Java向ES库中插入数据报错:java.lang.IllegalStateException: Request cannot be executed; I/O reactor status: STO
一、问题
在使用Java向ES库中插入数据时,第一次成功插入,第二次出现以下错误:
java.lang.IllegalStateException: Request cannot be executed; I/O reactor status: STOPPED at
问题原因
这里显示是连接中断,第一次遇到这个问题,比较疑惑为什么es的客户端会中断,理论上es client 是长连接,不停的有数据写入,连接一致存在,除非有服务端异常。在elasticsearch服务端查看日志,没有任何异常信息。
网上搜索错误信息原来是 Apache HTTPComponents 异步客户端问题。es官网有个issues详细的记录的这个问题的原因和修复建议。
官方的意见是 Apache HTTPComponents 异步客户端 使用了一个内部的I/O reactor 分发IO event。在某些情况下,IO reactor会记录程序调用栈中的异常或者Java NOI库中的异常,如果这些异常不被处理,I/O reactor会直接关闭,es client不可用,此时只能重启服务。es client中试图增加一个默认的 I/O reactor 异常处理逻辑但是在做了一些尝试后发现捕获I/O reactor后会导致SSL中断。而HTTPComponents 在版本5中已经修复了这个问题,最终官网给的建议是等待版本升级。
二、解决思路
解决问题的过程中参考了以下文档:
https://www.cnblogs.com/yangchongxing/p/15440197.html
https://github.com/elastic/elasticsearch/issues/42133
https://zhuanlan.zhihu.com/p/384269417
https://cloud.tencent.com/developer/article/1806886
主要获得解决方法的是以下:
https://github.com/elastic/elasticsearch/issues/39946
主要引用以下:
大概意思是说:
在每个线程需要时创建一个新的客户端,并在方法结束时关闭。这就解决了问题。
结合GPT获取解决方案:
java
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
public class EsClientManager {
private final ExecutorService executorService = Executors.newFixedThreadPool(10);
private final ThreadLocal<RestHighLevelClient> CLIENT_THREAD_LOCAL = ThreadLocal.withInitial(() -> {
RestHighLevelClient client = null;
try {
client = RestHighLevelClient.builder(new HttpHost("localhost", 9200, "http")).build();
return client;
} catch (IOException e) {
e.printStackTrace();
return null;
}
});
public RestHighLevelClient getClient() {
return CLIENT_THREAD_LOCAL.get();
}
public void closeClient(RestHighLevelClient client) {
CLIENT_THREAD_LOCAL.remove();
if (client != null) {
executorService.execute(() -> {
try {
client.close();
} catch (IOException e) {
e.printStackTrace();
}
});
}
}
}
在使用时,同样可以这样:
java
public class MyService {
public void someMethod() {
RestHighLevelClient client = EsClientManager.getClient();
try {
// 执行操作
} finally {
EsClientManager.closeClient(client);
}
}
}
这样,每个线程都会从EsClientManager获取一个客户端,并在方法结束时自动关闭。
线程池不允许使用 Executors 去创建,而是通过 ThreadPoolExecutor 的方式,进一步,优化:
java
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.LinkedBlockingQueue;
public class EsClientManager {
private final ExecutorService executorService;
private final ThreadLocal<RestHighLevelClient> CLIENT_THREAD_LOCAL = ThreadLocal.withInitial(() -> {
RestHighLevelClient client = null;
try {
client = RestHighLevelClient.builder(new HttpHost("localhost", 9200, "http")).build();
return client;
} catch (IOException e) {
e.printStackTrace();
return null;
}
});
public EsClientManager() {
// 配置 ThreadPoolExecutor
int corePoolSize = 10; // 核心线程数
int maximumPoolSize = 10; // 最大线程数
long keepAliveTime = 0L; // 空闲线程等待新任务的最长时间
TimeUnit unit = TimeUnit.MILLISECONDS; // keepAliveTime的时间单位
int queueCapacity = 100; // 工作队列的容量
ThreadPoolExecutor executor = new ThreadPoolExecutor(
corePoolSize,
maximumPoolSize,
keepAliveTime,
unit,
new LinkedBlockingQueue<>(queueCapacity), // 工作队列
runnable -> {
Thread thread = new Thread(runnable);
thread.setDaemon(false); // 设置线程是否为守护线程,false表示非守护线程
return thread;
}
);
this.executorService = Executors.unconfigurableExecutorService(executor);
}
public RestHighLevelClient getClient() {
return CLIENT_THREAD_LOCAL.get();
}
public void closeClient(RestHighLevelClient client) {
CLIENT_THREAD_LOCAL.remove();
if (client != null) {
executorService.execute(() -> {
try {
client.close();
} catch (IOException e) {
e.printStackTrace();
}
});
}
}
// 添加方法以允许关闭executorService
public void shutdown() {
executorService.shutdown();
}
public boolean isShutdown() {
return executorService.isShutdown();
}
public boolean isTerminated() {
return executorService.isTerminated();
}
}