Hi Tom,
I guess that at "On topic deletion will be applied on topic and message deletion." you meant something like "The TopicDeletionPolicy will be applied on topic and messages deletion". Paolo Patierno Senior Software Engineer (IoT) @ Red Hat Microsoft MVP on Azure & IoT Microsoft Azure Advisor Twitter : @ppatierno<http://twitter.com/ppatierno> Linkedin : paolopatierno<http://it.linkedin.com/in/paolopatierno> Blog : DevExperience<http://paolopatierno.wordpress.com/> ________________________________ From: Tom Bentley <t.j.bent...@gmail.com> Sent: Wednesday, September 27, 2017 9:47 AM To: dev@kafka.apache.org Subject: Re: [DISCUSS] KIP-201: Rationalising Policy interfaces I have updated the KIP to add a common policy interface for topic and message deletion. This included pulling ClusterState and TopicState interfaces up to the top level so that they can be shared between the two policies. Cheers, Tom On 26 September 2017 at 18:09, Edoardo Comar <eco...@uk.ibm.com> wrote: > Thanks Tom, > In my original KIP-170 I mentioned that the method > > public Map<String, Integer> topicsPartitionCount(); > > was just a starting point for a general purpose ClusterState > as it happened to be exactly the info we needed for our policy > implementation :-) > it definitely doesn't feel general purpose enough. > > what about > > interface ClusterState { > public TopicState topicState(String topicName); > public Set<String> topics(); > } > > I think that the implementation of ClusterState that the server will pass > to the policy.validate method > would just lazily tap into MetadataCache. No need for big upfront > allocations. > > ciao, > Edo > -------------------------------------------------- > > Edoardo Comar > > IBM Message Hub > > IBM UK Ltd, Hursley Park, SO21 2JN > > > > From: Tom Bentley <t.j.bent...@gmail.com> > To: dev@kafka.apache.org > Date: 26/09/2017 17:39 > Subject: Re: [DISCUSS] KIP-201: Rationalising Policy interfaces > > > > Hi Edoardo, > > > what about a single method in ClusterState > > > > interface ClusterState { > > public Map<String,TopicState> topicsState(); > > > > } > > > > which could return a read-only snapshot of the cluster metadata ? > > > > Sure that would work too. A concern with that is that we end up allocating > a potentially rather large amount for the Map and the collections present > in the TopicStates in order to provide the snapshot. The caller might only > be interested in one item from the TopicState for one topic in the map. > Accessing this information via methods means the caller only pays for what > they use. > > Cheers, > > Tom > > > > Unless stated otherwise above: > IBM United Kingdom Limited - Registered in England and Wales with number > 741598. > Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU >
