Hi, I'm running Kafka's new consumer with message handlers that can sometimes take a lot of time to return, and combining that with manual offset management (to get at-least-once semantics). Since poll() is the only way to heartbeat with the consumer, I have a thread that runs every 500 milliseconds that does the following:
1) Pause all partitions 2) Call poll(0) 3) Resume all partitions This generally works, but I'm occasionally seeing messages like this: java.lang.OutOfMemoryError: Direct buffer memory at java.nio.Bits.reserveMemory(Bits.java:658) at java.nio.DirectByteBuffer.<init>(DirectByteBuffer.java:123) at java.nio.ByteBuffer.allocateDirect(ByteBuffer.java:306) at sun.nio.ch.Util.getTemporaryDirectBuffer(Util.java:174) at sun.nio.ch.IOUtil.read(IOUtil.java:195) at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:379) at org.apache.kafka.common.network.PlaintextTransportLayer.read(PlaintextTransportLayer.java:108) at org.apache.kafka.common.network.NetworkReceive.readFromReadableChannel(NetworkReceive.java:97) at org.apache.kafka.common.network.NetworkReceive.readFrom(NetworkReceive.java:71) at org.apache.kafka.common.network.KafkaChannel.receive(KafkaChannel.java:153) at org.apache.kafka.common.network.KafkaChannel.read(KafkaChannel.java:134) at org.apache.kafka.common.network.Selector.poll(Selector.java:286) at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:256) at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.clientPoll(ConsumerNetworkClient.java:320) at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:213) at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:193) at org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:908) at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:853) Given this trace, I have the following questions: 1) Is there data loss when this happens? 2) How can I stop triggering this error? Thanks, Kanak
