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Hi,
Maximo 7.1.1.6 WebSphere 6.1.
We have three application servers in a cluster on each server.
Sometimes one application server will hang on a query and cause the CPU usage on
the server to go up.
I'd like to be able to restart the application server when that happens but I
don' want to just kill the sessions using that application server.
Is there a way to move those sessions from one application server to another or
to block any new sessions being given that application server?
Thanks,
Dave Bone
I think essentially the answer is no, you cannot move sessions. To block new
sessions you'd need to remove that server from your load balancing
distribution such that new sessions are not assigned to it, all depends on
what you use for balancing load as to what option you have there.
Can you identify the session that is causing the problem and terminate that?
Generally speaking a query shouldn't cause a CPU spike on the application
server unless it is returning vast quantities of data to the java heap and
causing garbage collection problems, are you able to track the available
heap at the time this occurs? I would enable GC logging, SQL Logging and the
MBOCount logging and compare these at the time the issue occurs, my guess
would be that this rogue query is resulting in heap saturation which sends
the garbage collector nuts trying to reclaim space which is what causes the
CPU to spike or saturate.
Chris.
On Wed, Oct 19, 2011 at 10:27 AM, in2data <in2data@yahoo.com> wrote:
> **
>
>
> Hi,
>
> Maximo 7.1.1.6 WebSphere 6.1.
>
> We have three application servers in a cluster on each server.
>
> Sometimes one application server will hang on a query and cause the CPU
> usage on
> the server to go up.
>
> I'd like to be able to restart the application server when that happens but
> I
> don' want to just kill the sessions using that application server.
>
> Is there a way to move those sessions from one application server to
> another or
> to block any new sessions being given that application server?
>
> Thanks,
>
> Dave Bone
>
>
>
Hi,
Thanks. I should have been looking at the cluster and not the applications servers. I think making the cluster member idle will work. I'll test and let you know.
Dave Bone
--- In MAXIMO@yahoogroups.com, Chris Lawless <lawlessc@...> wrote:
>
> I think essentially the answer is no, you cannot move sessions. To block new
> sessions you'd need to remove that server from your load balancing
> distribution such that new sessions are not assigned to it, all depends on
> what you use for balancing load as to what option you have there.
>
> Can you identify the session that is causing the problem and terminate that?
> Generally speaking a query shouldn't cause a CPU spike on the application
> server unless it is returning vast quantities of data to the java heap and
> causing garbage collection problems, are you able to track the available
> heap at the time this occurs? I would enable GC logging, SQL Logging and the
> MBOCount logging and compare these at the time the issue occurs, my guess
> would be that this rogue query is resulting in heap saturation which sends
> the garbage collector nuts trying to reclaim space which is what causes the
> CPU to spike or saturate.
>
> Chris.
>
> On Wed, Oct 19, 2011 at 10:27 AM, in2data <in2data@...> wrote:
>
> > **
> >
> >
> > Hi,
> >
> > Maximo 7.1.1.6 WebSphere 6.1.
> >
> > We have three application servers in a cluster on each server.
> >
> > Sometimes one application server will hang on a query and cause the CPU
> > usage on
> > the server to go up.
> >
> > I'd like to be able to restart the application server when that happens but
> > I
> > don' want to just kill the sessions using that application server.
> >
> > Is there a way to move those sessions from one application server to
> > another or
> > to block any new sessions being given that application server?
> >
> > Thanks,
> >
> > Dave Bone
> >
> >
> >
>
>
>
>
Hi,
It appears from what I've read in the WebSphere documentation that I can set the application server to Idle from the Integrated Solutions Console > Server Clusters > MAXIMOUICLUSTER > Cluster Members. Essentially what it does is set the weight for that application server to 0. If other servers with a higher weight are available in that cluster then they get all of the work. It does not close the open sessions so users can complete their work.
When we set up our application servers the instructions had us set the first weight to 2 and the others to 10. From the WebSphere documentation it appears you can have any combinations of values from 0 to 20. The weights are relative to the weights for the other servers. So to get an equal load balance across all three each should be set to the same weight.
I've set the problem application server to idle and once all sessions there close I'll restart that server.
I'll also change the weights to 10 for all of the application servers.
Thanks Chris for the response. It got me looking in the right area of the console.
Dave Bone
--- In MAXIMO@yahoogroups.com, "in2data" <in2data@...> wrote:
>
> Hi,
>
>
> Thanks. I should have been looking at the cluster and not the applications servers. I think making the cluster member idle will work. I'll test and let you know.
>
> Dave Bone
>
> --- In MAXIMO@yahoogroups.com, Chris Lawless <lawlessc@> wrote:
> >
> > I think essentially the answer is no, you cannot move sessions. To block new
> > sessions you'd need to remove that server from your load balancing
> > distribution such that new sessions are not assigned to it, all depends on
> > what you use for balancing load as to what option you have there.
> >
> > Can you identify the session that is causing the problem and terminate that?
