Hi Apoorv, Thanks for the KIP. I have some comments. AS0: These are broker metrics and not client metrics. I don't think the KIP states that and it probably should.
AS1: TotalShareFetchRequestsPerSec is inspired by the existing metric TotalFetchRequestsPerSec. That one is in the BrokerTopicMetrics group so I would expect the new metric to be in the same group. This comment applies to all of the ShareGroupMetrics broker metrics scoped to a topic. AS2: Similarly to TotalFetchRequestPerSec, does the new metric support omitting the topic tag in order to obtain the all-topic rate? I believe so because it follows the existing metrics. I guess the tag is actually `topic=([-.\w]+)` to copy the existing notation. AS3: What's a share release? Does it count releases which are made by ShareFetch/Acknowledge requests as well as implicit ones as a result of share session expiration or closure? AS4: I see there is FailedShareAcknowledgementRequestsPerSec. If this corresponds specifically to the ShareAcknowledge API, then the name should be FailedShareAcknowledgeRequestsPerSec. AS5: What does FailedShareAcknowledgementRequestsPerSec actually count? This is a per-topic metric and a ShareAcknowledge can mention several topics, but actually it can also operate on many acquired records specifying any of the different acknowledgement types that KIP-932 defines. AS6: Why no TotalShareAcknowledgementRequestsPerSec? AS7: I think I like the concept behind RequestTopicPartitionsFetchRatio, but it would really help to include some examples of how it works. You mention 4 potential causes for low ratios, so it would be nice to see how each of them would be evident from the metrics and configurations. This is going to be valuable information for operating this in production. AS8: As Jun mentioned, maybe a histogram would be appropriate for RequestTopicPartitionsFetchRatio. Then I wonder whether it's worth having a separate RequestTopicPartitionsFetchEmptyCount since those are requests for which the fetch ratio was 0. Thanks, Andrew ________________________________________ From: Jun Rao <j...@confluent.io.INVALID> Sent: 30 October 2024 23:07 To: dev@kafka.apache.org <dev@kafka.apache.org> Subject: Re: [DISCUSS] KIP-1103: Additional metrics for cooperative consumption Hi, Apoorv, Thanks for the KIP. A few comments. 1. TotalShareReleaseRequestsPerSec: This is a bit weird since there is no ShareReleaseRequest. 2. RequestTopicPartitionsFetchRatio and InFlightBatchMessageCount: It seems Histogram is more appropriate for them. 3. RequestTopicPartitionsFetchEmptyCount and AcquisitionLockTimeoutCount: The problem with using gauge is that if the value changes quickly, we may not be able to capture the occurrence of empty fetch or lock timeout. Meter captures those rare events better. Jun On Tue, Oct 29, 2024 at 8:48 AM Apoorv Mittal <apoorvmitta...@gmail.com> wrote: > Hi Everyone, > I would like to start a discussion on KIP-1103: > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-1103%3A+Additional+metrics+for+cooperative+consumption > > This KIP extends KIP-932 to provide additional metrics for > Queues/Cooperative consumption. > > Regards, > Apoorv Mittal >
