I am trying to install a kafka & zookeeper instance on a remote server. I only need 1 node of each actually because i only want to provide remote kafka for test purposes.
Kafka and Zookeeper are running from the Apache Kafka tarball you can find there (v0.0.9), inside a Docker image.
Trying to consume / produce using the provided scripts. And trying to produce using own java application. Everythinf is working fine if Kafka & ZK are installed on the local server.
Here is the error I get while trying to produce :
BrokerPartitionInfo:83 - Error while fetching metadata [{TopicMetadata for topic RSS ->
No partition metadata for topic RSS due to kafka.common.LeaderNotAvailableException}] for topic [RSS]: class kafka.common.LeaderNotAvailableException
Kafka properties tested
First :
borker.id=0
port=9092
host.name=<external-ip>
zookeeper.connect=localhost:<PORT>
Second:
borker.id=0
port=9092
host.name=<external-ip>
zookeeper.connect=<external-ip>:<PORT>
Third:
borker.id=0
port=9092
host.name=<external-ip>
zookeeper.connect=<external-ip>:<PORT>
advertised.host.name=<external-ip>
advertised.host.port=<external-ip>
Last:
borker.id=0
port=9092
host.name=</etc/host name>
zookeeper.connect=<external-ip>:<PORT>
advertised.host.name=<external-ip>
advertised.host.port=<external-ip>
Here is my "/etc/hosts"
127.0.0.1 kafka kafka
127.0.0.1 localhost
I followed the Getting Started, which if I understood is a localhost / signle server configurations. I cannot understand what I have to do to get this work with remote calls...
Thanks for your help !
EDIT 1
host.name=localhost
advertised.host.name=politik.cm-cloud.fr
Seems to allow a local consumer (on the server) and producer. But if we want to do the same from a remote server we get
[2015-12-09 12:44:10,826] WARN Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.net.NoRouteToHostException: No route to host
The error does not look like connectivity problem with Zookeeper / Kafka.
Just follow the instruction in "quickstart" from http://kafka.apache.org/
BrokerPartitionInfo:83 - Error while fetching metadata [{TopicMetadata for topic RSS ->
Additionally the error indicates there is no partition info i.e topic not yet created . Try creating topics first and then try to produce/consume because when producing to a non existent topic kafka will create the topic based on auto.create.topics.enable in server.properties but remotely it is better to create topics rathen than relying on auto create
Related
I recently started using Apache Kafka and was successful sending data from producer to consumer within Windows 10 and my Linux Mint 19.3 (VM) environments. Now I want to stream data from my VM to my Windows 10 environment.
Both environments are able to ping each other.
When I try to run my consumer on Windows 10, I get an "Error connecting to node VM-VirtualBox:9092'" followed by a "java.net.UnknownHostException: VM-VirtualBox". Strangely, Windows 10 is able to SEE the topics listed on the VM environment; and I am able to create and delete topics from Windows. But I just cannot connect.
Could someone point out what I'm doing wrong?
My server.properties include lines:
broker.id=0
Kafka Broker Advanced Configuration
Snippet (Safety Valve)
############################# Socket Server Settings #############################
# The address the socket server listens on. It will get the value returned from
# java.net.InetAddress.getCanonicalHostName() if not configured.
# FORMAT:
# listeners = listener_name://host_name:port
# EXAMPLE:
# listeners = PLAINTEXT://your.host.name:9092
#port=9092
#advertised.host.name=localhost
listeners=PLAINTEXT://0.0.0.0:9092
advertised.listeners = PLAINTEXT://VM-VirtualBox:9092
#advertised.listeners = PLAINTEXT://Windows10-7950:9092
domain:9092
I've also posted this on Reddit: https://www.reddit.com/r/apachekafka/comments/emqbms/virtualbox_streaming_data_from_vm_to_host_pc/
If Kafka is running on the host, you need to advertise the hosts hostname, or some address that the VM can resolve (it can be an IP address, too)
listeners=PLAINTEXT://0.0.0.0:9092
advertised.listeners = PLAINTEXT://EXTERNAL-HOST:9092
Otherwise, you need to edit the hosts file in the OS such that the DNS name is recognized
The reason you can list and create topics is because you're probably using Zookeeper, not the bootstrap address
I am trying to containerize a java server application which uses kafka. I observed this behavior,
Case 1 : Running as a single container uses bridge network
In this case it works well. So no problem.
Case 2 : Running as a single service uses overlay network (Swarm mode)
In this case, I got org.apache.kafka.common.errors.TimeoutException because of this unsuccessful connection,
WARN [2019-12-06T14:05:44,668] RequestSendThread: warn(): [Controller-0-to-broker-0-send-thread]: Controller 0's connection to broker 10.255.3.64:10101 (id: 0 rack: null) was unsuccessful
java.net.SocketTimeoutException: Failed to connect within 30000 ms
at kafka.controller.RequestSendThread.brokerReady(ControllerChannelManager.scala:270) [kafka_2.12-1.0.0.jar:?]
at kafka.controller.RequestSendThread.doWork(ControllerChannelManager.scala:223) [kafka_2.12-1.0.0.jar:?]
