QA - Aria Recovery
Contents
General Principles
Recovery is tested via the RQG, which provides a random workload against the
server, and then uses kill -9 to kill the process. After that, recovery is
attempted both by using maria_read_log and by restarting the mysqld
process. Once the server has started up, the tables are verified in various
ways, including ALTER|OPTIMIZE|ANALYZE|REPAIR TABLE as well SELECT
queries that read the table back and forth using various access methods.
A combinations .CC file named
lp:randgen/conf/engines/maria/maria_recovery.cc is used to define various
mysql options and RQG parameters that are relavant to recovery. Then, RQG's
combinations.pl script is used to run hundreds of individual test runs.
Each run uses a random permutation from the settings in the .CC file in
order to generate a unique workload that is then validated via the Recovery
RQG Reporter.
Individual tests
The following are the individual tests or test runs that must be completed or created in order to ensure that Aria recovery is solid.
Standard kill -9 testing
Done 2011-02-28 The standard conf/engines/maria/maria_recovery.cc
passes with no failures when run with hundreds of trials.
Testing with small block sizes
On hold pending 2 bug fixes related to --maria-block-size=1K and --maria-block-size=2K
Testing with small page cache size
Done 2011-03-04 Completed 400 rounds with
'--mysqld=--maria-block-size=4K --mysqld=--maria-pagecache-buffer-size=128K', '--mysqld=--maria-block-size=16K --mysqld=--maria-pagecache-buffer-size=256K', '--mysqld=--maria-block-size=32K --mysqld=--maria-pagecache-buffer-size=512K'
two pre-recovery crashes were filed, no recovery issues.
Killing and restarting the recovery process itself
In Progress
The AriaDoubleRecovery reporter currently attempts doble recovery via maria_read_log. The first invocation of maria_read_log is killed halfway through the process and the second invocation is left to complete the recovery.
Future testing will involve doing the same with the mysqld server in place of maria_read_log.
Another realistic workload
The usefullness of the SMF workload, derived from the SimpleMachines forum application means that another such workload is required in order to make sure no residual recovery bugs remain. Hopefully something can be cooked up using Wikipedia so that longer fields and blobs are exercised.
Transactional consistency
A transactional grammar that simulates transactions using LOCK TABLEs is required. The RecoveryConsistency Reporter can then be used to validate that no partial transactions appear in the database after recovery.
