On Mon, May 27, 2024 at 12:55 AM Torsten Förtsch <tfoertsch123@xxxxxxxxx> wrote:
On Sun, May 26, 2024 at 8:46 PM sud <suds1434@xxxxxxxxx> wrote:Would you agree that we should have two standby, one with default max_standby_streaming_delay (say 10 sec ) which will be mainly used as high availability and thus will be having minimal lag. and another standby with max_standby_streaming_delay as "-1" i.e. it will wait indefinitely for the SELECT queries to finish without caring about the lag, which will be utilized for the long running SELECT queries.And keep the hot_standby_feedback as ON for the first standby which is used as HA/high availability. And keep the hot_standby_feedback as OFF for the second standby which is utilized for long running SELECT queries, so that primary won't be waiting for the response/feedback from this standby to vacuum its old transactions and that will keep the transaction id wrap around issue from not happening because of the Read/Select queries on any of the standby.Sure. That could work. Perhaps also set statement_timeout on the first replica, just in case.
Thank you so much. Yes, planning to set it like below. Hope i am doing it correctly.
| Master/Primary | First Replica/Standby for High Availability | Second Replica for Reporting |
| hot_standby_feedback=ON | hot_standby_feedback=ON | hot_standby_feedback=OFF |
| max_standby_streaming_delay=10 sec | max_standby_streaming_delay=10 sec | max_standby_streaming_delay=-1 (Infinite) |
| statement_timeout = "2hrs" | statement_timeout="2hrs" | No statement_timeout i.e. infinite |
| idle_in_transaction_session_timeout=10minutes | idle_in_transaction_session_timeout=10minutes | No idle_in_transaction_session_timeout i.e. infinite |
| autovacuum_freeze_max_age=100M | autovacuum_freeze_max_age=100M | autovacuum_freeze_max_age=100M |
| Log_autovacuum_min_duration=0 | Log_autovacuum_min_duration=0 | Log_autovacuum_min_duration=0 |
