Hi Marc,
about the instrumentation of Maria threads; there are currently these
background threads (I grepped for pthread_create):
- one in maria_backup_engine.cc; lives for a period during online
backup, you can test by doing BACKUP with a Maria table
- one in ma_checkpoint.c: that's the checkpoint thread, it is created
when Maria starts and goes to sleep; it takes a checkpoint every 30th
second if there has been significant activity in Maria (for example,
more than 2 MB written to the transaction log) since the previous
checkpoint. This thread also takes a checkpoint when it is killed, which
can be done by entering "set global maria_checkpoint_interval=X" (this
kills the thread, restarts it with a period of X seconds instead of 30).
- one in ma_sort.c (ma_thr_find_all_keys), it's only used by Maria's
parallel table repair functionality. To test this you need to create a
table with CREATE TABLE ... ROW_FORMAT=DYNAMIC (the default data format
of Maria disables parallel repair), and start mysqld with
--maria-parallel-repair-threads=X with X>1. Note that the table will not
generate any logging because DYNAMIC isn't crash-safe (so you cannot
test that in the same go as testing checkpoints).
--
Mr. Guilhem Bichot <guilhem@stripped>
Sun Microsystems / MySQL, Lead Software Engineer
Bordeaux, France
www.sun.com / www.mysql.com
