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We have two production MySQL servers running Percona Server 5.5.42 and would like to set up a new server running Percona Server 5.7 as a slave to them. However, because there's such a gap in versions, the 5.7 slave is unable to get a server_uid back from the 5.5 master(s). The correct solution would be to upgrade the masters, which we are aware of, but due to time and resource constraints it's not possible at this time.

Is there any other work-around? If necessary I can downgrade the slave to 5.6 and come back around in the future and perform necessary upgrades on all servers. What would be the next best thing?

AlBlue
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jyncka
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2 Answers2

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Currently, a 5.7 slave cannot replicate from a 5.5 master because the attempt to read SERVER_UUID on slave connection will fail fatally if the variable does not exist on the master at all (which it does not on 5.5). This is MySQL bug https://bugs.mysql.com/bug.php?id=80962, tracked for Percona Server as https://bugs.launchpad.net/percona-server/+bug/1566642. The fix is in the source tree already and will be part of the next Percona Server 5.7.12-5 release, which should happen around middle of May.

I am not aware of any workaround for this bug, unless recompiling current PS 5.7 with the fix (a github PR is linked from the Launchpad bug) is an option.

Laurynas Biveinis
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  • That's perfect, we can handle upgrading to 5.7.12 in the future and that'll tide us over for awhile. – jyncka Apr 29 '16 at 18:27
  • @jyncka if this has helped you, consider marking the answer as correct by clicking on the tick mark just under the up/down votes. – AlBlue Apr 30 '16 at 07:12
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We had a project to upgrade from MySQL 5.5 to MySQL 5.7. The documentation suggests that we should go from 5.5 to 5.6 and then to 5.7. We found, though, that 5.7 can be a slave of 5.5.

We have replication running from Percona Server 5.5.50-38.0 to Percona Server 5.7.15-9 and this has been working for at least two months on several slaves running 5.7 replicating from a 5.5 master.

Santosh Mathew
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