Kafka expectantly shutting down. License topic could not be created - apache-kafka

On Kafka startup multiple messages are logged to kafka/logs/kafkaServer.out and contain:
INFO [Admin Manager on Broker 0]: Error processing create topic
request CreatableTopic(name='_confluent-license', numPartitions=1,
replicationFactor=3, assignments=[],
configs=[CreateableTopicConfig(name='cleanup.policy',
value='compact'), CreateableTopicConfig(name='min.insync.replicas',
value='2')]) (kafka.server.AdminManager)
After approx 15 minutes Kafka shuts down and outputted to
kafka/logs/kafkaServer.out is :
org.apache.kafka.common.errors.InvalidReplicationFactorException: Replication factor: 3 larger than available brokers: 1.
[2020-12-08 04:04:15,951] ERROR [KafkaServer id=0] Fatal error during KafkaServer startup. Prepare to shutdown
(kafka.server.KafkaServer)
org.apache.kafka.common.errors.TimeoutException: License topic could not be created
Caused by: org.apache.kafka.common.errors.InvalidReplicationFactorException:
Replication factor: 3 larger than available brokers: 1.
[2020-12-08 04:04:15,952] INFO [KafkaServer id=0] shutting down (kafka.server.KafkaServer)
It appears Kafka shuts down because the replication factor is set to 3 for the topic _confluent-license ? I'm not creating the topic _confluent-license, is this created as part of Kafka startup for licensing check ?
In attempt to fix I've modified /v5.5.0/etc/kafka/server.properties so that replication factor is 1 for internal topics:
############################# Internal Topic Settings #############################
# The replication factor for the group metadata internal topics "__consumer_offsets" and "__transaction_state"
# For anything other than development testing, a value greater than 1 is recommended for to ensure availability such as 3.
offsets.topic.replication.factor=1
transaction.state.log.replication.factor=1
instead of 3 :
#offsets.topic.replication.factor=3
#transaction.state.log.replication.factor=3
But this does not fix the issue and same logs are generated. The replication factor of __consumer_offsets is still 3. How to reduce the replication factor of topic _confluent-license from 3 to 1 ? Or could there be an alternative issue that is causing Kafka to shutdown ?

You should change the property confluent.license.topic.replication.factor by default it is 3.

(kafka.server.KafkaServer)
org.apache.kafka.common.errors.TimeoutException: License topic could
not be created Caused by:
org.apache.kafka.common.errors.InvalidReplicationFactorException:
Replication factor: 3 larger than available brokers: 1. [2020-12-08
04:04:15,952] INFO [KafkaServer id=0] shutting down
(kafka.server.KafkaServer)
The above error is due to the license topic having a default replication factor as 3. The same can be configured with confluent.license.topic.replication.factor to be equal to 1 if you have only 1 broker. The documentation for the same is here.
[2020-12-08 07:46:02,241] ERROR Error checking or creating metrics topic (io.confluent.metrics.reporter.ConfluentMetricsReporter)
org.apache.kafka.common.errors.InvalidReplicationFactorException: Replication factor: 2 larger than available brokers: 1.
The above error is due to the Confluent Metrics Reporter being enabled. The replication factor for the metric topic is defaulted at 3 and can be configured with confluent.metrics.reporter.topic.replicas to be 1 if you have just one broker. The documentation for the same is here.

The property confluent.license.topic.replication.factor is not working as expected.
Instead, we can try anyone of these properties confluent.license.replication.factor=1 or confluent.license.admin.replication.factor=1 if the number of broker is 1. This property is not in the documentation.

