Ok but form the conf you past you get

autocommit = 0

So if sysbench does not commit you may get into deadlock quiet fast

/svar

Stéphane Varoqui, Senior Consultant

Phone: +33 695-926-401, skype: svaroqui

http://www.mariadb.com

Le 9 juin 2017 à 09:27, J. Cassidy sean@jdcassidy.eu> a écrit :

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 MySQL
> (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 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
>
> http://www.jdcassidy.eu
>
> "Aut viam inveniam aut
> faciam" - Hannibal.
> _______________________________________________
> Mailing list: https://launchpad.net/~maria-discuss
> Post to :
> maria-discuss@lists.launchpad.net
> Unsubscribe : https://launchpad.net/~maria-discuss
> More help : https://help.launchpad.net/ListHelp
> --Mark Callaghan
> mdcallag@gmail.com
>
> 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.

> _______________________________________________
> Mailing list: https://launchpad.net/~maria-discuss
> Post to : maria-discuss@lists.launchpad.net
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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._______________________________________________
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Post to : maria-discuss@lists.launchpad.net
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