[pgpool-general: 8841] Re: DB Connection ERROR during a failover

[Gopikrishnan]

Hi all,

Is there a way to avoid this spurious failover execution?
Appreciate any help.

*Thanks*
*Gopi*


On Wed, Jun 14, 2023 at 10:58 AM Gopikrishnan <nksgopikrishnan at gmail.com>
wrote:

> Hi Bo,
>
> Thanks for your response. To avoid hitting this error,
> Is there a way to skip executing this failover since it is not the primary
> node that failed?
> I am using pgpool 4.0.4, Is this scenario enhanced in any later versions?
>
> *Thanks*
> *Gopi*
>
>
> On Wed, Jun 14, 2023 at 9:34 AM Bo Peng <pengbo at sraoss.co.jp> wrote:
>
>> Hi,
>>
>> > In my application, I see an error:
>> >
>> > Caused by: org.postgresql.util.PSQLException: FATAL: failed to create a
>> > backend connection
>> >   Detail: executing failover on backend
>> > at
>> >
>> org.postgresql.core.v3.ConnectionFactoryImpl.doAuthentication(ConnectionFactoryImpl.java:514)
>> > at
>> >
>> org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:141)
>> > at
>> >
>> org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:192)
>> >
>> > Is there a configuration I can use to make the connection wait for the
>> > failover to complete?
>>
>> Unfortunately, pgpool doesn't have such feature.
>> You need to add such retry logic in your application code.
>>
>> > Also, I can see that the failover was not indeed a failover, i.e the
>> > failover would eventually
>> > be skipped since it is not the primary node that failed:
>> >
>> > 2023-06-12_18:27:55 [failover.sh]: failed_node_id=1
>> failed_host=10.198.49.42
>> > 2023-06-12_18:27:55 [failover.sh]: old_master_node_id=0
>> > old_primary_node_id=0
>> > 2023-06-12_18:27:55 [failover.sh]: new_primary_node_id=0
>> > new_master_host=10.198.49.41
>> > 2023-06-12_18:27:55 [failover.sh]: Node 1 dies, but it's not the primary
>> > node. Skipping failover.
>>
>> Yes. Pgpool-II checks the role of the failed node in the failover script.
>> If the failed node is a standby node, pgpool just updates
>> the node status to DOWN and skips failover.
>>
>> --
>> Bo Peng <pengbo at sraoss.co.jp>
>> SRA OSS LLC
>> TEL: 03-5979-2701 FAX: 03-5979-2702
>> URL: https://www.sraoss.co.jp/
>>
>
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