Making Persistent Extractor Commands

Normally the lifespan of a command started by the File Extractor is limited to one data delivery interval. This causes difficulties in cases where useful information can only be obtained from data that is collected over a series of intervals.

It is possible to enable persistent commands, this is done differently depending on the platform.

Windows and UNIX/Linux

The 'DeliverInterval' instruction in File Extractor can be used to enable Persistent Commands. With Persistent Commands, the lifespan of the external command is not limited to one interval and it will be kept running as long as the data requestor (e.g. database collection or online display) keeps requesting data from the Extractor.

See the Extractor Script Instruction Entries section for details.

HPE NonStop

On HPE NonStop, using 'DeliverInterval' instruction can result in the File Extractor spawning processes on a continual basis. This is not ideal as spawning a new process on HPE NonStop is expensive.

However, it is possible to write TACL macros that can keep any commands running in the background from interval to interval. For details of this please contact IR Technical Support.

Provide feedback on this article