| From: | Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> |
|---|---|
| To: | Fujii Masao <masao(dot)fujii(at)gmail(dot)com> |
| Cc: | Yeb Havinga <yebhavinga(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Synchronous replication |
| Date: | 2010-08-03 15:35:47 |
| Message-ID: | 4C583753.70709@enterprisedb.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 27/07/10 13:29, Fujii Masao wrote:
> On Tue, Jul 27, 2010 at 7:39 PM, Yeb Havinga<yebhavinga(at)gmail(dot)com> wrote:
>> Fujii Masao wrote:
>> I noted the changes in XlogSend where instead of *caughtup = true/false it
>> now returns !MyWalSnd->sndrqst. That value is initialized to false in that
>> procedure and it cannot be changed to true during execution of that
>> procedure, or can it?
>
> That value is set to true in WalSndWakeup(). If WalSndWakeup() is called
> after initialization of that value in XLogSend(), *caughtup is set to false.
There's some race conditions with the signaling. If another process
finishes XLOG flush and sends the signal when a walsender has just
finished one iteration of its main loop, walsender will reset
xlogsend_requested and go to sleep. It should not sleep but send the
pending WAL immediately.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Joshua D. Drake | 2010-08-03 16:23:04 | Re: Develop item from TODO list |
| Previous Message | Yeb Havinga | 2010-08-03 15:34:05 | Re: patch for check constraints using multiple inheritance |