> > Generally speaking a query shouldn't cause a CPU spike on the application
> > server unless it is returning vast quantities of data to the java heap and
> > causing garbage collection problems, are you able to track the available
> > heap at the time this occurs? I would enable GC logging, SQL Logging and the
> > MBOCount logging and compare these at the time the issue occurs, my guess
> > would be that this rogue query is resulting in heap saturation which sends
> > the garbage collector nuts trying to reclaim space which is what causes the
> > CPU to spike or saturate.
> >
> > Chris.
> >
> > On Wed, Oct 19, 2011 at 10:27 AM, in2data <in2data@> wrote:
> >
> > > **
> > >
> > >
> > > Hi,
> > >
> > > Maximo 7.1.1.6 WebSphere 6.1.
> > >
> > > We have three application servers in a cluster on each server.
> > >
> > > Sometimes one application server will hang on a query and cause the CPU
> > > usage on
> > > the server to go up.
> > >
> > > I'd like to be able to restart the application server when that happens but
> > > I
> > > don' want to just kill the sessions using that application server.
> > >
> > > Is there a way to move those sessions from one application server to
> > > another or
> > > to block any new sessions being given that application server?
> > >
> > > Thanks,
> > >
> > > Dave Bone
> > >
> > >
> > >
> >
> >
> >
> >
>
Hi,
I was poking around with the plug-in.xml file.
Here's what I found out.
In the Websphere console you can change the cluster member weights to 0 but that has no effect until you go to the Web Server and Generate the Plug In. This actually changes the weights in the plug-in.xml file. Until the plug-in.xml file is changed the web server continues to use the previous weights in the file.
Or you can go to the plug-in.xml file and comment out the Server and PrimaryServers values for the application servers you want to make idle.
It's easier to use the Websphere console.
Nice thing is that users already logged in and using the application server you want to make idle can continue to work. Eventually all users will log out and you can work on the idle application server.
Dave Bone
--- In MAXIMO@yahoogroups.com, "in2data" <in2data@...> wrote:
>
> Hi,
>
> It appears from what I've read in the WebSphere documentation that I can set the application server to Idle from the Integrated Solutions Console > Server Clusters > MAXIMOUICLUSTER > Cluster Members. Essentially what it does is set the weight for that application server to 0. If other servers with a higher weight are available in that cluster then they get all of the work. It does not close the open sessions so users can complete their work.
>
> When we set up our application servers the instructions had us set the first weight to 2 and the others to 10. From the WebSphere documentation it appears you can have any combinations of values from 0 to 20. The weights are relative to the weights for the other servers. So to get an equal load balance across all three each should be set to the same weight.
>
> I've set the problem application server to idle and once all sessions there close I'll restart that server.
>
> I'll also change the weights to 10 for all of the application servers.
>
> Thanks Chris for the response. It got me looking in the right area of the console.
>
> Dave Bone
>
>
> --- In MAXIMO@yahoogroups.com, "in2data" <in2data@> wrote:
> >
> > Hi,
> >
> >
> > Thanks. I should have been looking at the cluster and not the applications servers. I think making the cluster member idle will work. I'll test and let you know.
> >
> > Dave Bone
> >
> > --- In MAXIMO@yahoogroups.com, Chris Lawless <lawlessc@> wrote:
> > >
> > > I think essentially the answer is no, you cannot move sessions. To block new
> > > sessions you'd need to remove that server from your load balancing
> > > distribution such that new sessions are not assigned to it, all depends on
> > > what you use for balancing load as to what option you have there.
> > >
> > > Can you identify the session that is causing the problem and terminate that?
> > > Generally speaking a query shouldn't cause a CPU spike on the application
> > > server unless it is returning vast quantities of data to the java heap and
> > > causing garbage collection problems, are you able to track the available
> > > heap at the time this occurs? I would enable GC logging, SQL Logging and the
> > > MBOCount logging and compare these at the time the issue occurs, my guess
> > > would be that this rogue query is resulting in heap saturation which sends
> > > the garbage collector nuts trying to reclaim space which is what causes the
> > > CPU to spike or saturate.
> > >
> > > Chris.
> > >
> > > On Wed, Oct 19, 2011 at 10:27 AM, in2data <in2data@> wrote:
> > >
> > > > **
> > > >
> > > >
> > > > Hi,
> > > >
> > > > Maximo 7.1.1.6 WebSphere 6.1.
> > > >
> > > > We have three application servers in a cluster on each server.
> > > >
> > > > Sometimes one application server will hang on a query and cause the CPU
> > > > usage on
> > > > the server to go up.
> > > >
> > > > I'd like to be able to restart the application server when that happens but
> > > > I
> > > > don' want to just kill the sessions using that application server.
> > > >
> > > > Is there a way to move those sessions from one application server to
> > > > another or
> > > > to block any new sessions being given that application server?
> > > >
> > > > Thanks,
> > > >
> > > > Dave Bone
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> >
>
+1 to this post! Regards, Alexey