[pgpool-general: 3979] Re: Possible connection leak
ishii at postgresql.org
Tue Aug 18 11:46:58 JST 2015
Does not reporduce here. Are sure that "Connected" field is 1 for both
the new and old database?
Database : test2
Username : t-ishii
Start time : 2015-08-18 11:40:05
Creation time: 2015-08-18 11:44:17
Major : 3
Minor : 0
Counter : 1
Backend PID : 6564
Connected : 1
PID : 6534
Backend ID : 0
SRA OSS, Inc. Japan
> Psql to pgpool.
> After logging into the Postgres database, then switch to another database, it would have 2 processes according to pcp_proc_info.
> Kind regards,
> On 18 Aug 2015, at 11:59 am, Tatsuo Ishii <ishii at postgresql.org> wrote:
>>> I'm current running pgpool-II 3.4.3-1 using pgpoolAdmin 3.4.1 on Rhel7.1.
>>> When I connect using psql to database1 via the virtual ip, then later switch over to another database2 using the "\c". Then switch back to database1. Pgpool creates 3 connections, which I can see in pgpoolAdmin->status->processes.
>>> If I continue to switch between the two databases, it will continue to increase the number of pgpool connections via the virtual ip. Eventually, these connections timeout when it reaches the child_life_time value or if it reaches the num_init_children limit, it will hang until a connection is available.
>> I don't know when you say "the number of pgpool connections", these
>> are from client (psql) to pgpool or pgpool to PostgreSQL. Because the
>> former will not increase as long as the number of psql you are using,
>> I assume you are referring to connections from pgpool to
>> The number could increase until num_init_children reaches. However
>> some of process are expected to accept connections from clients. You
>> could verify it by using "show pool_nodes". "pool_connected" column
>> indicates that the process is ready to accept connections from clients
>> (in this case 0).
>> Please remeber, however, that psql keeps old connection until \c
>> succeeds. For example, if num_init_children = 1, you are never able to
>> use \c.
>>> I have the connection_cache on.
>>> Is there something that I need to set?
>> You might want to set client_idle_limit.
>> Best regards,
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
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