[Bug 1657256] Re: Percona crashes when doing a a 'larger' update

[Robie Basak]

This needs Zesty fixed before we can upload SRUs, so unsubscribing
~ubuntu-sponsors for now. Please resubscribe ~ubuntu-sponsors once you
have a Zesty debdiff ready.

I realise they're two separate source packages, but from the POV of the
underlying reason for the "fix development first" SRU requirement this
is a technicality and the reasoning still applies to this case IMHO.

-- 
You received this bug notification because you are a member of Ubuntu
Sponsors Team, which is subscribed to the bug report.
https://bugs.launchpad.net/bugs/1657256

Title:
  Percona crashes when doing a a 'larger' update

Status in percona-xtradb-cluster-5.5 package in Ubuntu:
  In Progress
Status in percona-xtradb-cluster-5.6 package in Ubuntu:
  In Progress
Status in percona-xtradb-cluster-5.5 source package in Trusty:
  In Progress
Status in percona-xtradb-cluster-5.6 source package in Xenial:
  Confirmed
Status in percona-xtradb-cluster-5.6 source package in Yakkety:
  Confirmed
Status in percona-xtradb-cluster-5.6 source package in Zesty:
  In Progress

Bug description:
  [Impact]

   * Percona will segfault when exposed to medium load, almost imediately
   * This is because of a bug in upstream, which manifests only on PPC

  
  [Test Case]

   * Install and configure percona-xtradb-cluster-server
   * Make sure galera is enabled (by setting up wsrep_provider in configuration)
   * Run sysbench against configured node (only one node is needed, no need for proper cluster):
     # sysbench --test=oltp --oltp-test-mode=complex --max-time=60 --num-threads=110 run 
   * mysqld will segfault seconds withing starting the test

  
  [Regression Potential]

   * This is a cherry-pick from an upstream fix (https://jira.mariadb.org/browse/MDEV-6450)
   * This is not fixed in upstream Percona becasue Percona does not officially support non-intel archs.
   * Because code adds additional memory barriers there was a chance of performance degradation on i386/amd64. However, intensive sysbench syntetic loads proved this is not the case - there are no performance penalties.

  
  [Other Info]

   * Upstream commit:
  https://github.com/MariaDB/server/commit/40497577ffd9f85557b15e08ad913f627b2e9530

  
  [Original Description]

  I'm trying to set up percona-xtradb-cluster-5.5 on PPC machine. While
  the package installs fine, as soon as I run sysbench oltp becnhmark
  against it, Percona dies (even when I start the benchmark with just
  one connection).

  I can also crash mysql manually, by updating the sbtest table (which
  is created by the sysbench utility):

  mysql> update sbtest set pad = 'mario1' limit 1000000;
  ERROR 2013 (HY000): Lost connection to MySQL server during query

  Sometimes I need to repeat this update (with different values for
  'pad' field) few times. This happens regardless of whether I run the
  UPDATE inside the transaction or not.

  This is the assertion found in the log file:

  170117 21:10:55 InnoDB: Assertion failure in thread 70366668321152 in file buf0buf.ic line 1277
  InnoDB: Failing assertion: block->page.buf_fix_count > 0

  This is a single-node percona-xtradb-cluster server, without
  wsrep_provied configured, run inside 14.04 lxc container on 16.04
  host.

  I'm attaching the full log file, mysql configuration file and the core
  dumped.

  The version of the package installed is this 5.5.37-25.10+dfsg-
  0ubuntu0.14.04.2.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/percona-xtradb-cluster-5.5/+bug/1657256/+subscriptions