> > "Dead" and "Empty" states are transient: groups usually only leaves in this > state for a short while and then being deleted or transited to other > states.
This is not strictly true for the "Empty" state which we also use to represent simple groups which only use the coordinator to store offsets. I think we may as well cover all the states if we're going to cover any of them specifically. -Jason On Fri, Jul 21, 2017 at 9:45 AM, Guozhang Wang <wangg...@gmail.com> wrote: > My two cents: > > "Dead" and "Empty" states are transient: groups usually only leaves in this > state for a short while and then being deleted or transited to other > states. > > Since we have the existing "*NumGroups*" metric, `*NumGroups - > **NumGroupsRebalancing > - **NumGroupsAwaitingSync`* should cover the above three, where "Stable" > should be contributing most of the counts: If we have a bug that causes the > num.Dead / Empty to keep increasing, then we would observe `NumGroups` keep > increasing which should be sufficient for alerting. And trouble shooting of > the issue could be relying on the log4j. > > *Guozhang* > > On Fri, Jul 21, 2017 at 7:19 AM, Ismael Juma <ism...@juma.me.uk> wrote: > > > Thanks for the KIP, Colin. This will definitely be useful. One question: > > would it be useful to have a metric for for the number of groups in each > > possible state? The KIP suggests "PreparingRebalance" and "AwaitingSync". > > That leaves "Stable", "Dead" and "Empty". Are those not useful? > > > > Ismael > > > > On Thu, Jul 20, 2017 at 6:52 PM, Colin McCabe <cmcc...@apache.org> > wrote: > > > > > Hi all, > > > > > > I posted "KIP-180: Add a broker metric specifying the number of > consumer > > > group rebalances in progress" for discussion: > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP- > > > 180%3A+Add+a+broker+metric+specifying+the+number+of+ > > > consumer+group+rebalances+in+progress > > > > > > Check it out. > > > > > > cheers, > > > Colin > > > > > > > > > -- > -- Guozhang >