): f2b91c878cf4ec53c292caba7f5907d1ef724de4 > author: Oleksandr Byelkin > committer: Oleksandr Byelkin > timestamp: 2018-03-09 14:27:13 +0100 > message: > > Session tracking info support in mysqltest Add a test case for it. Don't forget to test whether ONCE modifier works. Regards, Sergei Chief Architect MariaDB and security(a)mariadb.org

1 0

Re: [Maria-developers] f2b91c878cf: Reset connection support in mysqltest
by Sergei Golubchik 09 Mar '18

09 Mar '18

Hi, Oleksandr! On Mar 09, Oleksandr Byelkin wrote: > revision-id: f2b91c878cf4ec53c292caba7f5907d1ef724de4 (mariadb-10.2.13-30-gf2b91c878cf) > parent(s): 8f98835bb86550a68a6c412d8417cc169dfdc206 > author: Oleksandr Byelkin > committer: Oleksandr Byelkin > timestamp: 2018-03-09 14:26:10 +0100 > message: > > Reset connection support in mysqltest You add a feature - add a test case for it too. Regards, Sergei Chief Architect MariaDB and security(a)mariadb.org

1 0

[Maria-developers] MariaDB 5.5, Jemalloc, TokuDB, RHEL
by Michal Schorm 08 Mar '18

08 Mar '18

Hello, so far we packed MariaDB 5.5 for RHEL 7 without TokuDB and without Jemalloc. Recently, a customer asked about the availability of TokuDB, so I'm doing a research, if its possible to pack it without any issues for the users updating. I have a several questions: 1) Is Jemmaloc used elsewhere from TokuDB ? 2) If yes, what all would be affected? Could any issues arise during update from build without Jemalloc to build with it? Any expected performance changes? 3) Would be the use of the bundled Jemalloc (on of the) best option(s)? 4) Anything else that I missed? -- Michal Schorm Associate Software Engineer Core Services - Databases Team Red Hat

2 1

[Maria-developers] Introduction as GSoC 2018 aspirant
by Arshdeep Singh Sachdeva 05 Mar '18

05 Mar '18

Dear MariaDB Developers, I am Arshdeep Singh Sachdeva, currently studying BTech ( C.S.E. ) from Punjab Engineering College, Chandigarh, India. I am interested in contibuting to MariaDB and participating in GSoC 2018 under your guidance. I am proficient in C++, python, linux, mysql. I have already used MariaDB in my projects in college. Also I am presently going through documentation and tutorials. Thanks.

1 0

[Maria-developers] Introduction as a GSoC aspirant
by Aman Jain 05 Mar '18

05 Mar '18

Hello developers and mentors I am Aman and I am interested in contributing to MariaDB as a GSoC'18 aspirant. I am familiar with C++, Web development, SQL, MongoDB and shell scripting and I have set up the MariaDB server. Please suggest me where I can find the source code so that I can get a better understanding of the project ideas and solve some issues to get started. Thanks Aman Jain

2 1

Re: [Maria-developers] [Commit] MDEV-12746 out-of-order retry
by Kristian Nielsen 17 Feb '18

