idle_in_transaction_session_timeout
A configuration parameter determining the length of time after which sessions with open transactions are terminated
idle_in_transaction_session_timeout is a configuration parameter determining the length of time after which sessions with open transactions are terminated. It is disabled by default.
idle_in_transaction_session_timeout was added in PostgreSQL 9.6.
Default value
The default value for idle_in_transaction_session_timeout is: 0 (disabled).
Change history
- PostgreSQL 9.6
- added (commit c6dda1f4)
Source code
GUC variable in src/backend/storage/lmgr/proc.c:
int IdleInTransactionSessionTimeout = 0;
GUC configuration in src/backend/utils/misc/guc.c:
{
{"idle_in_transaction_session_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the maximum allowed duration of any idling transaction."),
gettext_noop("A value of 0 turns off the timeout."),
GUC_UNIT_MS
},
&IdleInTransactionSessionTimeout,
0, 0, INT_MAX,
NULL, NULL, NULL
},
The timeout is initiated and executed in PostgresMain() (src/backend/tcop/postgres.c).
Examples
Demonstrating the effect of idle_in_transaction_session_timeout with an unrealistically short setting of 5s:
postgres=# SET idle_in_transaction_session_timeout = '5s'; SET postgres=# SHOW idle_in_transaction_session_timeout; idle_in_transaction_session_timeout ------------------------------------- 5s (1 row)
postgres=# SELECT clock_timestamp(); clock_timestamp ---------------------------- 2019-08-06 16:32:44.603+01 (1 row) Time: 1.772 ms postgres=# BEGIN ; BEGIN
... do nothing for at least 5 seconds ...
postgres=*# SELECT 1;
FATAL: terminating connection due to idle-in-transaction timeout
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Succeeded.
postgres=# SELECT clock_timestamp();
clock_timestamp
------------------------------
2019-08-06 16:32:52.92625+01
(1 row)
There will be an entry similar to the following in the server's log file:
[2019-08-06 16:32:50 CET] psql postgres postgres FATAL: 25P03: terminating connection due to idle-in-transaction timeout
References
- PostgreSQL documentation: idle_in_transaction_session_timeout
Useful links
- idle_in_transaction_session_timeout: Terminating idle transactions in PostgreSQL - April 2018 blog article by CyberTec