4 Replies Latest reply on Apr 20, 2016 4:02 AM by VishnuVinnakota

    How to size iCM


      Hi ALL,


      EBS R12.1.3



      How do you size up concurrent managers? or how do you know if it is too few or too many?

      Right now out Standard Manager is 70. Do they eat lots of CPU or Memory?




      Is this calculation accurate?


      What value to use? – Calculate it! Three parameters are important to estimate the “Sleep Seconds” (S) setting: the number of manager processes (N), the average utilization level (U) of concurrent managers (this setting will be explained later), and the average time of how long the request is allowed to be pending (T). As “Sleep Seconds” are effective only for the idle processes, it can be calculated using the following: S = N * (1 – U) * T.

      • Example 1: if N = 5 processes, U= 20%, T=20 seconds – let’s calculate the “Sleep Seconds” setting: S = 5 * (1 – 0.2) * 20 = 5 * 0.8 * 20 = 80 seconds. It seems high, but think about it – if the average utilization of 5 processes is 20%, then there are 4 idle processes at any given time. Each of these will have a sleep interval of 80 seconds, so on average the requests queue will be checked every 20 seconds.
      • Example 2: if N = 3 processes, U= 90%, T=20 seconds: S = 3 * (1 – 0.9) * 20 = 3 * 0.1 * 20 = 6 seconds.  This example reveals a problem as the calculated “Sleep Seconds” are lower than the requirement we have set – this means the requirement can’t be reached with the number of running processes. Think about it – we have 3 processes each utilized 90% of time; it’s impossible to meet the 20 seconds goal because all managers are busy most of the time. There simply aren’t enough processes to execute the incoming requests. The defined requirements can be reached only if at least one manager process is idle. This scenario also describes a “perfect world”, where all but one manager is busy, so all new requests are picked up in time and the processing overhead of the idle manager processes is minimal.


      Kind regards,


        • 1. Re: How to size iCM
          Pravin Takpire

          Number of concurrent managers always depends on the number of requests that it is going to process, which is ultimately processed by database server.

          Above formula looks ok, but in my view there is not standard One fit for all formula. It all depends on requirements, current infrastructure.



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          • 2. Re: How to size iCM

            I would recommend you to have a look at the Administer Screen frequently or run select count(*) from fnd_concurrent_requests where phase_code='R' every hour during peak and non-peak times.


            70 processes means the manager can run 70 concurrent requests at the same time. Though it is a little high, it may be needed based on the environment.


            Once you determine the peak time, create workshifts for managers: for e.g. During Audit - 50, General - 20, Night Batch Reporting - 70 etc.


            Yes. Each manager is a physical process and it consumes memory,cpu but planning is important.

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            • 3. Re: How to size iCM

              Thanks ALL,


              So it is okay to leave it at 70? My concern is there should be no pending or waiting jobs due to unavailability of iCMs.

              What I mean is 70 will not cause our system to slow down or degrade performance, as long as we have enough memory. or even if we do not really have lots of jobs to be run?



              Kind regards,

              • 4. Re: How to size iCM

                Each FND might consume when inactive not more than 20-30M so it shouldn't be a problem.


                But Always spend time on understanding actual need of managers so that you can define time shifts.

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