Hi all, In working on the patch for KIP-196: Add metrics to Kafka Connect framework, we realized that we have worker and connector/task IDs that are to be included in metrics and those don't currently have constraints on naming. I'd prefer to avoid adding naming restrictions or mangling names unnecessarily, and for users that define a custom metrics reporter the name mangling may be unexpected since their metrics system may not have the same limitations as JMX.
The text of the KIP is pretty JMX specific and doesn't really define where this mangling happens. Currently, it is being applied essentially as early as possible. I would like to propose moving the name mangling into the JmxReporter itself so the only impact is on JMX metrics, but other metrics reporters would see the original. In other words, leave system-specific name mangling up to that system. In the JmxReporter, the mangling could remain the same (though I think the mangling for principals is an internal implementation detail, whereas this name mangling is user-visible). The quota metrics on the broker would now be inconsistent with the others, but I think trying to be less JMX-specific given that we support pluggable reporters is the right direction to go. I think in practice this has no publicly visible impact and definitely no compatibility concerns, it just moves where we're doing the JMX name mangling. However, since discussion about metric naming/character substitutions had happened here recently I wanted to raise it here and make sure there would be agreement on this direction. (Long term I'd also like to get the required instantiation of JmxReporter removed as well, but that requires its own KIP.) Thanks, Ewen On Thu, Sep 14, 2017 at 2:09 AM, Tom Bentley <t.j.bent...@gmail.com> wrote: > Hi Mickael, > > I was just wondering why the restriction was imposed for Java clients the > first place, do you know? > > Cheers, > > Tom > > On 14 September 2017 at 09:16, Ismael Juma <ism...@juma.me.uk> wrote: > > > Thanks for the KIP Mickael. I suggest starting a vote. > > > > Ismael > > > > On Mon, Aug 21, 2017 at 2:51 PM, Mickael Maison < > mickael.mai...@gmail.com> > > wrote: > > > > > Hi all, > > > > > > I have created a KIP to cleanup the way client-ids are handled by > > > brokers and clients. > > > > > > Currently the Java clients have some restrictions on the client-ids > > > that are not enforced by the brokers. Using 3rd party clients, > > > client-ids containing any characters can be used causing some strange > > > behaviours in the way brokers handle metrics and quotas. > > > > > > Feedback is appreciated. > > > > > > Thanks > > > > > >
