使用Rest高级客户端检索数据或将数据插入弹性搜索时的SocketTimeoutException

Question

在检索/插入数据时，我将面对SocketTimeoutException。这种情况发生在10-30 request/second周围。这些请求是get/put的组合。

这是我的弹性结构：

• 3 master nodes每个4GB RAM
• 2 data nodes每个8GM RAM
• Azure负载均衡器，它连接到上面的数据节点(似乎只打开了9200端口)。java客户端连接到这个负载均衡器，因为它只公开。
• 弹性版本: 7.2.0
• Rest高级客户端： org.elasticsearch.client elasticsearch -rest-高级客户端7.2.0 org.elasticsearch elasticsearch 7.2.0

索引信息：

• 索引碎片:2
• 指数复制:1
• 索引总字段: 10000
• 基班纳索引的大小：27.2 MB& Primaries: 12.2MB
• 索引结构：{ "dev- Index "：{“dev”：{ "dataObj"：{ "type"："object"，"enabled"：false }，"generatedID"：{ "type"：“关键字”}，"transNames"：{//它的字符串“type”数组：“关键字”}
• 禁用动态映射。

下面是我的elastic Config文件。这里我有两个连接bean，一个用于读，另一个用于写到弹性。

ElasticConfig.java:

@Configuration
public class ElasticConfig {

    @Value("${elastic.host}")
    private String elasticHost;

    @Value("${elastic.port}")
    private int elasticPort;

    @Value("${elastic.user}")
    private String elasticUser;

    @Value("${elastic.pass}")
    private String elasticPass;

    @Value("${elastic-timeout:20}")
    private int timeout;

    @Bean(destroyMethod = "close")
    @Qualifier("readClient")
    public RestHighLevelClient readClient(){

        final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(elasticUser, elasticPass));

        RestClientBuilder builder = RestClient
                .builder(new HttpHost(elasticHost, elasticPort))
                .setHttpClientConfigCallback(httpClientBuilder -> 
                        httpClientBuilder
                                .setDefaultCredentialsProvider(credentialsProvider)
                                .setDefaultIOReactorConfig(IOReactorConfig.custom().setIoThreadCount(5).build())
                );

        builder.setRequestConfigCallback(requestConfigBuilder -> 
                requestConfigBuilder
                        .setConnectTimeout(10000)
                        .setSocketTimeout(60000)
                        .setConnectionRequestTimeout(0)
        );

        RestHighLevelClient restClient = new RestHighLevelClient(builder);
        return restClient;
    }

    @Bean(destroyMethod = "close")
    @Qualifier("writeClient")
    public RestHighLevelClient writeClient(){

        final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(elasticUser, elasticPass));

        RestClientBuilder builder = RestClient
                .builder(new HttpHost(elasticHost, elasticPort))
                .setHttpClientConfigCallback(httpClientBuilder -> 
                        httpClientBuilder
                                .setDefaultCredentialsProvider(credentialsProvider)
                                .setDefaultIOReactorConfig(IOReactorConfig.custom().setIoThreadCount(5).build())
                );

        builder.setRequestConfigCallback(requestConfigBuilder -> 
                requestConfigBuilder
                        .setConnectTimeout(10000)
                        .setSocketTimeout(60000)
                        .setConnectionRequestTimeout(0)
        );

        RestHighLevelClient restClient = new RestHighLevelClient(builder);
        return restClient;
    }

}

这是一个函数，它调用弹性，如果数据可用弹性，它就会得到它，否则它将生成数据&投入弹性。

public Object getData(Request request) {

    DataObj elasticResult = elasticService.getData(request);
    if(elasticResult!=null){
        return elasticResult;
    }
    else{
        //code to generate data
        DataObj generatedData = getData();//some function which will generated data
        //put above data into elastic by Async call.
        elasticAsync.putData(generatedData);
        return generatedData;
    }
}

ElasticService.java getData函数：

@Service
public class ElasticService {

    @Value("${elastic.index}")
    private String elasticIndex;

    @Autowired
    @Qualifier("readClient")
    private RestHighLevelClient readClient;

    public DataObj getData(Request request){
        String generatedId = request.getGeneratedID();

