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From: Robert Haas on 25 Jun 2010 11:49
On Wed, Jun 23, 2010 at 4:48 AM, Sander, Ingo (NSN - DE/Munich)
<ingo.sander(a)nsn.com> wrote:
> Sql query "select pg_last_xlog_receive_location(); " does not work during
> startup of standby database.
> TestScenario;
> We have a active-standby system with PostgreSQL Streaming Replication beta2.
> If the active database is up the database is in use (read/write queries will
> be performed). Then the standby PostgreSQL SR will be started (the complete
> database from the active side is copied to the standby side; nec. Files for
> starting streaming replication are created). Directly after the possibility
> to connect to the standby system, the above given sql query will be
> executed. To this timepoint the sql query delivers an error.

What is the error message?

> To a later
> timepoint (all wal segments are completly incooperated) the query delivers a
> valid result.
>
> Question:
> What is the reason for the error?
> Exists a command to find out if the standby database is really active to
> accept/can work with sql commands?

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Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company

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From: Simon Riggs on 27 Jun 2010 07:46
On Wed, 2010-06-23 at 10:48 +0200, Sander, Ingo (NSN - DE/Munich) wrote:

> Sql query "select pg_last_xlog_receive_location(); " does not work
> during startup of standby database.

Thanks for the report.

We need to understand more about what you are saying. There is no error
message with that text.

> TestScenario;
> We have a active-standby system with PostgreSQL Streaming Replication
> beta2. If the active database is up the database is in use (read/write
> queries will be performed). Then the standby PostgreSQL SR will be
> started (the complete database from the active side is copied to the
> standby side; nec. Files for starting streaming replication are
> created). Directly after the possibility to connect to the standby
> system, the above given sql query will be executed. To this timepoint
> the sql query delivers an error. To a later timepoint (all wal
> segments are completly incooperated) the query delivers a valid
> result.
>
> Question:
> What is the reason for the error?
> Exists a command to find out if the standby database is really active
> to accept/can work with sql commands?

Could you show us the log?

--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Training and Services


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