Here's an example of why I'm questioning this.  This is from a book by Robert 
Vaupel.  I know he's knowledgeable, but the explanation is confusing.

Using an average response time example he says "The running or in-flight 
transactions are also captured in order to make sure that long running and not 
ending transactions are used for managing the service class too.".

Why should a transaction that hasn't ended be relevant?

Sent from my iPhone

> On Feb 15, 2018, at 10:34 AM, Allan Staller <allan.stal...@hcl.com> wrote:
> 
> IIRC, WLM only uses ended transactions for the policy adjustment cycle.
> 
> Further suggested reading SYSTEM Programmers Guide to WLM:
> 
> www.redbooks.ibm.com/redbooks/pdfs/sg246472.pdf
> 
> -----Original Message-----
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On 
> Behalf Of Gerhard Adam
> Sent: Thursday, February 15, 2018 11:25 AM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: WLM and response time
> 
> I agree.  But the question remains.  How does WLM manage a response time that 
> is longer than the policy adjustment interval?  Is it only based on ended 
> transactions at that time (which would seem logical).
> 
> I've also seen a lot of recommendations from various sources talking about 
> short batch, which is what gave rise to the question.  Specifically the 
> recommendation used 5 initiators as the example.  
> 
> Also it doesn't matter if it is percentile or average response time.  What 
> makes me wonder is that it basically tenders the percentile useless.
> 
> For example, if I have an average response time of 1 sec, then it is easy to 
> see that enough transactions would end in an interval to provide samples to 
> evaluate.  However let's also say that there are some transactions that will 
> experience a response time of 60 seconds (and stay in the same period).  In 
> fact, this can happen with USS where transactions may show a response time of 
> 20 seconds.
> 
> Since these end during different policy adjustment intervals, it seems that 
> they are only a sporadic effect, because during the interval when none end, 
> the average response time would hold.  During the intervals when they do end, 
> the percentile would be applicable.
> 
> Yet wouldn't this cause me to perpetually fluctuate between exceeding goals 
> and meeting them?  After all during the intervals when I have no long running 
> transactions ending, I would show 100% meeting goals and exceed by goal.
> 
> Yet I don't recall ever seeing this kind of behavior.
> 
> Sent from my iPhone
> 
>> On Feb 15, 2018, at 6:17 AM, Allan Staller <allan.stal...@hcl.com> wrote:
>> 
>> Response time goals for batch do not (IMO) make any sense.
>> 
>> WLM is predicated on having enough samples to make an informed decision. If 
>> you only have 1 or 2 samples (ended transactions) in an interval, that is 
>> not statistically valid.
>> I would suggest a velocity goal be used in its place.
>> 
>> If queue time is needed to be considered, the I would expand the suggestion 
>> to include WLM managed initiators. This will change the velocity calculation 
>> to include queue time as part of the delay.
>> 
>> Suggested reading: 
>> ftp://public.dhe.ibm.com/s390/zos/wlm/WLMvelocity.pdf
>> 
>> HTH,
>> 
>> -----Original Message-----
>> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] 
>> On Behalf Of Gerhard Adam
>> Sent: Wednesday, February 14, 2018 9:40 PM
>> To: IBM-MAIN@LISTSERV.UA.EDU
>> Subject: Re: WLM and response time
>> 
>> Well, this may seem like an obvious answer, but I can't tell if I'm 
>> confusing myself or missing something.
>> 
>> If I use a long response time (like 10 minutes for batch), then I would 
>> think that I only consider that during the Performance Adjustment interval 
>> in which the transaction ends.  Yet that raises the question that if I have 
>> multiple jobs in such a service class, then over what interval must they end 
>>  to provide a meaningful metric?  Assuming they would all end within a 10 
>> second window seems implausible, so how can a response time goal 
>> realistically be managed at such high values?
>> 
>> In addition I recently read that even transactions that haven't ended can be 
>> used in the evaluation of goals, but that doesn't make sense since, by 
>> definition, they haven't ended.  Yet this is what percentile goals are 
>> supposed to represent.
>> 
>> So I guess my question involves how a policy adjustment interval addresses 
>> transaction that run longer than the time between intervals, or is it merely 
>> that they are only examined during the interval they actually end in?
>> 
>> Adam
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