Horton

Re: pg_ctl failover Re: Latches, signals, and waiting

Fujii Masao <masao.fujii@gmail.com>

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From: Fujii Masao <masao.fujii@gmail.com>
To: Itagaki Takahiro <itagaki.takahiro@gmail.com>
Cc: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers@postgresql.org
Date: 2011-01-13T05:10:26Z
Lists: pgsql-hackers

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Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Remove rare corner case for data loss when triggering standby server.

On Thu, Jan 13, 2011 at 11:29 AM, Itagaki Takahiro
<itagaki.takahiro@gmail.com> wrote:
> On Thu, Jan 13, 2011 at 00:14, Fujii Masao <masao.fujii@gmail.com> wrote:
>>> pg_ctl failover ? At the moment, the location of the trigger file is
>>> configurable, but if we accept a constant location like "$PGDATA/failover"
>>> pg_ctl could do the whole thing, create the file and send signal. pg_ctl on
>>> Window already knows how to send the "signal" via the named pipe signal
>>> emulation.
>>
>> The attached patch implements the above-mentioned pg_ctl failover.
>
> I have three comments:

Thanks for the review!

> - Will we call it "failover"? We will use the command also in "switchover"
>  operations. "pg_ctl promote" might be more neutral, but users might be
>  hard to imagine replication feature from "promote".

OK. Similarly, I should also change the word "failover" used in function and
variable names to the "promote"? For example,
#define PROMOTE_SIGNAL_FILE "promote" rather than
#define FAILOVER_SIGNAL_FILE "failover"?

> - pg_ctl should unlink failover_files when it failed to send failover signals.

Good catch.

> - "standby_triggered" variable might be renamed to "failover_triggered" or so.

Furthermore, "failover_triggered" should be renamed to "promote_triggered"?

Regards,

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