Bug #87995 Please backport to 5.7: default log-tc-size too small on POWER - 3 * ( 64K page
Submitted: 5 Oct 2017 14:30 Modified: 3 Nov 2017 15:58
Reporter: Robie Basak Email Updates:
Status: Closed Impact on me:
Category:MySQL Server: XA transactions Severity:S3 (Non-critical)
Version:5.7 OS:Ubuntu
Assigned to: CPU Architecture:ARM

[5 Oct 2017 14:30] Robie Basak
The bug is described at https://bugs.mysql.com/bug.php?id=80818. Please could you backport the fix to 5.7? In Ubuntu, I will cherry-pick the fix shortly as we (Canonical) have customers affected. If you could please backport to your 5.7 series, then that would help us with future updates.

How to repeat:
compile on Power hardware.

run ./mysql-test-run
[6 Oct 2017 7:37] Umesh Shastry
Hello Robie Basak,

Thank you for the report.
Verifying for the back-port request.

[3 Nov 2017 15:58] Paul Dubois
Posted by developer:
Fixed in 5.7.21.

The hardcoded memory page size of 8KB for the memory-mapped
transaction coordinator was too small for platforms such as ARM64 and
PowerPC where the page size is much larger. The server now invokes a
system call to get the page size of the current platform rather than
using a hardcoded value. A consequence for the --log-tc-size option
is that the minimum and default values are now 6 times the page size.
Also, the value must be a multiple of the page size. Thanks to Alexey
Kopytov for the patch.