Controlling connection records with the staletimeout value

Connections are considered stale when there has been no activity on that connection for the number of seconds specified in stale timeout. When the number of seconds has been exceeded with no activity, Load Balancer will remove that connection record from its tables, and subsequent traffic for that connection is discarded. The staletimeout command controls the way Load Balancer handles idle connections and the associated connection records.

About this task

Use the staletimeout command to control the period during which Load Balancer should keep connections in the "Established" state and accept traffic when no active traffic has been seen in the Dispatcher tables.

A client sends a FIN packet after it has sent all its packets so that the server will know that the transaction is finished. When Dispatcher receives the FIN packet, it marks the transaction from active state to FIN state. When a transaction is marked FIN, the memory that is reserved for the connection can be cleared.

Procedure

To change the staletimeout value, use the dscontrol executor set command.
Type the following at a command prompt:
dscontrol executor set staletimeout time
where the value for time is in seconds.
Avoid trouble: Some services might have staletimeout values of their own.
Note: For example, LDAP (Lightweight Directory Access Protocol) has a configuration parameter called idletimeout. When idletimeout seconds have been exceeded, an idle client connection will be forcibly closed. Idletimeout may also be set to 0, which means that the connection will never be forcibly closed.

Connectivity problems can occur when Load Balancer's stale timeout value is smaller than the service's timeout value. In the case of LDAP, for example, if the Load Balancer staletimeout value defaults to 6400 seconds, and there is no activity on the connection for 6400 seconds, Load Balancer will remove the connection record from its tables. Furthermore, if the idletimeout value at the LDAP server is larger than 6400 seconds (or set to 0), the client might still believe that it has a connection to the server. When the client sends packets, the packets will be discarded by Load Balancer. This causes the LDAP client to hang when a request is made to the server.

To avoid this problem, set the LDAP idletimeout to a nonzero value that is the same or smaller than the Load Balancer staletimeout value.