[mod_cluster-dev] Problems with Beta4

Mon Mar 16 12:39:16 EDT 2009

On Mon, 2009-03-16 at 11:18 -0500, Brian Stansberry wrote:
> Following is a list of issues I saw when playing with Beta4 on Windows. 
> Apologies if some of these are known issues / already fixed. I'll scan 
> JIRA now and open issues for any I don't see.
> 
> 1) Undeploy an app or shut down server, clients with an existing session 
>   do not fail over.  Following from access_log shows the issue. Last 404 
> occurs a couple seconds after the REMOVE-APP, so doesn't seem to be a race.
> 
> > 192.168.2.3 - - [16/Mar/2009:16:07:48 +0100] "STOP-APP / HTTP/1.0" 200 -
> > 127.0.0.1 - - [16/Mar/2009:16:07:48 +0100] "GET /load-demo/record HTTP/1.1" 503 1086
> > 127.0.0.1 - - [16/Mar/2009:16:07:48 +0100] "GET /load-demo/record HTTP/1.1" 503 1086
> > 127.0.0.1 - - [16/Mar/2009:16:07:48 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:48 +0100] "GET /load-demo/record HTTP/1.1" 503 1086
> > 127.0.0.1 - - [16/Mar/2009:16:07:48 +0100] "GET /load-demo/record HTTP/1.1" 503 1086
> > 127.0.0.1 - - [16/Mar/2009:16:07:48 +0100] "GET /load-demo/record HTTP/1.1" 503 1086
> > 192.168.2.3 - - [16/Mar/2009:16:07:48 +0100] "REMOVE-APP / HTTP/1.0" 200 -
> > 192.168.2.3 - - [16/Mar/2009:16:07:48 +0100] "STATUS / HTTP/1.0" 200 59
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record?destroy=true HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:49 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 192.168.2.3 - - [16/Mar/2009:16:07:49 +0100] "STATUS / HTTP/1.0" 200 59
> > 192.168.2.3 - - [16/Mar/2009:16:07:50 +0100] "STATUS / HTTP/1.0" 200 59
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record?destroy=true HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 200 21
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> > 127.0.0.1 - - [16/Mar/2009:16:07:51 +0100] "GET /load-demo/record HTTP/1.1" 404 999
> 
> 2) When you run with HAModClusterService, every 10 seconds there is 
> logging about a DRM replicantsChanged event and a new HASingletonMaster 
> election. (The election just picks the existing master.) That means the 
> DRM is being updated even when nothing has changed, which shouldn't happen.
> 
Filing a bug.

> 3) To get advertise to work, I had to add a AdvertiseGroup 
> 224.0.1.105:23364 directive to httpd.conf. The docs on jboss.org imply 
> that shouldn't be necessary since the value is just the default.
> 
> 4) The mod_cluster-manager status page reports Transfered: 0, Connected: 
> 0, Load: 0 Num sessions: 0 for all nodes, always; doesn't ever report 
> actual data. Also "Transfered" should be "Transferred"
> 
> 5) The mod_cluster-manager status page "SessionIDs" section lists 
> session ids, which is a security violation. Jean-Frederic, you mentioned 
> you wanted to remove this. In case you haven't, I tried to disable it by 
> setting Maxsessionid 0 in httpd.conf, but that had no effect.
> 
> 6) Playing with the demo's "Server Load Control" tab I tried to use the 
> "Heap Memory Use" control. I couldn't get this to have any effect on 
> load balancing.
> 
> a) The servlet isn't multiplying the duration value by 1000 to convert 
> seconds to ms. I'll fix this in just a sec after I send this.
> 
> b) but, even after adjusting for this I couldn't get any load balancing 
> effect by using "Heap Memory Use". Looking at the process in Task 
> Manager, it seemed the servlet was increasing heap usage. So I'm 
> concerned there is an issue with the load metric.
> 
Indeed there is.  The metric is holding a reference to the MemoryMXBean.
MXBean properties are loaded eagerly - thus the values you are seeing
are the heap numbers when the metric was first loaded.  Oops.  Filing a
bug.

> 7) Go into jmx-console, jboss.web:service=ModClusterService, invoke the 
> "disable" operation. Node logs this in server.log:
> 
> 009-03-16 17:15:58,765 ERROR 
> [org.jboss.modcluster.mcmp.impl.DefaultMCMPHandler] 
> (http-192.168.2.2-8080-2) Error [null: null: {4}] sending command DUMP 
> to proxy 192.168.2.3:6666, configuration will be reset
> 2009-03-16 17:16:55,250 ERROR 
> [org.jboss.modcluster.mcmp.impl.DefaultMCMPHandler] 
> (http-192.168.2.2-8080-2) Error [null: null: {4}] sending command 
> DISABLE-APP to proxy 192.168.2.3:6666, configuration will be reset
> 
Filing a bug.