Es 超时设置 high-level-client

照例，先上解决方案。我用的是es的high-level-client，不是spring-boot-starter-data-elasticsearch。

1、解决办法

1.1、自定义的RestHighLevelClient

在config配置类中,创建high-level-client时添加socket-timeout设置RequestConfigCallback。相关原理分析

@Configuration
public class ElasticRestJavaClientConfig {@Value("${elasticsearch.host}")private String hostList;@Beanpublic RestHighLevelClient restHighLevelClient() {//解析hostlist配置信息String[] split = hostList.split(",");//创建HttpHost数组，其中存放es主机和端口的配置信息HttpHost[] httpHostArray = new HttpHost[split.length];for (int i = 0; i < split.length; i++) {String item = split[i];httpHostArray[i] = new HttpHost(item.split(":")[0],Integer.parseInt(item.split(":")[1]), "http");}//核心,配置超时时间,添加configCallback,之后创建连接时会将超时设置到socket上RestClientBuilder.RequestConfigCallback requestConfigCallback = requestConfigBuilder -> requestConfigBuilder.setSocketTimeout(28_800_000);RestClientBuilder builder = RestClient.builder(httpHostArray).setRequestConfigCallback(requestConfigCallback);//创建RestHighLevelClient客户端return new RestHighLevelClient(builder);}
}

1.2、spring 装配的RestHighLevelClient

有两种方式，配置文件和自定义bean。相关原理spring 自动装配

1.2.1、配置文件

yml配置

spring:elasticsearch:rest:#单位毫秒read-timeout: 30connection-timeout: 30uris: ["http://localhost:9200","http://localhost:9201","http://localhost:9202"]

1.2.2 自定义bean

创建bean，并实现RestClientBuilderCustomizer即可

/*** 成为spring的bean*/
@Component
public class MyRestClientBuilderCustomizer implements RestClientBuilderCustomizer {@Overridepublic void customize(RestClientBuilder builder) {//配置超时RestClientBuilder.RequestConfigCallback configCallback = requestConfigBuilder -> requestConfigBuilder.setSocketTimeout(1000);//设置配置builder.setRequestConfigCallback(configCallback);}
}

2、分析-针对自定义的RestHighLevelClient

2.1、问题背景

我们的es集群需要定时做reindex操作，大概需要30分钟。在测试期间总是发现出现超时，抛出如下异常：

这张图片是专门为了测试用，超时设置的10毫秒。

按照方法名猜测，RestClient.performRequest里面执行超时，**extractAndWrapCause()**包装异常。接下来重点看看RestClient的方法

2.2、RestClient.performRequest

该方法是真正的执行方法，源码如下：

private Response performRequest(final NodeTuple<Iterator<Node>> nodeTuple,final InternalRequest request,Exception previousException) throws IOException {RequestContext context = request.createContextForNextAttempt(nodeTuple.nodes.next(), nodeTuple.authCache);HttpResponse httpResponse;try {//真正执行httpResponse = client.execute(context.requestProducer, context.asyncResponseConsumer, context.context, null).get();} catch(Exception e) {。。。。包装异常Exception cause = extractAndWrapCause(e);}   .....
}

可以看到，是真正执行是client这个成员变量执行的，我们看看这个client是什么

public class RestClient implements Closeable {//持有的成员变量private final CloseableHttpAsyncClient client;//构造方法RestClient(CloseableHttpAsyncClient client, Header[] defaultHeaders, List<Node> nodes, String pathPrefix,FailureListener failureListener, NodeSelector nodeSelector, boolean strictDeprecationMode) {this.client = client;this.defaultHeaders = Collections.unmodifiableList(Arrays.asList(defaultHeaders));this.failureListener = failureListener;this.pathPrefix = pathPrefix;this.nodeSelector = nodeSelector;this.warningsHandler = strictDeprecationMode ? WarningsHandler.STRICT : WarningsHandler.PERMISSIVE;setNodes(nodes);}
}

2.3 CloseableHttpAsyncClient

听名字应该是个httpClient，既然是httpClient应该有超时设置相关的，点进去看看。

public abstract class CloseableHttpAsyncClient implements HttpAsyncClient, Closeable {public abstract boolean isRunning();public abstract void start();@Overridepublic <T> Future<T> execute(final HttpAsyncRequestProducer requestProducer,final HttpAsyncResponseConsumer<T> responseConsumer,final FutureCallback<T> callback) {return execute(requestProducer, responseConsumer, HttpClientContext.create(), callback);}...
}

