Parallel doublewrite buffer file created when skip-innodb_doublewrite is set

[Sean]

I use Percona on top of ZFS, so I disable the doublewrite buffer since it's redundant and unnecessary. I do this with skip-innodb_doublewrite in /etc/mysql/my.cnf.

The new Percona 5.7.11-4 has added the new parallel doublewrite buffer feature and according to the log file (next line), this new buffer is being created.

[Note] InnoDB: Created parallel doublewrite buffer at /var/lib/mysql/xb_doublewrite, size 31457280 bytes

I don't think it's actually being used, since an "ls -l" in /var/lib/mysql shows a stale "last updated" timestamp for the xb_doublewrite file.

But it should not be created at all if doublewrites are disabled.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-3411