cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Tyler Hobbs (JIRA)" <>
Subject [jira] [Commented] (CASSANDRA-5746) HHOM.countPendingHints is a trap for the unwary
Date Tue, 16 Jul 2013 20:08:48 GMT


Tyler Hobbs commented on CASSANDRA-5746:

> What if we redefine the problem to be "how many hints have I generated for node X?" and
get rid of countPendingHints entirely?

That seems like a reasonable replacement metric for most purposes, but I can see where countPendingHints()
might still be useful.  However, in its current state, it seems too dangerous to leave in.
 Maybe pull it out in this ticket and open a new ticket for a better implementation if there's

I'm assuming we don't want to persist this one to disk. (Most RRD-style metric systems handle
normally monotonically increasing metrics resetting to 0 occasionally, so just counting hints
created since the node has been up should be fine.)
> HHOM.countPendingHints is a trap for the unwary
> -----------------------------------------------
>                 Key: CASSANDRA-5746
>                 URL:
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core, Tools
>            Reporter: Jonathan Ellis
>            Assignee: Tyler Hobbs
>             Fix For: 2.0.1
> countPendingHints can OOM the server fairly easily since it does a per-target seq scan
without paging.
> More generally, countPendingHints is far too slow to be useful for routine monitoring.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see:

View raw message