Is there any database for DevTest from which we can find the number of Simulators running on each VSE.?
If you wanted to list the VSEs and their associated services, one can use the REST api
Issuing a GET to http://<registry_machine>:1505/api/Dcm/VSEs/ for instance, will return a list of VSE's and virtual services, whereas issuing a get against http://<registry_machine>:1505/api/Dcm/VSEs/<VSE_name> woold return a list of virtual services running on <VSE_name.
See the REST api documentation and/or http://<registry_manchine>:1505/api/swagger for more information
We may need some clarification with regard to your question because what you call a simulator may not be the same as DevTest's definition of a simulator.
A starting point description of some the components can be found here: DevTest Server Components - DevTest Solutions - 10.0 - CA Technologies Documentation
A DevTest simulator is analogous to an instance of a virtual user, and the simulator's responsibility is to runs tests not virtual services. The DevTest Coordinator & Simulator collaborate to execute and report on test cases and test suites. A single Simulator server can execute / simulate up to 256 vUsers. The actual number varies based on the configuration of your DevTest environment and the size/scope of test case & suite activity. If you CLICK into the Portal -> Monitor -> Server Health, you can view some of the Coordinator and Simulator information:
The VSE, on the other hand, is more driven by the amount of activity on a given virtual service (i.e., transaction tps rates). Services are threaded and the TPS rates available to a VSE are differentiated based on licensing model (i.e., functional = ~10TPS per service vs. performance = unlimited). Available Memory, CPU Cores, and other environmental characteristics can determine the maximum throughput of the VSE server. The Portal -> Monitor -> Virtual Service Environments -> <yourVseName> link allows you to see number of TXNs against a given service and also TPS rates, at the service level.
These statistics are stored in the DevTest reporting database. It is possible (but not OOTB) to create a SQL query that provides a summarized view of these various statistics. Some customers also connect using BI tools and create custom reports. As an example, you could create a DevTest Test Case that connects to the DevTest database and queries for a summarized view of transactions running on the VSE. You would need to work with your DBA to determine the database to connect to, the JDBC jar to use, and the appropriate user ID / pwd for the connection. An example query might look something like this.
select VS_NAME, sum(TOTAL_COUNT) AS VS_Count from <yourDBMS>.vse_metrics_txn_counts group by VS_NAMEorder by vs_name
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