        GetRequest getRequest = new GetRequest()
                .index(elasticIndex)   //elastic index name
                .id(generatedId);   //retrieving by index id from elastic _id field (as key-value)

        DataObj result = null;
        try {
            GetResponse response = readClient.get(getRequest, RequestOptions.DEFAULT);
            if(response.isExists()) {
                ObjectMapper objectMapper = new ObjectMapper();
                result = objectMapper.readValue(response.getSourceAsString(), DataObj.class);
            }
        }  catch (Exception e) {
            LOGGER.error("Exception occurred during  fetch from elastic !!!! " + ,e);
        }
        return result;
    }

}

ElasticAsync.java异步提交数据函数：

@Service
public class ElasticAsync {

    private static final Logger LOGGER = Logger.getLogger(ElasticAsync.class.getName());

    @Value("${elastic.index}")
    private String elasticIndex;

    @Autowired
    @Qualifier("writeClient")
    private RestHighLevelClient writeClient;

    @Async
    public void putData(DataObj generatedData){
     ElasticVO updatedRequest = toElasticVO(generatedData);//ElasticVO matches to the structure of index given above.

        try {
            ObjectMapper objectMapper = new ObjectMapper();
            String jsonString = objectMapper.writeValueAsString(updatedRequest);

            IndexRequest request = new IndexRequest(elasticIndex);
            request.id(generatedData.getGeneratedID());
            request.source(jsonString, XContentType.JSON);
            request.setRefreshPolicy(WriteRequest.RefreshPolicy.NONE);
            request.timeout(TimeValue.timeValueSeconds(5));
            IndexResponse indexResponse = writeClient.index(request, RequestOptions.DEFAULT);
            LOGGER.info("response id: " + indexResponse.getId());

            }

        } catch (Exception e) {
            LOGGER.error("Exception occurred during saving into elastic !!!!",e);
        }


    }

}

以下是在将数据保存到弹性过程中发生异常时堆栈跟踪的某些部分：

2019-07-19 07:32:19.997 ERROR [data-retrieval,341e6ecc5b10f3be,1eeb0722983062b2,true] 1 --- [askExecutor-894] a.c.s.a.service.impl.ElasticAsync        : Exception occurred during saving into elastic !!!!

java.net.SocketTimeoutException: 60,000 milliseconds timeout on connection http-outgoing-34 [ACTIVE]
at org.elasticsearch.client.RestClient.extractAndWrapCause(RestClient.java:789) ~[elasticsearch-rest-client-7.2.0.jar!/:7.2.0]
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:225) ~[elasticsearch-rest-client-7.2.0.jar!/:7.2.0]
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:212) ~[elasticsearch-rest-client-7.2.0.jar!/:7.2.0]
    at org.elasticsearch.client.RestHighLevelClient.internalPerformRequest(RestHighLevelClient.java:1448) ~[elasticsearch-rest-high-level-client-7.2.0.jar!/:7.2.0]
    at org.elasticsearch.client.RestHighLevelClient.performRequest(RestHighLevelClient.java:1418) ~[elasticsearch-rest-high-level-client-7.2.0.jar!/:7.2.0]
    at org.elasticsearch.client.RestHighLevelClient.performRequestAndParseEntity(RestHighLevelClient.java:1388) ~[elasticsearch-rest-high-level-client-7.2.0.jar!/:7.2.0]
    at org.elasticsearch.client.RestHighLevelClient.index(RestHighLevelClient.java:836) ~[elasticsearch-rest-high-level-client-7.2.0.jar!/:7.2.0]


Caused by: java.net.SocketTimeoutException: 60,000 milliseconds timeout on connection http-outgoing-34 [ACTIVE]
    at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.timeout(HttpAsyncRequestExecutor.java:387) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.client.InternalIODispatch.onTimeout(InternalIODispatch.java:92) ~[httpasyncclient-4.1.3.jar!/:4.1.3]
    at org.apache.http.impl.nio.client.InternalIODispatch.onTimeout(InternalIODispatch.java:39) ~[httpasyncclient-4.1.3.jar!/:4.1.3]
    at org.apache.http.impl.nio.reactor.AbstractIODispatch.timeout(AbstractIODispatch.java:175) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.BaseIOReactor.sessionTimedOut(BaseIOReactor.java:263) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.timeoutCheck(AbstractIOReactor.java:492) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.BaseIOReactor.validate(BaseIOReactor.java:213) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:280) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:104) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:591) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    ... 1 common frames omitted

