+1. On Thu, Jun 16, 2016 at 3:47 PM, Ismael Juma <ism...@juma.me.uk> wrote:
> +1 (binding) > > On Thu, Jun 16, 2016 at 11:50 PM, Grant Henke <ghe...@cloudera.com> wrote: > > > I would like to initiate the voting process for the "KIP-4 Create Topics > > Schema changes". This is not a vote for all of KIP-4, but specifically > for > > the create topics changes. I have included the exact changes below for > > clarity: > > > > > > Create Topics Request (KAFKA-2945 > > > <https://issues.apache.org/jira/browse/KAFKA-2945>) > > > > > > CreateTopics Request (Version: 0) => [create_topic_requests] timeout > > > create_topic_requests => topic num_partitions replication_factor > > [replica_assignment] [configs] > > > topic => STRING > > > num_partitions => INT32 > > > replication_factor => INT16 > > > replica_assignment => partition_id [replicas] > > > partition_id => INT32 > > > replicas => INT32 > > > configs => config_key config_value > > > config_key => STRING > > > config_value => STRING > > > timeout => INT32 > > > > > > CreateTopicsRequest is a batch request to initiate topic creation with > > > either predefined or automatic replica assignment and optionally topic > > > configuration. > > > > > > Request semantics: > > > > > > 1. Must be sent to the controller broker > > > 2. If there are multiple instructions for the same topic in one > > > request an InvalidRequestException will be logged on the broker and > > the > > > client will be disconnected. > > > - This is because the list of topics is modeled server side as a > > > map with TopicName as the key > > > 3. The principal must be authorized to the "Create" Operation on the > > > "Cluster" resource to create topics. > > > - Unauthorized requests will receive a > > ClusterAuthorizationException > > > 4. > > > > > > Only one from ReplicaAssignment or (num_partitions + > > replication_factor > > > ), can be defined in one instruction. > > > - If both parameters are specified an InvalidRequestException will > be > > > logged on the broker and the client will be disconnected. > > > - In the case ReplicaAssignment is defined number of partitions > and > > > replicas will be calculated from the supplied replica_assignment. > > > - In the case of defined (num_partitions + replication_factor) > > > replica assignment will be automatically generated by the server. > > > - One or the other must be defined. The existing broker side auto > > > create defaults will not be used > > > (default.replication.factor, num.partitions). The client > > implementation can > > > have defaults for these options when generating the messages. > > > - The first replica in [replicas] is assumed to be the preferred > > > leader. This matches current behavior elsewhere. > > > 5. Setting a timeout > 0 will allow the request to block until the > > > topic metadata is "complete" on the controller node. > > > - Complete means the local topic metadata cache been completely > > > populated and all partitions have leaders > > > - The topic metadata is updated when the controller sends out > > > update metadata requests to the brokers > > > - If a timeout error occurs, the topic could still be created > > > successfully at a later time. Its up to the client to query for > > the state > > > at that point. > > > 6. Setting a timeout <= 0 will validate arguments and trigger the > > > create topics and return immediately. > > > - This is essentially the fully asynchronous mode we have in the > > > Zookeeper tools today. > > > - The error code in the response will either contain an argument > > > validation exception or a timeout exception. If you receive a > > timeout > > > exception, because you asked for 0 timeout, you can assume the > > message was > > > valid and the topic creation was triggered. > > > 7. The request is not transactional. > > > 1. If an error occurs on one topic, the others could still be > > > created. > > > 2. Errors are reported independently. > > > > > > QA: > > > > > > - Why is CreateTopicsRequest a batch request? > > > - Scenarios where tools or admins want to create many topics > should > > > be able to with fewer requests > > > - Example: MirrorMaker may want to create the topics downstream > > > - What happens if some topics error immediately? Will it > > > return immediately? > > > - The request will block until all topics have either been > created, > > > errors, or the timeout has been hit > > > - There is no "short circuiting" where 1 error stops the other > > > topics from being created > > > - Why implement "partial blocking" instead of fully async or fully > > > consistent? > > > - See Cluster Consistent Blocking > > > < > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-4+-+Command+line+and+centralized+administrative+operations#KIP-4-Commandlineandcentralizedadministrativeoperations-cluster-consistent-blocking > > > > > > below > > > - Why require the request to go to the controller? > > > - The controller is responsible for the cluster metadata and its > > > propagation > > > - See Request Forwarding > > > < > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-4+-+Command+line+and+centralized+administrative+operations#KIP-4-Commandlineandcentralizedadministrativeoperations-request > > > > > > below > > > > > > Create Topics Response > > > > > > > > > > > > CreateTopics Response (Version: 0) => [topic_error_codes] > > > topic_error_codes => topic error_code > > > topic => STRING > > > error_code => INT16 > > > > > > CreateTopicsResponse contains a map between topic and topic creation > > > result error code (see New Protocol Errors > > > < > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-4+-+Command+line+and+centralized+administrative+operations#KIP-4-Commandlineandcentralizedadministrativeoperations-NewProtocolErrors > > > > > > ). > > > > > > > The KIP is available here for reference (linked to the Create Topics > schema > > section): > > * > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-4+-+Command+line+and+centralized+administrative+operations#KIP-4-Commandlineandcentralizedadministrativeoperations-CreateTopicsRequest(KAFKA-2945) > > < > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-4+-+Command+line+and+centralized+administrative+operations#KIP-4-Commandlineandcentralizedadministrativeoperations-CreateTopicsRequest(KAFKA-2945) > > >* > > > > A pull request is available implementing the proposed changes here: > > https://github.com/apache/kafka/pull/1489 > > > > Here is a link to the past discussion on the mailing list: > > * > > > http://search-hadoop.com/m/uyzND1rfG6v1oixmZ&subj=+DISCUSS+KIP+4+Create+Topic+Schema > > < > > > http://search-hadoop.com/m/uyzND1rfG6v1oixmZ&subj=+DISCUSS+KIP+4+Create+Topic+Schema > > >* > > > > Thank you, > > Grant > > -- > > Grant Henke > > Software Engineer | Cloudera > > gr...@cloudera.com | twitter.com/gchenke | linkedin.com/in/granthenke > > > -- -- Guozhang
