如何使用 DriverConfigLoader 增加 Cassandra Java 驱动程序中的默认超时？

Question

关于 Spring Webflux Reactive Cassandra 应用程序的小问题。

在使用 Webflux 和反应式 Cassandra 设置 Spring Boot 2.6.4 时，我使用该应用程序在 Cassandra 表中插入一些数据。

一切正常，直到负载更高时，我看到一个问题（附加堆栈跟踪）

事实是，阅读一些文档，我认为这段代码将有助于解决问题：（

    @Bean
    public DriverConfigLoaderBuilderCustomizer defaultProfile(){
      return builder -> builder
        .withInt(DefaultDriverOption.METADATA_SCHEMA_REQUEST_TIMEOUT, 5000)
        .build();
    }

这是我的 Cassandra 配置，请注意我正在使用 CqlSession.builder())

    protected CqlSession cqlLocalSession() {
      return CqlSession.builder()
        .addContactEndPoint(new DefaultEndPoint(new InetSocketAddress(contactPoints, port)))
        .withKeyspace(keyspace)
        .withLocalDatacenter(datacenter)
        .withAuthCredentials(username, passPhrase)
        .build();
    }

不幸的是，DriverConfigLoaderBuilderCustomizer 似乎不起作用，因为我仍然面临 PT2S 后查询超时的问题； （我至少期望看到 PT5S。

请问问题是什么，以及如何正确增加超时？

谢谢

org.springframework.data.cassandra.CassandraUncategorizedException: ReactivePreparedStatementCallback; CQL [INSERT INTO mutable (x,y,z) VALUES (?,?,?)]; Query timed out after PT2S; nested exception is com.datastax.oss.driver.api.core.DriverTimeoutException: Query timed out after PT2S
    at org.springframework.data.cassandra.core.cql.CassandraExceptionTranslator.translate(CassandraExceptionTranslator.java:162) ~[spring-data-cassandra-3.3.2.jar!/:3.3.2]
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException:
Error has been observed at the following site(s):
    *__checkpoint ⇢ Handler myHandler [DispatcherHandler]
Original Stack Trace:
        at org.springframework.data.cassandra.core.cql.CassandraExceptionTranslator.translate(CassandraExceptionTranslator.java:162) ~[spring-data-cassandra-3.3.2.jar!/:3.3.2]
        at org.springframework.data.cassandra.core.cql.ReactiveCassandraAccessor.translate(ReactiveCassandraAccessor.java:149) ~[spring-data-cassandra-3.3.2.jar!/:3.3.2]
        at org.springframework.data.cassandra.core.cql.ReactiveCqlTemplate.lambda$translateException$15(ReactiveCqlTemplate.java:820) ~[spring-data-cassandra-3.3.2.jar!/:3.3.2]
        at reactor.core.publisher.Flux.lambda$onErrorMap$28(Flux.java:6911) ~[reactor-core-3.4.15.jar!/:3.4.15]
        at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onError(FluxOnErrorResume.java:94) ~[reactor-core-3.4.15.jar!/:3.4.15]
        at org.springframework.cloud.sleuth.instrument.reactor.ScopePassingSpanSubscriber.onError(ScopePassingSpanSubscriber.java:96) ~[spring-cloud-sleuth-instrumentation-3.1.1.jar!/:3.1.1]
        at reactor.core.publisher.MonoFlatMapMany$FlatMapManyMain.onError(MonoFlatMapMany.java:204) ~[reactor-core-3.4.15.jar!/:3.4.15]
        at reactor.core.publisher.FluxContextWrite$ContextWriteSubscriber.onError(FluxContextWrite.java:121) ~[reactor-core-3.4.15.jar!/:3.4.15]
        at org.springframework.cloud.sleuth.instrument.reactor.ScopePassingSpanSubscriber.onError(ScopePassingSpanSubscriber.java:96) ~[spring-cloud-sleuth-instrumentation-3.1.1.jar!/:3.1.1]
        at reactor.core.publisher.MonoCompletionStage.lambda$subscribe$0(MonoCompletionStage.java:80) ~[reactor-core-3.4.15.jar!/:3.4.15]
        at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859) ~[na:na]
        at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837) ~[na:na]
        at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506) ~[na:na]
        at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2088) ~[na:na]
        at com.datastax.oss.driver.internal.core.cql.CqlPrepareAsyncProcessor.lambda$process$1(CqlPrepareAsyncProcessor.java:71) ~[java-driver-core-4.13.0.jar!/:na]
        at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859) ~[na:na]
        at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837) ~[na:na]
        at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506) ~[na:na]
        at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2088) ~[na:na]
        at com.datastax.oss.driver.internal.core.cql.CqlPrepareHandler.setFinalError(CqlPrepareHandler.java:320) ~[java-driver-core-4.13.0.jar!/:na]
        at com.datastax.oss.driver.internal.core.cql.CqlPrepareHandler.lambda$scheduleTimeout$1(CqlPrepareHandler.java:163) ~[java-driver-core-4.13.0.jar!/:na]
        at io.netty.util.HashedWheelTimer$HashedWheelTimeout.run(HashedWheelTimer.java:715) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
        at io.netty.util.concurrent.ImmediateExecutor.execute(ImmediateExecutor.java:34) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
        at io.netty.util.HashedWheelTimer$HashedWheelTimeout.expire(HashedWheelTimer.java:703) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
        at io.netty.util.HashedWheelTimer$HashedWheelBucket.expireTimeouts(HashedWheelTimer.java:790) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
        at io.netty.util.HashedWheelTimer$Worker.run(HashedWheelTimer.java:503) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
        at java.base/java.lang.Thread.run(Thread.java:829) ~[na:na]
Caused by: com.datastax.oss.driver.api.core.DriverTimeoutException: Query timed out after PT2S
    at com.datastax.oss.driver.internal.core.cql.CqlPrepareHandler.lambda$scheduleTimeout$1(CqlPrepareHandler.java:163) ~[java-driver-core-4.13.0.jar!/:na]
    at io.netty.util.HashedWheelTimer$HashedWheelTimeout.run(HashedWheelTimer.java:715) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
    at io.netty.util.concurrent.ImmediateExecutor.execute(ImmediateExecutor.java:34) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
    at io.netty.util.HashedWheelTimer$HashedWheelTimeout.expire(HashedWheelTimer.java:703) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
    at io.netty.util.HashedWheelTimer$HashedWheelBucket.expireTimeouts(HashedWheelTimer.java:790) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
    at io.netty.util.HashedWheelTimer$Worker.run(HashedWheelTimer.java:503) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.74.Final.jar!/:4.1.74.Final]
    at java.base/java.lang.Thread.run(Thread.java:829) ~[na:na]

