Authenticated Sessions at the HTTP level for the iControl API (HTTP Headers?)

You're probably talking way over my head so this response will probably sound stupid but the first thing that comes to mind is a OneConnect profile. Could that be used in your situation to pool connections?

I believe the method you are looking for is called setMaintainSession. It is located on the Axis BindingStub objects. Setting it to true will perform the first authentication using HTTP basic auth, then will insert the BigIPAuthCookie (returned in the first response) in subsequent requests. The auth cookie should be checked before HTTP basic auth is attempted. Here is my test code, which is based upon the iControl JAR available on DevCentral (I also had to add the axis and axis-jaxrpc JARs to my CLASSPATH):

import iControl.*;

public class AuthCookieTest {
    public static void main(String[] args) {
        iControl.Interfaces bigip = new iControl.Interfaces();
        bigip.initialize("test-ltm-01", "admin", "admin");
        
        try {
            SystemSystemInfoBindingStub systemInfoStub = bigip.getSystemSystemInfo();
            systemInfoStub.setMaintainSession(true);
            systemInfoStub.get_version();
            systemInfoStub.get_version();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

That should cut down on the TACACS chattiness as only the first call will require a TACACS query for authentication. Let me know if that does the trick.

Assuming your client making the call supports cookies. Many programatic interfaces do not generally support cookie handling so you would have to capture the returned cookie with your code and ensure you resend it in subsequent iControl requests for this to work.