如何配置JMeter始终使用新的SSL会话ID？

Question

I am trying to benchmark SSL handshakes per second using a variety of tools, JMeter included. I have successfully created a test plan that meets my needs except I now want to test how the SSL handshakes per second compare with and without SSL session reuse. As I understand, by default Java has an unlimited size SSL session cache and entries expire after 24 hours.

I've tried using the JMeter properties "https.use.cached.ssl.context" and "https.sessioncontext.shared", but even when these properties are false it doesn't meet my needs. When both are false, the first HTTPS request in the thread uses a new session id, but each HTTPS request after that in the thread reuses a session id. Even if I set the undocumented Java property "javax.net.ssl.sessionCacheSize" to 1 to only allow one SSL session ID to be cached, if I have 10 threads making a total of 5 HTTP requests each, I see 10 new SSL session negotiated, and 40 SSL sessions reused (verified with ssldump and STunnel logs).

Is it possible through JMeter or Java to have every HTTPS request use a new SSL session id?

Answer 1

This works:

• https.use.cached.ssl.context=false is set in user.properties
• AND use either HTTPClient 3.1 or 4 implementations for HTTP Request

EDIT (after Kaelen comment): Setting the https.use.cached.ssl.context property to false (with HTTPClient 3.1/4) does work, the only tricky part is that the SSL session context only gets reset at the end of an iteration of the Thread Group . In the test plan the thread group did not iterate, there was an infinite loop inside the group that ran until a # of requests occurred. Because the thread group never iterated, the SSL context wasn't reset.

In this case remove the Loop inside Thread Group and configure number of iterations in Thread Group.