Re: Ned to understand why all the idle connections

Thanks!
And an example of connection pooling is pgBouncer ?

On Thu, Apr 23, 2020 at 2:41 PM David G. Johnston <
david(dot)g(dot)johnston(at)gmail(dot)com> wrote:

> On Thursday, April 23, 2020, David Gauthier <davegauthierpg(at)gmail(dot)com>
> wrote:
>
>> Hi:
>>
>> psql (9.6.7, server 11.3) on linux
>>
>> I have what appear to be a log of idle connections to my DB. Query of
>> pg_stat_activity indicates well over half (127/206) are like this...
>>
>>
>> dvdb=# select state_change,wait_event_type,wait_event,state,backend_type
>> from pg_stat_activity where query = '';
>> state_change | wait_event_type | wait_event |
>> state | backend_type
>>
>> -------------------------------+-----------------+---------------------+-------+------------------------------
>> 2020-04-23 12:57:58.215854-04 | Client | ClientRead |
>> idle | client backend
>>
>> What does this indicate?
>>
>> The vast majority of the connections are through perl/dbi. If a
>> connection is made, and is currently not doing anything, does it appear in
>> pg_stat_activity as "idle" ? If, in DBI, $dbh->disconnect is used whenever
>> the DB is no longer needed, will it disconnect from the DB and NOT appear
>> as an idle in pg_stat_activity ?
>>
>> If there are any other column s in pg_stat-activity you'd like to see, or
>> any other query in any of the system tables, please advise.
>>
>
> If the server has an active, authenticated, connection/process running it
> shows up here. Yes, idle is the state used to denote the the session is
> “not doing anything”...
>
> $dbh->disconnect typically will indeed close the connection. There can be
> exceptions if your architecture uses connection pooling.
>
> David J.
>
>