[MDEV-5186]  /usr/bin/mysqld_safe doesn't have NUMA options support Created: 2013-10-25  Updated: 2014-01-07  Resolved: 2013-11-12

Status: Closed
Project: MariaDB Server
Component/s: None
Affects Version/s: 5.5.33a
Fix Version/s: 5.5.34

Type: Bug Priority: Major
Reporter: Aleksey Sanin (Inactive) Assignee: Sergei Golubchik
Resolution: Fixed Votes: 0
Labels: None

Issue Links:
Relates
relates to MDEV-5507 Add the possibility set default param... Closed

 Description   

MariaDB-server 5.5.33a doesn't support NUMA options in /usr/bin/mysqld_safe

http://www.percona.com/doc/percona-server/5.5/performance/innodb_numa_support.html

Note that these options present in MariaDB-Galera-server 5.5.33a



 Comments   
Comment by Elena Stepanova [ 2013-10-28 ]

Assigned to Jan as apparently InnoDB-related, not as Galera-related.

Comment by Jan Lindström (Inactive) [ 2013-10-31 ]

Yes, there is general new numa option for mysqld_safe that launches mysqld with numactl using numactl --interleave=all. I have not experience how useful that option is because it requires hardware supporting numactl.

Percona has introduced some additional configuration parameters for InnoDB to further support numa. All these options are available if you use xtradb storage engine not Oracle InnoDB storage engine.

I will leave the decision about mysqld_save for someone else.

Comment by Aleksey Sanin (Inactive) [ 2013-10-31 ]

These options are very useful: http://blog.jcole.us/2010/09/28/mysql-swap-insanity-and-the-numa-architecture/

We've had numerous swap usage alerts on the standalone MariaDB machine until we figured out that these options are not implemented in "pure" MariaDB (and are implemented in MariaDB-Galera):

  • Before the change (N0 is overloaded when N1 is empty)
  1. perl numa-maps-summary.pl < /proc/24432/numa_maps
    N0 : 8034951 ( 30.65 GB)
    N1 : 2288796 ( 8.73 GB)
    active : 69235 ( 0.26 GB)
    anon : 10301726 ( 39.30 GB)
    dirty : 10301756 ( 39.30 GB)
    mapmax : 400 ( 0.00 GB)
    mapped : 22074 ( 0.08 GB)
  • After the change (N0 and N1 are roughly equal)
  1. perl numa-maps-summary.pl < /proc/1670/numa_maps
    N0 : 5138584 ( 19.60 GB)
    N1 : 5138174 ( 19.60 GB)
    active : 46102 ( 0.18 GB)
    anon : 10274076 ( 39.19 GB)
    dirty : 10274084 ( 39.19 GB)
    mapmax : 457 ( 0.00 GB)
    mapped : 2735 ( 0.01 GB)

As I said, we've had daily swap usage alerts before the change and we have no alerts for about a week which proves that these options made the difference

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