MATLAB: Do I get “Unexpected end of file from server” when the MPS is under a heavy load

load-testing performance-testing stress-testingMATLAB Production Server

I get the following exception when stress-testing my MPS with JMeter:
 java.net.SocketException: Unexpected end of file from server
    at sun.reflect.GeneratedConstructorAccessor82.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection$10.run(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection$10.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.net.www.protocol.http.HttpURLConnection.getChainedException(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at java.net.HttpURLConnection.getResponseCode(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(Unknown Source)
    at org.apache.jmeter.protocol.http.sampler.HTTPJavaImpl.readResponse(HTTPJavaImpl.java:260)
    at org.apache.jmeter.protocol.http.sampler.HTTPJavaImpl.sample(HTTPJavaImpl.java:513)
    at org.apache.jmeter.protocol.http.sampler.HTTPSamplerProxy.sample(HTTPSamplerProxy.java:74)
    at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1146)
    at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1135)
    at org.apache.jmeter.threads.JMeterThread.executeSamplePackage(JMeterThread.java:465)
    at org.apache.jmeter.threads.JMeterThread.processSampler(JMeterThread.java:410)
    at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:241)
    at java.lang.Thread.run(Unknown Source)
  Caused by: java.net.SocketException: Unexpected end of file from server
    at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source)
    at sun.net.www.http.HttpClient.parseHTTP(Unknown Source)
    at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source)
    at sun.net.www.http.HttpClient.parseHTTP(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(Unknown Source)
    at java.net.URLConnection.getHeaderFieldLong(Unknown Source)
    at java.net.URLConnection.getContentLengthLong(Unknown Source)
    at java.net.URLConnection.getContentLength(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getContentLength(Unknown Source)
    at org.apache.jmeter.protocol.http.sampler.HTTPJavaImpl.readResponse(HTTPJavaImpl.java:226)
    ... 8 more
Is this simply because MPS cannot handle that many concurrent requests? Is there a limit to the number of concurrent requests that can be handled by MPS? If so, what is that limit?
It seems like MPS might queue up requests somehow. If that's true is this behavior documented anywhere? I would like to know the limit to the queue and if there are any timeouts for requests sitting in the queue.

Best Answer

I figured out what was happening. I was calling my MPS through a load balancer and the load balancer had an idle timeout set to 60 seconds. It was returning a gateway timeout response but JMeter showed the exception above so it wasn't obvious. I increased the timeout on the lb and no longer got these exceptions.
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