My problem is that Storm KafkaSpout stopped to consume messages from Kafka topic after a period of time. When debug is enabled in storm, I get the log file like this:
2016-07-05 03:58:26.097 o.a.s.d.task [INFO] Emitting: packet_spout __metrics [#object[org.apache.storm.metric.api.IMetricsConsumer$TaskInfo 0x2c35b34f "org.apache.storm.metric.api.IMetricsConsumer$TaskInfo@2c35b34f"] [#object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x798f1e35 "[__ack-count = {default=0}]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x230867ec "[__sendqueue = {sojourn_time_ms=0.0, write_pos=5411461, read_pos=5411461, overflow=0, arrival_rate_secs=0.0, capacity=1024, population=0}]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x7cdec8eb "[__complete-latency = {default=0.0}]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x658fc59 "[__skipped-max-spout = 0]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x3c1f3a50 "[__receive = {sojourn_time_ms=4790.5, write_pos=2468305, read_pos=2468304, overflow=0, arrival_rate_secs=0.20874647740319383, capacity=1024, population=1}]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x262d7906 "[__skipped-inactive = 0]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x73648c7e "[kafkaPartition = {Partition{host=slave103:9092, topic=packet, partition=12}/fetchAPICallCount=0, Partition{host=slave103:9092, topic=packet, partition=12}/fetchAPILatencyMax=null, Partition{host=slave103:9092, topic=packet, partition=12}/lostMessageCount=0, Partition{host=slave103:9092, topic=packet, partition=12}/fetchAPILatencyMean=null, Partition{host=slave103:9092, topic=packet, partition=12}/fetchAPIMessageCount=0}]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x4e43df61 "[kafkaOffset = {packet/totalLatestCompletedOffset=154305947, packet/partition_12/spoutLag=82472754, packet/totalEarliestTimeOffset=233919465, packet/partition_12/earliestTimeOffset=233919465, packet/partition_12/latestEmittedOffset=154307691, packet/partition_12/latestTimeOffset=236778701, packet/totalLatestEmittedOffset=154307691, packet/partition_12/latestCompletedOffset=154305947, packet/totalLatestTimeOffset=236778701, packet/totalSpoutLag=82472754}]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x49fe816b "[__transfer-count = {__ack_init=0, default=0, __metrics=0}]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x63e2bdc0 "[__fail-count = {}]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x3b17bb7b "[__skipped-throttle = 1086120]"] #object[org.apache.storm.metric.api.IMetricsConsumer$DataPoint 0x1315a68c "[__emit-count = {__ack_init=0, default=0, __metrics=0}]"]]]
2016-07-05 03:58:55.042 o.a.s.d.executor [INFO] Processing received message FOR -2 TUPLE: source: __system:-1, stream: __tick, id: {}, [30]
2016-07-05 03:59:25.042 o.a.s.d.executor [INFO] Processing received message FOR -2 TUPLE: source: __system:-1, stream: __tick, id: {}, [30]
2016-07-05 03:59:25.946 o.a.s.d.executor [INFO] Processing received message FOR -2 TUPLE: source: __system:-1, stream: __metrics_tick, id: {}, [60]
My test topology is really simple, One KafkaSpout and another Counter Bolt. When the topology works fine, the value between FOR and TUPLE is a positive number; when the topology stops to consume the message, the value becomes negative. so I'm curious about what causes the problem of Processing received message FOR -2 TUPLE, and how to fix this problem?
By the way, my experiment environment is:
OS: Red Hat Enterprise Linux Server release 7.0 (Maipo)
Kafka: 0.10.0.0
Storm: 1.0.1