17 Feb '18

andrei.elkin(a)pp.inet.fi writes: > commit 3cebb54e6387a7eace1757c82ed0efd6e11590b9 > Author: Andrei Elkin <andrei.elkin(a)mariadb.com> > Date: Fri Feb 9 15:00:23 2018 +0200 > > MDEV-12746 rpl.rpl_parallel_optimistic_nobinlog fails committing > out of order at retry > > The 2nd issue was out of order commit by transactions that > are ordered after an erroring out transaction. The latter was possible > in the test thanks to the above retry failure. > Out-of-order committing was done despite the slave was stopping. Let me see if I understand this correctly: Normally, a transaction in optimistic parallel replication cannot commit out of order because it either waits for the prior transaction to commit first, or, if the prior transaction has stopped with an error earlier, then the following transaction will not even start. But in this case, during retry, there was missing the check that the prior transaction stopped with an error. Therefore, the following transaction's wait_for_prior_commit() does nothing, and it wrongly goes ahead and runs and even commits, even though an earlier transaction failed and replication is stopping. Correct? That's a nice catch of a subtle, but potentially serious bug. I wonder how this is possible though. As I recall, when a transaction fails, this failure is marked in the wait_for_prior_commit data structures. So the retrying transaction should have gotten an error in wait_for_prior_commit() and aborted the retries. So why does this not happen in this case? > The test failures were of two sorts. One is that the number of potential > temporary errors actually exceeds the default value of the slave retry > option. > Increased @@global.slave_transaction_retries fixes that part. Hm, this shouldn't be needed, I think. The retry waits for all prior transactions to commit first, so after the first retry no further retries should be caused by other parallel replication workers. So I would expect this problem to be a side-effect of the other, real issue, and this increase should not be needed (and might hide another problem later, if left in). > diff --git a/sql/rpl_parallel.cc b/sql/rpl_parallel.cc > index 34f9113f7fe..9f1d23a1161 100644 > --- a/sql/rpl_parallel.cc > +++ b/sql/rpl_parallel.cc > @@ -745,7 +761,25 @@ retry_event_group(rpl_group_info *rgi, rpl_parallel_thread *rpt, > for (;;) > { > mysql_mutex_lock(&entry->LOCK_parallel_entry); > - register_wait_for_prior_event_group_commit(rgi, entry); > + if (entry->stop_on_error_sub_id == (uint64) ULONGLONG_MAX || > +#ifndef DBUG_OFF > + (DBUG_EVALUATE_IF("simulate_mdev_12746", 1, 0)) || > +#endif > + rgi->gtid_sub_id < entry->stop_on_error_sub_id) > + { > + register_wait_for_prior_event_group_commit(rgi, entry); > + } > + else > + { > + /* > + An earlier transaction by another worker may have not had not > + have the current one in subsequent committers list and thus > + the actual induced error status could not have been sumbitted. > + So it should be set by ourselves now. > + */ This comment is hard to understand - what do you mean here? > + if (!rgi->worker_error) > + rgi->worker_error= 1; > + } I would have expected an abort (goto err) here (or well just below, after unlocking the mutex). Is this not needed, and if so, why not? > @@ -716,12 +724,20 @@ retry_event_group(rpl_group_info *rgi, rpl_parallel_thread *rpt, > unregistering (and later re-registering) the wait. > */ > if(thd->wait_for_commit_ptr) > - thd->wait_for_commit_ptr->unregister_wait_for_prior_commit(); > + thd->wait_for_commit_ptr->unregister_wait_for_prior_commit(); Indentation? - Kristian.

2 5

[Maria-developers] Developers Unconference in New York
by Ian Gilfillan 16 Feb '18

16 Feb '18

A final reminder about the Developers Unconference happening in New York on Sat 24 and Sun 25 February, just before M|18. https://mariadb.org/2018-mariadb-developers-unconference/ Please sign up on the Meetup page if you are going to be attending: https://www.meetup.com/MariaDB-Developers/events/244375856/ Hope to see you there!

1 0

[Maria-developers] Google Summer of Code 2018 - MariaDB Foundation accepted
by Colin Charles 14 Feb '18

14 Feb '18

Hi, I just noticed this piece of good news — MariaDB Foundation is accepted to participate in the Google Summer of Code 2018 again — https://summerofcode.withgoogle.com/ There is an already healthy list of ideas: https://mariadb.com/kb/en/library/google-summer-of-code-2018/ Many already have mentors from MariaDB Corporation or MariaDB Foundation. Some are looking for mentors. Happy coding this summer! cheers, -colin -- Colin Charles, http://bytebot.net/blog/ twitter: @bytebot | skype: colincharles "First they ignore you, then they laugh at you, then they fight you, then you win." -- Mohandas Gandhi

1 0