Обсуждение: The last WAL segment of the old timeline is not archived for a while after archive recovery

Hi,

In archive recovery, the last applied WAL segment may not have
.ready file in spite of not having been archived yet. Then, this
segment is not archived until a future checkpoint creates .ready
file. It's a little dangerous that there is the WAL segment which
is not archived for a while.

Attached patch fixes this problem. Is this worth committing?

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center

Fujii Masao wrote:
> In archive recovery, the last applied WAL segment may not have
> .ready file in spite of not having been archived yet. Then, this
> segment is not archived until a future checkpoint creates .ready
> file. It's a little dangerous that there is the WAL segment which
> is not archived for a while.
> 
> Attached patch fixes this problem. Is this worth committing?

Yeah, I think it is. Applied.

BTW, I notice that we have the same problem with WAL files that have 
been manually copied into pg_xlog, in the unlikely corner case that the 
"backup redo point", ControlData->checkpointCopy, points to the 
first-ever WAL file. That's because we then skip the 
RemoveOldXlogFiles() step in the startup checkpoint, which normally 
creates the .ready files for all but the last WAL file. I don't think 
that happens in practice, and if it does, the files will still be 
archived at the next checkpoint, so I think we can leave it as it is.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com

Hi,

On Thu, Apr 23, 2009 at 4:51 AM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:
> Fujii Masao wrote:
>>
>> In archive recovery, the last applied WAL segment may not have
>> .ready file in spite of not having been archived yet. Then, this
>> segment is not archived until a future checkpoint creates .ready
>> file. It's a little dangerous that there is the WAL segment which
>> is not archived for a while.
>>
>> Attached patch fixes this problem. Is this worth committing?
>
> Yeah, I think it is. Applied.

Thanks a lot!

Regards,

-- 
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center