Optional Inputs

The optional inputs to GDS include the following:

• Stop command

• Probe command

• Timeout for start method

• Timeout for stop method

• Timeout for fault monitor probe

• Child monitor level (only with GDS using command line interface)

Stop Command

The stop command is supposed to stop the application and not return until the application has been completely stopped. It should be a UNIX command complete with its arguments that is acceptable by hatimerun.

If the stop command is provided, the GDS stop method launches the stop command with 80% of the timeout. Regardless of the outcome of launching the stop command, the GDS stop method still sends SIGKILL with 15% of the stop timeout. The remaining 5% of the time is assumed to have been used by the house keeping overhead.

If the stop command is omitted, the GDS tries to stop the application using signals. GDS first sends SIGTERM with 80% of the stop timeout. If the SIGTERM fails to stop the application, GDS then sends SIGKILL with 15% of the stop timeout. The remaining 5% of the time is assumed to have been used by the house keeping overhead.

Probe Command

The probe command checks the health of the given application. It should be a UNIX command complete with its arguments that is acceptable by hatimerun. The exit status of the probe command is used to determine the severity of the failure of the application. This exit status, called probe status, must be an integer between 0 (for success) and 100 (for complete failure). The probe status is used with in the GDS probing algorithm to take the decision of restarting the application locally, versus failing it over to another node.

If the probe command is omitted and the application uses network, GDS provides its own simple probe. This alternative probe simply connects to the application on the given hostname and port number. If the connect succeeds, it disconnects immediately. If both connect and disconnect succeed, the application is deemed to be running healthily.

The probe provided with GDS is only intended to be a simple substitute for the fully functioning application specific probe.

Start Method Timeout

The default timeout for the start method is 300 seconds.

Stop Method Timeout

The default timeout for the stop method is 300 seconds.

Fault Monitor Probe Timeout

The default timeout for the fault monitor probe is 30 seconds.

Child Monitor Level

This option provides more control over what level of processes get monitored through PMF. It denotes the level up to which the forked children processes have to be monitored. This is the -C argument to the pmfadm command. See the pfmadm(1M) man page for more details.

This option can only be specified using the command line interface. This option cannot be specified if you are using the SunPlex Agent Builder.