Re: Archiving control (a part of synch rep patches)

Hi,

On Wed, Dec 24, 2008 at 7:26 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>
> On Wed, 2008-12-24 at 19:04 +0900, Fujii Masao wrote:
>> Hi,
>>
>> On Wed, Dec 24, 2008 at 4:39 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>> > (3)
>> > Revert the arhive status file of the specified file from .done to .ready.
>> > This would try to archive the corresponding xlog file again. The archive
>> > status of only skipped xlog file can be reverted.
>> >
>> > We resume xlog archiving by using (2) and (3), when replication
>> > ends.
>>
>> Umm.. reverting is very tricky, then it might become hotbeds of bugs.
>> So, I will reconsider the method of resuming archive.
>
> Yeh, don't do that.
>
> No worries if we send a few files too many. Tears if we miss just one.
>
> * Turn it off for the *next* file to be archived. Keep track of last
> file sent.

OK

> * Turn it on again, mark *all* WAL files as .ready in sequence low to
> high, as long as they are higher than the last file sent.

You mean as follows?

- we don't create .ready during replication.
- we create .ready of the xlog files which are higher than the
last sent when replication ends, and forbid that subsequent
checkpoint create .ready of lower xlog files.

Regards,

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