diff --git a/kafka-streams/kafka-streams-dlq-sample/.gitignore b/kafka-streams/kafka-streams-dlq-sample/.gitignore new file mode 100644 index 0000000..2af7cef --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/.gitignore @@ -0,0 +1,24 @@ +target/ +!.mvn/wrapper/maven-wrapper.jar + +### STS ### +.apt_generated +.classpath +.factorypath +.project +.settings +.springBeans + +### IntelliJ IDEA ### +.idea +*.iws +*.iml +*.ipr + +### NetBeans ### +nbproject/private/ +build/ +nbbuild/ +dist/ +nbdist/ +.nb-gradle/ \ No newline at end of file diff --git a/kafka-streams/kafka-streams-dlq-sample/.mvn/wrapper/maven-wrapper.jar b/kafka-streams/kafka-streams-dlq-sample/.mvn/wrapper/maven-wrapper.jar new file mode 100644 index 0000000..9cc84ea Binary files /dev/null and b/kafka-streams/kafka-streams-dlq-sample/.mvn/wrapper/maven-wrapper.jar differ diff --git a/kafka-streams/kafka-streams-dlq-sample/.mvn/wrapper/maven-wrapper.properties b/kafka-streams/kafka-streams-dlq-sample/.mvn/wrapper/maven-wrapper.properties new file mode 100644 index 0000000..c315043 --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/.mvn/wrapper/maven-wrapper.properties @@ -0,0 +1 @@ +distributionUrl=https://repo1.maven.org/maven2/org/apache/maven/apache-maven/3.5.0/apache-maven-3.5.0-bin.zip diff --git a/kafka-streams/kafka-streams-dlq-sample/README.adoc b/kafka-streams/kafka-streams-dlq-sample/README.adoc new file mode 100644 index 0000000..38b1680 --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/README.adoc @@ -0,0 +1,52 @@ +== What is this app? + +This is an example of a Spring Cloud Stream processor using Kafka Streams support. + +This is a demonstration of deserialization errors and DLQ in Kafka Streams binder. + +The example is based on the word count application from the https://github.com/confluentinc/examples/blob/3.2.x/kafka-streams/src/main/java/io/confluent/examples/streams/WordCountLambdaExample.java[reference documentation]. +It uses a single input and a single output. +In essence, the application receives text messages from an input topic and computes word occurrence counts in a configurable time window and report that in an output topic. +This sample uses lambda expressions and thus requires Java 8+. + +==== Starting Kafka in a docker container + +* Skip steps 1-3 if you already have a non-Docker Kafka environment. + +1. Go to the docker directory in this repo and invoke the command `docker-compose up -d`. +2. Ensure that in the docker directory and then invoke the script `start-kafka-shell.sh` +3. cd $KAFKA_HOME +4. Start the console producer: + +Assuming that you are running kafka on a docker container on mac osx. Change the zookeeper IP address accordingly otherwise. + +`bin/kafka-console-producer.sh --broker-list 192.168.99.100:9092 --topic words` +5. Start the console consumer: + +Assuming that you are running kafka on a docker container on mac osx. Change the zookeeper IP address accordingly otherwise. + +`bin/kafka-console-consumer.sh --bootstrap-server 192.168.99.100:9092 --topic counts` + +=== Running the app: + +Go to the root of the repository and do: `./mvnw clean package` + +`java -jar target/kstream-word-count-0.0.1-SNAPSHOT.jar` + +* By default we use the docker container IP (mac osx specific) in the `application.yml` for Kafka broker and zookeeper. +Change it in `application.yml` (which requires a rebuild) or pass them as runtime arguments as below. + +`spring.cloud.stream.kstream.binder.brokers=` + +`spring.cloud.stream.kstream.binder.zkNodes=` + +The default application.yml file demonstrates native decoding by Kafka. +The default value serializer is set to IntegerSerde and from the console send some ascii text data. +You will see that the messages erred on deserialization end up in the DLQ topic - words-count-dlq. + +There is another yaml file provided (by-framework-decoding.yml). +Use that as application.yml to see when it works when the deserialization done by the framework. +In this case also, the messages on error appear in the DLQ topic. + +Look in the console for what is doing the serialization/deserializtion. +You will see messages as below on the console: + +"Native decoding is disabled for input. Inbound message conversion done