使用Elastic Search 5.5.0获得最佳性能时如何正确关闭原始RestClient？ [英] How to Properly Close Raw RestClient When Using Elastic Search 5.5.0 for Optimal Performance?
问题描述
使用Spring Boot 1.5.4.RELEASE微服务使用ElasticSearch提供的低级Rest Client连接到ElasticSearch 5.5.0实例。
Am using a Spring Boot 1.5.4.RELEASE Microservice to connect to an ElasticSearch 5.5.0 instance using the low level Rest Client that ElasticSearch provides.
pom。 xml
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.4.RELEASE</version>
</parent>
<dependencies>
<!-- Spring -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- Elasticsearch -->
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>5.5.0</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>transport</artifactId>
<version>5.5.0</version>
</dependency>
<!-- Apache Commons -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.6</version>
</dependency>
<!-- Jackson -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.8.9</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.8.9</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.8.9</version>
</dependency>
<!-- Log4j -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<!-- JUnit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<!-- Swagger -->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>2.6.1</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>2.6.1</version>
<scope>compile</scope>
</dependency>
</dependencies>
一切都设置正确但经过一系列点击后，客户端应用报告了HTTP 500错误是日志文件中出现的内容：
Everything is setup correctly but after a bunch of hits, client apps were reporting an HTTP 500 error and this is what appeared in the log files:
java.io.IOException: Too many open files
at sun.nio.ch.IOUtil.makePipe(Native Method) ~[na:1.8.0_141]
at sun.nio.ch.EPollSelectorImpl.<init>(EPollSelectorImpl.java:65) ~[na:1.8.0_141]
at sun.nio.ch.EPollSelectorProvider.openSelector(EPollSelectorProvider.java:36) ~[na:1.8.0_141]
at java.nio.channels.Selector.open(Selector.java:227) ~[na:1.8.0_141]
at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor.<init>(AbstractMultiworkerIOReactor.java:142) ~[httpcore-nio-4.4.5.jar!/:4.4.5]
at org.apache.http.impl.nio.reactor.DefaultConnectingIOReactor.<init>(DefaultConnectingIOReactor.java:79) ~[httpcore-nio-4.4.5.jar!/:4.4.5]
at org.apache.http.impl.nio.client.IOReactorUtils.create(IOReactorUtils.java:43) ~[httpasyncclient-4.1.3.jar!/:4.1.3]
at org.apache.http.impl.nio.client.HttpAsyncClientBuilder.build(HttpAsyncClientBuilder.java:666) ~[httpasyncclient-4.1.3.jar!/:4.1.3]
at org.elasticsearch.client.RestClientBuilder.createHttpClient(RestClientBuilder.java:202) ~[rest-5.5.0.jar!/:5.5.0]
at org.elasticsearch.client.RestClientBuilder.build(RestClientBuilder.java:180) ~[rest-5.5.0.jar!/:5.5.0]
at com.myapp.controller.SearchController.getSearchQueryResults(SearchController.java:94) ~[classes!/:1.0]
在SearchController里面（//注释是第94行之后的第二行）：
Inside SearchController (the second line after the // comment is line 94):
@RestController
@RequestMapping("/api/v1")
public class SearchController {
@RequestMapping(value = "/search", method = RequestMethod.GET, produces="application/json" )
public ResponseEntity<Object> getSearchQueryResults(@RequestParam(value = "criteria") String criteria) throws IOException {
// Setup HTTP Headers
HttpHeaders headers = new HttpHeaders();
headers.add("Content-Type", "application/json");
// Setup RestClient
RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200))
.setRequestConfigCallback(new RestClientBuilder.RequestConfigCallback() {
@Override
public RequestConfig.Builder customizeRequestConfig(RequestConfig.Builder requestConfigBuilder) {
return requestConfigBuilder.setConnectTimeout(5000).setSocketTimeout(60000);
}
}).setMaxRetryTimeoutMillis(60000).build();
// Setup query and send and return ResponseEntity...
}
}
显然，在调用restClient.performRequest（）方法后它从未关闭过......
Its obvious that what it was never closed after calling the restClient.performRequest() method...
所以，我把它放到我的代码中：
So, I put this into my code:
Response response = null;
try {
// Submit Query and Obtain Response
response = restClient.performRequest("POST", endPoint, Collections.singletonMap("pretty", "true"), entity);
}
catch (IOException e) {
LOG.error("\n\n\tException: " + e + "\n\n");
e.printStackTrace();
}
finally {
restClient.close();
}
在Elastic Search的文档中读取RestClient类是线程安全的...
Read on Elastic Search's documentation that the RestClient class is thread-safe...
另外，请阅读有关restClient.performRequestAsync（）方法的信息，但我对线程缺乏经验，文档中的描述含糊不清。
Also, read about the restClient.performRequestAsync() method but am somewhat inexperienced with threads and the description inside the documentation is vague.
问题：
-
我的解决方案是最好的处理和关闭一堆套接字资源的方法？
Is my solution the best way to handle and close a bunch of socket resources?
如果有人能告诉我一个更好的方法来使用弹性搜索的低级RestClient，我将不胜感激它不会导致相同的问题，因为套接字资源没有被释放导致HTTP 500.我应该使用restClient.performRequestAsync吗？有人可以提供一个例子吗？
Would appreciate if someone could show me a better way to use the low level RestClient with Elastic Search in sense that it won't cause the same issue with the socket resources not being freed resulting in an HTTP 500. Should I be using restClient.performRequestAsync? Could someone please provide an example?
感谢您花时间阅读此内容......
Thank you for taking the time to read this...
推荐答案
在每个请求上创建 RestClient 并不是一个好习惯。您应该通过如下所示的配置bean创建单个实例：
It's is not a good practice to create a RestClient on every single request. You should create a single instance via a configuration bean like the one below:
@Configuration
public class ElasticsearchConfig {
@Value("${elasticsearch.host}")
private String host;
@Value("${elasticsearch.port}")
private int port;
@Bean
public RestClient restClient() {
return RestClient.builder(new HttpHost(host, port))
.setRequestConfigCallback(new RestClientBuilder.RequestConfigCallback() {
@Override
public RequestConfig.Builder customizeRequestConfig(RequestConfig.Builder requestConfigBuilder) {
return requestConfigBuilder.setConnectTimeout(5000).setSocketTimeout(60000);
}
}).setMaxRetryTimeoutMillis(60000).build();
}
}
然后在你的 SearchController中类可以像这样注入它（并且还可以在容器关闭时添加一个清理方法来关闭 restClient 实例）：
And then in your SearchController class you can inject it like this (and also add a cleanup method to close the restClient instance when your container goes down):
@RestController
@RequestMapping("/api/v1")
public class SearchController {
@Autowired
private RestClient restClient;
@RequestMapping(value = "/search", method = RequestMethod.GET, produces="application/json" )
public ResponseEntity<Object> getSearchQueryResults(@RequestParam(value = "criteria") String criteria) throws IOException {
// Setup HTTP Headers
HttpHeaders headers = new HttpHeaders();
headers.add("Content-Type", "application/json");
// Setup query and send and return ResponseEntity...
Response response = this.restClient.performRequest(...);
}
@PreDestroy
public void cleanup() {
try {
logger.info("Closing the ES REST client");
this.restClient.close();
} catch (IOException ioe) {
logger.error("Problem occurred when closing the ES REST client", ioe);
}
}
}
这篇关于使用Elastic Search 5.5.0获得最佳性能时如何正确关闭原始RestClient？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
