将 JedisPool 与 Tomcat 一起使用，资源不会返回到池中
Using JedisPool with Tomcat, resources not being returned back to pool
查看 redis client list 的输出，我看到目前有 600 个活跃客户端，并且还在继续增长。这是一个输出片段：
id=285316 addr=x.x.x.x:55699 fd=14131 name= age=53055 idle=53029 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=sismember
id=285317 addr=x.x.x.x:55700 fd=14132 name= age=53055 idle=53050 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=sismember
这是我的代码：
Listener.java:
import com.sun.jersey.api.model.AbstractResourceModelContext;
import com.sun.jersey.api.model.AbstractResourceModelListener;
import javax.ws.rs.ext.Provider;
@Provider
public class Listener implements AbstractResourceModelListener {
@Override
public void onLoaded(AbstractResourceModelContext modelContext) {
RedisManager.getInstance().connect();
}
}
RedisManager.java:
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
public class RedisManager {
private static final RedisManager instance = new RedisManager();
private static JedisPool pool;
private RedisManager() {
}
public final static RedisManager getInstance() {
return instance;
}
public void connect() {
JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMaxTotal(5000);
poolConfig.setTestOnBorrow(true);
poolConfig.setTestOnReturn(true);
poolConfig.setMaxIdle(50);
poolConfig.setMinIdle(1);
poolConfig.setTestWhileIdle(true);
poolConfig.setNumTestsPerEvictionRun(10);
poolConfig.setTimeBetweenEvictionRunsMillis(60000);
pool = new JedisPool(poolConfig, "redis_hostname");
}
public void release() {
pool.destroy();
}
public Jedis getJedis() {
return pool.getResource();
}
public void returnJedis(Jedis jedis) {
pool.returnResourceObject(jedis);
}
}
APIServlet.java:
@Path("/")
public class APIService {
@GET
@Path("/lookup")
@Produces(MediaType.APPLICATION_JSON)
public Response getMsg(@QueryParam("email") String email,
@QueryParam("pretty") String pretty
) throws JSONException {
Jedis jedis = RedisManager.getInstance().getJedis();
if (jedis.sismember("inprocess", email)) {
RedisManager.getInstance().returnJedis(jedis);
return Response.status(202).entity("{\"status\":202, " +
"\"processing\":{\"type\":\"Lookup performed\", " +
"\"message\":\"We're performing analysis on this " +
"record. Result should be ready in a few minutes" +
".\"}}").build();
}
Person person = new Person();
person.lookup(person);
ObjectMapper mapper = new ObjectMapper();
String jsonString = mapper.writeValueAsString(person);
JSONObject jsonObj = new JSONObject(jsonString);
jsonObj.remove("objectID");
jsonObj.remove("data_quality");
jsonObj.put("status", 200);
RedisManager.getInstance().returnJedis(jedis);
if (!jsonObj.isNull("name") && !jsonObj.get("name").equals("")) {
if (hasPretty) {
return Response.status(200).entity(jsonObj.toString(4))
.build();
}
return Response.status(200).entity(jsonObj.toString()).build();
}
return Response.status(404).entity("{\"status\":404, " +
"\"error\":{\"type\":\"Data Not Found.\", " +
"\"message\":\"We were not able to find data " +
"on this email.\"}}").build();
}
}
Maven 依赖关系:
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-server</artifactId>
<version>1.8</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-json</artifactId>
<version>1.8</version>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.7.2</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>commons-validator</groupId>
<artifactId>commons-validator</artifactId>
<version>1.2.0</version>
</dependency>
Listener 创建一个 RedisManager 实例以在整个应用程序中使用——这应该只在启动时发生一次（注意：我不知道如何在关闭时调用 destroy，如果知道的话会很高兴）。在整个程序中，Jersey 路由中使用了 JedisPool 的这个实例，如 APIServlet.java 所示。在路线中，我得到一个 JedisPool 资源，然后在路线的任何部分 return 之前，我 return 资源。
发生的事情是资源似乎没有被 returned（或者我对池的理解是错误的）。一段时间后，与我的 Redis 实例的连接增长到 maxTotal 5,000，然后我开始收到错误 "could not get a resource from the pool," 和 Tomcat 死亡。
我注意到的一些事情：
似乎有大量 ESTABLISHED https 连接存在（对此不是 100% 肯定，但似乎是这样）。
所有空闲的 Redis 客户端（好吧，几乎所有空闲的）都有一个 sismember 命令。
注意：我没有包含完整的 APIService.java 代码，因为我确实不允许这样做。我包含的片段确实给出了代码的整体要点。我在整个 APIService.java 代码（return 404、return 429 等）中 returning，并且在每个 return 之前我确保我是 return将资源添加到池中。
最后，这里是堆栈跟踪：
10-Feb-2016 08:04:23.161 SEVERE [http-nio-443-exec-14] com.sun.jersey.spi.container.ContainerResponse.mapMappableContainerException The RuntimeException could not be mapped to a response, re-throwing to the HTTP container
redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
at redis.clients.util.Pool.getResource(Pool.java:50)
at redis.clients.jedis.JedisPool.getResource(JedisPool.java:86)
at co.talentiq.api.APIService.getMsg(APIService.java:63)
at sun.reflect.GeneratedMethodAccessor52.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.sun.jersey.spi.container.JavaMethodInvokerFactory.invoke(JavaMethodInvokerFactory.java:60)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:205)
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
第一：如果您已经初始化了池，请不要创建新池：
public class RedisManager {
...
