Performance monitoring in BPM server

To monitor active session count and transactions,following counters from Performance modules:

Transaction Manager
Servlet Session Manager
IBM_BPM_Portal_BPM75Node01_server1#portal.war  under Servlet Session Manager.

Here is a simple description of how to view the current performance activity on the server and how to enable logging of statistics gathered by Tivoli Performance Viewer:

Procedure

• View current performance activity

1.   Click Monitoring and Tuning > Performance Viewer > Current Activity in the administrative console navigation tree.

2.    Select Server, then click the name of the server whose activity you want to monitor. You can alternatively select the check box for the server whose activity you want to monitor, then click Start Monitoring. To start monitoring multiple servers at the same time, select the servers then click Start Monitoring.

3.    Select Performance Modules.

4.    Select the check box beside the name of each performance module that you want to view.  Expand the tree by clicking + next to a node and shrink it by clicking – next to a node.

5.    Click View Modules. A chart or table providing the requested data is displayed on the right side of the page. Charts are displayed by default.

Each module has several counters associated with it. These counters are displayed in a table underneath the data chart or table. Selected counters are displayed in the chart or table. You can add or remove counters from the chart or table by selecting or clearing the check box next to them. By default, the first three counters for each module are shown.

You can select up to 20 counters and display them in the TPV in the Current Activity mode.

6.    Optional: To remove a module from a chart or table, clear the check box next to the module then click View Modules again.

7.    Optional: To view the data in a table, click View Table on the counter selection table. To toggle back to a chart, click View Graph.

8.     Optional: To view the legend for a chart, click Show Legend. To hide the legend, click Hide Legend.

9.    When you have finished monitoring the performance of your events, click Tivoli Performance Viewer, select the server you were monitoring, and click Stop Monitoring.

• Log performance statistics

While monitoring is active on a server, you can log the data from all the PMI counters that are currently enabled and record the results in a TPV log file. You can view the TPV log file for a particular time period multiple times, selecting different combinations of up to 20 counters each time. You have the flexibility to observe the relationships among different performance measures in the server during a particular period.

1.    Click Start Logging when viewing summary reports or performance modules.

2.    When finished, click Stop Logging. By default, the log files are stored in the profile_root/logs/tpv directory on the node on which the server is running. The TPV automatically compresses the log file when it finishes writing to it to conserve space. There must only be a single log file in each compressed file and it must have the same name as the compressed file.

3.    Click Monitoring and Tuning > Performance Viewer > View Logs in the administrative console navigation tree to view the logs

Also I recommend to take a look at this or http://www.slideshare.net/itsolvs/tivoli-perfviewer guide with screen shots(begin with Part3 using Tivoli performance viewer). 

For monitor the process part ,you can use the Monitoring > Instrumentation(Monitor) in the process admin console.

monitoring the system components to determine system health and the need for further tuning as follows:

 For each physical machine in the topology, including front-end and back-end servers such as web and database servers, monitor the following processes using the relevant OS tools (such as vmstat, iostat, netstat, or their operating system-specific equivalents):

– Processor core use
– Memory use
– Disk use
– Network use
Complete the following actions for each Java virtual machine (JVM) process started on a physical machine (for example, process server, messaging engine server, and other components):
– Use tools such as ps or their equivalents to get core and memory usage per process.
– Collect verbose garbage collection (verbosegc) statistics to obtain information about Java memory usage.
 For each BPM server or messaging engine JVM, use a tool such as IBM Tivoli® Performance Viewer, or the WebSphere Performance Tuning Toolkit  (http://www.ibm.com/developerworks/websphere/downloads/peformtuning.html), to monitor these types of data:
– Data connection pool use for each data source.
– Thread pool use for each thread pool (Web container, default, and Work Managers).

 Monitor the database systems. This includes the databases for the Process Center, Process Server, Peformance Data Warehouse, Business Monitor, and any other applications that are part of the BPM solution. BPM solutions are often very database intensive, so ensuring excellent performance for the databases is critical. Use the database vendor’s monitoring tools, along with operating system tools such as io-stat,
vmstat, or the equivalent.

Refer the material from below link.
http://www.redbooks.ibm.com/redpapers/pdfs/redp4935.pdf