Resolution: Not A Problem
Affects Version/s: 4.0.3
Fix Version/s: None
Environment:Java 6, Tomcat 6, JBoss 5.1
First, thanks for an awesome piece of work in HttpClient. I use it every day and it is very useful to me.
HttpClient's default settings include adding an...
...header to every PostMethod. This seems to interact poorly with Tomcat's (and possibly other Java EE containers) FormAuthenticator. I tested on both Tomcat 6 and JBoss 5.1.0 (which I believe uses a fork of Tomcat). Testing both with/without the 'Expect' header I see '/j_security_check' login times of:
With Expect header: 2012ms
Without Expect header: 8ms
So the default is some 250x slower. This is without a database or any other complicating factors. It can make a dramatic difference if you are using HttpClient to simulate logging in and retrieving information.
I include a test WAR. To deploy it:
1. Copy into /webapps
2. Edit conf/tomcat-users.xml to enable the tomcat/tomcat username/password
3. Run Tomcat
4. Hit http://localhost:8080/ExpectTest
5. Log in as tomcat/tomcat
6. Hit 'Start Test'
The issue can be worked around by removing the RequestExpectContinue interceptor, but it takes a lot of digging through code to realise this. Otherwise you may simply conclude 'HttpClient is slow'.
According to the HTTP spec (http://www.w3.org/Protocols/rfc2616/rfc2616-sec8.html#sec8.2.3), the 100 header "allows a client that is sending a request message with a request body to determine if the origin server is willing to accept the request (based on the request headers) before the client sends the request body. In some cases, it might either be inappropriate or highly inefficient for the client to send the body if the server will reject the message without looking at the body". So perhaps this setting should only apply for 'large' POST bodies, not for simple 'j_username=Foo&j_password=Bar' bodies?