进去发现是模板抽象类，子类有多个，不太好确定是哪个。我们换个思路，该类的实例是RestClient的构造方法中有用到，我们可以RsetcLIent的构造方法的调用

2.3、RestClinet构造方法调用

通过idea在方法上右键，fine use找到调用关系

可以看到是在RestClientBuilder.build()方法中，进入看看

2.4、RestClientBuilder.build()

进入源码查看，可以看到build()中调用了createHttpClient（）的方法。而且还有DEFAULT_SOCKET_TIMEOUT_MILLIS的关键字，一看就是和超时相关的

根据第一行代码，setSocketTimeout()返回了RequestConfig.Builder，说明RequestConfig.Builder中有超时相关的配置。同时在if判断的方法中，**requestConfigCallback.customizeRequestConfig()**看名字应该就是我们修改配置的地方。

综上所述，可以看到超时设置可以RequestConfig.Builder以及RequestConfigCallback有关。我们先看RequestConfig.Builder。

2.5 RequestConfig.Builder

看名字应该是和请求配置相关的类，

public static class Builder {//超时 private int socketTimeout;//公开方法public Builder setSocketTimeout(final int socketTimeout) {this.socketTimeout = socketTimeout;return this;}
}

可见，在Builder类中有超时的设置方法，现在就是找在哪可以设置超时了，我们进入RequestConfigCallback看看。

2.6、RestClientBuilder.RequestConfigCallback

RequestConfigCallback是RestClientBuilder的一个内部接口，也就是说我们要实现该接口。

/*** Callback used the default {@link RequestConfig} being set to the {@link CloseableHttpClient}* @see HttpClientBuilder#setDefaultRequestConfig*/
public interface RequestConfigCallback {//实现该方法，对builder超时进行设置RequestConfig.Builder customizeRequestConfig(RequestConfig.Builder requestConfigBuilder);
}

可以看到，接口唯一的方法是customizeRequestConfig（），参数是RequestConfig.Builder，返回值也是RequestConfig.Builder。也就是说，我们可以通过该方法覆写RequestConfig.Builder的超时设置并返回回去。

实现子类如下

//采用匿名类
RestClientBuilder.RequestConfigCallback test = new RestClientBuilder.RequestConfigCallback() {@Overridepublic RequestConfig.Builder customizeRequestConfig(RequestConfig.Builder requestConfigBuilder){requestConfigBuilder.setSocketTimeout(1000);return requestConfigBuilder;}
};//上述代码可简化成lamba表达式
RestClientBuilder.RequestConfigCallback requestConfigCallback = requestConfigBuilder -> requestConfigBuilder.setSocketTimeout(28_800_000);

现在就是缺如何设置RequestConfigCallback，看类注释，提示我们看HttpClientBuilder.setDefaultRequestConfig方法。

2.6、HttpClientBuilder.setDefaultRequestConfig

源码如下，可以看到是设置RequestConfigCallback的方法。

public RestClientBuilder setRequestConfigCallback(RequestConfigCallback requestConfigCallback) {Objects.requireNonNull(requestConfigCallback, "requestConfigCallback must not be null");this.requestConfigCallback = requestConfigCallback;return this;
}

3、总结

综上所述，解决思路

实现RestClientBuilder.RequestConfigCallback，覆盖RequestConfig.Builder的超时设置
通过HttpClientBuilder.setDefaultRequestConfig设置RestClientBuilder.RequestConfigCallback

4、Spring自动装配

Spring装配的RestHighLevelClient的两种解决方法都在spring自动装配的配置类RestClientAutoConfiguration中。我们来看看是如何导入并自动装配的

4.1、spring.factories

在spring-boot-autoconfigure.jar的spring.factories有RestClientAutoConfiguration的导入，

# Auto Configure
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
...省略其他
org.springframework.boot.autoconfigure.elasticsearch.rest.RestClientAutoConfiguration,\

4.2、RestClientAutoConfiguration

RestClientAutoConfiguration又导入了其他的配置类，且该类的条件是类路径上有RestClient.class。也就是说，只要用了spring boot+elasticsearch-rest-client，就会开启自动配置。源码如下：