by Spring Cloud Stream." + +"Native encoding is disabled for counts. Outbound message conversion done by Spring Cloud Stream. + diff --git a/kafka-streams/kafka-streams-dlq-sample/docker/docker-compose.yml b/kafka-streams/kafka-streams-dlq-sample/docker/docker-compose.yml new file mode 100644 index 0000000..ecf41fb --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/docker/docker-compose.yml @@ -0,0 +1,14 @@ +version: '2' +services: + zookeeper: + image: wurstmeister/zookeeper + ports: + - "2181:2181" + kafka: + image: wurstmeister/kafka + ports: + - "9092:9092" + environment: + KAFKA_ADVERTISED_HOST_NAME: 192.168.99.100 + KAFKA_ADVERTISED_PORT: 9092 + KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181 diff --git a/kafka-streams/kafka-streams-dlq-sample/docker/start-kafka-shell.sh b/kafka-streams/kafka-streams-dlq-sample/docker/start-kafka-shell.sh new file mode 100755 index 0000000..62663e4 --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/docker/start-kafka-shell.sh @@ -0,0 +1,2 @@ +#!/bin/bash +docker run --rm -v /var/run/docker.sock:/var/run/docker.sock -e HOST_IP=$1 -e ZK=$2 -i -t wurstmeister/kafka /bin/bash diff --git a/kafka-streams/kafka-streams-dlq-sample/mvnw b/kafka-streams/kafka-streams-dlq-sample/mvnw new file mode 100755 index 0000000..5bf251c --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/mvnw @@ -0,0 +1,225 @@ +#!/bin/sh +# ---------------------------------------------------------------------------- +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +# ---------------------------------------------------------------------------- + +# ---------------------------------------------------------------------------- +# Maven2 Start Up Batch script +# +# Required ENV vars: +# ------------------ +# JAVA_HOME - location of a JDK home dir +# +# Optional ENV vars +# ----------------- +# M2_HOME - location of maven2's installed home dir +# MAVEN_OPTS - parameters passed to the Java VM when running Maven +# e.g. to debug Maven itself, use +# set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000 +# MAVEN_SKIP_RC - flag to disable loading of mavenrc files +# ---------------------------------------------------------------------------- + +if [ -z "$MAVEN_SKIP_RC" ] ; then + + if [ -f /etc/mavenrc ] ; then + . /etc/mavenrc + fi + + if [ -f "$HOME/.mavenrc" ] ; then + . "$HOME/.mavenrc" + fi + +fi + +# OS specific support. $var _must_ be set to either true or false. +cygwin=false; +darwin=false; +mingw=false +case "`uname`" in + CYGWIN*) cygwin=true ;; + MINGW*) mingw=true;; + Darwin*) darwin=true + # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home + # See https://developer.apple.com/library/mac/qa/qa1170/_index.html + if [ -z "$JAVA_HOME" ]; then + if [ -x "/usr/libexec/java_home" ]; then + export JAVA_HOME="`/usr/libexec/java_home`" + else + export JAVA_HOME="/Library/Java/Home" + fi + fi + ;; +esac + +if [ -z "$JAVA_HOME" ] ; then + if [ -r /etc/gentoo-release ] ; then + JAVA_HOME=`java-config --jre-home` + fi +fi + +if [ -z "$M2_HOME" ] ; then + ## resolve links - $0 may be a link to maven's home + PRG="$0" + + # need this for relative symlinks + while [ -h "$PRG" ] ; do + ls=`ls -ld "$PRG"` + link=`expr "$ls" : '.*-> \(.*\)$'` + if expr "$link" : '/.*' > /dev/null; then + PRG="$link" + else + PRG="`dirname "$PRG"`/$link" + fi + done + + saveddir=`pwd` + + M2_HOME=`dirname "$PRG"`/.. + + # make it fully qualified + M2_HOME=`cd "$M2_HOME" && pwd` + + cd "$saveddir" + # echo Using m2 at $M2_HOME +fi + +# For Cygwin, ensure paths are in UNIX format before anything is touched +if $cygwin ; then + [ -n "$M2_HOME" ] && + M2_HOME=`cygpath --unix "$M2_HOME"` + [ -n "$JAVA_HOME" ] && + JAVA_HOME=`cygpath --unix "$JAVA_HOME"` + [ -n "$CLASSPATH" ] && + CLASSPATH=`cygpath --path --unix "$CLASSPATH"` +fi + +# For Migwn, ensure paths are in UNIX format before anything is touched +if $mingw ; then + [ -n "$M2_HOME" ] && + M2_HOME="`(cd "$M2_HOME"; pwd)`" + [ -n "$JAVA_HOME" ] && + JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`" + # TODO classpath? +fi + +if [ -z "$JAVA_HOME" ]; then + javaExecutable="`which javac`" + if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then + # readlink(1) is not available as standard on Solaris 10. + readLink=`which readlink` + if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then + if $darwin ; then + javaHome="`dirname \"$javaExecutable\"`" + javaExecutable="`cd \"$javaHome\" && pwd -P`/javac" + else + javaExecutable="`readlink -f \"$javaExecutable\"`" + fi + javaHome="`dirname \"$javaExecutable\"`" + javaHome=`expr "$javaHome" : '\(.