Re: Unresolved repliaction hang and stop problem.

On 2021-Jun-16, Ha Ka wrote:

> Here is the upload with generated reports: https://easyupload.io/p38izx
> passwd: johS5jeewo

OK, so I downloaded that and this is the interesting entry in the
profile for the broken case:

# Samples: 5K of event 'cpu-clock'
# Event count (approx.): 59989898390
#
# Children Self Command Shared Object Symbol
# ........ ........ ........ ............. ..................................
#
100.00% 0.00% postgres postgres [.] exec_replication_command
|
---exec_replication_command
WalSndLoop
XLogSendLogical
LogicalDecodingProcessRecord
|
--99.51%--ReorderBufferQueueChange
|
|--96.06%--hash_seq_search
|
|--1.78%--ReorderBufferSerializeTXN
| |
| --0.52%--errstart
|
--0.76%--deregister_seq_scan

What this tells me is that ReorderBufferQueueChange is spending a lot of
time doing hash_seq_search, which probably is the one in
ReorderBufferTXNByXid.

I have, as yet, no idea what this means.

--
Álvaro Herrera 39°49'30"S 73°17'W