# derby.drda.keepAlive

Indicates whether SO_KEEPALIVE is enabled on sockets. The keepAlive mechanism is used to detect when clients disconnect unexpectedly. A keepalive probe is sent to the client if a long time (by default, more than two hours) passes with no other data being sent or received. The derby.drda.keepAlive property is used to detect and clean up connections for clients on powered-off machines or clients that have disconnected unexpectedly.

If the property is set to false, Derby will not attempt to clean up disconnected clients. The keepAlive mechanism might be disabled if clients need to resume work without reconnecting even after being disconnected from the network for some time. To disable keepAlive probes on Network Server connections, set this property to false.

#### Syntax

    derby.drda.keepAlive=[true|false]

#### Default

True.

#### Example

    derby.drdra.keepAlive=false

#### Static or dynamic

Static. You must restart the Network Server for changes to take effect.

Parent topic: Setting Network Server properties
Related reference
derby.drda.host
derby.drda.logConnections
derby.drda.maxThreads
derby.drda.minThreads
derby.drda.portNumber
derby.drda.securityMechanism
derby.drda.startNetworkServer
derby.drda.streamOutBufferSize
derby.drda.timeslice
derby.drda.traceAll
derby.drda.traceDirectory