Hi, Rajini, Thanks for the updated KIP. I agree that those additional metrics can be useful. I was thinking what would an admin do if the value of one of those metrics is abnormal. An admin probably want to determine which client causes the abnormaly. So, a couple of more comments below.
10. About FetchDownConversionsMs. Should we model it at the topic level or at the request level as a new latency component like messageConversionTime in addition to the existing localTime, requestQueueTime, etc? The benefit of the latter is that we can include it in the request log and use it to figure out which client is doing the conversion. Also, should we also track the conversion time in the producer? 11. About ProduceBatchSize. Currently, the largest chunk of memory is allocated at the request level (mostly produce request). So, instead of ProduceBatchSize , perhaps we can add a request size metric for each type of request and also include it in the request log. This way, if there is a memory issue, we can trace it back to a particular client. Similarly, for ProduceUncompressedBatchSize, would it be better to track it at the request level as something like temporaryMemorySize and include it in the request log? Thanks, Jun On Tue, Aug 29, 2017 at 10:07 AM, Roger Hoover <roger.hoo...@gmail.com> wrote: > Great suggestions, Ismael and thanks for incorporating them, Rajini. > > Tracking authentication success and failures (#3) across listeners seems > very useful for cluster administrators to identify misconfigured client or > bad actors, especially until all clients implement KIP-152 which will add > an explicit error code for authentication failures. Currently, clients > just get disconnected so it's hard to distinguish authentication failures > from any other error that can cause disconnect. This broker-side metric is > useful regardless but can help fill this gap until all clients support KIP > 152. > > Just to be clear, the ones called `successful-authentication-rate` and > `failed-authentication-rate` will also have failed-authentication-count > and successful-authentication-count to match KIP 187? > > On Tue, Aug 29, 2017 at 7:26 AM, Rajini Sivaram <rajinisiva...@gmail.com> > wrote: > > > Hi Ismael, > > > > Thank you for the suggestions. The additional metrics sound very useful > and > > I have added them to the KIP. > > > > Regards, > > > > Rajini > > > > On Tue, Aug 29, 2017 at 5:34 AM, Ismael Juma <ism...@juma.me.uk> wrote: > > > > > Hi Rajini, > > > > > > There are a few other metrics that could potentially be useful. I'd be > > > interested in what you and the community thinks: > > > > > > 1. The KIP currently includes `FetchDownConversionsPerSec`, which is > > > useful. In the common case, one would want to avoid down conversion by > > > using the lower message format supported by most of the consumers. > > However, > > > there are good reasons to use a newer message format even if there are > > some > > > legacy consumers around. It would be good to quantify the cost of these > > > consumers a bit more clearly. Looking at the request metric > `LocalTimeMs` > > > provides a hint, but it may be useful to have a dedicated > > > `FetchDownConversionsMs` metric. > > > > > > 2. Large messages can cause GC issues (it's particularly bad if fetch > > down > > > conversion takes place). One can currently configure the max message > > batch > > > size per topic to keep this under control, but that is the size after > > > compression. However, we decompress the batch to validate produce > > requests > > > and we decompress and recompress during fetch downconversion). It would > > be > > > helpful to have topic metrics for the produce message batch size after > > > decompression (and perhaps compressed as well as that would help > > understand > > > the compression ratio). > > > > > > 3. Authentication success/failures per second. This is helpful to > > > understand if some clients are misconfigured or if bad actors are > trying > > to > > > authenticate. > > > > > > Thoughts? > > > > > > Ismael > > > > > > > > > > > > On Wed, Aug 23, 2017 at 2:53 AM, Jun Rao <j...@confluent.io> wrote: > > > > > > > Hi, Rajini, > > > > > > > > Yes, if those error metrics are registered dynamically, we could > worry > > > > about expiration later. > > > > > > > > Thanks, > > > > > > > > Jun > > > > > > > > On Fri, Aug 18, 2017 at 1:55 AM, Rajini Sivaram < > > rajinisiva...@gmail.com > > > > > > > > wrote: > > > > > > > > > Perhaps we could register dynamically for now. If we find that the > > cost > > > > of > > > > > retaining these is high, we can add the code to expire them later. > Is > > > > that > > > > > ok? > > > > > > > > > > Regards, > > > > > > > > > > Rajini > > > > > > > > > > > > > > > > > > > > On Fri, Aug 18, 2017 at 9:41 AM, Ismael Juma <ism...