Classified as: {OPEN}
> Just for confirmation your settings are still?:
> autovacuum_max_workers = 10
> log_autovacuum_min_duration = 0
Yes.
> You said previously:
> "The only way I can find of getting the analyzer back is to restart Postgres."
>
> To be clear this means:
> 1) The lfm database is dropped/created.
Yes, using dropdb and pg_restore
> 2) There is a round of autovacuum immediately after the lfm is restored.
Yes, some tables in the lfm database, but not all, an apparently random selection, anywhere between 2 and 21 tables, across the lfm schemas, public & pg_catalog.
> 3) autovacuum then goes silent.
Yes. Dead in a ditch. But with no errors.
> 4) Before the next drop/create lfm you restart the Postgres server and autovacuum starts again.
I haven't restarted in a week, and the pattern remains, with a bit of analyze at each reload of lfm, and then nothing.
> What is in the logs when you do the restart?
Nothing notable:
1) denied connections, while restarting
2) authorized connections
3) auto analyze going into overdrive:
See below
> Is there some process that runs shortly after the drop/create lfm cycle?
Not that I can see.
Extract of postgres log for a typical restart :
2024-05-13 05:56:19.151 GMT [4688]: [99-1] db=,user=,app=,client= LOG: shutting down
2024-05-13 05:56:19.162 GMT [4688]: [100-1] db=,user=,app=,client= LOG: checkpoint starting: shutdown immediate
2024-05-13 05:56:19.751 GMT [344]: [1-1] db=[unknown],user=[unknown],app=[unknown],client=11.22.33.44 LOG: connection received: host=11.22.33.44 port=54730
2024-05-13 05:56:19.752 GMT [344]: [2-1] db=postgres,user=a_a,app=[unknown],client=11.22.33.44 FATAL: the database system is shutting down
2024-05-13 05:56:19.843 GMT [4324]: [1-1] db=[unknown],user=[unknown],app=[unknown],client=11.22.33.44 LOG: connection received: host=11.22.33.44 port=54731
2024-05-13 05:56:19.845 GMT [4324]: [2-1] db=lfm2,user=fs_admin,app=[unknown],client=11.22.33.44 FATAL: the database system is shutting down
...
2024-05-13 05:56:20.319 GMT [4688]: [101-1] db=,user=,app=,client= LOG: checkpoint complete: wrote 326 buffers (0.1%); 0 WAL file(s) added, 0 removed, 0 recycled; write=0.073 s, sync=1.006 s, total=1.168 s; sync files=33, longest=0.281 s, average=0.031 s; distance=588 kB, estimate=26425 kB
2024-05-13 05:57:13.889 GMT [4220]: [1-1] db=,user=,app=,client= LOG: database system was shut down at 2024-05-13 05:56:20 GMT
2024-05-13 05:57:13.921 GMT [4236]: [1-1] db=[unknown],user=[unknown],app=[unknown],client=11.22.33.44 LOG: connection received: host=11.22.33.44 port=54863
2024-05-13 05:57:13.922 GMT [4236]: [2-1] db=postgres,user=a_a,app=[unknown],client=11.22.33.44 FATAL: the database system is starting up
...
2024-05-13 05:57:14.572 GMT [4868]: [1-1] db=[unknown],user=[unknown],app=[unknown],client=11.22.33.44 LOG: connection received: host=11.22.33.44 port=54869
2024-05-13 05:57:14.608 GMT [4868]: [2-1] db=lfm2,user=fs_admin,app=[unknown],client=11.22.33.44 LOG: connection authenticated: identity="fs_admin" method=md5 (E:/PostgreSQL/15/data/pg_hba.conf:108)
2024-05-13 05:57:14.608 GMT [4868]: [3-1] db=lfm2,user=fs_admin,app=[unknown],client=11.22.33.44 LOG: connection authorized: user=fs_admin database=lfm2
...
2024-05-13 05:57:29.305 GMT [6048]: [1-1] db=,user=,app=,client= LOG: automatic analyze of table "lfm.fs.ij"
avg read rate: 7.813 MB/s, avg write rate: 0.000 MB/s
buffer usage: 350 hits, 5 misses, 0 dirtied
system usage: CPU: user: 0.01 s, system: 0.00 s, elapsed: 0.00 s
2024-05-13 05:57:44.209 GMT [6140]: [1-1] db=,user=,app=,client= LOG: automatic vacuum of table "lfm2.fs.ij": index scans: 0
pages: 0 removed, 2 remain, 2 scanned (100.00% of total)
tuples: 1 removed, 2 remain, 0 are dead but not yet removable
removable cutoff: 597176608, which was 0 XIDs old when operation ended
new relfrozenxid: 597176605, which is 372 XIDs ahead of previous value
index scan not needed: 0 pages from table (0.00% of total) had 0 dead item identifiers removed
avg read rate: 7.481 MB/s, avg write rate: 5.611 MB/s
buffer usage: 37 hits, 4 misses, 3 dirtied
WAL usage: 3 records, 2 full page images, 15749 bytes
system usage: CPU: user: 0.00 s, system: 0.00 s, elapsed: 0.00 s
2024-05-13 05:57:59.312 GMT [6064]: [1-1] db=,user=,app=,client= LOG: automatic vacuum of table "postgres.a.acap": index scans: 1
pages: 0 removed, 1 remain, 1 scanned (100.00% of total)
tuples: 56 removed, 24 remain, 0 are dead but not yet removable
removable cutoff: 597176633, which was 0 XIDs old when operation ended
new relfrozenxid: 597176559, which is 14186 XIDs ahead of previous value
index scan needed: 1 pages from table (100.00% of total) had 56 dead item identifiers removed
index "app_ctxt_area_pk": pages: 6 in total, 0 newly deleted, 3 currently deleted, 3 reusable
index "acap_area_hix": pages: 27 in total, 0 newly deleted, 0 currently deleted, 0 reusable
index "acap_process_id_ix": pages: 2 in total, 0 newly deleted, 0 currently deleted, 0 reusable
avg read rate: 18.881 MB/s, avg write rate: 6.743 MB/s
buffer usage: 104 hits, 14 misses, 5 dirtied
WAL usage: 1 records, 1 full page images, 7577 bytes
system usage: CPU: user: 0.00 s, system: 0.00 s, elapsed: 0.00 s
Phil Horder
Database Mechanic
Thales
Land & Air Systems
{OPEN}
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