When we switched from tomcat 6.0.35 to 6.0.36, the initial load of our sign on page became extremely slow. In 6.0.35, it would load in about 2 seconds; in 6.0.36, it loads in about 60 seconds.
Our environment is an IBM mainframe running z/OS. Tomcat runs under USS (Unix System Services). The JVM version is java version "1.6.0" Java(TM) SE Runtime Environment (build pmz3160sr13-20130207_01(SR13)). When we remove the protocol="org.apache.coyote.http11.Http11NioProtocol" from the server.xml, the page loads in about 2 seconds -- the same a tomcat version 6.0.35. So I have narrowed this down to one configuration change. We need to have NIO enabled, as we use Netty to do some of our IO; therefore, leaving the option disabled is not possible for us. I ran Wireshark against 6.0.35 and 6.0.36 with NIO enabled hoping to see a large discrepancy in the number of packets sent, but the packet counts were very similar. I ran Fiddler and did see that files over 50KB in size were the slow ones; oddly, jar files (we have a swing applet on our sign on page) that were much larger than the slower .gif and .js files, were served very quickly. I am not sure how to proceed. Jerry
