Hello , Did you take a look into the patches from the previous mail ? What do you think about my proposal ? Could you please say if there are any objections in regard to it?
Thank you in advance, Andrei Yahorau From: Andrei Yahorau/IBA To: pgsql-hack...@postgresql.org, Cc: Mikalai Keida/IBA@IBA Date: 20/07/2018 11:43 Subject: Adding TCP_USER_TIMEOUT support for libpq/psqlodbc Hello PostgreSQL Community! Not long ago I faced the situation concerning ODBC/libpq client hanging in case of some network problems. I had a discussion regarding this issue within pgsql-o...@postgresql.org and got some suggestions. Here is this discussion: https://www.postgresql.org/message-id/OF33DF00A3.D6444835-ON432582C3.003EA7C5-432582C3.0045562B%40iba.by In a few words the suggestion was to use pqopt keepalive options for ODBC configuration for example as follows: pqopt = keepalives=1 keepalives_idle=5 keepalives_count=1 keepalives_interval=1 But under some circumstances it can be not reliable and the connection can loose its keepalives properties and it can remain hanging. Here is a quote from our discussion: Hmm it seems keepalive stops while waiting for ack. Therefore it's a matter of retransmission control You can use TCP_USER_TIMEOUT on linux but the option is not used in libpq. In my opinion it make sense to add the support of TCP_USER_TIMEOUT socket option to libpq/psqlodbc connection. The attachment contains a patch with the source code changes regarding this issue. In my implementation it can be configured by new keepalives_user_timeout option within pqopt parameter. [attachment "0001_TCP_USER_TIMEOUT_libpq-int.patch" deleted by Andrei Yahorau/IBA] [attachment "0001_TCP_USER_TIMEOUT_fe-connect.patch" deleted by Andrei Yahorau/IBA] Best regards, Andrei Yahorau
