Add ability to controll WebJob history for continuous WebJobs

[nibras85]

From reading the documentation, I see that I can control the history size for a triggered WebJob using the WEBJOBS_HISTORY_SIZE flag as explained here. I however, couldn't see any knob I can use to control the history length for continuous WebJobs.

I have a continuous WebJob listening to a queue that gets millions of messages and my Storage Account is getting filled quickly because of that. If possible, I'd like to limit the invocation history logs for this continuous WebJob.

[mathewc]

I believe this is a duplicate of #560. That issue tracks the feature request for log retention policies. You're talking about the Dashboard storage logs, right?

Until that feature work is done, your only other options are:

• Apply TraceLevelAttribute to your high throughput function to limit or disable the logging for that single function.
• Turn Dashboard logging off completely. Of course this is not an option if you're dependent on these logs.

[christopheranderson]

We're locking down new features for the next release, so I'm going to pop this into backlog for now.