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Update git submodules 

* Update charm-percona-cluster from branch 'master'
  - Merge "wsrep_slave_threads: default to 48 on bionic"
  - OpenDev Migration Patch
    
    This commit was bulk generated and pushed by the OpenDev sysadmins
    as a part of the Git hosting and code review systems migration
    detailed in these mailing list posts:
    
    http://lists.openstack.org/pipermail/openstack-discuss/2019-March/003603.html
    http://lists.openstack.org/pipermail/openstack-discuss/2019-April/004920.html
    
    Attempts have been made to correct repository namespaces and
    hostnames based on simple pattern matching, but it's possible some
    were updated incorrectly or missed entirely. Please reach out to us
    via the contact information listed at https://opendev.org/ with any
    questions you may have.
    
  - wsrep_slave_threads: default to 48 on bionic
    
    This improves performance significantly for environments constrained by
    calls to sync() such as HDDs or lower-end SSDs (or just very busy
    environments running many queries)
    
    By default the the queries from other nodes are only processed with
    1 thread, which means they will always run slower than on the master and
    any long running query will hold up all other queries behind it.
    
    Additionally, when multiple queries commit at once the server can
    combine them together into a single on-disk sync ('group commit') which
    is not possible otherwise. This optimisation appears to only occur on
    Bionic (Percona 5.7) and not Xenial (Percona 5.6).
    
    On Bionic, default to 48 threads which experimentally is a good number
    for OpenStack environments without being too crazy high. Galera ensures
    that queries that are dependent on each other are still executed
    sequentially and generally it is not expected to cause replication
    inconsistencies.
    
    However Percona Cluster 5.6 on Xenial appears to have a bug handling
    foreign key constraints that causes them to be violated (LP #1823850).
    The result is that the slave node crashes out and has to do a full SST
    to recover. The same issue is not present on the master. Thus we leave
    the default wsrep_slave_threads=1 on Xenial to avoid this issue for now
    particularly since Xenial does not appear to be able to use Group Commit
    to optimise the number of sync requests generated by the queries - so
    this option does not really improve performance there anyway.
    
    Partial-Bug: #1822903
    Change-Id: Ic9cdd6562f30a3e52aa3d26fea53ba7c2bbdc771
This commit is contained in:
Zuul 2019-04-26 07:48:49 +00:00 committed by Gerrit Code Review
parent ef6cb2d0d5
commit 5a2b75fb0b
1 changed files with 1 additions and 1 deletions
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charm-percona-cluster

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Subproject commit 9b7d7d6a02ba8947d5bbd7f8b8fcd7fd45823145
Subproject commit 9fc4f23b808e34bdfd9929152ae5e20ac407a24a