SocketTimeoutException while retrieving or inserting data into Elastic Search by using Rest High Level Client

I'm facing SocketTimeoutException while retrieving/inserting data from/to elastic. This is happening when there are around 10-30 request/second. These requests are combination of get/put.

Here is my elastic configuration(it's on azure):

  • 3 master nodes each of 4GB RAM
  • 2 data nodes each of 8GM RAM
  • Azure load balancer which connects to above data node (seems only 9200 port is opened on it)
  • Elastic Version: 7.2.0
  • Rest High Level Client:

Index Information:

  • Index shards: 2

  • Index replica: 1

  • Index total fields: 10000

  • Size of index from kibana: Total-27.2 MB & Primaries: 12.2MB

  • Index structure:

    {"dev-index":{"mappings":{"properties":{"dataObj": 
    {"type":"object","enabled":false},"generatedID":{"type":"keyword"},"transNames": 
    {"type":"keyword"}}}}}
    
  • Dynamic mapping is disabled.

Following is my elastic Config file. Here I've two connection bean, one is for read & another for write to elastic.

ElasticConfig.java:

@Configuration
public class ElasticConfig {

    
    private String elasticHost;
    private int elasticPort;
    private String elasticUser;
    private String elasticPass;
    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;
    }

}

Here is the function which makes a call to elastic, if data is available in elastic it will take it else it will generate data & put into elastic.

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 Function:

@Service
public class ElasticService {

    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 Async Put Data Function:

@Service
public class ElasticAsync {

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

    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);
        }
    }

}

Here is the some part of the stack trace when exception is occurred during saving data into elastic:(will add in follow up comment)

I've gone through couple of stackoverflow & elastic related blogs where they have mentioned this issue could be due to RAM & cluster configuration of elastic. Then I've changed my shards from 5 to 2 as there were only two data nodes. Also increased ram of Data nodes from 4GB to 8GB, as I get to know that elastic will use only 50% of total RAM. The occurrences of exception have decreased but problem still persist.

What I'm missing from java/elastic configuration point of view which frequently throwing this kind of SocketTimeoutException ?

Due to limit to post, I have removed some information form OP. So here are the missing things from OP:
Maven Dependency:

    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>7.2.0</version>
    </dependency>
    
    <dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>7.2.0</version>
    </dependency>

Here is the some part of the stack trace when exception is occurred during saving data into elastic:

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

Here is the some part of the stack trace when exception is occurred during retrieving data into elastic:

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

The values of all global level variables of ElasticConfig are taken using @Value annotation & same is applied wherever i've used global variable private String elasticIndex;

Link to complete stackoverflow post.