Re: Terminate the idle sessions

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Best regards
Japin Li

On Nov 17, 2020, at 7:59 AM, David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com<mailto:david(dot)g(dot)johnston(at)gmail(dot)com>> wrote:

On Mon, Nov 16, 2020 at 5:41 AM Li Japin <japinli(at)hotmail(dot)com<mailto:japinli(at)hotmail(dot)com>> wrote:
Thanks for your review! Attached.

Reading the doc changes:

I'd rather not name postgres_fdw explicitly, or at least not solely, as a reason for setting this to zero. Additionally, using postgres_fdw within the server doesn't cause issues, its using postgres_fdw and the remote server having this setting set to zero that causes a problem.

<note>
Consider setting this for specific users instead of as a server default. Client connections managed by connection poolers, or initiated indirectly like those by a remote postgres_fdw using server, should probably be excluded from this timeout.

Text within <para> should be indented one space (you missed both under listitem).

Thanks for your suggest! How about change document as follows:

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 6c4e2a1fdc..23e691a7c5 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -8281,17 +8281,17 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
</term>
<listitem>
<para>
- Terminate any session that has been idle for longer than the specified amount of time.
+ Terminate any session that has been idle for longer than the specified amount of time.
</para>
<para>
- If this value is specified without units, it is taken as milliseconds.
- A value of zero (the default) disables the timeout.
+ If this value is specified without units, it is taken as milliseconds.
+ A value of zero (the default) disables the timeout.
</para>

<note>
<para>
- This parameter should be set to zero if you use postgres_fdw or some
- connection-pooling software, because connections might be closed unexpectedly.
+ This parameter should be set to zero if you use some connection-pooling software, or
+ PostgreSQL servers used by postgres_fdw, because connections might be closed unexpectedly.
</para>
</note>

I'd suggest a comment that aside from a bit of resource consumption idle sessions do not interfere with the long-running stability of the server, unlike idle-in-transaction sessions which are controlled by the other configuration setting.

Could you please explain how the idle-in-transaction interfere the long-running stability?

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Best regards
Japin Li