diff options
| author | Andres Freund | 2023-05-17 18:18:35 +0000 |
|---|---|---|
| committer | Andres Freund | 2023-05-17 18:18:35 +0000 |
| commit | 093e5c57d506783a95dd8feddd9a3f2651e1aeba (patch) | |
| tree | 95de46d45e866ed9a059a18f546690e675370cb8 /doc | |
| parent | 52676dc2e016df5cd842a4f6073b25ee8e681b9f (diff) | |
Add writeback to pg_stat_io
28e626bde00 added the concept of IOOps but neglected to include writeback
operations. ac8d53dae5 added time spent doing these I/O operations. Without
counting writeback, checkpointer write time in the log often differed
substantially from that in pg_stat_io. To fix this, add IOOp IOOP_WRITEBACK
and track writeback in pg_stat_io.
Bumps catversion.
Author: Melanie Plageman <[email protected]>
Reviewed-by: Kyotaro Horiguchi <[email protected]>
Reported-by: Andres Freund <[email protected]>
Discussion: https://postgr.es/m/20230419172326.dhgyo4wrrhulovt6%40awork3.anarazel.de
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/src/sgml/monitoring.sgml | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 9842f820915..df5242fa80f 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -3870,6 +3870,32 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i <row> <entry role="catalog_table_entry"> <para role="column_definition"> + <structfield>writebacks</structfield> <type>bigint</type> + </para> + <para> + Number of units of size <varname>op_bytes</varname> which the process + requested the kernel write out to permanent storage. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>writeback_time</structfield> <type>double precision</type> + </para> + <para> + Time spent in writeback operations in milliseconds (if + <xref linkend="guc-track-io-timing"/> is enabled, otherwise zero). This + includes the time spent queueing write-out requests and, potentially, + the time spent to write out the dirty data. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> <structfield>extends</structfield> <type>bigint</type> </para> <para> |