以下是在将数据检索为弹性时发生异常时堆栈跟踪的某些部分：

2019-07-19 07:22:37.844 ERROR [data-retrieval,104cf6b2ab5b3349,b302d3d3cd7ebc84,true] 1 --- [o-8080-exec-346] a.c.s.a.service.impl.ElasticService      : Exception occurred during  fetch from elastic !!!! 

java.net.SocketTimeoutException: 60,000 milliseconds timeout on connection http-outgoing-30 [ACTIVE]
    at org.elasticsearch.client.RestClient.extractAndWrapCause(RestClient.java:789) ~[elasticsearch-rest-client-7.1.1.jar!/:7.1.1]
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:225) ~[elasticsearch-rest-client-7.1.1.jar!/:7.1.1]
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:212) ~[elasticsearch-rest-client-7.1.1.jar!/:7.1.1]
    at org.elasticsearch.client.RestHighLevelClient.internalPerformRequest(RestHighLevelClient.java:1433) ~[elasticsearch-rest-high-level-client-7.1.1.jar!/:7.1.1]
    at org.elasticsearch.client.RestHighLevelClient.performRequest(RestHighLevelClient.java:1403) ~[elasticsearch-rest-high-level-client-7.1.1.jar!/:7.1.1]
    at org.elasticsearch.client.RestHighLevelClient.performRequestAndParseEntity(RestHighLevelClient.java:1373) ~[elasticsearch-rest-high-level-client-7.1.1.jar!/:7.1.1]
    at org.elasticsearch.client.RestHighLevelClient.get(RestHighLevelClient.java:699) ~[elasticsearch-rest-high-level-client-7.1.1.jar!/:7.1.1]



Caused by: java.net.SocketTimeoutException: 60,000 milliseconds timeout on connection http-outgoing-30 [ACTIVE]
        at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.timeout(HttpAsyncRequestExecutor.java:387) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.client.InternalIODispatch.onTimeout(InternalIODispatch.java:92) ~[httpasyncclient-4.1.3.jar!/:4.1.3]
    at org.apache.http.impl.nio.client.InternalIODispatch.onTimeout(InternalIODispatch.java:39) ~[httpasyncclient-4.1.3.jar!/:4.1.3]
    at org.apache.http.impl.nio.reactor.AbstractIODispatch.timeout(AbstractIODispatch.java:175) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.BaseIOReactor.sessionTimedOut(BaseIOReactor.java:263) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.timeoutCheck(AbstractIOReactor.java:492) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.BaseIOReactor.validate(BaseIOReactor.java:213) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:280) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:104) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:591) ~[httpcore-nio-4.4.11.jar!/:4.4.11]
    ... 1 common frames omitted

我浏览了几个与stackoverflow和elastic相关的博客，他们提到这个问题可能是由于弹性的RAM & cluster配置造成的。然后，我将碎片从5更改为2，因为只有两个数据节点。数据节点的内存也从4GB增加到8GB，因为我知道弹性只会使用总50%的RAM。异常的发生有所减少，但问题仍然存在。

有什么办法可以解决这个问题呢？从java/弹性配置的角度来看，经常抛出这种SocketTimeoutException的是什么？如果您需要更多关于配置的详细信息，请告诉我。

Answer 1

我们也遇到了同样的问题，在深入挖掘之后，我找到了根本原因:客户端与弹性服务器之间的防火墙配置不匹配，tcp内核配置保持活跃。

防火墙在3600秒后丢弃空闲连接。问题是tcp保持活动的内核参数设置为7200秒(默认为RedHat 6.x/7.x)：

sysctl -n net.ipv4.tcp_keepalive_time
7200

因此，在发送“保持生命”探针之前，连接就会被丢弃。弹性http客户机中的asyncHttpClient似乎不能很好地处理掉的连接，它只是等待套接字超时。

因此，请检查是否有任何网络设备(负载平衡器、防火墙、代理等)。在您的客户机和服务器之间，它具有会话超时或类似的状态，或者增加了超时时间，或者降低了tcp_keep_alive内核参数。