Re: transaction blocking on COMMIT

2021-05-27 Thread Bob Jolliffe
No brtfs. We are going to try turning off synchronous_commit temporarily to see if there are underlying I/O issues. On Mon, 24 May 2021 at 22:59, Alexey M Boltenkov wrote: > > On 05/24/21 19:24, Christophe Pettus wrote: > > > >> On May 24, 2021, at 09:22, Bob Jolliffe wrote: > >> > >> It is har

Re: transaction blocking on COMMIT

2021-05-24 Thread Alexey M Boltenkov
On 05/24/21 19:24, Christophe Pettus wrote: On May 24, 2021, at 09:22, Bob Jolliffe 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

Re: transaction blocking on COMMIT

2021-05-24 Thread Christophe Pettus
> On May 24, 2021, at 09:22, Bob Jolliffe 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 machi

Re: transaction blocking on COMMIT

2021-05-24 Thread Bob Jolliffe
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 b

Re: transaction blocking on COMMIT

2021-05-24 Thread Vijaykumar Jain
No worries, There were some threads earlier which mentioned some automated changes to disk by the provider that resulted in some slowness. But otherwise also, do you query system, disk metrics. Do you see any anomaly in disk io (wait) when you saw blocking? If it did, did the io return to norma

Re: transaction blocking on COMMIT

2021-05-24 Thread Bob Jolliffe
Hello Jain Sorry forgot to indicate: it is running the ubuntu packaged version 13.3 on ubuntu 20.04. It is not in the cloud, but is a VM in a government datacentre. I am not sure of the underlying hyperviser. I could find out. Regards Bob On Mon, 24 May 2021 at 12:35, Vijaykumar Jain wrote

Re: transaction blocking on COMMIT

2021-05-24 Thread Vijaykumar Jain
I think there have been similar issues reported earlier as well. But it would be too early to generalize. Where is the db server running? Cloud? Also what is the version ? On Mon, May 24, 2021, 5:00 PM Bob Jolliffe wrote: > I am seeing a strange issue on a database using jdbc. Regularly, 4

transaction blocking on COMMIT

2021-05-24 Thread Bob Jolliffe
I am seeing a strange issue on a database using jdbc. Regularly, 4 or 5 times a day, I see something like a "stutter", where a bundle of maybe 30 transactions suddenly finish at the same time. It looks like (it is quite hard to catch this exactly) that the lead transaction which has been blockin