All, as discussed yesterday, here is my setup and configuration. ************************************************************* 16 VCPU 64GB Memory, DB size 12 GB (In RAM), MariaDB 10.1.24* Single Image. No clustering or outside network interaction * SuSE SLES 12 SP2 using a 4.4.49-92 kernel * ************************************************************* ### Sysbench R/W - 64 Threads sysbench 0.5: multi-threaded system evaluation benchmark Running the test with following options: Number of threads: 64 Report intermediate results every 2 second(s) Initializing random number generator from seed (42). Threads started! [ 2s] threads: 64, tps: 51141.62, reads: 717023.15, writes: 204757.48, response time: 4.72ms (99%), errors: 54.00, reconnects: 0.00 [ 4s] threads: 64, tps: 47938.19, reads: 671195.72, writes: 191759.28, response time: 4.65ms (99%), errors: 5.00, reconnects: 0.00 [ 6s] threads: 64, tps: 46908.41, reads: 656790.25, writes: 187640.64, response time: 4.65ms (99%), errors: 2.50, reconnects: 0.00 [ 8s] threads: 64, tps: 45940.12, reads: 643191.64, writes: 183781.47, response time: 4.44ms (99%), errors: 3.00, reconnects: 0.00 [ 10s] threads: 64, tps: 45789.91, reads: 641083.20, writes: 183161.13, response time: 4.77ms (99%), errors: 2.00, reconnects: 0.00 [ 12s] threads: 64, tps: 45408.37, reads: 635825.16, writes: 181672.97, response time: 4.80ms (99%), errors: 1.50, reconnects: 0.00 [ 14s] threads: 64, tps: 44319.93, reads: 620440.07, writes: 177262.74, response time: 4.50ms (99%), errors: 0.50, reconnects: 0.00 [ 16s] threads: 64, tps: 44634.78, reads: 624843.97, writes: 178523.13, response time: 4.71ms (99%), errors: 0.50, reconnects: 0.00 . . . [ 572s] threads: 64, tps: 24980.71, reads: 349707.39, writes: 99924.32, response time: 5.92ms (99%), errors: 0.00, reconnects: 0.00 [ 574s] threads: 64, tps: 25337.03, reads: 354796.98, writes: 101355.13, response time: 6.19ms (99%), errors: 0.00, reconnects: 0.00 [ 576s] threads: 64, tps: 25196.31, reads: 352683.33, writes: 100777.24, response time: 6.49ms (99%), errors: 0.00, reconnects: 0.00 [ 578s] threads: 64, tps: 25235.61, reads: 353317.05, writes: 100941.94, response time: 5.94ms (99%), errors: 0.00, reconnects: 0.00 [ 580s] threads: 64, tps: 25241.11, reads: 353395.59, writes: 100956.96, response time: 6.09ms (99%), errors: 0.00, reconnects: 0.00 [ 582s] threads: 64, tps: 25146.18, reads: 352056.04, writes: 100599.73, response time: 5.96ms (99%), errors: 0.00, reconnects: 0.00 [ 584s] threads: 64, tps: 25242.59, reads: 353362.72, writes: 100978.85, response time: 6.21ms (99%), errors: 0.00, reconnects: 0.00 [ 586s] threads: 64, tps: 25297.02, reads: 354187.80, writes: 101166.58, response time: 5.89ms (99%), errors: 0.00, reconnects: 0.00 [ 588s] threads: 64, tps: 25070.60, reads: 350944.86, writes: 100283.39, response time: 6.33ms (99%), errors: 0.00, reconnects: 0.00 [ 590s] threads: 64, tps: 25115.20, reads: 351666.84, writes: 100466.81, response time: 6.21ms (99%), errors: 0.00, reconnects: 0.00 [ 592s] threads: 64, tps: 25165.11, reads: 352314.52, writes: 100668.94, response time: 5.98ms (99%), errors: 0.00, reconnects: 0.00 [ 594s] threads: 64, tps: 25165.99, reads: 352322.89, writes: 100703.97, response time: 6.30ms (99%), errors: 0.00, reconnects: 0.00 [ 596s] threads: 64, tps: 24854.73, reads: 347945.66, writes: 99370.90, response time: 6.17ms (99%), errors: 0.00, reconnects: 0.00 [ 598s] threads: 64, tps: 24888.16, reads: 348463.80, writes: 99556.16, response time: 6.21ms (99%), errors: 0.00, reconnects: 0.00 [ 600s] threads: 64, tps: 25158.22, reads: 352195.58, writes: 100633.38, response time: 5.94ms (99%), errors: 0.00, reconnects: 0.00 OLTP test statistics: queries performed: read: 256244548 write: 73212536 other: 36606172 total: 366063256 transactions: 18302990 (30454.11 per sec.) read/write requests: 329457084 (548179.44 per sec.) other operations: 36606172 (60908.54 per sec.) ignored errors: 192 (0.32 per sec.) reconnects: 0 (0.00 per sec.) General statistics: total time: 601.0023s total number of events: 18302990 total time taken by event execution: 38450.5507s response time: min: 0.42ms avg: 2.10ms max: 62.26ms approx. 