生产环境中偶尔会出现以下异常，
2020-01-29 17:10:46.085 ERROR 2852 --- [o-8022-exec-258] c.c.p.common.dao.SearchDao : Search person by id failed
java.net.SocketTimeoutException: 30,000 milliseconds timeout on connection http-outgoing-832 [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: 30,000 milliseconds timeout on connection http-outgoing-832 [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-4.1.4.jar!/:4.1.4]
at org.apache.http.impl.nio.client.InternalIODispatch.onTimeout(InternalIODispatch.java:39) ~[httpasyncclient-4.1.4.jar!/:4.1.4]
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]
但这只是一个简单的查询，而不是一个复杂的查询
curl 'http://localhost:9201/person/_doc/30154410564?pretty'
在这段时间内，负载非常低
那么为什么会存在这些超时异常呢？并且有很多搜索查询但是为什么只有这个简单的query by id可能会导致这个异常？
人物索引是从Oracle DB同步的，有一个定时任务，每隔10分钟会同步变化的人物索引，如果在这段时间内访问人物索引，会导致30,000 milliseconds timeout. 那么如何解决呢？而且好像Java客户端访问会出现这种现象，而curl命令行访问则不会出现这种现象。
PS：
health status index uuid pri rep docs.count docs.deleted store.size pri.store.size
green open person jb3msRw5S9ixgXN5SLd6bw 1 0 140754205 19239587 19.8gb 19.8gb
并且在这个时候有为人员索引写的索引
休息客户端配置：
private final RestHighLevelClient restHighLevelClient;
restHighLevelClient = new RestHighLevelClient(RestClient.builder(new HttpHost(host, port)));