Re: Streaming Replication between PostGreSQL 9.2.2 on Red Hat and PostGreSQL 9.2.24 on Debian

Hi,

- Doing Streaming Replication between different minor version of PG is
possible but not recommended [2]

- Doing Streaming Replication between different OSes is not recommended
pre ICU (pg10), please check you glibc versions. [1]

[1]
https://www.postgresql.org/message-id/BA6132ED-1F6B-4A0B-AC22-81278F5AB81E@tripadvisor.com
[2] https://www.postgresql.org/docs/9.2/static/warm-standby.html (planning
section)

Hoep this helps.

Cheers
Ben

2018-05-22 10:13 GMT+02:00 Jonatan Evald Buus <
jonatan(dot)buus(at)cellpointmobile(dot)com>:

> Thanks Ian, thank you for pointing out the obvious.
> It appears that Debian's *pg_dropcluster* command had unexpected
> consequences.... you live, you pull out your hair in frustration and you
> learn.
>
> I now have streaming replication working as we expected, can you confirm
> that my *(somewhat unusual scenario?) *shouldn't cause any problems?
> Specifically:
> - Using Streaming Replication between two PostGreSQL instances with
> different minor versions will work *(9.2.2 on RHEL and 9.2.24 on Debian)*
> - Using Streaming Replication between two servers running different
> operating systems *(RHEL 5.5 and Debian 8 / 9) *will work
>
> Greatly appreciate your insight
>
> Cheers
> Jona
>
> On 21 May 2018 at 13:27, Ian Barwick <ian(dot)barwick(at)2ndquadrant(dot)com> wrote:
>
>> On 05/21/2018 07:18 PM, Jonatan Evald Buus wrote:
>> > Hi there,
>> >
>> > I'm trying to configure streaming replication between a Red Hat server
>> > running PostGreSQL 9.2.2 and a Debian server running PostGreSQL 9.2.24
>> > with Hot Standby enabled.
>> >
>> > While the base backup works fine using /pg_basebackup/, I get the
>> following
>> > errors with hot standby enabled on the Debian slave when starting
>> PostGreSQL:
>>
>> > /WARNING: WAL was generated with wal_level=minimal, data may be
>> missing/
>> > /HINT: This happens if you temporarily set wal_level=minimal without
>> taking a new base backup./
>> > /FATAL: hot standby is not possible because wal_level was not set to
>> "hot_standby" on the master server/
>> > /HINT: Either set wal_level to "hot_standby" on the master, or turn
>> off hot_standby here/
>> >
>> > If I turn Hot Standby off on the Debian Slave I get the following
>> errors:
>> > /FATAL: database system identifier differs between the primary and
>> standby/
>> > /DETAIL: The primary's identifier is 5940475598986796885, the
>> standby's identifier is 6557962695089036503./
>>
>> The standby clearly hasn't been cloned from the primary, otherwise the
>> identifiers would be the same. Are you sure the PostgreSQL instance
>> running on the standby is the one you backed up with pg_basebackup?
>>
>>
>> Regards
>>
>> Ian Barwick
>>
>> --
>> Ian Barwick http://www.2ndQuadrant.com/
>> PostgreSQL Development, 24x7 Support, Training & Services
>>
>
>
>
> --
> Jonatan Evald Buus
> CTO, CellPoint Mobile
> www.cellpointmobile.com
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