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* Replication lag in Postgres
@ 2024-07-12 15:11 Mukesh Tanuku <[email protected]>
2024-07-12 15:43 ` Re: Replication lag in Postgres Laurenz Albe <[email protected]>
2024-07-13 09:34 ` Re: Replication lag in Postgres Muhammad Imtiaz <[email protected]>
0 siblings, 2 replies; 4+ messages in thread
From: Mukesh Tanuku @ 2024-07-12 15:11 UTC (permalink / raw)
To: [email protected]
Hello everyone.
Firstly thanks to the community members who are addressing all the queries
that are posted. Those give us more insights about the issues/doubts in the
postgres.
I have a question with postgres HA setup.
We are setting up a 2 node postgres cluster with async streaming
replication, we want to define a RPO (Recovery point objective) in case of
primary failure.
How can we best define the RPO in this setup? since it's an async streaming
replication setup there might be a chance of data loss which is
proportional to the replication delay.
Is there any way we can configure the delay duration, like for example to
make sure every 10 mins the standby sync has to happen with primary?
Thank you
Regards
Mukesh T
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: Replication lag in Postgres
2024-07-12 15:11 Replication lag in Postgres Mukesh Tanuku <[email protected]>
@ 2024-07-12 15:43 ` Laurenz Albe <[email protected]>
2024-07-13 06:02 ` Re: Replication lag in Postgres Mukesh Tanuku <[email protected]>
1 sibling, 1 reply; 4+ messages in thread
From: Laurenz Albe @ 2024-07-12 15:43 UTC (permalink / raw)
To: Mukesh Tanuku <[email protected]>; [email protected]
On Fri, 2024-07-12 at 20:41 +0530, Mukesh Tanuku wrote:
> I have a question with postgres HA setup.
> We are setting up a 2 node postgres cluster with async streaming replication, we want to
> define a RPO (Recovery point objective) in case of primary failure.
>
> How can we best define the RPO in this setup? since it's an async streaming replication
> setup there might be a chance of data loss which is proportional to the replication delay.
>
> Is there any way we can configure the delay duration, like for example to make sure every
> 10 mins the standby sync has to happen with primary?
When there is a delay, it is usually because replay at the standby is delayed.
The WAL information is still replicated. You won't lose that information on
failover; it will just make the failover take longer.
Unless you have a network problem, you should never lose more than a fraction
of a second.
Yours,
Laurenz Albe
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: Replication lag in Postgres
2024-07-12 15:11 Replication lag in Postgres Mukesh Tanuku <[email protected]>
2024-07-12 15:43 ` Re: Replication lag in Postgres Laurenz Albe <[email protected]>
@ 2024-07-13 06:02 ` Mukesh Tanuku <[email protected]>
0 siblings, 0 replies; 4+ messages in thread
From: Mukesh Tanuku @ 2024-07-13 06:02 UTC (permalink / raw)
To: Laurenz Albe <[email protected]>; +Cc: [email protected]
Thank you for the information Laurenz Albe
On Fri, Jul 12, 2024 at 9:13 PM Laurenz Albe <[email protected]>
wrote:
> On Fri, 2024-07-12 at 20:41 +0530, Mukesh Tanuku wrote:
> > I have a question with postgres HA setup.
> > We are setting up a 2 node postgres cluster with async streaming
> replication, we want to
> > define a RPO (Recovery point objective) in case of primary failure.
> >
> > How can we best define the RPO in this setup? since it's an async
> streaming replication
> > setup there might be a chance of data loss which is proportional to the
> replication delay.
> >
> > Is there any way we can configure the delay duration, like for example
> to make sure every
> > 10 mins the standby sync has to happen with primary?
>
> When there is a delay, it is usually because replay at the standby is
> delayed.
> The WAL information is still replicated. You won't lose that information
> on
> failover; it will just make the failover take longer.
>
> Unless you have a network problem, you should never lose more than a
> fraction
> of a second.
>
> Yours,
> Laurenz Albe
>
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: Replication lag in Postgres
2024-07-12 15:11 Replication lag in Postgres Mukesh Tanuku <[email protected]>
@ 2024-07-13 09:34 ` Muhammad Imtiaz <[email protected]>
1 sibling, 0 replies; 4+ messages in thread
From: Muhammad Imtiaz @ 2024-07-13 09:34 UTC (permalink / raw)
To: Mukesh Tanuku <[email protected]>; +Cc: [email protected]
Hi,
I recommend the following configurations/options in this case:
• wal_sender_timeout: This setting determines how long the primary server
waits for the standby server to acknowledge receipt of WAL data. Adjusting
this can help ensure timely data transfer.
• wal_keep_size: Ensures that enough WAL files are retained for the standby
to catch up if it falls behind.
• checkpoint_timeout: Adjust the checkpoint frequency to ensure WAL files
are regularly flushed and sent to the standby server regularly.
• pg_receivewal: Use this tool to continuously archive WAL files to a safe
location.It will helpful if there is a delay in streaming replication, you
have a backup of WAL files.
Regards,
Muhammad Imtiaz
On Fri, 12 Jul 2024, 20:11 Mukesh Tanuku, <[email protected]> wrote:
> Hello everyone.
> Firstly thanks to the community members who are addressing all the queries
> that are posted. Those give us more insights about the issues/doubts in the
> postgres.
>
> I have a question with postgres HA setup.
> We are setting up a 2 node postgres cluster with async streaming
> replication, we want to define a RPO (Recovery point objective) in case of
> primary failure.
>
> How can we best define the RPO in this setup? since it's an async
> streaming replication setup there might be a chance of data loss which is
> proportional to the replication delay.
>
> Is there any way we can configure the delay duration, like for example to
> make sure every 10 mins the standby sync has to happen with primary?
>
> Thank you
> Regards
> Mukesh T
>
>
^ permalink raw reply [nested|flat] 4+ messages in thread
end of thread, other threads:[~2024-07-13 09:34 UTC | newest]
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2024-07-12 15:11 Replication lag in Postgres Mukesh Tanuku <[email protected]>
2024-07-12 15:43 ` Laurenz Albe <[email protected]>
2024-07-13 06:02 ` Mukesh Tanuku <[email protected]>
2024-07-13 09:34 ` Muhammad Imtiaz <[email protected]>
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