@juma.me.uk> > > > wrote: > > > > > > > > > > > Can we quantify the cost of having these metrics around if they > are > > > > > > dynamically registered? Given that the maximum is bounded at > > > > development > > > > > > time, is it really worth all the extra code? > > > > > > > > > > > > Ismael > > > > > > > > > > > > On Fri, Aug 18, 2017 at 9:34 AM, Rajini Sivaram < > > > > rajinisiva...@gmail.com > > > > > > > > > > > > wrote: > > > > > > > > > > > > > Jun, > > > > > > > > > > > > > > It feels more consistent to add errors as yammer metrics > similar > > to > > > > > other > > > > > > > request metrics. Perhaps we could add some code to track and > > remove > > > > > these > > > > > > > if unused? It is a bit more work, but it would keep the > externals > > > > > > > consistent. > > > > > > > > > > > > > > Ismael/Manikumar, > > > > > > > > > > > > > > Agree that version as a String attribute makes more sense. > > > > > Unfortunately, > > > > > > > the whole KafkaMetric implementation is written around a single > > > > > "double" > > > > > > > type, so introducing a new type is a big change. But I suppose > it > > > can > > > > > be > > > > > > > done. I have updated the KIP. > > > > > > > > > > > > > > Regards, > > > > > > > > > > > > > > Rajini > > > > > > > > > > > > > > > > > > > > > On Fri, Aug 18, 2017 at 7:42 AM, Manikumar < > > > > manikumar.re...@gmail.com> > > > > > > > wrote: > > > > > > > > > > > > > > > I agree it will be good if we can add "commit id/version" as > > an > > > > > > > > attribute value. > > > > > > > > It will be easy to parse. But as of now, KafkaMetric supports > > > only > > > > > > > > numerical values. > > > > > > > > > > > > > > > > On Fri, Aug 18, 2017 at 5:49 AM, Ismael Juma < > > ism...@juma.me.uk> > > > > > > wrote: > > > > > > > > > > > > > > > > > Hi Rajini, > > > > > > > > > > > > > > > > > > About the gauges, I was thinking that the attribute would > be > > > the > > > > > > value > > > > > > > > > (i.e. commit id or version). I understand that Kafka > Metrics > > > > > doesn't > > > > > > > > > support this (unlike Yammer Metrics), but would it make > sense > > > to > > > > > add? > > > > > > > > > > > > > > > > > > Ismael > > > > > > > > > > > > > > > > > > On Thu, Aug 17, 2017 at 2:54 PM, Rajini Sivaram < > > > > > > > rajinisiva...@gmail.com > > > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > Hi Ismael, > > > > > > > > > > > > > > > > > > > > Thank you for the review. > > > > > > > > > > > > > > > > > > > > 1. Agree on keeping it simple with dynamic registration > and > > > no > > > > > > > expiry. > > > > > > > > > Will > > > > > > > > > > wait for Jun's feedback before updating KIP. > > > > > > > > > > 2. I have switched to two metrics for commit-id and > version > > > > (not > > > > > > sure > > > > > > > > if > > > > > > > > > it > > > > > > > > > > matches what you meant). I also added the client-id tag > > which > > > > is > > > > > > used > > > > > > > > in > > > > > > > > > > all metrics from clients. > > > > > > > > > > > > > > > > > > > > Regards, > > > > > > > > > > > > > > > > > > > > Rajini > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Thu, Aug 17, 2017 at 10:55 AM, Ismael Juma < > > > > ism...@juma.me.uk > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > Thanks for the KIP, Rajini. I think this is helpful > too. > > A > > > > few > > > > > > > minor > > > > > > > > > > > comments. > > > > > > > > > > > > > > > > > > > > > > 1. About the number of metrics and expiration, if we > > > > > dynamically > > > > > > > > > register > > > > > > > > > > > metrics for the error codes, the number is likely to be > > > much > > > > > > lower > > > > > > > > than > > > > > > > > > > > 30*30, probably less than 100. If we were using Kafka > > > Metrics > > > > > for > > > > > > > > this, > > > > > > > > > > we > > > > > > > > > > > could easily add a long expiration period to be > > > conservative, > > > > > > but I > > > > > > > > am > > > > > > > > > > not > > > > > > > > > > > sure this is supported by Yammer Metrics. If it is not, > > > > there's > > > > > > an > > > > > > > > > > argument > > > > > > > > > > > for keeping it simple. > > > > > > > > > > > > > > > > > > > > > > 2. Would it make sense to use 2 gauges for the version > > and > > > > > commit > > > > > > > id? > > > > > > > > > It > > > > > > > > > > > seems more intuitive than having those values as tags. > > > > > > > > > > > > > > > > > > > > > > Ismael > > > > > > > > > > > > > > > > > > > > > > On Thu, Aug 17, 2017 at 10:19 AM, Rajini Sivaram < > > > > > > > > > > rajinisiva...