Github user steveloughran commented on the pull request:
https://github.com/apache/spark/pull/9571#issuecomment-159996634
Added reworked design
* all metrics go through the `MetricsSystem`; the providers return an
optional `Source` from the `start()` call.
* `FsHistoryProvider` metrics split lookups of missing files from failed
attempts to replay the logs.
* `FsHistoryProvider` metrics include time of the mergeListing() operation,
which can be quite the CPU killer.
* There's a `HealthSource` for health checks; it's being explicitly managed
in the HistoryServer.
* And there's an initial health check for the FS, which simply returns FS
safe/mode flag.
Really, the health check logic needs its own `HealthSystem` for the
register/unregister. Trying to design one that spans all the applications is
more complex and I'm trying to avoid that.
Furthermore, those operations which fail asynchronous and just have
exceptions logged should have their exceptions saved to another health check (I
may implement that). That way the health check will react to live system
failures, including things like the log directory being deleted during a run.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
