Hello, Thanks sebb, see my notes below. On Mon, Mar 25, 2013 at 6:21 PM, sebb <[email protected]> wrote:
> On 25 March 2013 14:17, Philippe Mouawad <[email protected]> > wrote: > > Hello, > > I noticed a strange behaviour when Load Testing an application recently. > > > > There was a Load Balancer in the middle: > > > > - Using Java Implementation I had around 8% of error > > What kinds of error? > > Session is lost, so it means load balancer redirects to other Apache ignoring Session Stickiness. > > - Using HC3 or HC4 Implementations it was 0% > > > > > > I am sure it comes from Load Balancing as if it pointed on only one > Apache > > then there was no issue. > > Note that the Java implementation may reuse connections between threads. > That's one reason JMeter started using HC3 and HC4. > > > Now playing around with some Java System properties, I discovered that > > setting *-Dhttp.keepAlive=false* fixed the error issue: > > That suggests it might be the connection reuse. > Agree > > > - > > > http://docs.oracle.com/javase/6/docs/technotes/guides/net/http-keepalive.html > > > > Another way to fix this was to uncheck KeepAlive checkbox in samplers. > > Likewise, that should stop cross-thread connection sharing, as it will > stop any sharing. > > > > > Now my question is: > > > > - Is this regular ? It seems strange to me that HC31 and HC4 impl do > not > > have this behaviour > > - If yes, we should absolutely document this behaviour no ? > > I think it is; but it could perhaps be made more obvious. > Where is it ? Didn't see any mention of -Dhttp.keepAlive in docs > > > - Could it be a JDK 7 bug ?java version "1.7.0_13" > > No, it's by design. > > In theory the connnection sharing should be OK (otherwise I assume > Java would not do it), but maybe there is a subtle bug in the > application that relies on independent connections. > > I think it is something like this or a Load Balancer issue. But as it is not easy to simulate using Browser, it is hard to prove. > > > > > > Note that tested application was not perfect as it had many Content > > Encoding behaviour and other non fully standard issues. > > > > Thanks for you notes. > > Regards > > Philippe > -- Cordialement. Philippe Mouawad.
