我正在使用 Spring Boot 1.5.4.RELEASE 微服务连接到使用 ElasticSearch 提供的低级别 Rest Client 的 ElasticSearch 5.5.0 实例。
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>
一切都已正确设置,但在多次点击后,客户端应用程序报告 HTTP 500 错误,这就是日志文件中显示的内容:
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 内部(//注释后的第二行是第 94 行):
@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...
}
}
很明显,在调用 restClient.performRequest() 方法后,它从未关闭过...
因此,我将其放入我的代码中:
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();
}
阅读 Elastic Search 的文档,了解 RestClient 类是线程安全的...
此外,阅读有关 restClient.performRequestAsync() 方法的信息,但我对线程有些缺乏经验,并且文档中的描述含糊不清。
问题:
我的解决方案是处理和关闭一堆套接字资源的最佳方式吗?
如果有人能告诉我一个更好的方法来使用低级别的 RestClient 和 Elastic Search,我将不胜感激,因为它不会导致相同的问题,即套接字资源未被释放导致 HTTP 500。应该我正在使用 restClient.performRequestAsync?有人可以举个例子吗?
感谢您花时间阅读本文...
最佳答案
在每个请求上都创建一个 RestClient
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:
@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();
}
}
然后在您的 SearchController
类中,您可以像这样注入(inject)它(并添加一个清除方法以在您的容器关闭时关闭 restClient
实例):
@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);
}
}
}
关于java - 使用 Elastic Search 5.5.0 时如何正确关闭 Raw RestClient 以获得最佳性能?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/46166955/