5 Replies Latest reply on May 24, 2019 1:46 AM by Andrew Waters

    Number of ECA Engines

    Danny Fleer
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      I have a question regarding the number of ECA Enginge: Could someone please explain how BMC Discovery determines the number of ECA Engines to start?


      I assumed that the number equals the number of available CPU cores, but on one appliance BMC Discovery uses only 2 Engines, even though the CPU has 4 cores:


      139700925560640: 2019-05-10 14:36:41,952: reasoning.ecacontroller: INFO: 4 CPUs. Creating 2 ECA Engines.

      139700925560640: 2019-05-10 14:36:41,953: reasoning.ecacontroller: INFO: Creating 2 ECA Engines


      On other systems with 4 cores BMC Discovery creates 4 Engines.

        • 1. Re: Number of ECA Engines
          Andrew Waters

          It is related to the number of CPUs and the size of swap and memory.

          • 2. Re: Number of ECA Engines
            Danny Fleer

            Thank you Andrew Waters.


            In my case the both appliances are using default resources and the same CPU. The only difference is that the appliance having 4 Engines is Version and the appliance having 2 Engines is Version


            4 Engines (



            2 Engines (


            It seems to be related to the Swap, which covers "Baseline" in the first, but not in the second case.


            Regarding the discovery performance, does it matter that only half of the number of Engines is available?

            • 3. Re: Number of ECA Engines
              Davin Lindner-Green

              What log file are you referencing in your original post, Danny? The one where you are counting the number of ECA engines? I'm trying to see how many concurrent discovery engines/processes/threads are getting created, to gauge potential network impact. Unfortunately I don't know the answer to your follow on questions...but do note that you can configure how many requests each engine can process (Administration > Discovery Configuration > Maximum concurrent discovery request per engine). I guess you could increase that if you wanted to boost throughput.




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              • 4. Re: Number of ECA Engines
                Andrew Waters

                tw_svc_reasoning.log contains the information for an appliance. You do not need to look in there are the UI will show you the number of ECA engines in the appliance status.

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                • 5. Re: Number of ECA Engines
                  Andrew Waters

                  In 11.2 and later the ECA engine count was limited when you do not have much memory to prevent excessive swapping meaning that 11.2 and later you will get 2 ECA engines rather than 4 with your current configuration.

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