public void connect() {
if(pool != null) {
System.out.println("Already exists");
return;
}
JedisPoolConfig poolConfig = new JedisPoolConfig();
...
其次...您的日志中是否有来自 getMsg 方法的异常？
public Response getMsg(@QueryParam("email") String email,
@QueryParam("pretty") String pretty
您应该将池化资源的所有工作都包装到 try-catch-finally 中，并且始终 return finally 块中的资源。注意：确保不要 return 资源（在本例中为 jedis）池化两次。
Jedis jedis;
try {
jedis = RedisManager.getInstance().getJedis();
...
} finally {
if (jedis != null) {
RedisManager.getInstance().returnJedis(jedis);
jedis = null;
}
}
顺便说一句：您可以围绕您的 jedis get/return 代码创建一个小型 AutoCloseable 包装器并使用 java 尝试使用资源 - https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html
带有 try-with-resource 的代码片段
public void release() {
pool.destroy();
}
public static class JedisWrapper implements AutoCloseable {
private final JedisPoolConfig pool;
private final Jedis jedis;
public JedisWrapper(JedisPoolConfig pool, Jedis jedis) {
this.pool = pool;
this.jedis = jedis;
}
public Jedis get() {
return jedis;
}
@Override
public void close() {
pool.returnResourceObject(jedis);
}
}
public JedisWrapper getJedis() {
return new JedisWrapper(pool, pool.getResource());
}
// you can delete this method
public void returnJedis(Jedis jedis) {
pool.returnResourceObject(jedis);
}
以后在使用处
public Response getMsg(@QueryParam("email") String email,
@QueryParam("pretty") String pretty
) throws JSONException {
try(JedisWrapper jw = ...) {
Jedis jedis = jw.get();
...
}
查看 redis client list 的输出，我看到目前有 600 个活跃客户端，并且还在继续增长。这是一个输出片段：
id=285316 addr=x.x.x.x:55699 fd=14131 name= age=53055 idle=53029 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=sismember
id=285317 addr=x.x.x.x:55700 fd=14132 name= age=53055 idle=53050 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=sismember
这是我的代码：
Listener.java:
import com.sun.jersey.api.model.AbstractResourceModelContext;
import com.sun.jersey.api.model.AbstractResourceModelListener;
import javax.ws.rs.ext.Provider;
@Provider
public class Listener implements AbstractResourceModelListener {
@Override
public void onLoaded(AbstractResourceModelContext modelContext) {
RedisManager.getInstance().connect();
}
}
RedisManager.java:
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
public class RedisManager {
private static final RedisManager instance = new RedisManager();
private static JedisPool pool;
private RedisManager() {
}
public final static RedisManager getInstance() {
return instance;
}
public void connect() {
JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMaxTotal(5000);
poolConfig.setTestOnBorrow(true);
poolConfig.setTestOnReturn(true);
poolConfig.setMaxIdle(50);
poolConfig.setMinIdle(1);
poolConfig.setTestWhileIdle(true);
poolConfig.setNumTestsPerEvictionRun(10);
poolConfig.setTimeBetweenEvictionRunsMillis(60000);
pool = new JedisPool(poolConfig, "redis_hostname");
}
public void release() {
pool.destroy();
}
public Jedis getJedis() {
return pool.getResource();
}
public void returnJedis(Jedis jedis) {
pool.returnResourceObject(jedis);
}
}
APIServlet.java:
@Path("/")
public class APIService {
@GET
@Path("/lookup")
@Produces(MediaType.APPLICATION_JSON)
public Response getMsg(@QueryParam("email") String email,
@QueryParam("pretty") String pretty
) throws JSONException {
Jedis jedis = RedisManager.getInstance().getJedis();
if (jedis.sismember("inprocess", email)) {
RedisManager.getInstance().returnJedis(jedis);
return Response.status(202).entity("{\"status\":202, " +
"\"processing\":{\"type\":\"Lookup performed\", " +
"\"message\":\"We're performing analysis on this " +
"record. Result should be ready in a few minutes" +
".\"}}").build();
}
Person person = new Person();
person.lookup(person);
ObjectMapper mapper = new ObjectMapper();
String jsonString = mapper.writeValueAsString(person);
JSONObject jsonObj = new JSONObject(jsonString);
