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Re: If SyncRepWaitForLSN() fails, would the postgres backend do a roll-back? - Mailing list pgsql-hackers

From Tatsuo Ishii
Subject Re: If SyncRepWaitForLSN() fails, would the postgres backend do a roll-back?
Date
Msg-id 20160608.194356.2193217335998729028.t-ishii@sraoss.co.jp
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In response to If SyncRepWaitForLSN() fails, would the postgres backend do a roll-back?  (Rui Hai Jiang <ruihaij@gmail.com>)
Responses Re: If SyncRepWaitForLSN() fails, would the postgres backend do a roll-back?
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> Hi,
> 
> I'm researching the synchronous replication. I see the backend of the
> Primary Server calls SyncRepWaitForLSN() to wait for the Standby Server to
> write the WAL records.
> 
> If some thing happens, such as network failure or disk failure, causes the
> Standby Server fail to receive WAL records or fail to write WAL records,
> would the backend of the Primary Server catch and handle this failure?
> Would the backend roll-back the transactions? Would the backend continue to
> work?

I don't think the backend would roll back the transaction because when
SyncRepWaitForLSN() is called, the transaction has been already
committed. There's no way to roll back a transaction which has been
committed.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp

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