99 percentile: 5.62ms Threads fairness: events (avg/stddev): 285984.2188/3788.79 execution time (avg/stddev): 600.7899/0.00 ================================================================================================================= ### Excerpt from MariaDB Error Log (Thousands of similiar messages). . . . 2017-06-08 8:10:44 4395980287248 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction 2017-06-08 8:10:44 4353081699600 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction 2017-06-08 8:10:44 4353087458576 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction 2017-06-08 8:10:44 4360227998992 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction 2017-06-08 8:10:44 4353073515792 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction 2017-06-08 8:10:44 4390705949968 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction 2017-06-08 8:10:44 4360227392784 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction 2017-06-08 8:10:44 4353087458576 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction 2017-06-08 8:10:44 4353073515792 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction 2017-06-08 8:10:44 4353087458576 [ERROR] mysqld: Deadlock found when trying to get lock; try restarting transaction . . . =================================================================================================================== The configuration below has been tried and tested and works across on different architectures e.g. S390X and S390X. [mysqld_safe] user=root password='' [mysqld] symbolic-links=0 open_files_limit = 65535 # was 102400 max_allowed_packet = 16M # was 768M max-connect-errors = 1000000 connect_timeout = 120 # was 60 performance-schema = false net_read_timeout = 720 log-warnings=2 #####files and sockets # innodb_log_group_home_dir= /data-lun22/logs pid-file=/tmp/mysqld.pid.sysbench port = 3306 # log-error=/var/log/mariadb/mariadb-error-john.log log-error=/var/log/mariadb/mariadb-error-john.log general_log_file=/var/log/mariadb/mariadb-john.log long_query_time = 0 slow_query_log = 0 # slow_query_log_file = /var/log/mariadb/mariadb-slowquery.log # general-log # general_log_file=/var/log/mariadb/mariadb-general.log ##### MariaDB temporary tables # tmpdir in RAM tmpdir = /mnt/tmpdir #####non innodb options (fixed) max_connections = 4000 back_log = 150 table_open_cache = 8000 # was 2048 # was 4000 # was 8000 key_buffer_size = 16M query_cache_type = 0 #was 1 # was 0 join_buffer_size = 32K sort_buffer_size = 32K autocommit = 0 thread-cache-size = 50 table-definition-cache = 1024 table-open-cache = 2048 ####fixed innodb options innodb_file_per_table = true innodb_open_files = 4096 # was 8192 # was 4096 innodb_data_file_path = ibdata1:250M:autoextend innodb_flush_log_at_trx_commit = 2 innodb_flush_method = O_DIRECT_NO_FSYNC innodb_log_buffer_size = 256M innodb_log_file_size = 4G # was 14G # was 4G innodb_log_files_in_group = 2 innodb_buffer_pool_size = 36G #was 8G # was 48G innodb_buffer_pool_instances = 8 # 16 # was 6 # was 32 innodb_adaptive_hash_index_partitions = 32 innodb_thread_concurrency = 0 ####tuning for RAM disk innodb_adaptive_flushing = 1 innodb_flush_neighbors = 0 innodb_io_capacity = 8000 # was 20000 innodb_io_capacity_max = 40000 innodb_lru_scan_depth = 4096 innodb_purge_threads = 2 innodb_read_io_threads = 2 innodb_write_io_threads = 2 <*> Note NMON reports 35% memory usage in the middle of the abovementioned Banchmark ergo the DB is in cache. No paging. ++ Note The R/W TPS rate are "respectable" based on observations from countless other runs ran on other configurations/architecture. The TPS rates would obviously improve if the deadlock situation outlined above was resolved. So there you have it. Any tips / pointers that would enlighten me are much appreciated. Regards, JC Privet Sergey, do not think I have a problem with my config(s). I am not on the machine at the moment.
