Re: Why there are no max_wal_receivers

On 10/06/2013 09:53 PM, Amit Langote wrote:
> Hi,
>
> On Mon, Oct 7, 2013 at 12:02 PM, 高健 <luckyjackgao(at)gmail(dot)com> wrote:
>> Hello :
>>
>>
>> I found that for PG9.2.4, there is parameter max_wal_senders,
>>
>> But there is no parameter of max_wal_receivers.
>>
>>
>
> max_wal_senders is the maximum number of WAL sender processes that a
> primary server can create in response to requests from the standby
> servers. One WAL sender process is created on the primary server for
> each standby which would running the corresponding WAL receiver. So
> there is one-to-one mapping between WAL senders and WAL receivers
> (standbys).

Just to add, pg_basebackup also counts against the total of receivers:

http://www.postgresql.org/docs/9.3/interactive/app-pgbasebackup.html

>
> --
> Amit Langote
>
>

--
Adrian Klaver
adrian(dot)klaver(at)gmail(dot)com