Hi Wasim,
I think you might have misinterpreted the explanation given to you. The cancellation of the query on the standby server isn't related to the load on the primary server. It happens that when you run queries on a hot standby, the replication is temporarily paused in order to not modify data the running queries on the standby server need. Once the queries end, replication resumes.
The problem of this behaviour is that the standby server starts to fall behind in relation to the master, a scenario which presents a risky condition: if the master happens to fail while the replica is delayed you end up with data loss.
To avoid having a standby server lagging too far behind Postgres will cancel long running queries on the replica. The parameter max_standby_streaming_delay defines the maximum replication delay the standby will tolerate. Default is 30 seconds. Increase the value to allow for longer running queries on the standby server bearing in mind that you could end up with data loss if the master fails at the wrong moment.
A working alternative is to have one standby server exclusively for replication purposes and another standby for reporting/read-only queries where you can increase the max_standby_streaming_delay to accommodate your long running queries. Of course, this will require additional computing and storage resources.
Cheers,
Fernando.
El jue, 25 jul 2024 a la(s) 3:41 p.m., Wasim Devale (wasimd60@xxxxxxxxx) escribió:
Our company's production in the evening only and has heavy loading and unloading of data. So I can suggest them not to run the long running queries in bulk for analysis at that peak time and will ask them to use them off peak hours. Correct? Any suggestions from you.
On Fri, 26 Jul, 2024, 12:05 am Scott Ribe, <scott_ribe@xxxxxxxxxxxxxxxx> wrote:> On Jul 25, 2024, at 11:17 AM, Wasim Devale <wasimd60@xxxxxxxxx> wrote:
>
> So how to tackle the above error.
???
The two options to mitigate this, and their side effects, were explained to you. What more do you want?