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:64) [kafka_2.12-1.0.0.jar:?]
I don't know much about kafka and can't understand How overlay network affects the kafka process while it works well in bridge network ?
Edit 1:
Almost found the problem... In docker swarm mode, container have two ip address because of the two interfaces bridge and overlay. The ips are endpoint:172.19.0.3, 10.255.3.65.
While trying to connect to the container (inside from the same container),
Bridge I/F : 172.19.0.3 : 10101 - can connect. means telent 172.19.0.3 10101 works.
Overlay I/F :10.155.3.65 : 10101 - can't connect to the port, but can ping works.
The virtual ip 10.155.3.65 which is used by kafka that makes TimeoutException.
Cannot connect to the localhost port while using overlay ip (but can ping). Why this scenario happens ?
Answer:
My bad. I have used default overlay that made the problem.. https://docs.docker.com/network/overlay/ .
Created an --attachable custom overlay network solved this issue.
docker network create -d overlay --attachable my-attachable-overlay
I was running through the tutorial here: http://kafka.apache.org/documentation.html#introduction
When I get to "Step 7: Use Kafka Connect to import/export data" and attempt to start two connectors I am getting the following errors:
ERROR Failed to flush WorkerSourceTask{id=local-file-source-0}, timed out while waiting for producer to flush outstanding messages, 1 left
ERROR Failed to commit offsets for WorkerSourceTask
Here is the portion of the tutorial:
Next, we'll start two connectors running in standalone mode, which means they run in a single, local, dedicated process. We provide three configuration files as parameters. The first is always the configuration for the Kafka Connect process, containing common configuration such as the Kafka brokers to connect to and the serialization format for data. The remaining configuration files each specify a connector to create. These files include a unique connector name, the connector class to instantiate, and any other configuration required by the connector.
bin/connect-standalone.sh config/connect-standalone.properties config/connect-file-source.properties config/connect-file-sink.properties
I have spent some time looking for a solution, but was unable to find anything useful. Any help is appreciated.
Thanks!
The reason I was getting this error was because the first server I created using the config/server.properties was not running. I am assuming that because it is the lead of the topic, the messages could not be flushed and the offsets could not be committed.
Once I started the kafka server using the server propertes (config/server.properties) This issue was resolved.
You need to start Kafka server and Zookeeper before running Kafka Connect.
You need to exec the cmds in "Step 2: Start the server" below first:
bin/zookeeper-server-start.sh config/zookeeper.properties
bin/kafka-server-start.sh config/server.properties
from here:https://mail-archives.apache.org/mod_mbox/kafka-users/201601.mbox/%3CCAK0BMEpgWmL93wgm2jVCKbUT5rAZiawzOroTFc_A6Q=GaXQgfQ#mail.gmail.com%3E
You need to start zookeeper and kafka server first before running that line.
start zookeeper
bin/zookeeper-server-start.sh config/zookeeper.properties
start multiple kafka servers
bin/kafka-server-start.sh config/server.properties
bin/kafka-server-start.sh config/server-1.properties
bin/kafka-server-start.sh config/server-2.properties
start connectors
bin/connect-standalone.sh config/connect-standalone.properties config/connect-file-source.properties config/connect-file-sink.properties
Then you will see some lines are written into test.sink.txt:
foo
bar
And you can start the consumer to check it:
bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic connect-test --from-beginning
{"schema":{"type":"string","optional":false},"payload":"foo"}
{"schema":{"type":"string","optional":false},"payload":"bar"}
If you configure your Kafka Broker with a hostname such as my.sandbox.com make sure that you modify the config/connect-standalone.properties accordingly:
bootstrap.servers=my.sandbox.com:9092
On Hortonworks HDP the default port is 6667, hence the setting is
bootstrap.servers=my.sandbox.com:6667
If Kerberos is enabled you will need the following settings as well (without SSL):
security.protocol=PLAINTEXTSASL
producer.security.protocol=PLAINTEXTSASL
producer.sasl.kerberos.service.name=kafka
consumer.security.protocol=PLAINTEXTSASL
consumer.sasl.kerberos.service.name=kafka
I'm just getting started with Apache Kafka/Zookeeper and have been running into issues trying to set up a cluster on AWS. Currently I have three servers:
One running Zookeeper and two running Kafka.
I can start the Kafka servers without issue and can create topics on both of them. However, the trouble comes when I try to start a producer on one machine and a consumer on the other:
on the Kafka producer:
kafka-console-producer.sh --broker-list <kafka server 1 aws public dns>:9092,<kafka server 2 aws public dns>:9092 --topic samsa
on the Kafka consumer:
kafka-console-consumer.sh --zookeeper <zookeeper server ip>:2181 --topic samsa
I type in a message on the producer ("hi") and nothing happens for a while. Then I get this message:
ERROR Error when sending message to topic samsa with key: null, value: 2 bytes
with error: Failed to update metadata after 60000 ms.
