On 2021-01-22 11:54, kuroda.hay...@fujitsu.com wrote:
Dear Ikeda-san,
This patch cannot be applied to the HEAD, but anyway I put a comment.
```
+ /*
+ * Measure i/o timing to fsync WAL data.
+ *
+ * The wal receiver skip to collect it to avoid performance
degradation of standy servers.
+ * If sync_method doesn't have its fsync method, to skip too.
+ */
+ if (!AmWalReceiverProcess() && track_wal_io_timing &&
fsyncMethodCalled())
+ INSTR_TIME_SET_CURRENT(start);
```
I think m_wal_sync_time should be collected even if the process is
WalRecevier.
Because all wal_fsync should be recorded, and
some performance issues have been aleady occurred if
track_wal_io_timing is turned on.
I think it's strange only to take care of the walrecevier case.
Kuroda-san, Thanks for your comments.
Although I thought that the performance impact may be bigger in standby
servers
because WALReceiver didn't use wal buffers, it's no need to be
considered.
I agreed that if track_wal_io_timing is turned on, the primary server's
performance degradation occurs too.
I will make rebased and modified.
Regards,
--
Masahiro Ikeda
NTT DATA CORPORATION