@gmail.com> > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > Hi Jun, > > > > > > > > > > > > > > > > > > > > > > > > Thank you for the review. > > > > > > > > > > > > > > > > > > > > > > > > 1. Makes sense. I have updated the KIP. > > > > > > > > > > > > 2. Moved to a new group ZooKeeperClient > > > > > > > > > > > > 3. It is a gauge, so it will have a single attribute > > > called > > > > > > Value > > > > > > > > > with > > > > > > > > > > a > > > > > > > > > > > > constant value of 1. > > > > > > > > > > > > > > > > > > > > > > > > Regards, > > > > > > > > > > > > > > > > > > > > > > > > Rajini > > > > > > > > > > > > > > > > > > > > > > > > On Thu, Aug 17, 2017 at 3:16 AM, Jun Rao < > > > j...@confluent.io > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > Hi, Rajini, > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks for the KIP. A few comments. > > > > > > > > > > > > > > > > > > > > > > > > > > 1. We have 30+ requests and 30+ error code and > > growing. > > > > So, > > > > > > the > > > > > > > > > > > > combination > > > > > > > > > > > > > can be large. Perhaps it's useful to expire an > error > > > > metric > > > > > > if > > > > > > > > it's > > > > > > > > > > no > > > > > > > > > > > > > longer updated after some time? We did something > > > similar > > > > > for > > > > > > > the > > > > > > > > > > quota > > > > > > > > > > > > > metric. > > > > > > > > > > > > > > > > > > > > > > > > > > 2. It's a bit weird to put the ZK latency metric > > under > > > > > > > > > > > > > type=SessionExpireListener. > > > > > > > > > > > > > Perhaps it's more intuitive to put it in a separate > > > type. > > > > > > > > > > > > > > > > > > > > > > > > > > 3. For the client version metric, since we > > representing > > > > > > > commit_id > > > > > > > > > and > > > > > > > > > > > > > version as tags in the metric name. So the mbean > will > > > > have > > > > > no > > > > > > > > > > > attributes? > > > > > > > > > > > > > > > > > > > > > > > > > > Jun > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Wed, Aug 16, 2017 at 4:05 PM, Roger Hoover < > > > > > > > > > > roger.hoo...@gmail.com> > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > I think it would useful to make clear somewhere > for > > > > each > > > > > > > > metric, > > > > > > > > > > the > > > > > > > > > > > > > level > > > > > > > > > > > > > > at which it's counted. I don't know all the > > details > > > of > > > > > the > > > > > > > > Kafka > > > > > > > > > > > > > protocol > > > > > > > > > > > > > > but it might be something like > > > > > > > > > > > > > > > > > > > > > > > > > > > > ProduceRequest, Fetch Request - counted at > > > > per-partition > > > > > > > level > > > > > > > > > > > > > > All other requests are 1:1 with client requests? > > > > > > > > > > > > > > > > > > > > > > > > > > > > Cheers, > > > > > > > > > > > > > > > > > > > > > > > > > > > > Roger > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Wed, Aug 16, 2017 at 4:02 PM, Roger Hoover < > > > > > > > > > > > roger.hoo...@gmail.com> > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Rajini, > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thank you for the KIP. These are very helpful > > > > > additions. > > > > > > > > One > > > > > > > > > > > > question > > > > > > > > > > > > > > on > > > > > > > > > > > > > > > the error code metrics: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Will the total error counting happen at the the > > > level > > > > > of > > > > > > > > topic > > > > > > > > > > > > > partition? > > > > > > > > > > > > > > > For example, if a single ProduceRequest > contains > > > > > messages > > > > > > > to > > > > > > > > > > append > > > > > > > > > > > > to > > > > > > > > > > > > > 3 > > > > > > > > > > > > > > > partitions and say all 3 appends are > successful, > > > the > > > > > > > counter > > > > > > > > > > > > > > > for kafka.network:type=RequestMetrics,name= > > > > > > > > > ErrorsPerSec,request= > > > > > > > > > > > > > > ProduceRequest,error=0 > > > > > > > > > > > > > > > will be incremented by 3? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Roger > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Wed, Aug 16, 2017 at 12:10 PM, Rajini > Sivaram > > < > > > > > > > > > > > > > > rajinisiva...@gmail.com> > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >> I have created a KIP to add some additional > > > metrics > > > > to > > > > > > > > support > > > > > > > > > > > > health > > > > > > > > > > > > > > >> checks: > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> https://cwiki.apache.org/ > > > > > confluence/display/KAFKA/KIP- > > > > > > > > 188+-+ > > > > > > > > > > > > > > >> Add+new+metrics+to+support+health+checks > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> Feedback and suggestions are welcome. > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> Regards, > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> Rajini > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