From memory, with 16 Cores / 32 VCPU, 64 GB memory, buffer pools, logs etc. tailored to this configuration, the TPS rate is
64 threads - R/O 73K R/W 26K 128 threads - R/O 71K R/W 23K. I am putting the DB in RAM of course to obviate I/O issues. I am interested in seeing what is happening with the CPU caches and nest.. NMON tells me that for the R/O runs I have approximately 85% User, 12-14% System and the rest Idle - this stays consistent throughout the run (300 seconds R/O, 600 seconds R/W) which is reasonable. On the R/W runs, NMONs CPU usage display shows that some CPUs are barely firing, or only intermittently and the granularity I had with R/O is gone. This would seem to tie in with what I see in the MariaDB log - headwinds, violent storms and deadlocks. Any further information you require, please let me know. Regards, JC Hi! I just tried this on x86: 40 threads against single table having 10k rows. No deadlocks, "tps: 12372.40, reads: 173219.52, writes: 49490.51". This is with latest snapshot of 10.1 and sysbench 1.0. I believe you shouldn't see deadlocks on such a big data set. Probably something is wrong with your configs? Regards, Sergey On Thu, Jun 08, 2017 at 04:51:31PM +0200, J. Cassidy wrote:
Hello Mark,
appreciate the
reply.
The OLTP table size and OLTP size give me a
DB size of appx 12GB. This is what I want. I have in the
meantime, looked at some older logs and see that whatever amount of threads I
specify (8, 16,32, 64 or 128), the deadlock messages are still surfacing in the
R/W phase of Sysbench. I even dropped in two different MariaDB release levels (10.0.19, 10.1.24) to see whether it would make a difference, deadlock still there. I am using Sysbench 0.5 for these tests. I am currently using MariaDB 10.1.24 - built directly on the machine. S390x by the way, but the problem is also
occuring on an X86-64 box.
Regards,
JC
I run sysbench frequently with
(not MariaDB yet) and don't recall ever seeing this error. But I use much larger values for --oltp-table-size. You used 85937 and I use 1M or larger. Maybe there is too much data contention with smaller tables, even if a large number of tables is used (128 in your case). I use a smaller number of tables - between 4 and 20. On Thu, Jun 8, 2017 at 12:48 AM, J. Cassidy sean@jdcassidy.eu> wrote: Hello all,
have used Sysbench extensively to test MariaDB CPU load factors between various architectures.
I am noticing massive amounts of "[ERROR] mysqld: Deadlock found when
MySQL trying to get lock; try restarting transaction" in the
MariaDB error log during the R/W phase. The Sysbench R/W TPS rates are still
respectable for my purposes, but how do I
correct this condition?? Can I ignore this / must live with it? I have tried three different MariaDB releases (10.0.19, 10.1.12, 10.1.24) to narrow things down, but this message (x 1000's) is happening across all releases in the Sysbench R/W phase.
Here is the Sysbench command that drives the workload against MariaDB -
sysbench --test=lua/oltp.lua --oltp_tables_count=128 --oltp-table-size=85937
--rand-seed=42 --rand-type=uniform --num-threads=128 --oltp-read-only=off
--report-interval=2 --mysql-socket=/var/lib/mysql/mysql.sock --max-time=201 --max-requests=0 --mysql-user=root --percentile=99 run
Would anyone have a tip / idea /pointer?
Regards,
JC
John Cassidy
Obere Bühlstrasse 21 8700 Küsnacht (ZH) Switzerland / Suisse / Schweiz
Mobile: +49 152 58961601 (Germany) Mobile: +352 621 577 149 (Luxembourg) Mobile: +41 78 769 17 97 (CH) Landline: +41 44 509 1957
"Aut viam inveniam aut
faciam" - Hannibal.
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John Cassidy
Obere
Bühlstrasse 21
8700 Küsnacht (ZH)
Switzerland / Suisse / Schweiz
Mobile: +49
152 58961601 (Germany)
Mobile: +352 621 577 149 (Luxembourg)
Mobile:
+41 78 769 17 97 (CH) Landline: +41 44 509 1957
"Aut viam inveniam aut faciam" - Hannibal.
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John Cassidy Obere Bühlstrasse 21 8700 Küsnacht (ZH) Switzerland / Suisse / Schweiz Mobile: +49 152 58961601 (Germany) Mobile: +352 621 577 149 (Luxembourg) Mobile: +41 78 769 17 97 (CH) Landline: +41 44 509 1957 http://www.jdcassidy.eu "Aut viam inveniam aut faciam" - Hannibal. John Cassidy Obere Bühlstrasse 21 8700 Küsnacht (ZH) Switzerland / Suisse / Schweiz Mobile: +49 152 58961601 (Germany) Mobile: +352 621 577 149 (Luxembourg) Mobile: +41 78 769 17 97 (CH) Landline: +41 44 509 1957 http://www.jdcassidy.eu "Aut viam inveniam aut faciam" - Hannibal.