(org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
On the consumer side I get this message, which repeats periodically:
WARN Fetching topic metadata with correlation id # for topics [Set(samsa)] from broker [BrokerEndPoint(<broker.id>,<producer's advertised.host.name>,9092)] failed (kafka.client.ClientUtils$)
java.nio.channels.ClosedChannelException
at kafka.network.BlockingChannel.send(BlockingChannel.scala:110)
at kafka.producer.SyncProducer.liftedTree1$1(SyncProducer.scala:75)
at kafka.producer.SyncProducer.kafka$producer$SyncProducer$$doSend(SyncProducer.scala:74)
at kafka.producer.SyncProducer.send(SyncProducer.scala:119)
at kafka.client.ClientUtils$.fetchTopicMetadata(ClientUtils.scala:59)
at kafka.client.ClientUtils$.fetchTopicMetadata(ClientUtils.scala:94)
at kafka.consumer.ConsumerFetcherManager$LeaderFinderThread.doWork(ConsumerFetcherManager.scala:66)
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:63)
After a while, the producer will then start rapidly throwing this error message with # increasing incrementally:
WARN Error while fetching metadata with correlation id # : {samsa=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
Not sure where to go from here. Let me know if more details about my configuration files are needed
This was a configuration issue.
In order to get it running several changes to config files had to happen:
In config/server.properties on each Kafka server:
host.name: <Public IP>
advertised.host.name: <AWS Public DNS Address>
In config/producer.properties on each Kafka server:
metadata.broker.list: <Producer Server advertised.host.name>:<Producer Server port>,<Consumer Server advertised.host.name>:<Consumer Server port>
In /etc/hosts on each Kafka server, change 127.0.0.1 localhost localhost.localdomain to:
<Public IP> localhost localhost.localdomain
I'm trying to work with the kafka API in java. I'm using the following maven dependency:
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-clients</artifactId>
<version>0.8.2.0</version>
</dependency>
I'm having trouble connecting to a remote kafka server.
I changed the kafka 'server.properties' file port attribute to be port 8080.
I can start both the zookeeper and the kafka server no problem.
I can also use the console producer and consumer applications that came with the kafka download. (Scala 2.10 version)
I'm using the following client code to create a remote KafkaProducer
Properties propsProducer = new Properties();
propsProducer.put("bootstrap.servers", "172.xx.xx.xxx:8080");
propsProducer.put("key.serializer", org.apache.kafka.common.serialization.ByteArraySerializer.class);
propsProducer.put("value.serializer", org.apache.kafka.common.serialization.ByteArraySerializer.class);
propsProducer.put("topic.metadata.refresh.interval.ms", "0");
KafkaProducer<byte[], byte[]> m_kafkaProducer = new KafkaProducer<byte[], byte[]>(propsProducer);
Once I've created the producer, I can run the following line and get valid topic info returned, granted strTopic is an existing topic name.
List<PartitionInfo> partitionInfo = m_kafkaProducer.partitionsFor(strTopic);
When I try to send a message, I do the following:
ProducerRecord<byte[], byte[]> prMessage = new ProducerRecord<byte[],byte[]>(strTopic, strMessage.getBytes());
RecordMetadata futureData = m_kafkaProducer.send(prMessage).get();
The call to send() blocks indefinitely and when I manually terminate the process, I see that the ERROR Closing socket because of error on kafka server(IOException, Connection Reset by Peer) error.
Also, it's worth nothing that the host.name, advertised.host.name, and advertised.port properties are all still commented out on the 'server.properties' file. Oh, and if I change the line:
propsProducer.put("bootstrap.servers", "172.xx.xx.xxx:8080");
to
propsProducer.put("bootstrap.servers", "127.0.0.1:8080");
and run it on the same server as where the kafka server is installed, it works but I'm trying to work with it remotely.
Appreciate any help and if I can clarify at all let me know.
After lots of digging, I decided to implement the example found here: Kafka Producer Example. I shortened the code and didn't implement a partitioner class. I updated my pom with the dependency listed and I was still having the same issue. Ultimately, I made some configuration changes and everything worked.
The final piece of the puzzle was defining the Kafka server in /etc/hosts of both the server and the client machines. I added the following to both files.
172.xx.xx.xxx serverHost1
Again, the x's are just masks. Then, I set the advertised.host.name in the server.properties file to serverHost1. NOTE: I got that IP after running an ifconfig on the server machine.
I changed the line
propsProducer.put("metadata.broker.list", "172.xx.xx.xxx:8080");
to
propsProducer.put("metadata.broker.list", "serverHost1:8080");
The Kafka API didn't like the fact that I was defining an IP as a string. Instead it was looking up the IP from within the etc/hosts file although the documentation says:
"Hostname the broker will advertise to producers and consumers. If not set, it uses the value for "host.name" if configured. Otherwise, it will use the value returned from java.net.InetAddress.getCanonicalHostName()."
Which will just return the IP, in the string form, I was previously using if not defined in etc/hosts of client machine, otherwise it returns the name paired with the IP (serverHost1 in my case). Also, I never did set the value of host.name either.