@Configuration(proxyBeanMethods = false)
//条件
@ConditionalOnClass(RestClient.class)
//属性配置相关
@EnableConfigurationProperties(RestClientProperties.class)
//真正的装配类，都是在里面
@Import({ RestClientConfigurations.RestClientBuilderConfiguration.class,RestClientConfigurations.RestHighLevelClientConfiguration.class,RestClientConfigurations.RestClientFallbackConfiguration.class })
public class RestClientAutoConfiguration {}

可以看见，Import的都是RestClientConfigurations的内部类，我们进入RestClientConfigurations看看。

4.3、RestClientConfigurations

RestClientConfigurations就是真正的配置类了，该类创建RestClientBuilder，并基于RestClientBuilder创建了RestHighLevelClient，有三个内部类：

RestClientBuilderConfiguration：创建RestClientBuilder，yml的配置项在此处解析，如host，time-out等
RestHighLevelClientConfiguration：基于builder创建RestHighLevelClient，需要有RestHighLevelClient.class
RestClientFallbackConfiguration：RestClient回调配置

4.3.1、RestClientBuilderConfiguration

该类是创建RestClientBuilder，其他配置类通过RestClientBuilder创建RestHighLevelClient。源码如下：

@Configuration(proxyBeanMethods = false)
static class RestClientBuilderConfiguration {@Bean@ConditionalOnMissingBean//条件，缺少则创建RestClientBuilder elasticsearchRestClientBuilder(RestClientProperties properties,ObjectProvider<RestClientBuilderCustomizer> builderCustomizers) {//配置的连接地址设置HttpHost[] hosts = properties.getUris().stream().map(HttpHost::create).toArray(HttpHost[]::new);RestClientBuilder builder = RestClient.builder(hosts);PropertyMapper map = PropertyMapper.get();map.from(properties::getUsername).whenHasText().to((username) -> {CredentialsProvider credentialsProvider = new BasicCredentialsProvider();Credentials credentials = new UsernamePasswordCredentials(properties.getUsername(),properties.getPassword());credentialsProvider.setCredentials(AuthScope.ANY, credentials);builder.setHttpClientConfigCallback((httpClientBuilder) -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider));});//读取yml配置文件的超时配置并设置builder.setRequestConfigCallback((requestConfigBuilder) -> {map.from(properties::getConnectionTimeout).whenNonNull().asInt(Duration::toMillis).to(requestConfigBuilder::setConnectTimeout);map.from(properties::getReadTimeout).whenNonNull().asInt(Duration::toMillis)//超时.to(requestConfigBuilder::setSocketTimeout);return requestConfigBuilder;});//自定义的bean，覆写配置builderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(builder));return builder;}}

4.3.2、RestHighLevelClientConfiguration

该类基于RestClientBuilder创建RestHighLevelClient，源码如下：

@Configuration(proxyBeanMethods = false)
@ConditionalOnClass(RestHighLevelClient.class)//条件，
static class RestHighLevelClientConfiguration {//创建RestHighLevelClient@Bean@ConditionalOnMissingBeanRestHighLevelClient elasticsearchRestHighLevelClient(RestClientBuilder restClientBuilder) {return new RestHighLevelClient(restClientBuilder);}@Bean@ConditionalOnMissingBeanRestClient elasticsearchRestClient(RestClientBuilder builder,ObjectProvider<RestHighLevelClient> restHighLevelClient) {RestHighLevelClient client = restHighLevelClient.getIfUnique();if (client != null) {return client.getLowLevelClient();}return builder.build();}}

4.4 RestClientProperties

该类是配置文件的映射类，前缀是spring.elasticsearch.rest，我们可以看看有那些可以用的配置项：

@ConfigurationProperties(prefix = "spring.elasticsearch.rest")
public class RestClientProperties {/*** Comma-separated list of the Elasticsearch instances to use.*///默认地址private List<String> uris = new ArrayList<>(Collections.singletonList("http://localhost:9200"));/*** Credentials username.*/private String username;/*** Credentials password.*/private String password;/*** Connection timeout.默认1秒*/private Duration connectionTimeout = Duration.ofSeconds(1);/*** Read timeout.默认30秒*/private Duration readTimeout = Duration.ofSeconds(30);
}