Databases Reference
In-Depth Information
who_blocks: thread 2 from localhost:40298
idle_in_trx: 1016
max_wait_time: 37
num_waiters: 8
The result shows that thread 2 has now been idle for a much longer time, and at least
one thread has been waiting for up to 37 seconds for it to release its locks. There are
eight threads waiting for thread 2 to finish its work and commit.
We've found that idle-in-transaction locking is a common cause of emergency prob-
lems, and is sometimes difficult for people to diagnose. The
pt-kill
tool from Percona
Toolkit can be configured to kill long-running idle transactions to prevent this situation.
Percona Server itself also supports an idle transaction timeout parameter to accomplish
the same thing.
