I'm facing the same issue, and seeing this I realized that the retry is happening on my side too in each host (I have 3 host and the exception happens in 3 threads). I wanted to post it since you might face the same issue or someone else might come to this post because of the same SocketConnection Exception.
Searching the official docs, the HighLevelRestClient uses under the hood the RestClient, and the RestClient uses CloseableHttpAsyncClient which have a connection pool. ElasticSearch specifies that you should close the connection once that you are done, (which sounds ambiguous the definition of "done" in an application), but in general in internet I have found that you should close it when the application is closing or ending, rather than when you finished querying.
Now on the official documentation of apache they have an example to handle the connection pool, which i'm trying to follow, I'll try to replicate the scenario and will post if that fixes my issue, the code can be found here:
https://hc.apache.org/httpcomponents-asyncclient-dev/httpasyncclient/examples/org/apache/http/examples/nio/client/AsyncClientEvictExpiredConnections.java
This is what i have so far:
@Bean(name = "RestHighLevelClientWithCredentials", destroyMethod = "close")
public RestHighLevelClient elasticsearchClient(ElasticSearchClientConfiguration elasticSearchClientConfiguration,
RestClientBuilder.HttpClientConfigCallback httpClientConfigCallback) {
return new RestHighLevelClient(
RestClient
.builder(getElasticSearchHosts(elasticSearchClientConfiguration))
.setHttpClientConfigCallback(httpClientConfigCallback)
);
}
@Bean
@RefreshScope
public RestClientBuilder.HttpClientConfigCallback getHttpClientConfigCallback(
PoolingNHttpClientConnectionManager poolingNHttpClientConnectionManager,
CredentialsProvider credentialsProvider
) {
return httpAsyncClientBuilder -> {
httpAsyncClientBuilder.setSSLHostnameVerifier(NoopHostnameVerifier.INSTANCE);
httpAsyncClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
httpAsyncClientBuilder.setConnectionManager(poolingNHttpClientConnectionManager);
return httpAsyncClientBuilder;
};
}
public class ElasticSearchClientManager {
private ElasticSearchClientManager.IdleConnectionEvictor idleConnectionEvictor;
/**
* Custom client connection manager to create a connection watcher
*
* @param elasticSearchClientConfiguration elasticSearchClientConfiguration
* @return PoolingNHttpClientConnectionManager
*/
@Bean
@RefreshScope
public PoolingNHttpClientConnectionManager getPoolingNHttpClientConnectionManager(
ElasticSearchClientConfiguration elasticSearchClientConfiguration
) {
try {
SSLIOSessionStrategy sslSessionStrategy = new SSLIOSessionStrategy(getTrustAllSSLContext());
Registry<SchemeIOSessionStrategy> sessionStrategyRegistry = RegistryBuilder.<SchemeIOSessionStrategy>create()
.register("http", NoopIOSessionStrategy.INSTANCE)
.register("https", sslSessionStrategy)
.build();
ConnectingIOReactor ioReactor = new DefaultConnectingIOReactor();
PoolingNHttpClientConnectionManager poolingNHttpClientConnectionManager =
new PoolingNHttpClientConnectionManager(ioReactor, sessionStrategyRegistry);
idleConnectionEvictor = new ElasticSearchClientManager.IdleConnectionEvictor(poolingNHttpClientConnectionManager,
elasticSearchClientConfiguration);
idleConnectionEvictor.start();
return poolingNHttpClientConnectionManager;
} catch (IOReactorException e) {
throw new RuntimeException("Failed to create a watcher for the connection pool");
}
}
private SSLContext getTrustAllSSLContext() {
try {
return new SSLContextBuilder()
.loadTrustMaterial(null, (x509Certificates, string) -> true)
.build();
} catch (Exception e) {
throw new RuntimeException("Failed to create SSL Context with open certificate", e);
}
}
public IdleConnectionEvictor.State state() {
return idleConnectionEvictor.evictorState;
}
@PreDestroy
private void finishManager() {
idleConnectionEvictor.shutdown();
}
public static class IdleConnectionEvictor extends Thread {
private final NHttpClientConnectionManager nhttpClientConnectionManager;
private final ElasticSearchClientConfiguration elasticSearchClientConfiguration;
@Getter
private State evictorState;
private volatile boolean shutdown;
public IdleConnectionEvictor(NHttpClientConnectionManager nhttpClientConnectionManager,
ElasticSearchClientConfiguration elasticSearchClientConfiguration) {
super();
this.nhttpClientConnectionManager = nhttpClientConnectionManager;
this.elasticSearchClientConfiguration = elasticSearchClientConfiguration;
}
@Override
public void run() {
try {
while (!shutdown) {
synchronized (this) {
wait(elasticSearchClientConfiguration.getExpiredConnectionsCheckTime());
// Close expired connections
nhttpClientConnectionManager.closeExpiredConnections();
// Optionally, close connections
// that have been idle longer than 5 sec
nhttpClientConnectionManager.closeIdleConnections(elasticSearchClientConfiguration.getMaxTimeIdleConnections(),
TimeUnit.SECONDS);
this.evictorState = State.RUNNING;
}
}
} catch (InterruptedException ex) {
this.evictorState = State.NOT_RUNNING;
}
}
private void shutdown() {
shutdown = true;
synchronized (this) {
notifyAll();
}
}
public enum State {
RUNNING,
NOT_RUNNING
}
}
}
