Ted, actually you are the one mixing the terminology. WLM application environments (AE's) are either available or quiesced. When an application (in the DB2 stored procedure/UDF case, DB2) requests a connection to an AE, if the AE is quiesced, the request is failed, if available, then WLM will determine if an address space is currently running with matching performance characteristics, and if the address space has an available task. If so, the work is passed to that address space. If the current address space does not have an available task, then WLM will look at the limits, and either start an additional address space, or put the caller in a wait until a task becomes available. If no address space is started, WLM will attempt to start one. Once started, the address spaces remain running for 60 minutes after the last request is completed. The note about matching performance characteristics is important, because WLM can start multiple address spaces, even if limited to one per system, because the 1 per system is really one per system per callers service class. If you have 4 service classes running DB2 work (TSO, DDF, CICS, BATCH etc), you could have 4 AE address spaces running. Also, the process of resuming (making available) or quiescing AE's is via a WLM VARY, not a MODIFY.
Wayne Driscoll Product Developer JME Software LLC NOTE: All opinions are strictly my own. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Ted MacNEIL Sent: Thursday, February 07, 2008 10:27 AM To: [email protected] Subject: Re: WLM for toddlers >As far as I know that is not true. The appl env. asid is created on demand. You are mixing terminology. There is the application environment which consists of: 1. An 8-byte name. 2. A 32-byte lable. 3. An associated PROC, with optional parameters. 4. A limit. If the application environment is stopped, the PROC is never invoked. If the application environment is started then the PROC is invoked, as needed, subject to the limits specified. All AE's are started everywhere, by default, when you IPL. It takes a modify command applied to the WLM to start and stop AE's. The WLM will not start an AE that is stopped. It will invoke more PROCs, if applicable, if the AE is started. This is independent of DB2, except DB2 will use the associated PROC for DDF work. DB2 is not the only sub-system that uses AE's. I worked with an ISV that used them as well. We kept it under tight control, by stopping the AE on all systems where it didn't run. And, during testing, we kept the limit to one per SYSPLEX. Since, we couldn't control when the user was submitting tests, we would stop the AE, whenever we had to do (sub-system or application) maintenance. We did the same with DDF. We were comparing the ISV product to DB2/DDF. - Too busy driving to stop for gas! ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
