On 05/24/21 19:24, Christophe Pettus wrote:
On May 24, 2021, at 09:22, Bob Jolliffe <bobjolliffe@xxxxxxxxx> wrote:
It is hard to say as it only happens for 30s couple of times per day.
Everything does return to normal after the blocking transaction is
committed. It could be a disk thing or even a network issue (the java
app is on a different machine to the db). But I never saw
transactions blocked in commit before so was wondering if there is any
rational set of reasons why it might do that.
One thing you can check is to turn off synchronous_commit (understanding the possibility of "time loss" in the event of a system crash). If that mitigates the problem, the issue is likely the I/O subsystem blocking during the fsync() operation.
Just a question. Is there a btrfs(with compression maybe) around? 30
seconds is a commit(file system) timeout for btrfs. Some processes like
btrfs cleaner/allocate/worker on top of CPU/io use?