Related

Kafka: Partitions reassignment not happening

I am getting an error while migrating data between Kafka brokers.
I am using kafka-reassignment tool to reassign partitions to a different broker without any throttling(because it didn't worked with the below command.). There were around 400 partitions of 50 topics.
Apache Kafka 1.1.0
Confluent Docker Image tag : 4.1.0
Command:
kafka-reassign-partitions --zookeeper IP:2181 --reassignment-json-file proposed.json --execute —throttle 100000000
After some time, I am able to see the below error continuously on the target broker.
[2019-09-21 11:24:07,625] INFO [ReplicaFetcher replicaId=4, leaderId=0, fetcherId=0] Error sending fetch request (sessionId=514675011, epoch=INITIAL) to node 0: java.io.IOException: Connection to 0 was disconnected before the response was read. (org.apache.kafka.clients.FetchSessionHandler)
[2019-09-21 11:24:07,626] WARN [ReplicaFetcher replicaId=4, leaderId=0, fetcherId=0] Error in response for fetch request (type=FetchRequest, replicaId=4, maxWait=500, minBytes=1, maxBytes=10485760, fetchData={TOPIC-4=(offset=4624271, logStartOffset=4624271, maxBytes=104
8576), TOPIC-2=(offset=1704819, logStartOffset=1704819, maxBytes=1048576), TOPIC-8=(offset=990485, logStartOffset=990485, maxBytes=1048576), TOPIC-1=(offset=1696764, logStartOffset=1696764, maxBytes=1048576), TOPIC-7=(offset=991507, logStartOffset=991507, maxBytes=10485
76), TOPIC-5=(offset=988660, logStartOffset=988660, maxBytes=1048576)}, isolationLevel=READ_UNCOMMITTED, toForget=, metadata=(sessionId=514675011, epoch=INITIAL)) (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 0 was disconnected before the response was read
at org.apache.kafka.clients.NetworkClientUtils.sendAndReceive(NetworkClientUtils.java:97)
at kafka.server.ReplicaFetcherBlockingSend.sendRequest(ReplicaFetcherBlockingSend.scala:96)
at kafka.server.ReplicaFetcherThread.fetch(ReplicaFetcherThread.scala:220)
at kafka.server.ReplicaFetcherThread.fetch(ReplicaFetcherThread.scala:43)
at kafka.server.AbstractFetcherThread.processFetchRequest(AbstractFetcherThread.scala:146)
at kafka.server.AbstractFetcherThread.doWork(AbstractFetcherThread.scala:111)
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:82)
Zookeeper status:
ls /admin/reassign_partitions
[]
I am using t2.medium type EC2 instances and gp2 type EBS volumes with 120GB size.
I am able to connect to the zookeeper from all brokers.
[zk: localhost:2181(CONNECTED) 3] ls /brokers/ids [0, 1, 2, 3]
I am using IP address for all brokers, so DNS mismatch is also not the case.
Also, I am not able to see any topic scheduled for reassignment in zookeeper.
[zk: localhost:2181(CONNECTED) 2] ls /admin/reassign_partitions
[]
Interestingly, I can see data is pilling up for the partitions which are not listed above. But the partitions listed in the error are not getting migrated as of now.
I am using confluent kafka docker image.
Kafka Broker Setting:
https://gist.github.com/ethicalmohit/cd44f580356ca02250760a307d90b54d
If you can give us some more details on your topology maybe we can understand better the problem.
Some thoughts:
- Can you connect via zookeeper-cli at kafka-0:2181 ? kafka-0 resolves to the correct host ?
- If reassignment is in progress either you have to manual stop this by deleting the appropriate key in zookeeper (warning, this may make some topic or partition broken) either you have to wait for this job to finish. Can you monitor the ongoing reassignment and give some info about that ?
This has been solved by increasing the value of replica.socket.receive.buffer.bytes in all destination brokers.
After changing the above parameter and restarting broker. I was able to see the data in above-mentioned partitions.

Kafka broker are keep on restarting?

I have 4 kafka brokers and 3 zookeepers deployed upon kubernetes. Out of 4 only 2 kafka brokers are working and rest 2 keep shutting down and restart with below error:
Exiting because log truncation is not allowed for partition byfn-sys-channel-0, current leader's latest offset 2 is less than replica's latest offset 21 (kafka.server.ReplicaFetcherThread)
Below is the config of kafka
KAFKA_ZOOKEEPER_CONNECT zookeeper0:2181,zookeeper1:2181,zookeeper2:2181
KAFKA_UNCLEAN_LEADER_ELECTION_ENABLE false
KAFKA_REPLICA_FETCH_MAX_BYTES 103809024
KAFKA_MIN_INSYNC_REPLICAS 1
KAFKA_MESSAGE_MAX_BYTES 103809024
KAFKA_LOG_RETENTION_MS -1
KAFKA_LOG_DIRS /var/kafkas/kafka2
KAFKA_DEFAULT_REPLICATION_FACTOR 3
KAFKA_BROKER_ID 2
KAFKA_ADVERTISED_LISTENERS PLAINTEXT://kafka2:9092
Please let me know how can i fix this ?
Kafka halting because log truncation is not allowed for topic error shuttng down kafka nodes
Above link shows if log truncation is not allowed for a topic

