1. Start the production and consumption process using 127.0.0.1:
1) Start the producer process:
bin/kafka-console-producer.sh--broker-list 127.0.0.1:9092--topic test
Input message:
This is MSG
Producer Process Error:
[2016-06-03 11:33:47,934] WARN Bootstrap broker 127.0.0.1:9092 Disconnected (org.apache.kafka.clients.NetworkClient)
[2016-06-03 11:33:49,554] WARN Bootstrap broker 127.0.0.1:9092 Disconnected (org.apache.kafka.clients.NetworkClient)
process is mainly implemented by the above highlighted code section, for example, a 10-partition topic, the same group has three Consumerid for AAA,CCC,BBB consumers1 by the latter two pieces of code, get Consumerid list and partition partition list are already sorted, soCurconsumers= (AAA,BBB,CCC)Curpartitions= (0,1,2,3,4,5,6,7,8,9)2NPARTSPERCONSUMER=10/3 =3nconsumerswithextrapart=10%3 =13 Assuming the current client ID is AAAmyconsumerposition= Cur
some time ago in the Kafka QQ Group was asked about this--about how Java consumer dynamically modify topic subscription issues. It's really a good question to think about it, because if you simply hold the consumer instance in another thread and then call subscribe to modify it, the
1. OverviewIn Kafka, there are two types of consumer APIs, one for high-level consumer APIs and the other for low-level consumer APIs. In the article "Advanced Consumer API", the API implementation of its advanced consumption is introduced. Let's introduce another
The producers are as follows:
public class KafkaProduce1 {public
static void Main (string[] args) throws ioexception{
String topic= "test";
Properties prop = new properties ();
Prop.load (KafkaProduce1.class.getClassLoader (). getResourceAsStream ("producer.properties"));
producer
The producer.properies configuration is as follows:
# List of brokers used for bootstrapping knowledge about the rest of the cluster
# FORMAT:HOST1:PORT1,HOST2:PORT2. .
metad
consumer crashes trigger rebalancing, and when the new consumer tries to update the offset information, it will cause the missing message, as shown in:Pull and consume of messagesConsumer if a message exists during the last message pull, it is returned directly, otherwise the pull cancellation request is resent from the previously updated pull offset location.Pull cancellation request to the
I here Kafka consumer code is copied online, is to open a thread monitoring Kafka topic, a message on the processing. The code to begin with is this:
public void Kafkastart () {final String topic = HipchatAction.properties.getProperty ("Kafka.hipchat.topic"); Final int partitionnum = integer.valueof (HipchatAction.properties.getProperty ("Kafka.hipchat.topic.par
); Mapconsumerconnector.createmessagestreams (map); List); //Create List of 4 threads to consume from each of the partitionsExecutorservice executor = Executors.newfixedthreadpool (4); //consume the messages in the threads for(FinalKafkastreamstream:streams) {Executor.submit (NewRunnable () { Public voidrun () { for(Messageandmetadata msgandmetadata:stream) {//Process Message (Msgandmetadata.message ())System.out.println ("topic:" +msgandmetadata.topic ()); Message Message=(Message) msgandmeta
At present the Central Library Org.apache.kafka is compiled with jdk1.7, so run in 1.6 of the JVM will be errorSolution:1. Download Kafka source code, local SBT to install, pre-compile java-version confirm that the JDK version in Classpath is 1.62. After compiling the package successfully, go to the core/target/scala_2.8.0/of the current Kafka directory, find kafka
CONSUMERFETCHERMANAGER5. Generate timed tasks, according to the configuration of auto.commit.interval.ms to submit the displacement, the default is 1 minutes to submit the displacement to the zookeeper is to periodically save the consumed message displacement to zookeeper, the specific logic is very simple, This article does not dwell on here. We only care about the fourth step in the previous step-creating Consumerfetchermanager. So, what does Consumerfetchermanager do with it? As the name imp
)); Stringdecoder Keydecoder = new Stringdecoder (new Verifiableproperties ());Stringdecoder Valuedecoder = new Stringdecoder (new Verifiableproperties ()); MapConsumer.createmessagestreams (Topiccountmap,keydecoder,valuedecoder);kafkastreamConsumeriterator int messagecount = 0;while (It.hasnext ()) {System.out.println (It.next (). message ());messagecount++;if (Messagecount = = 100) {SYSTEM.OUT.PRINTLN ("Consumer end of the total consumption of" + Me
In the use of Kafka high-level consumer, the use of multi-threaded consumption data times wrong, simple analysis of the reason for download , Consumeriterator will not be blocked when the message and set the internal state to failed, which throws an exception when other threads access it.Java code 650) this.width=650; "class=" star "src=" Http://woodding2008.iteye.com/images/icon_star.png "alt=" Favorites
Error phenomenon:Java client programming as the consumer of Kafka, connecting Kafka's broker error650) this.width=650; "Src=" https://s4.51cto.com/wyfs02/M00/91/6A/wKiom1j12BGgUkKgAACUSA5Q0tU565.png-wh_500x0-wm_ 3-wmp_4-s_64493172.png "title=" Qq20170418170758.png "alt=" Wkiom1j12bggukkgaacusa5q0tu565.png-wh_50 "/>Error reason analysis:When the server configuration or network environment is poor, there will
Error process:650) this.width=650; "Src=" https://s1.51cto.com/wyfs02/M00/91/60/wKiom1j1sYHyYBNNAADoGsBpPEc665.png-wh_500x0-wm_ 3-wmp_4-s_1657427620.png "title=" Qq20170418142553.png "alt=" Wkiom1j1syhyybnnaadogsbppec665.png-wh_50 "/>Cause: Host name mapped IP error, resulting in no communication between nodesWorkaround: Configure IP and hostname mappings on each machineVi/etc/hosts650) this.width=650; "Src=" https://s2.51cto.com/wyfs02/M01/91/5F/wKioL1j1skjRcJXNAAAZuUAeA9Q879.png-wh_500x0-wm_ 3
/envpython#-*-coding:utf-8-*-importsysfromkafka importkafkaconsumerimportjson__metaclass__=typeclassconsumer: def__init__ (self,kafkaserver= ' 127.0.0.1 ', kafkaport= ' 9092 ', groupid= ' TestGroup ', clientid= "Test", topic= ' test '): "" " is used to set up consumer configuration information, which can be found in the source code, and the following are the necessary parameters. :p Aramkafkaserver:kafka Server ip :p Aramkafkaport:kafka Work Port :P
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