通过Jmeter进行负载测试时，Tomcat 7中的连接拒绝错误

Question

My application is pointing to cloudant DB which supports high active connections. When I am trying to hit 500 concurrent hits, my API shows,

org.apache.http.conn.HttpHostConnectException: Connection to https://Testing.com:xxx refused
at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:190)
at org.apache.http.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:294)
at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:645)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:480)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805)
at org.apache.jmeter.protocol.http.sampler.HTTPHC4Impl.sample(HTTPHC4Impl.java:286)
at org.apache.jmeter.protocol.http.sampler.HTTPSamplerProxy.sample(HTTPSamplerProxy.java:62)
at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1088)
at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1077)
at org.apache.jmeter.threads.JMeterThread.process_sampler(JMeterThread.java:428)
at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:256)
at java.lang.Thread.run(Unknown Source)

Caused by: java.net.ConnectException: Connection timed out: connect
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(Unknown Source)
    at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.connect(Unknown Source)
    at org.apache.http.conn.ssl.SSLSocketFactory.connectSocket(SSLSocketFactory.java:549)
    at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:180)
    ... 12 more

In tomcat server.xml, My max threads is 500, acceptCount is 500 and connection timeout is 20000. Still it shows the above mentioned error. I could see a pattern like only those threads between 100-250 are getting failed in consecutive runs. Can someone please help me on this

Answer 1

Please check Database connection pool maxtotal. It might be less and you may need to increase it.