Kafka mirror maker duplicates when DCs are isolated

We have 5 kafka 1.0.0 clusters:
4 of them are made of 3 nodes and are in different regions in the world
the last one is made of 5 nodes and is an aggregate only cluster.
We are using MirrorMaker (later referenced as MM) to read from the regional clusters and copy the data in the aggregate cluster in our HQ datacenter.
And not sure about where to run it we have currently 2 cases in our prod environment:
MM in the region: reading locally and pushing to aggregate cluster in remote data-center (DC), before committing offsets locally. I tend to call this the push mode (pushing the data)
MM in the DC of the aggregate cluster: reading remotely the data, writing it locally before committing the offsets on remote DC.
What happened is that we got the entire DC where we have our aggregate server totally isolated from a network point of view. And in both cases, we got duplicated records in our aggregate cluster.
Push mode = MM local to the regional cluster, pushing data to remote aggregate cluster
MM started to throw errors like this:
WARN [Producer clientId=producer-1] Got error produce response with correlation id 674364 on topic-partition <topic>-4, retrying (2147483646 attempts left). Error: NETWORK_EXCEPTION (org.apache.kafka.clients.producer.internals.Sender)
then:
WARN [Producer clientId=producer-1] Connection to node 1 could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
which is ok so far because of idempotence.
But finally we got errors like:
ERROR Error when sending message to topic debug_sip_callback-delivery with key: null, value: 1640 bytes with error: (org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
org.apache.kafka.common.errors.TimeoutException: Expiring 1 record(s) for <topic>-4: 30032 ms has passed since batch creation plus linger time
ERROR Error when sending message to topic <topic> with key: null, value: 1242 bytes with error: (org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
java.lang.IllegalStateException: Producer is closed forcefully.
causing MM to stop and I think this is the problem causing duplicates (I need to dig the code, but could be that it lost information about idempotence and on restart it resumed from previously committed offsets).
Pull mode = MM local to the aggregate cluster, pulling data from remote regional cluster
MM instances (with logs at INFO level in this case) started seeing the broker as dead:
INFO [Consumer clientId=mirror-maker-region1-agg-0, groupId=mirror-maker-region1-agg] Marking the coordinator kafka1.region1.internal:9092 (id: 2147483646 rack: null) dead (org.apache.kafka.clients.consumer.internals.AbstractCoordinator)
At the same time on the broker side, we got:
INFO [GroupCoordinator 1]: Member mirror-maker-region1-agg-0-de2af312-befb-4af7-b7b0-908ca8ecb0ed in group mirror-maker-region1-agg has failed, removing it from the group (kafka.coordinator.group.GroupCoordinator)
...
INFO [GroupCoordinator 1]: Group mirror-maker-region1-agg with generation 42 is now empty (__consumer_offsets-2) (kafka.coordinator.group.GroupCoordinator)
Later on MM side, a lot of:
WARN [Consumer clientId=mirror-maker-region1-agg-0, groupId=mirror-maker-region1-agg] Connection to node 2 could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
and finally when network came back:
ERROR [Consumer clientId=mirror-maker-region1-agg-0, groupId=mirror-maker-region1-agg] Offset commit failed on partition <topic>-dr-8 at offset 382424879: The coordinator is not aware of this member. (org.apache.kafka.clients.consumer.internals.ConsumerCoordinator)
i.e., it could not commit in region1 the offsets written on agg because of the rebalancing. And it resumed after rebalance from previously successfully committed offset causing duplicates.
Configuration
Our MM instances are configured like this:
For our consumer:
bootstrap.servers=kafka1.region1.intenal:9092,kafka2.region1.internal:9092,kafka3.region1.internal:9092
group.id=mirror-maker-region-agg
auto.offset.reset=earliest
isolation.level=read_committed
For our producer:
bootstrap.servers=kafka1.agg.internal:9092,kafka2.agg.internal:9092,kafka3.agg.internal:9092,kafka4.agg.internal:9092,kafka5.agg.internal:9092
compression.type=none
request.timeout.ms=30000
max.block.ms=60000
linger.ms=15000
max.request.size=1048576
batch.size=32768
buffer.memory=134217728
retries=2147483647
max.in.flight.requests.per.connection=1
acks=all
enable.idempotence=true
Any idea how we can get the "only once" delivery on top of exactly once in case of 30 min isolated DCs?

