On Fri, Aug 23, 2019, at 11:08, Stanislav Kozlovski wrote: > Thanks for the KIP, this is very helpful > > I had an offline discussion with Jason and we discussed the semantics of > the underMinIsr/atMinIsr metrics. The current proposal would expose a gap > where we could report URP but no MinIsr. > A brief example: > original replica set = [0,1,2] > new replica set = [3,4,5] > isr = [0, 3, 4] > config.minIsr = 3 > > As the KIP said > > In other words, we will subtract the AddingReplica from both the total > replicas and the current ISR when determining URP satisfaction. > We would report URP=2 (1 and 2 are not in ISR) but not underMinIsr, as we > have an ISR of 3. > Technically, any produce requests with acks=all would succeed, so it would > be false to report `underMinIsr`. We thought it'd be good to keep both > metrics consistent, so a new proposal is to use the following algorithm: > ``` > isUrp == size(original replicas) - size(isr) > 0 > ```
Hi Stan, That's a good point. Basically we should regard the size of the original replica set as the desired replication factor, and calculate the URPs based on that. +1 for this. (I assume Jason will update the KIP...) best, Colin > > Taking that into account, +1 from me! (non-binding) > > On Fri, Aug 23, 2019 at 7:00 PM Colin McCabe <cmcc...@apache.org> wrote: > > > +1 (binding). > > > > cheers, > > Colin > > > > On Tue, Aug 20, 2019, at 10:55, Jason Gustafson wrote: > > > Hi All, > > > > > > I'd like to start a vote on KIP-352, which is a follow-up to KIP-455 to > > > fix > > > a long-known shortcoming of URP reporting and to improve reassignment > > > monitoring: > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-352%3A+Distinguish+URPs+caused+by+reassignment > > > . > > > > > > Note that I have added one new metric following the discussion. It seemed > > > useful to have a lag metric for reassigning partitions. > > > > > > Thanks, > > > Jason > > > > > > > > -- > Best, > Stanislav >
