Jmeter: TCP Sampler error: 500 ReadException: Error reading from server, bytes read: 0

Question

While checking TCP connection from Jmeter TCP Sampler, we are getting below error:

Response code: 500
Response message: org.apache.jmeter.protocol.tcp.sampler.ReadException: Error reading from server, bytes read: 0

We tried changing EOL, Connect & Response timeouts, Re-use connection & Close connection settings, but no luck.

Jmeter TCP Sampler log:

2018-04-24 12:09:09,740 INFO o.a.j.e.StandardJMeterEngine: Running the test!
2018-04-24 12:09:09,741 INFO o.a.j.s.SampleEvent: List of sample_variables: []
2018-04-24 12:09:09,745 INFO o.a.j.g.u.JMeterMenuBar: setRunning(true, *local*)
2018-04-24 12:09:09,755 INFO o.a.j.e.StandardJMeterEngine: Starting ThreadGroup: 1 : DS Requests
2018-04-24 12:09:09,756 INFO o.a.j.e.StandardJMeterEngine: Starting 1 threads for group DS Requests.
2018-04-24 12:09:09,764 INFO o.a.j.e.StandardJMeterEngine: Thread will continue on error
2018-04-24 12:09:09,765 INFO o.a.j.t.ThreadGroup: Starting thread group... number=1 threads=1 ramp-up=5 perThread=5000.0 delayedStart=false
2018-04-24 12:09:09,765 INFO o.a.j.t.ThreadGroup: Started thread group number 1
2018-04-24 12:09:09,765 INFO o.a.j.e.StandardJMeterEngine: All thread groups have been started
2018-04-24 12:09:09,766 INFO o.a.j.t.JMeterThread: Thread started: DS Requests 1-1
2018-04-24 12:09:09,767 INFO o.a.j.p.t.s.TCPClientImpl: Using platform default charset:windows-1252
2018-04-24 12:09:09,767 INFO o.a.j.p.t.s.TCPSampler: Using eolByte=10
2018-04-24 12:09:09,787 ERROR o.a.j.p.t.s.TCPSampler: 
org.apache.jmeter.protocol.tcp.sampler.ReadException: Error reading from server, bytes read: 0
    at org.apache.jmeter.protocol.tcp.sampler.TCPClientImpl.read(TCPClientImpl.java:131) ~[ApacheJMeter_tcp.jar:3.3 r1808647]
    at org.apache.jmeter.protocol.tcp.sampler.TCPSampler.sample(TCPSampler.java:403) [ApacheJMeter_tcp.jar:3.3 r1808647]
    at org.apache.jmeter.threads.JMeterThread.executeSamplePackage(JMeterThread.java:498) [ApacheJMeter_core.jar:3.3 r1808647]
    at org.apache.jmeter.threads.JMeterThread.processSampler(JMeterThread.java:424) [ApacheJMeter_core.jar:3.3 r1808647]
    at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:255) [ApacheJMeter_core.jar:3.3 r1808647]
    at java.lang.Thread.run(Unknown Source) [?:1.8.0_144]
Caused by: java.net.SocketException: Connection reset
    at java.net.SocketInputStream.read(Unknown Source) ~[?:1.8.0_144]
    at java.net.SocketInputStream.read(Unknown Source) ~[?:1.8.0_144]
    at java.net.SocketInputStream.read(Unknown Source) ~[?:1.8.0_144]
    at org.apache.jmeter.protocol.tcp.sampler.TCPClientImpl.read(TCPClientImpl.java:114) ~[ApacheJMeter_tcp.jar:3.3 r1808647]
    ... 5 more
2018-04-24 12:09:09,788 INFO o.a.j.t.JMeterThread: Thread is done: DS Requests 1-1
2018-04-24 12:09:09,788 INFO o.a.j.t.JMeterThread: Thread finished: DS Requests 1-1
2018-04-24 12:09:09,789 INFO o.a.j.e.StandardJMeterEngine: Notifying test listeners of end of test
2018-04-24 12:09:09,789 INFO o.a.j.g.u.JMeterMenuBar: setRunning(false, *local*)

Please suggest how to fix this issue.

Answer 1

Checking connectivity using TCP Sampler is not the best idea, I would recommend going for JSR223 Sampler and Socket class instead:

def sock = new Socket()
def host = "example.com" // change it to your host
def port = 80 // change it to your port
def timeout = 1000 // change it to your timeout (in milliseconds)
sock.setSoTimeout(1000)
sock.connect(new InetSocketAddress(host, port))

if (sock.isConnected()) {
    log.info('Connection established')
    SampleResult.setSuccessful(true)
}
else {
    log.info('Server is not listening')
    SampleResult.setSuccessful(false)
}

See Apache Groovy - Why and How You Should Use It article for more information on enhancing your JMeter test with Groovy scripting.

---

In the majority of cases it is much easier to use HTTP Raw Request plugin than the TCP Sampler.