High CPU usage for VANWEBUI task
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High CPU usage for VANWEBUI task


Article ID: 107569


Updated On:


Vantage Storage Resource Manager


The Vantage WEB interface task was reporting High CPU usage.
The customer needed  to ask all the folks in their team to quit their Vantage Web UI browsers to solve the problem.
They would like to know why the high CPU usage appeared when they actually ran the reports or anything on a different sysplex. 
Also, they would like to know if there is a way to identify which user was the culprit for the high CPU usage and any other things/commands we can issue on this. 


Web Client version


1) Upgrade to the current Web Client version 14.0.4 provided by PTF SS04168 (CA VANTAGE WEB CLIENT 14.0.4 - PAX). 
Version was the initial version of the Web UI and had some performance issues, which have been resolved in the meantime. 
So you should upgrade to the current Web Client version 14.0.4 provided by PTF SS04168 (CA VANTAGE WEB CLIENT 14.0.4 - PAX) anyway. 
Download the PTF SS04168.
Then, during the installation creates a new Run time ZFS and tells to reuse the actual Vantage WebDB so at first start it will convert the old WebDB to the new version and you will keep all you have already setup. 

Note: 14.0.4 includes some important enhancements: 
* create Summary Objects 
* create Joined Objects 
* create General Object Automation Scripts 
* create Private and Public Dashboards 
* Export Dashboard Charts 

2) High CPU usage especially for Charts
High CPU usage can be relative, as it really depends on how and what purpose you are using the Web UI. 
For example, it is known that if in one Dashboard there are several Widgets with graphs, plus opened several tabs, high cpu can be noticed. 
So it is recommended to have only open tabs in the Web UI which are really needed, as we do not limit customers in the number of open objects. 
There is no limit of open objects in the Web UI. 
Also, if some Charts are created, they spend more CPU than using Tables. 

3) Monitoring
For live monitoring, please see under Object tree: 
=> CA Vantage Internal Management => Users => LU2USER Table 
In this object there is information about each user, the number of open TCBs and clients they using. 
Column "Windows" correspond of number of opened objects. The more "Windows" a user has opened, the more CPU he is using. 

4) zIIP usage
Regarding zIIP usage, the VANWEBUI address space will use ZIIP processor when ever it can. 
As the Web UI part is written in Java, and by default JVM on z/OS runs on zIIP processor, it will most of time use zIIP CPU. 
In case that all zIIP are busy by other processes some processing can be done by GP. 
To see the CPU time in zIIP, use SYSVIEW command ACTIVITY, System Activity, filter by job, and shift right to look for column IIPtime. 

As per our experience, 90% of all CPU time for the VANWEBUI task is done on zIIP, while for the Vantage host task 40% of cpu time is on zIIP. 
For the host this can be checked via the Vantage Web UI, see: 
=> CA Vantage Internal Management => CPU Usage and HPCS => zIIP Time For Address Spaces