从同一程序调用 cassandra 和弹性搜索时出现异常

Question

我正在尝试将我在 cassandra 的数据索引到云中托管的弹性搜索中。我能够使用传输客户端轻松地通过弹性搜索连接虚拟数据并为其编制索引。但是，当我在我的 pom 文件中添加 datastax 驱动程序依赖项以连接到 cassandra 时，我得到了以下例外。奇怪的是我什至没有连接到 cassandra 集群。 提前致谢

线程 "main" java.lang.AbstractMethodError 中的异常：io.netty.util.concurrent.MultithreadEventExecutorGroup.newChild(Ljava/util/concurrent/Executor;[Ljava/lang/Object;)Lio/netty/util/concurrent/EventExecutor; 在 io.netty.util.concurrent.MultithreadEventExecutorGroup.(MultithreadEventExecutorGroup.java:84) 在 io.netty.util.concurrent.MultithreadEventExecutorGroup.(MultithreadEventExecutorGroup.java:58) 在 io.netty.util.concurrent.MultithreadEventExecutorGroup.(MultithreadEventExecutorGroup.java:47) 在 io.netty.channel.MultithreadEventLoopGroup.(MultithreadEventLoopGroup.java:49) 在 io.netty.channel.nio.NioEventLoopGroup.(NioEventLoopGroup.java:68) 在 io.netty.channel.nio.NioEventLoopGroup.(NioEventLoopGroup.java:63) 在 io.netty.channel.nio.NioEventLoopGroup.(NioEventLoopGroup.java:54) 在 org.elasticsearch.transport.netty4.Netty4Transport.createBootstrap(Netty4Transport.java:201) 在 org.elasticsearch.transport.netty4.Netty4Transport.doStart(Netty4Transport.java:172) 在 org.elasticsearch.xpack.security.transport.netty4.SecurityNetty4Transport.doStart(SecurityNetty4Transport.java:74) 在 org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:69) 在 org.elasticsearch.transport.TransportService.doStart(TransportService.java:196) 在 org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:69) 在 org.elasticsearch.client.transport.TransportClient.buildTemplate(TransportClient.java:208) 在 org.elasticsearch.client.transport.TransportClient.(TransportClient.java:268) 在 org.elasticsearch.transport.client.PreBuiltTransportClient.(PreBuiltTransportClient.java:125) 在 org.elasticsearch.xpack.client.PreBuiltXPackTransportClient.(PreBuiltXPackTransportClient.java:55) 在 org.elasticsearch.xpack.client.PreBuiltXPackTransportClient.(PreBuiltXPackTransportClient.java:50) 在 org.elasticsearch.xpack.client.PreBuiltXPackTransportClient.(PreBuiltXPackTransportClient.java:46)

Answer 1

为了解决 DataStax java 驱动程序对 Netty 的依赖性和其他库对 Maven 的依赖性之间的潜在冲突，您可以使用驱动程序 jar 的 'shaded' 分类器，如驱动程序文档中所述'Using the shaded jar' page:

<dependency>
    <groupId>com.datastax.cassandra</groupId>
    <artifactId>cassandra-driver-core</artifactId>
    <version>3.2.0</version>
    <classifier>shaded</classifier>
    <!-- Because the shaded JAR uses the original POM, you still need
        to exclude this dependency explicitly: -->
    <exclusions>
        <exclusion>
        <groupId>io.netty</groupId>
        <artifactId>*</artifactId>
        </exclusion>
    </exclusions>
</dependency>

请注意，如果您不使用 maven，gradle 等其他构建工具应该有指定分类器的方法，否则您可以直接从 maven 下载阴影 jar。

Answer 2

我用这个 pom.xml 并且对我有用

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mycompany</groupId>
    <artifactId>mavenproject2</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
         <cassandra-driver-core.version>3.1.2</cassandra-driver-core.version>
        <cassandra-unit.version>3.1.1.0</cassandra-unit.version>
        <datastax-cassandra.version>4.1.0</datastax-cassandra.version>
    </properties>
    <dependencies>
       
            <dependency>
            <groupId>com.datastax.cassandra</groupId>
            <artifactId>cassandra-driver-core</artifactId>
            <version>${cassandra-driver-core.version}</version>
            <optional>true</optional>
            <exclusions>
                <exclusion>
                    <groupId>com.google.guava</groupId>
                    <artifactId>guava</artifactId>
                </exclusion>
                 <exclusion>
        <groupId>io.netty</groupId>
        <artifactId>*</artifactId>
        </exclusion>
            </exclusions>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.cassandraunit/cassandra-unit -->
        <dependency>
            <groupId>org.cassandraunit</groupId>
            <artifactId>cassandra-unit</artifactId>
            <version>${cassandra-unit.version}</version>
                <exclusions>
        <exclusion>
        <groupId>io.netty</groupId>
        <artifactId>*</artifactId>
        </exclusion>
    </exclusions>
        </dependency>
        <!-- DataStax Cassandra -->
        <dependency>
           <groupId>com.datastax.cassandra</groupId>
    <artifactId>cassandra-driver-core</artifactId>
    <version>3.2.0</version>
    <classifier>shaded</classifier>
    <!-- Because the shaded JAR uses the original POM, you still need
        to exclude this dependency explicitly: -->
    <exclusions>
        <exclusion>
        <groupId>io.netty</groupId>
        <artifactId>*</artifactId>
        </exclusion>
    </exclusions>
        </dependency>
        <dependency>
            <groupId>com.datastax.oss</groupId>
            <artifactId>java-driver-query-builder</artifactId>
            <version>${datastax-cassandra.version}</version>
        </dependency>
         <dependency>
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-api</artifactId>
       <version>1.7.5</version>
   </dependency>
   <dependency>
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-simple</artifactId>
       <version>1.6.4</version>
   </dependency>
 <dependency>
  <groupId>com.datastax.oss</groupId>
  <artifactId>java-driver-core-shaded</artifactId>
  <version>4.5.1</version>
</dependency>

    </dependencies>
    
</project>

从同一程序调用 cassandra 和弹性搜索时出现异常

Exception while calling cassandra and elastic search from same program

java

cassandra-2.0

datastax-java-driver

elasticsearch-5