On 08/21/2015 11:16 AM, Rich Schaaf wrote:
> I’m running into a problem where the connection between application its
> database is timing out after 12 hours.
>
> Here’s the context:
>
> ·Two servers (one running the application and another hosting the
> database) in the Amazon AWS environment on different subnets within a
> virtual private cloud
>
> ·The server hosting the application is running Ubuntu 14.04.2 LTS
>
> ·The server hosting the database is running Ubuntu 14.04.2 LTS and
> PostgreSQL version 9.4.4
>
> ·An stunnel connection is provisioned from the client to the database.
> The app server is running stunnel version 4.53 with the following
> stunnel.conf settings:
>
> ; PID is created inside the chroot jail
>
> pid = /stunnel4.pid
>
> [postgres-<host>]
>
> client = yes
>
> protocol = pgsql
>
> accept = 5432
>
> connect = <host>:5432
>
> options = NO_TICKET
>
> retry = yes
>
> ·The database is provisioned to only accept “hostssl” type connections
> from the application server
>
> I’ve enabled the logging of PostgreSQL connections and disconnections
> and I see that for connections that terminate before the associated
> query completes, the session time shown in the disconnect message is 12
> hours plus three or four seconds.
Is there anything else in the log at this point in time that looks like
it might be related?
What is the actual disconnect message?
>
> I see this problem with both of the default tcp_keepalives settings of:
>
> #tcp_keepalives_idle = 0
>
> #tcp_keepalives_interval = 0
>
> #tcp_keepalives_count = 0
>
> And with the following settings:
>
> tcp_keepalives_idle = 120
>
> tcp_keepalives_interval = 120
>
> tcp_keepalives_count = 5
>
> I don’t see the disconnect problem for long-running queries that use a
> local database connection.
>
> Any advice on what might be causing remote database connections to drop
> after 12 hours (and how to work around the issue)?
>
> Kind regards,
> Rich
>
--
Adrian Klaver
adrian.klaver@aklaver.com