When does kafka change leader?

I was running my services that work with kafka already for a year and no spontaneous changes of leader happens.
But for the last 2 weeks that started happens quite often.
Kafka log on that:
[2015-09-27 15:35:14,826] INFO [ReplicaFetcherManager on broker 2]
Removed fetcher for partitions [myTopic] (kafka.server.ReplicaFetcherManager)
[2015-09-27 15:35:14,830] INFO Truncating log myTopic-0 to offset 11520979. (kafka.log.Log)
[2015-09-27 15:35:14,845] WARN [Replica Manager on Broker 2]: Fetch request with correlation id 713276 from client ReplicaFetcherThread-0-2 on partition [myTopic,0] failed due to Leader not local for partition [myTopic,0] on broker 2 (kafka.server.ReplicaManager)
[2015-09-27 15:35:14,857] WARN [Replica Manager on Broker 2]: Fetch request with correlation id 256685 from client mirrormaker-1 on partition [myTopic,0] failed due to Leader not local for partition [myTopic,0] on broker 2 (kafka.server.ReplicaManager)
[2015-09-27 15:35:20,171] INFO [ReplicaFetcherManager on broker 2] Removed fetcher for partitions [myTopic,0] (kafka.server.ReplicaFetcherManager)
What can cause switching leader? If there is info in some kafka documentation - please - just point the link. I've failed to find.
System configuration
kafka version: kafka_2.10-0.8.2.1
os: Red Hat Enterprise Linux Server release 6.5 (Santiago)
server.properties (differs from default):
broker.id=001
socket.send.buffer.bytes=1048576
socket.receive.buffer.bytes=1048576
socket.request.max.bytes=104857600
log.flush.interval.messages=10000
log.flush.interval.ms=1000
log.retention.bytes=-1
controlled.shutdown.enable=true
auto.create.topics.enable=false
It appears like lead broker is down for that partition. It might be that data directroy(log.dirs) configured in server.properties is out of space and broker is not able to accommodate.
Also, what is replication factor of topic and cluster size of brokers?
I am assuming you have one topic and one partition with a replication factor of 2. Which is not a good configuration for optimal Kafka performance and consumers.
Your Logs are not clear enough for leader switch. Major issue in your topic may be having the only one leader due to the only partition. Now the single file in your logs is getting bigger in size day by day. Kafka internally does rebalancing at some level(details are not confirmed). That can be the reason for your leader switch. But i am not sure.
Also in your 2nd log line its says some of the logs are truncated. Can you please go though the logs in details and check is this happening only after truncation?
As you already mentioned you already checked your Kafka log directory files and their size. Please run the describe when you got this issue. The leader switch will reflect here as well. Or if you can setup some dashboard that will display the leader for past time. Then it will be easy for you to find the root cause.
bin/kafka-topics.sh --describe --zookeeper Zookeeperhost:Port --topic TopicName
Suggestion: i will suggest you to create a new topic with more partitions(read Kafka documentation to get a good idea about optimum number of partitions) and start writing to it. Or you can check, how to change partitions for current topic.
Last Thing: Is leader switch causing some issues in your Clients or you are worried only about warnings?

Why isn't kafka continuing to work on fail of one of the brokers?