*\)/bin'` + JAVA_HOME="$javaHome" + export JAVA_HOME + fi + fi +fi + +if [ -z "$JAVACMD" ] ; then + if [ -n "$JAVA_HOME" ] ; then + if [ -x "$JAVA_HOME/jre/sh/java" ] ; then + # IBM's JDK on AIX uses strange locations for the executables + JAVACMD="$JAVA_HOME/jre/sh/java" + else + JAVACMD="$JAVA_HOME/bin/java" + fi + else + JAVACMD="`which java`" + fi +fi + +if [ ! -x "$JAVACMD" ] ; then + echo "Error: JAVA_HOME is not defined correctly." >&2 + echo " We cannot execute $JAVACMD" >&2 + exit 1 +fi + +if [ -z "$JAVA_HOME" ] ; then + echo "Warning: JAVA_HOME environment variable is not set." +fi + +CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher + +# traverses directory structure from process work directory to filesystem root +# first directory with .mvn subdirectory is considered project base directory +find_maven_basedir() { + + if [ -z "$1" ] + then + echo "Path not specified to find_maven_basedir" + return 1 + fi + + basedir="$1" + wdir="$1" + while [ "$wdir" != '/' ] ; do + if [ -d "$wdir"/.mvn ] ; then + basedir=$wdir + break + fi + # workaround for JBEAP-8937 (on Solaris 10/Sparc) + if [ -d "${wdir}" ]; then + wdir=`cd "$wdir/.."; pwd` + fi + # end of workaround + done + echo "${basedir}" +} + +# concatenates all lines of a file +concat_lines() { + if [ -f "$1" ]; then + echo "$(tr -s '\n' ' ' < "$1")" + fi +} + +BASE_DIR=`find_maven_basedir "$(pwd)"` +if [ -z "$BASE_DIR" ]; then + exit 1; +fi + +export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"} +echo $MAVEN_PROJECTBASEDIR +MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS" + +# For Cygwin, switch paths to Windows format before running java +if $cygwin; then + [ -n "$M2_HOME" ] && + M2_HOME=`cygpath --path --windows "$M2_HOME"` + [ -n "$JAVA_HOME" ] && + JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"` + [ -n "$CLASSPATH" ] && + CLASSPATH=`cygpath --path --windows "$CLASSPATH"` + [ -n "$MAVEN_PROJECTBASEDIR" ] && + MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"` +fi + +WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain + +exec "$JAVACMD" \ + $MAVEN_OPTS \ + -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \ + "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \ + ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@" diff --git a/kafka-streams/kafka-streams-dlq-sample/mvnw.cmd b/kafka-streams/kafka-streams-dlq-sample/mvnw.cmd new file mode 100644 index 0000000..019bd74 --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/mvnw.cmd @@ -0,0 +1,143 @@ +@REM ---------------------------------------------------------------------------- +@REM Licensed to the Apache Software Foundation (ASF) under one +@REM or more contributor license agreements. See the NOTICE file +@REM distributed with this work for additional information +@REM regarding copyright ownership. The ASF licenses this file +@REM to you under the Apache License, Version 2.0 (the +@REM "License"); you may not use this file except in compliance +@REM with the License. You may obtain a copy of the License at +@REM +@REM http://www.apache.org/licenses/LICENSE-2.0 +@REM +@REM Unless required by applicable law or agreed to in writing, +@REM software distributed under the License is distributed on an +@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +@REM KIND, either express or implied. See the License for the +@REM specific language governing permissions and limitations +@REM under the License. +@REM ---------------------------------------------------------------------------- + +@REM ---------------------------------------------------------------------------- +@REM Maven2 Start Up Batch script +@REM +@REM Required ENV vars: +@REM JAVA_HOME - location of a JDK home dir +@REM +@REM Optional ENV vars +@REM M2_HOME - location of maven2's installed home dir +@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands +@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a key stroke before ending +@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven +@REM e.g. to debug Maven itself, use +@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000 +@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files +@REM ---------------------------------------------------------------------------- + +@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on' +@echo off +@REM enable echoing my setting MAVEN_BATCH_ECHO to 'on' +@if "%MAVEN_BATCH_ECHO%" == "on" echo %MAVEN_BATCH_ECHO% + +@REM set %HOME% to equivalent of $HOME +if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%") + +@REM Execute a user defined script before this one +if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre +@REM check for pre script, once with legacy .bat ending and once with .cmd ending +if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat" +if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd" +:skipRcPre + +@setlocal + +set ERROR_CODE=0 + +@REM To isolate internal variables from possible post scripts, we use another setlocal +@setlocal + +@REM ==== START VALIDATION ==== +if not "%JAVA_HOME%" == "" goto OkJHome + +echo. +echo Error: JAVA_HOME not found in your environment. >&2 +echo Please set the JAVA_HOME variable in your environment to match the >&2 +echo location of your Java installation. >&2 +echo. +goto error + +:OkJHome +if exist "%JAVA_HOME%\bin\java.exe" goto init + +echo. +echo Error: JAVA_HOME is set to an invalid directory. >&2 +echo JAVA_HOME = "%JAVA_HOME%" >&2 +echo Please set the JAVA_HOME variable in your environment to match the >&2 +echo location of your Java installation. >&2 +echo. +goto error + +@REM ==== END VALIDATION ==== + +:init + +@REM Find the project base dir, i.e. the directory that contains the folder ".mvn". +@REM Fallback to current working directory if not found. + +set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR% +IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir + +set EXEC_DIR=%CD% +set WDIR=%EXEC_DIR% +:findBaseDir +IF EXIST "%WDIR%"\.mvn goto baseDirFound +cd .. +IF "%WDIR%"=="%CD%" goto baseDirNotFound +set WDIR=%CD% +goto findBaseDir + +:baseDirFound +set MAVEN_PROJECTBASEDIR=%WDIR% +cd "%EXEC_DIR%" +goto endDetectBaseDir + +:baseDirNotFound +set MAVEN_PROJECTBASEDIR=%EXEC_DIR% +cd "%EXEC_DIR%" + +:endDetectBaseDir + +IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig + +@setlocal EnableExtensions EnableDelayedExpansion +for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a +@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS% + +:endReadAdditionalConfig + +SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe" + +set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar" +set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain + +%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %* +if ERRORLEVEL 1 goto error +goto end + +:error +set ERROR_CODE=1 + +:end +@endlocal & set ERROR_CODE=%ERROR_CODE% + +if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost +@REM check for post script, once with legacy .bat ending and once with .cmd ending +if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat" +if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd" +:skipRcPost + +@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on' +if "%MAVEN_BATCH_PAUSE%" == "on" pause + +if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE% + +exit /B %ERROR_CODE% diff --git a/kafka-streams/kafka-streams-dlq-sample/pom.xml b/kafka-streams/kafka-streams-dlq-sample/pom.xml new file mode 100644 index 0000000..9a0d09a --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/pom.xml @@ -0,0 +1,83 @@ + + + 4.0.0 + + kafka.streams.dlq.sample + kafka-streams-dlq-sample + 0.0.1-SNAPSHOT + jar + + kafka-streams-dlq-sample + Demo project for Spring Boot + + + org.springframework.boot + spring-boot-starter-parent + 2.0.0.BUILD-SNAPSHOT + + + + + UTF-8 + UTF-8 + 1.8 + Finchley.BUILD-SNAPSHOT + + + + + org.springframework.boot + spring-boot-starter + + + org.springframework.kafka + spring-kafka + 2.1.3.BUILD-SNAPSHOT + + + org.springframework.cloud + spring-cloud-stream-binder-kafka-streams + 2.0.0.BUILD-SNAPSHOT + + + + org.springframework.boot + spring-boot-starter-test + test + + + + + + + org.springframework.cloud + spring-cloud-dependencies + ${spring-cloud.version} + pom + import + + + + + + + + org.springframework.boot + spring-boot-maven-plugin + + + + + + + spring-milestones + Spring Milestones + http://repo.spring.io/libs-milestone-local + + false + + + + + diff --git a/kafka-streams/kafka-streams-dlq-sample/src/main/java/kafka/streams/dlq/sample/KafkaStreamsDlqSample.java b/kafka-streams/kafka-streams-dlq-sample/src/main/java/kafka/streams/dlq/sample/KafkaStreamsDlqSample.java new file mode 100644 index 0000000..bf21f8f --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/src/main/java/kafka/streams/dlq/sample/KafkaStreamsDlqSample.java @@ -0,0 +1,96 @@ +package kafka.streams.dlq.sample; + +import org.apache.kafka.common.serialization.Serdes; +import org.apache.kafka.streams.KeyValue; +import org.apache.kafka.streams.kstream.KStream; +import org.apache.kafka.streams.kstream.TimeWindows; +import org.springframework.beans.factory.annotation.Autowired; +import org.springframework.boot.SpringApplication; +import org.springframework.boot.autoconfigure.EnableAutoConfiguration; +import org.springframework.boot.autoconfigure.SpringBootApplication; +import org.springframework.cloud.stream.annotation.EnableBinding; +import org.springframework.cloud.stream.annotation.StreamListener; +import org.springframework.cloud.stream.binder.kafka.streams.annotations.KafkaStreamsProcessor; +import org.springframework.messaging.handler.annotation.SendTo; + +import java.util.Arrays; +import java.util.Date; + +@SpringBootApplication +public class KafkaStreamsDlqSample { + + public static void main(String[] args) { + SpringApplication.run(KafkaStreamsDlqSample.class, args); + } + + @EnableBinding(KafkaStreamsProcessor.class) + @EnableAutoConfiguration + public static class WordCountProcessorApplication { + + @Autowired + private TimeWindows timeWindows; + + @StreamListener("input") + @SendTo("output") + public KStream process(KStream input) { + + return input + .flatMapValues(value -> Arrays.asList(value.toLowerCase().split("\\W+"))) + .map((key, value) -> new KeyValue<>(value, value)) + .groupByKey(Serdes.String(), Serdes.String()) + .count(timeWindows, "WordCounts-1") + .toStream() + .map((key, value) -> new KeyValue<>(null, new WordCount(key.key(), value, new Date(key.window().start()), new Date(key.window().end())))); + } + } + + static class WordCount { + + private String word; + + private long count; + + private Date start; + + private Date end; + + WordCount(String word, long count, Date start, Date end) { + this.word = word; + this.count = count; + this.start = start; + this.end = end; + } + + public String getWord() { + return word; + } + + public void setWord(String word) { + this.word = word; + } + + public long getCount() { + return count; + } + + public void setCount(long count) { + this.count = count; + } + + public Date getStart() { + return start; + } + + public void setStart(Date start) { + this.start = start; + } + + public Date getEnd() { + return end; + } + + public void setEnd(Date end) { + this.end = end; + } + } +} diff --git a/kafka-streams/kafka-streams-dlq-sample/src/main/java/kafka/streams/dlq/sample/WordCountExample.java b/kafka-streams/kafka-streams-dlq-sample/src/main/java/kafka/streams/dlq/sample/WordCountExample.java new file mode 100644 index 0000000..5421c5e --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/src/main/java/kafka/streams/dlq/sample/WordCountExample.java @@ -0,0 +1,101 @@ +package kafka.streams.dlq.sample; + +import org.apache.kafka.common.serialization.Serde; +import org.apache.kafka.common.serialization.Serdes; +import org.apache.kafka.streams.KafkaStreams; +import org.apache.kafka.streams.StreamsBuilder; +import org.apache.kafka.streams.StreamsConfig; +import org.apache.kafka.streams.errors.LogAndContinueExceptionHandler; +import org.apache.kafka.streams.kstream.KStream; +import org.apache.kafka.streams.kstream.KTable; +import org.apache.kafka.streams.kstream.Produced; + +import java.util.Arrays; +import java.util.Properties; +import java.util.regex.Pattern; + +public class WordCountExample { + public static void