[tor-bugs] #19720 [Metrics/CollecTor]: CollecTor should be re-configurable without restart

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#19720: CollecTor should be re-configurable without restart
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 Reporter:  iwakeh             |          Owner:  iwakeh
     Type:  enhancement        |         Status:  needs_review
 Priority:  High               |      Milestone:  CollecTor 1.0.0
Component:  Metrics/CollecTor  |        Version:
 Severity:  Normal             |     Resolution:
 Keywords:  ctip               |  Actual Points:
Parent ID:                     |         Points:
 Reviewer:                     |        Sponsor:
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Comment (by karsten):

 Okay, I agree with most design decisions here, except for one that might
 confuse operators more than necessary: the modified time of the
 configuration file should not be checked once per minute (or even more
 often) but rather at the start of a new module run.  Imagine a situation
 where the next execution is less than 1 minute away and the operator makes
 a quick change to the configuration file.  There's no way for them to find
 out whether that change will make it into the next run or not, because the
 thread might check in 1 second or in 59 seconds.  Can we change that by
 taking out the thread and having modules check whether the configuration
 has changed?

 A possible downside of this approach is that configuration problems cannot
 be found until the next module execution.  But I think that's also when
 operators would expect problems to show up, not randomly 0-60 seconds
 after writing the configuration file.

 Ideally, we'd have a shell script that we use to reload the configuration
 file and possibly to verify it without loading it.  But that's for later.

 Does this make sense?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/19720#comment:8>
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