Adrian Klaver <adrian.klaver@aklaver.com> writes:
> On 4/17/19 5:39 AM, Ajay Pratap wrote:
>> I am using PostgreSQL 10.7 as the database, and have Java web app. My
>> app takes a lock on the database using the following command whenever my
>> server is starting.
>> /select /pg_try_advisory_lock/(100)/
>> To make sure only one instance of the App is using the database at a time.
>> There have been several instances when my server crashes(or stops/ or
>> kill), but this lock still remained on the PostgreSQL. Ideally, this
>> should not happen because TCP connection breaks if one of the peers
>> dies, but it happens otherwise.
>> To solve this problem PostgreSQL needs to break the connection if the
>> client dies.
> But the problem as you describe it is that the server dies not the client.
An advisory lock wouldn't survive a server reboot, so there's something
not very accurate about this description.
I suspect what the OP wants is quicker detection of client connection
loss, and yes, messing with TCP timeouts and/or keepalive is the only way.
regards, tom lane