Thanks Jonathan, I didn't spot that JIRA. Phil
-----Original Message----- From: Jonathan Bond [mailto:jb...@netflix.com.INVALID] Sent: 12 April 2016 14:08 To: users@kafka.apache.org Subject: Re: KafkaProducer 0.9.0.1 continually sends metadata requests Phil, In our case this bug placed significant load on our brokers. We raised a bug https://issues.apache.org/jira/browse/KAFKA-3358 to get this resolved. On Tue, Apr 12, 2016 at 5:39 AM Phil Luckhurst <phil.luckhu...@encycle.com> wrote: > With debug logging turned on we've sometimes seen our logs filling up > with the kafka producer sending metadata requests every 100ms e.g. > > 2016-04-08 10:39:33,592 DEBUG [kafka-producer-network-thread | > phil-pa-1] > org.apache.kafka.clients.NetworkClient: Sending metadata request > ClientRequest(expectResponse=true, callback=null, > request=RequestSend(header={api_key=3,api_version=0,correlation_id=249 > ,client_id=phil-pa-1}, body={topics=[phil-pa-1-device-update]}), > isInitiatedByNetworkClient, createdTimeMs=1460108373592, sendTimeMs=0) > to node 0 > 2016-04-08 10:39:33,592 DEBUG [kafka-producer-network-thread | > phil-pa-1] > org.apache.kafka.clients.Metadata: Updated cluster metadata version > 248 to Cluster(nodes = [Node(0, ta-eng-kafka2, 9092)], partitions = > [Partition(topic = phil-pa-1-device-update, partition = 0, leader = 0, > replicas = [0,], isr = [0,]]) > 2016-04-08 10:39:33,698 DEBUG [kafka-producer-network-thread | > phil-pa-1] > org.apache.kafka.clients.NetworkClient: Sending metadata request > ClientRequest(expectResponse=true, callback=null, > request=RequestSend(header={api_key=3,api_version=0,correlation_id=250 > ,client_id=phil-pa-1}, body={topics=[phil-pa-1-device-update]}), > isInitiatedByNetworkClient, createdTimeMs=1460108373698, sendTimeMs=0) > to node 0 > 2016-04-08 10:39:33,698 DEBUG [kafka-producer-network-thread | > phil-pa-1] > org.apache.kafka.clients.Metadata: Updated cluster metadata version > 249 to Cluster(nodes = [Node(0, ta-eng-kafka2, 9092)], partitions = > [Partition(topic = phil-pa-1-device-update, partition = 0, leader = 0, > replicas = [0,], isr = [0,]]) > > These metadata requests continue to be sent every 100ms > (retry.backoff.ms) until we stop the process. > > This only seems to happen if the KafkaProducer instance is created but > not used to publish a message for 5 minutes. After 5 minutes ( > metadata.max.age.ms) the producer thread sends a metadata request to > the server that has an empty topics list and the server responds with > the partition information for *all* topics hosted on the server. > > 2016-04-11 14:16:39,320 DEBUG [kafka-producer-network-thread | > phil-pa-1] > org.apache.kafka.clients.NetworkClient: Sending metadata request > ClientRequest(expectResponse=true, callback=null, > request=RequestSend(header={api_key=3,api_version=0,correlation_id=0,c > lient_id=phil-pa-1}, body={topics=[]}), isInitiatedByNetworkClient, > createdTimeMs=1460380599289, > sendTimeMs=0) to node -1 > > If we then use that KafkaProducer instance to send a message the next > 'Sending meta request' will just be for the topic we have sent the > message to and this then triggers the flood of retry requests as noted above. > > If we ensure we send the first message within the time set by > metadata.max.age.ms (default 5 minutes) then everything works as > expected and the metadata requests do not continually get retried. > > In many cases I can understand that creating a KafkaProducer and then > not using it within 5 minutes is not usual but in our case we're > creating it when our REST based application starts up and we can't > guarantee that a message will be published within that time. To get > around this we are currently posting a test message to the topic right > after creating the KafkaProducer prevents it happening. > > I'm not sure if this is worthy of a fix but I thought I'd post it here > in case someone else hits the same problem. > > Regards, > Phil Luckhurst >
