Re: CORRUPTION on TOAST table - Mailing list pgsql-general

From Soni M
Subject Re: CORRUPTION on TOAST table
Date
Msg-id CAAMgDXkUqppkO2K9QpmYX=MqztY=iPywcznQfR7H8Yxfi_rN6Q@mail.gmail.com
Whole thread Raw
In response to Re: CORRUPTION on TOAST table  (Soni M <diptatapa@gmail.com>)
List pgsql-general
It seems that it was the Postgres bug on replica, after upgrading minor version to 9.1.21 on replica1, the corruption goes away.

Thanks everyone for the help

On Tue, Apr 5, 2016 at 1:32 AM, Soni M <diptatapa@gmail.com> wrote:
Hello Adrian, thanks for the response.

master data also located on SAN

Yes, each replica is it own VM with its own virtual disk/volume as served up from the same SAN

Raw disk mappings are a way for ESX to present a SAN volume directly to a VM instead of creating a virtual disk.

no unexpected messages detected.

On Sun, Apr 3, 2016 at 11:23 PM, Adrian Klaver <adrian.klaver@aklaver.com> wrote:
On 04/02/2016 08:38 PM, Soni M wrote:
Hello Everyone,

We face TOAST table corruption.

One master and two streaming replicas. The corruption happen only on
both streaming replicas.

We did found the corrupted rows. Selecting on this row, return (on both
replica) : unexpected chunk number 0 (expected 1) for toast value
1100613112 in pg_toast_112517
selecting this row on master does not return corruption error, but
return correct result instead.

Previously, dump on a replica return : unexpected chunk number 0
(expected 1) for toast value 3234098599 in pg_toast_112517 (please note
the toast value is different)

This table size is 343 GB, contain around 206,179,697 live tuples. We
found that the corruption happen on the biggest column (this column and
its pkey sized around 299 GB total).


on both replica :
fsync NEVER turned off.
none unexpected power loss nor OS crash.

How can the corruption occurs ? and how can I resolve them ?

Meant to add to previous post.

Do you see anything in the replica Postgres logs that indicate a problem with the replication process?

Or any other unexpected messages prior to the point you did the select on the replica(s)?



Thank so much for the help.

Cheers \o/

--
Regards,

Soni Maula Harriz


--
Adrian Klaver
adrian.klaver@aklaver.com



--
Regards,

Soni Maula Harriz



--
Regards,

Soni Maula Harriz

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