压力测试负载均衡出现连接错误java.net.ConnectException: Connection refused: connect

Question

在10000个并发时，普通tomcat 用jmeter压力测试正常，nginx负载均衡会出现部分（占总并发的0%-80%）Connection refused: connect异常，完整错误信息如下：

java.net.ConnectException: Connection refused: connect
	at java.net.DualStackPlainSocketImpl.connect0(Native Method)
	at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
	at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
	at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
	at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
	at java.net.PlainSocketImpl.connect(Unknown Source)
	at java.net.SocksSocketImpl.connect(Unknown Source)
	at java.net.Socket.connect(Unknown Source)
	at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:121)
	at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:180)
	at org.apache.jmeter.protocol.http.sampler.hc.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:318)
	at org.apache.jmeter.protocol.http.sampler.MeasuringConnectionManager$MeasuredConnection.open(MeasuringConnectionManager.java:114)
	at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:610)
	at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:445)
	at org.apache.http.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:835)
	at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
	at org.apache.jmeter.protocol.http.sampler.HTTPHC4Impl.executeRequest(HTTPHC4Impl.java:697)
	at org.apache.jmeter.protocol.http.sampler.HTTPHC4Impl.sample(HTTPHC4Impl.java:455)
	at org.apache.jmeter.protocol.http.sampler.HTTPSamplerProxy.sample(HTTPSamplerProxy.java:74)
	at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1189)
	at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1178)
	at org.apache.jmeter.threads.JMeterThread.executeSamplePackage(JMeterThread.java:490)
	at org.apache.jmeter.threads.JMeterThread.processSampler(JMeterThread.java:416)
	at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:250)
	at java.lang.Thread.run(Unknown Source)

查看request请求，发现这些连接拒绝的都是request headers不完整造成的，如下：

java.net.ConnectException: Connection refused: connect
	at java.net.DualStackPlainSocketImpl.connect0(Native Method)
	at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
	at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
	at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
	at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
	at java.net.PlainSocketImpl.connect(Unknown Source)
	at java.net.SocksSocketImpl.connect(Unknown Source)
	at java.net.Socket.connect(Unknown Source)
	at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:121)
	at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:180)
	at org.apache.jmeter.protocol.http.sampler.hc.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:318)
	at org.apache.jmeter.protocol.http.sampler.MeasuringConnectionManager$MeasuredConnection.open(MeasuringConnectionManager.java:114)
	at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:610)
	at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:445)
	at org.apache.http.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:835)
	at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
	at org.apache.jmeter.protocol.http.sampler.HTTPHC4Impl.executeRequest(HTTPHC4Impl.java:697)
	at org.apache.jmeter.protocol.http.sampler.HTTPHC4Impl.sample(HTTPHC4Impl.java:455)
	at org.apache.jmeter.protocol.http.sampler.HTTPSamplerProxy.sample(HTTPSamplerProxy.java:74)
	at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1189)
	at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1178)
	at org.apache.jmeter.threads.JMeterThread.executeSamplePackage(JMeterThread.java:490)
	at org.apache.jmeter.threads.JMeterThread.processSampler(JMeterThread.java:416)
	at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:250)
	at java.lang.Thread.run(Unknown Source)

nginx最大连接数设置的是20480*8。求指点

Answer 1

请问楼主解决了吗？

Answer 2

谢谢给出解决思路。但直接访问tomcat不会报错，应该能排除tomcat连接满的原因吧？

Answer 3

tomcat的连接数满了，造成请求在nginx阻塞，请确认tomcat服务的线程池大小，tomcat实例数及服务每秒响应时间