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[Robert Lyon <robertl@xxxxxxxxxxxxxxx>]

Hi Kevin,

We recently changed how we do transactions in mahara to avoid deadlock
issues, see https://bugs.launchpad.net/mahara/+bug/1492919

The fix for that looks to be causing your problem, which is: Statement
based binlogging does not work in isolation level READ UNCOMMITTED and
READ COMMITTED since the necessary locks cannot be taken.

The recommended fix for this is exactly what you have done, to change
the BINLOG_FORMAT variable to MIXED. This allows MySQL to automatically
switch between ROW and STATEMENT based logging as required.

For others who stumble upon this:

To change to row based binary logging, set the following in /etc/my.cnf (or your my.cnf if it's elsewhere):
binlog_format=row

Cheers

Robert

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https://bugs.launchpad.net/bugs/1509351

Title:
  MySQL binlog_format preventing install

Status in Mahara:
  New

Bug description:
  Mahara version 15.10.0
  Centos
  MySQL/MariaDB

  Hi,

  I tried to install 15.10 on my dev server today and it didn't complete
  the DB setup.

  The logs had the following message:

  [WAR] e3 (lib/dml.php:933) Failed to get a recordset: mysqli error:
  [1665: Cannot execute statement: impossible to write to binary log
  since BINLOG_FORMAT = STATEMENT and at least one table uses a storage
  engine limited to row-based logging. InnoDB is limited to row-logging
  when transaction isolation level is READ COMMITTED or READ
  UNCOMMITTED.] in EXECUTE("DELETE FROM "config" WHERE "field" =
  '_upgrade' "), referer: http://a.website.co.uk/admin/upgrade.php

  It installed fine once I'd I changed the BINLOG_FORMAT to MIXED first
  of all by using the following commands :

  SET GLOBAL binlog_format=MIXED;
  SET SESSION binlog_format=MIXED;
  SET binlog_format=MIXED;

  I've now set it permanently in the my.cnf by adding
  binlog_format=MIXED

  I assume binlog_format=STATEMENT is the default as I've never set it
  before and my other servers are set to STATEMENT

  I think that I installed a development version of 15.10 previously
  without this issue, my memory on that is not clear though.

  I guess the questions are:

  Can the pre-install check test for this?

  Is this an issue once Mahara is actually running or only on install?

  If it is only on install can the the commands above be used to changed the binlog_format during install and then set it back?
  (I was using a privileged MySQL when the commands were issued so I don't know if they can be run by a user set up to access the Mahara db)

  Kevin

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