database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-10-21 02:52:47 +03:00
Code Activity

Adjust max_slot_wal_keep_size behavior per review

Browse Source 
In pg_replication_slot, change output from normal/reserved/lost to
reserved/extended/unreserved/ lost, which better expresses the possible
states particularly near the time where segments are no longer safe but
checkpoint has not run yet.

Under the new definition, reserved means the slot is consuming WAL
that's still under the normal WAL size constraints; extended means it's
consuming WAL that's being protected by wal_keep_segments or the slot
itself, whose size is below max_slot_wal_keep_size; unreserved means the
WAL is no longer safe, but checkpoint has not yet removed those files.
Such as slot is in imminent danger, but can still continue for a little
while and may catch up to the reserved WAL space.

Also, there were some bugs in the calculations used to report the
status; fixed those.

Backpatch to 13.

Reported-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20200616.120236.1809496990963386593.horikyota.ntt@gmail.com
This commit is contained in:
Alvaro Herrera
2020-06-24 14:23:39 -04:00
parent 0188bb8253
commit b8fd4e02c6
5 changed files with 97 additions and 54 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
src/include/access/xlog.h
View File

@@ -270,8 +270,10 @@ extern CheckpointStatsData CheckpointStats;
typedef enum WALAvailability
{
WALAVAIL_INVALID_LSN, /* parameter error */
WALAVAIL_NORMAL, /* WAL segment is within max_wal_size */
WALAVAIL_RESERVED, /* WAL segment is reserved by a slot */
WALAVAIL_RESERVED, /* WAL segment is within max_wal_size */
WALAVAIL_EXTENDED, /* WAL segment is reserved by a slot or
* wal_keep_segments */
WALAVAIL_UNRESERVED, /* no longer reserved, but not removed yet */
WALAVAIL_REMOVED /* WAL segment has been removed */
} WALAvailability;