I/O dispatch worker terminated abnormally

Below code i have written to fetch all the records based on index, but getting exception

try (RestHighLevelClient client = new RestHighLevelClient(
				RestClient.builder(HttpHost.create("http://localhost:9200")))) {

			client.indices().getAsync(new GetIndexRequest("logs"), RequestOptions.DEFAULT,
					new ActionListener<GetIndexResponse>() {

						@Override
						public void onResponse(GetIndexResponse response) {

							MappingMetaData indexMappings = response.getMappings().get("logs");
							Map<String, Object> indexTypeMappings = indexMappings.getSourceAsMap();
							List<AliasMetaData> indexAliases = response.getAliases().get("logs");
							String numberOfShardsString = response.getSetting("logs", "logs.number_of_shards");
						}

						@Override
						public void onFailure(Exception e) {
							// TODO Auto-generated method stub

						}
					});
			client.close();
			return null;
		} catch (Exception e) {
			e.printStackTrace();
		}
Nov 15, 2019 12:17:51 PM org.apache.http.impl.nio.client.CloseableHttpAsyncClientBase$1 run

    SEVERE: I/O reactor terminated abnormally

    org.apache.http.nio.reactor.IOReactorException: I/O dispatch worker terminated abnormally

    at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor.execute(AbstractMultiworkerIOReactor.java:359)

    at org.apache.http.impl.nio.conn.PoolingNHttpClientConnectionManager.execute(PoolingNHttpClientConnectionManager.java:221)

    at org.apache.http.impl.nio.client.CloseableHttpAsyncClientBase$1.run(CloseableHttpAsyncClientBase.java:64)

    at java.lang.Thread.run(Thread.java:748)