-
1. Re: AS7 modcluster load-metric capacity values
rhusar Mar 27, 2012 9:29 AM (in response to pavel.orehov)The capacity is the capacity of that metric, so in your case its 1024 indeed.
-
2. Re: AS7 modcluster load-metric capacity values
mbabacek Mar 27, 2012 9:28 AM (in response to pavel.orehov)1 of 1 people found this helpfulHi Pavel,
just a note regarding mem metric usage: I can not recommend it: MODCLUSTER-288, because it returns something different than you probably expect.
-
3. Re: AS7 modcluster load-metric capacity values
pavel.orehov Mar 27, 2012 10:19 AM (in response to pavel.orehov)Thanks for quick responses.
Any idea for sessions capacity ?
-
4. Re: AS7 modcluster load-metric capacity values
rhusar Mar 27, 2012 10:22 AM (in response to pavel.orehov)Any idea for sessions capacity ?
Do some testing on standard workflow in your application and figure out how many sessions are working OK (you also need to count in the delay between requests people typicall do and depending on what is acceptable for you monitor for CPU usage below 100%, remaining memory, good reponse times, etc) and that will be the capacity per server.
-
5. Re: AS7 modcluster load-metric capacity values
pavel.orehov Mar 28, 2012 3:07 AM (in response to rhusar)I would like to be able to pefrom more checked fine tunning of capacities.
Is there is a way I can see/debug the actual load values returned from cpu,heap and sessions load providers before it caclucated with weight and capacity ?
-
6. Re: AS7 modcluster load-metric capacity values
rhusar Mar 28, 2012 4:59 AM (in response to pavel.orehov)1 of 1 people found this helpfulGood question, the way I do it is
- just set only one metric at a time
- and configure no history/decay so that you get immediate numbers.
- Then do some steady load
- and observe how the number changes in the /mod_cluster-manager console
HTH,
Rado
-
7. Re: AS7 modcluster load-metric capacity values
johanvermeij Aug 23, 2012 9:00 PM (in response to rhusar)Can you point me to a list of load-metric type values ?
I would like to try roundrobin for testing, is that still available.
I currently use <load-metric type="busyness"/>
I want to try load leveling the "dumb" way because only master and one (of two) slaves is active at one time, the other one hangs on a timeout
-
8. Re: AS7 modcluster load-metric capacity values
jfclere Aug 24, 2012 3:46 AM (in response to johanvermeij)try <simple-load-provider/> the load_factor will be 1.
-
9. Re: AS7 modcluster load-metric capacity values
mpgong Dec 12, 2012 9:28 AM (in response to pavel.orehov)Didn't want to start a new thread, but a quick question about what the load capacity for cpu. If i put in 1 does that mean 100% and if i put 2 does that mean 50% and so on?
Thanks
-
10. Re: AS7 modcluster load-metric capacity values
mbabacek Dec 12, 2012 9:37 AM (in response to mpgong)No, capacity for CPU does not affect the calculation in any way. It is your average load divided by number of cores available to JVM. For instance, if you have 4 cores, your maximum "average load" value might be 400. This figure divided by 4 is Load returned. So, if you set your quad core on fire, it will return Load ~ 99 or so...
-
11. Re: AS7 modcluster load-metric capacity values
pferraro Dec 12, 2012 4:11 PM (in response to mbabacek)Actually, that's not quite correct. Capacity does indeed affect the load calculation.
The server side load calculation logic for mod_cluster is described in detail here:
http://docs.jboss.org/mod_cluster/1.2.0/html/java.load.html
If you set the capacity of your cpu metric to 2, the load number reported to the load balancer for the current node will be half of what it normally would be. The result is that the node will under-report its load to the load balancer, causing it to receive more requests in response than it normally would. If your goal instead is to over-report the load of a node, you would want to give it a fractional value, e.g. capacity="0.5".
-
12. Re: AS7 modcluster load-metric capacity values
mbabacek Dec 13, 2012 5:12 AM (in response to pferraro)Meh, yes, mea culpa. Paul is right. For the sake of clearness:
Load is obtained in AverageSystemLoadMetric as:
double load = this.bean.getSystemLoadAverage(); return load / this.bean.getAvailableProcessors();
However, the capacity is applied as same as for other metrics in DynamicLoadBalanceFactorProvider in this way:
this.recordLoad(metricLoadHistory, metric.getLoad(engine) / metric.getCapacity());