Hi
On Wed, Jun 5, 2024 at 5:10 AM Mohan NBSPS <mohan.nbs.ont@xxxxxxxxx> wrote:
thank you,we are not using slots due to storage related issues that could occur if the network is broken.
Slots are very useful and it will ensure that the Standby will not lag behind the master and master will retain the WAL Files if standy did not apply them yet, the storage is consideration but only incase of network failure but this wont be a very big consideration.
Regards
Kashif Zeeshan
Bitnine Global
sorry, my question was incomplete.I see few very old (over 2 years) WAL files remain in the secondary (primary is clean with onlynew WAL files).On Mon, Jun 3, 2024 at 9:33 PM vignesh kumar <vigneshkumar.venugopal@xxxxxxxxxxx> wrote:You can use slot based replication, so that postgres knows which WAL FILE to retain and delete. however, if you're not concerned about storage, but then the replica go for WAL storage or WAL hub kind of solutions..
From: Kashif Zeeshan <kashi.zeeshan@xxxxxxxxx>
Sent: Sunday, June 2, 2024 5:17:57 PM
To: mohan.nbs.ont@xxxxxxxxx <mohan.nbs.ont@xxxxxxxxx>
Cc: pgsql-admin@xxxxxxxxxxxxxxxxxxxx <pgsql-admin@xxxxxxxxxxxxxxxxxxxx>
Subject: Re: postgrsql 9.5: Old WAL files remain in secondary `pg_xlog`Hi Mohsn
There can be multiple reasons for that.
1. If the archiving process on the standby is not working correctly, old WAL files will not be removed.2. Ensure that the configuration settings for WAL management are correctly set on both primary and standby3. If checkpoints are not happening frequently enough, WAL files will accumulate.
To diagnose the issue
1. Ensure that the replication between the primary and the standby is working correctly.
On Primary ServerSELECT client_addr, state, sent_lsn, write_lsn, flush_lsn, replay_lsn
FROM pg_stat_replication;
On Standby ServerSELECT pg_last_wal_receive_lsn(), pg_last_wal_replay_lsn();
2. Check if the archiving process on the standby is working properly. Look for any errors or warnings in the PostgreSQL logs related to WAL archiving.3. Ensure that the standby server has the correct restore command configured to fetch the archived WAL files.
RegardsKashif ZeeshanBitnine Global
On Sat, Jun 1, 2024 at 4:01 AM Mohan NBSPS <mohan.nbs.ont@xxxxxxxxx> wrote:
Hello Community,
Although the WAL retaining settings are default (max size 1GB),`wal_keep_segments` is 25, checkpoint target is 2.5 minutes(default).I noticed a few WAL files in secondary nodes (streaming replication) `pg_xlog`folder.
What could be the reason why postgresql did not delete these ?
Thank youRegardsMohan
