Re: Primary keepalive message not appearing in Logical Streaming Replication

From: Virendra Negi <viren(dot)negi(at)teliax(dot)com>
To: Michael Loftis <mloftis(at)wgops(dot)com>
Cc: pgsql-hackers(at)lists(dot)postgresql(dot)org
Subject: Re: Primary keepalive message not appearing in Logical Streaming Replication
Date: 2019-09-15 14:36:24
Message-ID: CAAhTPordxr6F759t-AOWW0vegSbniWjJjN0MuTE6NOYJ1FfE7w@mail.gmail.com
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Oh I miss the documentation link there you go
https://www.postgresql.org/docs/9.5/protocol-replication.html

On Sun, Sep 15, 2019 at 8:05 PM Virendra Negi <viren(dot)negi(at)teliax(dot)com> wrote:

> Agreed but why is there a message specification for it describe in the
> documentation and it ask to client reply back if a particular *bit* is
> set.(1 means that the client should reply to this message as soon as
> possible, to avoid a timeout disconnect. 0 otherwise)
>
>
> Primary keepalive message (B)
> Byte1('k')
>
> Identifies the message as a sender keepalive.
> Int64
>
> The current end of WAL on the server.
> Int64
>
> The server's system clock at the time of transmission, as microseconds
> since midnight on 2000-01-01.
> Byte1
>
> 1 means that the client should reply to this message as soon as possible,
> to avoid a timeout disconnect. 0 otherwise.
>
> The receiving process can send replies back to the sender at any time,
> using one of the following message formats (also in the payload of a
> CopyData message):
>
>
> On Sun, Sep 15, 2019 at 7:39 PM Michael Loftis <mloftis(at)wgops(dot)com> wrote:
>
>>
>>
>> On Fri, Sep 13, 2019 at 07:12 Virendra Negi <viren(dot)negi(at)teliax(dot)com>
>> wrote:
>>
>>> Implemented the Logical Streaming Replication thing are working fine I
>>> see the XLogData message appearing and I'm able to parse them.
>>>
>>> But I haven't see any "Primary Keepalive message" yet. I had tried
>>> setting the *tcp_keepalive_interval*, *tcp_keepalives_idle* both from
>>> client runtime paramter and well as from postgresql.conf still no clue of
>>> it.
>>>
>>> Any information around it?
>>>
>>
>> Both of these options are not in the Pg protocol. They are within the OS
>> TCP stack and are not visible to the applications at all.
>>
>>>
>>>
>>>
>>> --
>>
>> "Genius might be described as a supreme capacity for getting its
>> possessors
>> into trouble of all kinds."
>> -- Samuel Butler
>>
>

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