jsonObj.remove("objectID");
jsonObj.remove("data_quality");
jsonObj.put("status", 200);
RedisManager.getInstance().returnJedis(jedis);
if (!jsonObj.isNull("name") && !jsonObj.get("name").equals("")) {
if (hasPretty) {
return Response.status(200).entity(jsonObj.toString(4))
.build();
}
return Response.status(200).entity(jsonObj.toString()).build();
}
return Response.status(404).entity("{\"status\":404, " +
"\"error\":{\"type\":\"Data Not Found.\", " +
"\"message\":\"We were not able to find data " +
"on this email.\"}}").build();
}
}
Maven 依赖关系:
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-server</artifactId>
<version>1.8</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-json</artifactId>
<version>1.8</version>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.7.2</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>commons-validator</groupId>
<artifactId>commons-validator</artifactId>
<version>1.2.0</version>
</dependency>
Listener 创建一个 RedisManager 实例以在整个应用程序中使用——这应该只在启动时发生一次（注意：我不知道如何在关闭时调用 destroy，如果知道的话会很高兴）。在整个程序中，Jersey 路由中使用了 JedisPool 的这个实例，如 APIServlet.java 所示。在路线中，我得到一个 JedisPool 资源，然后在路线的任何部分 return 之前，我 return 资源。
发生的事情是资源似乎没有被 returned（或者我对池的理解是错误的）。一段时间后，与我的 Redis 实例的连接增长到 maxTotal 5,000，然后我开始收到错误 "could not get a resource from the pool," 和 Tomcat 死亡。
我注意到的一些事情：
似乎有大量 ESTABLISHED https 连接存在（对此不是 100% 肯定，但似乎是这样）。
所有空闲的 Redis 客户端（好吧，几乎所有空闲的）都有一个 sismember 命令。
注意：我没有包含完整的 APIService.java 代码，因为我确实不允许这样做。我包含的片段确实给出了代码的整体要点。我在整个 APIService.java 代码（return 404、return 429 等）中 returning，并且在每个 return 之前我确保我是 return将资源添加到池中。
最后，这里是堆栈跟踪：
10-Feb-2016 08:04:23.161 SEVERE [http-nio-443-exec-14] com.sun.jersey.spi.container.ContainerResponse.mapMappableContainerException The RuntimeException could not be mapped to a response, re-throwing to the HTTP container
redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
at redis.clients.util.Pool.getResource(Pool.java:50)
at redis.clients.jedis.JedisPool.getResource(JedisPool.java:86)
at co.talentiq.api.APIService.getMsg(APIService.java:63)
at sun.reflect.GeneratedMethodAccessor52.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.sun.jersey.spi.container.JavaMethodInvokerFactory.invoke(JavaMethodInvokerFactory.java:60)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:205)
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
第一：如果您已经初始化了池，请不要创建新池：
public class RedisManager {
...
public void connect() {
if(pool != null) {
System.out.println("Already exists");
return;
}
JedisPoolConfig poolConfig = new JedisPoolConfig();
...
其次...您的日志中是否有来自 getMsg 方法的异常？
public Response getMsg(@QueryParam("email") String email,
@QueryParam("pretty") String pretty
您应该将池化资源的所有工作都包装到 try-catch-finally 中，并且始终 return finally 块中的资源。注意：确保不要 return 资源（在本例中为 jedis）池化两次。
Jedis jedis;
try {
jedis = RedisManager.getInstance().getJedis();
...
} finally {
if (jedis != null) {
RedisManager.getInstance().returnJedis(jedis);
jedis = null;
}
}
顺便说一句：您可以围绕您的 jedis get/return 代码创建一个小型 AutoCloseable 包装器并使用 java 尝试使用资源 - https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html
带有 try-with-resource 的代码片段
public void release() {
pool.destroy();
}
public static class JedisWrapper implements AutoCloseable {
private final JedisPoolConfig pool;
private final Jedis jedis;
public JedisWrapper(JedisPoolConfig pool, Jedis jedis) {
this.pool = pool;
this.jedis = jedis;
}
public Jedis get() {
return jedis;
}
@Override
public void close() {
pool.returnResourceObject(jedis);
}
}
public JedisWrapper getJedis() {
return new JedisWrapper(pool, pool.getResource());
}
// you can delete this method
public void returnJedis(Jedis jedis) {
pool.returnResourceObject(jedis);
}
以后在使用处
public Response getMsg(@QueryParam("email") String email,
@QueryParam("pretty") String pretty
) throws JSONException {
try(JedisWrapper jw = ...) {
Jedis jedis = jw.get();
...
}