Defining values for Web Service workload

Products

• Endevor

Issue/Introduction

Setting up Web Services on a single Endevor Prod instance.
In order to setup the ENF parameters, what are the best values for the CCI property file definition found in the CSIQOPTN lib?
What values must be coded to serve the developer community if over 600+ users?

The default number present in the CSIQ file is below : 
MAX#_SERVICES=100,
MAX#_CLIENTS=1,
MAX#_PROCESSES=100,

Environment

Component: Endevor

Resolution

The number of STCs started by the web services is controlled in the configuration files on Tomcat via these parameters: 

  PoolInitSize=
  PoolIncrSize=
  PoolMaxSize=

• PoolIncrSize
  Specifies the size of the batches of extra STCs that are started when a shortage of STCs is detected. (If an STC shortage is detected, the total number of STCs that can be added to the initial permanent pool of STCs is limited by the PoolMaxSize value.)
  Values: 0-5
  Default: 1
• PoolInitSize
  Specifies the number of initial STCs in the STC pool. The STCs are created when Web Services is initiated, and at least this many STCs will always remain active in the pool. Each STC in the pool can transmit API requests from different clients to Endevor on the mainframe.
  Values: 0-20
  Default: 0
• PoolMaxSize
  Specifies the maximum number of live permanent and incremental STCs in the pool. The STC pool maintenance thread maintains up to this number of STCs in the pool. If the maximum numbers of STCs are fully utilized, incoming web service calls are queued for the number of seconds that is specified by the ConnectionTimeout value.
  Values: 0-40
  Default: 0

There should be no need to change the ENF parameters unless the PoolMaxSize is set less than 101.

For 600 users, 100 would be excessive, the pool size should be based on how many concurrently executing requests (users submitting a command or refreshing a UI) is expected at peak times. A short spike in concurrent requests due to random chance is acceptable, some users will just experience a longer wait time at that moment.  

Then to start for an expected number of user around 600, start with defining PoolMaxSize=30 and check the number of STCs are running during peak hours, adjust this value based on that.

Additional Information

For further information, see "STC parameters" from Chapter "Create the Web Services Configuration File"