Bug #31927 Endless loop when updating from 1.1 to 1.2 if contains data before and after DST
Submitted: 29 Oct 2007 19:51 Modified: 6 Nov 2007 15:03
Reporter: Bill Weber Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Enterprise Monitor: Server Severity:S1 (Critical)
Version:1.2.0.7657 OS:Any
Assigned to: Darren Oldag CPU Architecture:Any

[29 Oct 2007 19:51] Bill Weber
Description:
If there was data collected both before and after Daylight Savings Time using 1.1, there is an endless loop encountered during the update procss. The update process is automatically run the first time the Enterprise Monitor is started after running the update installer.

How to repeat:
- install 1.1 dashboard and agent(s)
- start and collect data before and after (spans) Daylight Savings Time
- run 1.2 installer
- start 1.2 dashboard
[29 Oct 2007 20:27] Darren Oldag
the migration code path has the very bug that the migration was intended to fix -- namely, that the TIMESTAMP column cannot be trusted to accurately work across daylight saving time switchovers when used in conjunction with the JDBC driver and system default timezones.

so, a similar fix as was done for the dc_* tables themselves will be applied to the migration log table.  that is -- use BIGINT column to store epoch milliseconds.
[29 Oct 2007 20:38] Darren Oldag
fix applied as described in previous comment.

patch committed to trunk, r7876.

awaiting review for inclusion into 1.2* release and maintenance trees.
[30 Oct 2007 18:27] Darren Oldag
in build 1.2.0.7879
[31 Oct 2007 16:50] Bill Weber
Verified fixed in 1.2.0.7879.
[6 Nov 2007 15:03] Peter Lavin
Added to the changelog.