main(String[] args) throws Exception{ + + final String bootstrapServers = args.length > 0 ? args[0] : "localhost:9092"; + + + // Set up serializers and deserializers, which we will use for overriding the default serdes + // specified above. + final Serde stringSerde = Serdes.String(); + final Serde longSerde = Serdes.Long(); + + // In the subsequent lines we define the processing topology of the Streams application. + final StreamsBuilder builder = new StreamsBuilder(); + + // Construct a `KStream` from the input topic "TextLinesTopic", where message values + // represent lines of text (for the sake of this example, we ignore whatever may be stored + // in the message keys). + // + // Note: We could also just call `builder.stream("TextLinesTopic")` if we wanted to leverage + // the default serdes specified in the Streams configuration above, because these defaults + // match what's in the actual topic. However we explicitly set the deserializers in the + // call to `stream()` below in order to show how that's done, too. + final KStream textLines = builder.stream("words"); + + final Pattern pattern = Pattern.compile("\\W+", Pattern.UNICODE_CHARACTER_CLASS); + + final KTable wordCounts = textLines + // Split each text line, by whitespace, into words. The text lines are the record + // values, i.e. we can ignore whatever data is in the record keys and thus invoke + // `flatMapValues()` instead of the more generic `flatMap()`. + .flatMapValues(value -> Arrays.asList(pattern.split(value.toLowerCase()))) + // Count the occurrences of each word (record key). + // + // This will change the stream type from `KStream` to `KTable` + // (word -> count). In the `count` operation we must provide a name for the resulting KTable, + // which will be used to name e.g. its associated state store and changelog topic. + // + // Note: no need to specify explicit serdes because the resulting key and value types match our default serde settings + .groupBy((key, word) -> word) + .count(); + + // Write the `KTable` to the output topic. + wordCounts.toStream().to("counts", Produced.with(stringSerde, longSerde)); + + final Properties streamsConfiguration = new Properties(); + // Give the Streams application a unique name. The name must be unique in the Kafka cluster + // against which the application is run. + streamsConfiguration.put(StreamsConfig.APPLICATION_ID_CONFIG, "wordcount-lambda-example"); + streamsConfiguration.put(StreamsConfig.CLIENT_ID_CONFIG, "wordcount-lambda-example-client"); + // Where to find Kafka broker(s). + streamsConfiguration.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers); + // Specify default (de)serializers for record keys and for record values. + streamsConfiguration.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName()); + streamsConfiguration.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName()); + // Records should be flushed every 10 seconds. This is less than the default + // in order to keep this example interactive. + streamsConfiguration.put(StreamsConfig.COMMIT_INTERVAL_MS_CONFIG, 1000); + // For illustrative purposes we disable record caches + streamsConfiguration.put(StreamsConfig.CACHE_MAX_BYTES_BUFFERING_CONFIG, 0); + + streamsConfiguration.put(StreamsConfig.DEFAULT_DESERIALIZATION_EXCEPTION_HANDLER_CLASS_CONFIG, + LogAndContinueExceptionHandler.class); + + // Now that we have finished the definition of the processing topology we can actually run + // it via `start()`. The Streams application as a whole can be launched just like any + // normal Java application that has a `main()` method. + final KafkaStreams streams = new KafkaStreams(builder.build(), streamsConfiguration); + // Always (and unconditionally) clean local state prior to starting the processing topology. + // We opt for this unconditional call here because this will make it easier for you to play around with the example + // when resetting the application for doing a re-run (via the Application Reset Tool, + // http://docs.confluent.io/current/streams/developer-guide.html#application-reset-tool). + // + // The drawback of cleaning up local state prior is that your app must rebuilt its local state from scratch, which + // will take time and will