I am under the impression that with two brokers with sync turned on my kafka setup should keep on working even on fail of one of the broker.
To test it I made a new topic named topicname. Its description is as follows:
Topic:topicname PartitionCount:1 ReplicationFactor:1 Configs:
Topic: topicname Partition: 0 Leader: 0 Replicas: 0 Isr: 0
Then I ran producer.sh and consumer.sh in the following way:
bin/kafka-console-producer.sh --broker-list localhost:9092,localhost:9095 sync --topic topicname
bin/kafka-console-consumer.sh --zookeeper localhost:2181 --topic topicname --from-beginning
Till both the brokers were working I saw that messages were being received properly by the consumer, but when I killed one of the instance of the brokers through kill command then the consumer stopped showing me any new messages. Instead it showed me the following error message:
WARN [ConsumerFetcherThread-console-consumer-57116_ip-<internalipvalue>-1438604886831-603de65b-0-0], Error in fetch Name: FetchRequest; Version: 0; CorrelationId: 865; ClientId: console-consumer-57116; ReplicaId: -1; MaxWait: 100 ms; MinBytes: 1 bytes; RequestInfo: [topicname,0] -> PartitionFetchInfo(9,1048576). Possible cause: java.nio.channels.ClosedChannelException (kafka.consumer.ConsumerFetcherThread)
[2015-08-03 12:29:36,341] WARN Fetching topic metadata with correlation id 1 for topics [Set(topicname)] from broker [id:0,host:<hostname>,port:9092] failed (kafka.client.ClientUtils$)
java.nio.channels.ClosedChannelException
at kafka.network.BlockingChannel.send(BlockingChannel.scala:100)
at kafka.producer.SyncProducer.liftedTree1$1(SyncProducer.scala:73)
at kafka.producer.SyncProducer.kafka$producer$SyncProducer$$doSend(SyncProducer.scala:72)
at kafka.producer.SyncProducer.send(SyncProducer.scala:113)
at kafka.client.ClientUtils$.fetchTopicMetadata(ClientUtils.scala:58)
at kafka.client.ClientUtils$.fetchTopicMetadata(ClientUtils.scala:93)
at kafka.consumer.ConsumerFetcherManager$LeaderFinderThread.doWork(ConsumerFetcherManager.scala:66)
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:60)
I had this similar problem, setting the producer config "topic.metadata.refresh.interval.ms" to -1 (or whatever value is suitable for you) solved the issue for me.
So in my case , I had 3 broker (multi broker set up on my local machine) and created the topic with 3 partitions and replication factor 2.
Test set up:
Before the producer config:
Tried 3 brokers running , killed one of the brokers after producer started, the local Zookeeper updated the ISR and topic metadata info (removed down broker as leader) but the producer did not pick it up (may be due to default 10 mins refresh time).So messages end up failing. I get send exceptions.
After the producer config (-1 in my case):
Tried 3 brokers running , killed one of the brokers after producer started, the local Zookeeper updated the ISR info (removed down broker as leader), the producer refreshed the new ISR/topic metadata info and messages send did not fail.
-1 makes it refresh topic metadata on each failed attempt so may be you want to reduce the refresh time to something reasonable instead.
I think there are two things can make your consumer not work after a broker down for kafka HA cluster:
--replication-factor should bigger than 1 for your topic. so every topic partition can have at least one backup.
replication factor for internal topics for kafka configuration should also bigger than 1:
offsets.topic.replication.factor = 3
transaction.state.log.replication.factor = 3
transaction.state.log.min.isr = 2
This two modification make my producer and consumer still work after broker shutdown (5 broker and every broker goes down once) .
You can see in the topic description that you posted that your topic has only a single replica.
With a single replica there is no fault tolerance and if broker 0 (the broker that contains the replica) goes away, the topic will be unavailable.
Create a topic with more replicas (with --replication-factor 3) to have fault tolerance in case of crashes.
I had run into into the same problem even when using a topic with replication factor of 2.
Setting the following property on the producer worked for me.
"metadata.max.age.ms". (Kafka-0.8.2.1)
Else, my Producer was waiting for 1 minute by default to fetch the new leader and start contacting it
For a topic with replication factor N, Kafka tolerate up to N-1 server failures. E.g. having a replication factor 3 will allow you to handle upto 2 server failure.