Answer 1

您在驱动程序上配置了错误的选项。 METADATA_SCHEMA_REQUEST_TIMEOUT 是检索架构的请求的超时时间。

Java 驱动程序的默认请求超时为 basic.request.timeout (查看参考配置)：

datastax-java-driver {
  basic.request {
    timeout = 2 seconds
  }
}

basic.request.timeout 的等效类型化驱动程序选项是 REQUEST_TIMEOUT (参考 TypedDriverOption.java)。

我应该指出，增加请求超时几乎总是不是处理您所面临的问题的正确方法，因为您只是隐藏了问题而没有真正解决根本原因。

正如您在文章开头已经指出的那样，当负载较高时就会出现问题。您收到 DriverTimeoutException 的原因是协调器没有及时响应，不难得出结论，这是由于节点过载造成的。

Cassandra 中的写入速度非常快，因为突变被附加到commitlog 的末尾——没有磁盘寻道。如果用于提交日志的磁盘速度较慢或无法跟上写入速度，您需要查看：

• 使用更快的磁盘，
• 将提交日志安装在单独的磁盘/卷上，以便它不会与读取竞争相同的 IO，
• 通过添加更多节点（将负载分散到更多节点）来增加集群的容量，或者
• 以上所有操作。

Answer 2

您还可以通过将 DefaultDriverOption.METADATA_SCHEMA_ENABLED 设置为 false 来解决此问题。

kotlin 响应式数据 cassandra 的示例如下：

@Configuration
@EnableReactiveCassandraRepositories
    class CassandraConfiguration(
        private val cassandraProperties: CassandraProperties,
    ) : AbstractReactiveCassandraConfiguration() {
    
    ...
    ...
    
    override fun getDriverConfigLoaderBuilderConfigurer(): DriverConfigLoaderBuilderConfigurer? {
            return DriverConfigLoaderBuilderConfigurer{ builder: ProgrammaticDriverConfigLoaderBuilder ->
                builder
                    .withString(DefaultDriverOption.METADATA_SCHEMA_ENABLED, "false")
                    .build()
            }
        }
        
    }

Answer 3

如果您在创建架构时遇到错误，您可以配置advanced.metadata.schema.request-timeout，并且在执行某些非架构查询时出现错误，您可以配置与basic.request.timeout。示例如下：

datastax-java-driver {
  basic.request.timeout = 5 seconds
  advanced.metadata.schema.request-timeout = 10 seconds
}