require reading all the state-relevant data from the Kafka cluster over the network. + // Thus in a production scenario you typically do not want to clean up always as we do here but rather only when it + // is truly needed, i.e., only under certain conditions (e.g., the presence of a command line flag for your app). + // See `ApplicationResetExample.java` for a production-like example. + streams.cleanUp(); + streams.start(); + + // Add shutdown hook to respond to SIGTERM and gracefully close Kafka Streams + Runtime.getRuntime().addShutdownHook(new Thread(streams::close)); + } + +} diff --git a/kafka-streams/kafka-streams-dlq-sample/src/main/resources/application.yml b/kafka-streams/kafka-streams-dlq-sample/src/main/resources/application.yml new file mode 100644 index 0000000..4d8a6b3 --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/src/main/resources/application.yml @@ -0,0 +1,27 @@ +spring.cloud.stream.bindings.output.contentType: application/json +spring.cloud.stream.kafka.streams.binder.configuration.commit.interval.ms: 1000 +spring.cloud.stream.kafka.streams.binder.configuration: + default.key.serde: org.apache.kafka.common.serialization.Serdes$StringSerde + default.value.serde: org.apache.kafka.common.serialization.Serdes$IntegerSerde + application.id: default +spring.cloud.stream.bindings.output: + destination: counts + producer: + headerMode: raw + #useNativeEncoding: true +spring.cloud.stream.bindings.input: + destination: words + group: group1 + consumer: + headerMode: raw + useNativeDecoding: true +spring.cloud.stream.kafka.streams.bindings.input.consumer.dlqName: words-count-dlq +spring.cloud.stream.kafka.streams.binder: + brokers: localhost #192.168.99.100 + zkNodes: localhost #192.168.99.100 + serdeError: sendToDlq + + + + + diff --git a/kafka-streams/kafka-streams-dlq-sample/src/main/resources/by-framework-decoding.yml b/kafka-streams/kafka-streams-dlq-sample/src/main/resources/by-framework-decoding.yml new file mode 100644 index 0000000..8a81ee1 --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/src/main/resources/by-framework-decoding.yml @@ -0,0 +1,25 @@ +spring.cloud.stream.bindings.output.contentType: application/json +spring.cloud.stream.kafka.streams.binder.configuration.commit.interval.ms: 1000 +spring.cloud.stream.kafka.streams.binder.configuration: + default.key.serde: org.apache.kafka.common.serialization.Serdes$StringSerde + default.value.serde: org.apache.kafka.common.serialization.Serdes$StringSerde + application.id: default +spring.cloud.stream.bindings.output: + destination: counts + producer: + headerMode: raw + #useNativeEncoding: true +spring.cloud.stream.bindings.input: + contentType: foo/bar + destination: words + group: group1 + consumer: + headerMode: raw + useNativeDecoding: false +spring.cloud.stream.kafka.streams.bindings.input.consumer.dlqName: words-count-dlq +spring.cloud.stream.kafka.streams.binder: + brokers: localhost #192.168.99.100 + zkNodes: localhost #192.168.99.100 + serdeError: sendToDlq + + diff --git a/kafka-streams/kafka-streams-dlq-sample/src/main/resources/logback.xml b/kafka-streams/kafka-streams-dlq-sample/src/main/resources/logback.xml new file mode 100644 index 0000000..870ac9e --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/src/main/resources/logback.xml @@ -0,0 +1,12 @@ + + + + + %d{ISO8601} %5p %t %c{2}:%L - %m%n + + + + + + + \ No newline at end of file diff --git a/kafka-streams/kafka-streams-dlq-sample/src/test/java/kafka/streams/dlq/sample/KafkaStreamsDlqExampleTests.java b/kafka-streams/kafka-streams-dlq-sample/src/test/java/kafka/streams/dlq/sample/KafkaStreamsDlqExampleTests.java new file mode 100644 index 0000000..cb31324 --- /dev/null +++ b/kafka-streams/kafka-streams-dlq-sample/src/test/java/kafka/streams/dlq/sample/KafkaStreamsDlqExampleTests.java @@ -0,0 +1,18 @@ +package kafka.streams.dlq.sample; + +import org.junit.Ignore; +import org.junit.Test; +import org.junit.runner.RunWith; +import org.springframework.boot.test.context.SpringBootTest; +import org.springframework.test.context.junit4.SpringRunner; + +@RunWith(SpringRunner.class) +@SpringBootTest +public class KafkaStreamsDlqExampleTests { + + @Test + @Ignore + public void contextLoads() { + } + +}