From: davek@informix.com (David Kosenko)
Newsgroups: comp.databases.informix
Subject: Re: OnLine.USERS.parameter
Date: 7 Jan 93 17:29:05 GMT
Organization: Informix Software, Inc.

Bharat Shah writes:
>Hi,
>
>We have been using SCO-OnLine since last three years and I have yet to figure 
>out the **TRUE** meaning of the USERS shared memory parameter.
>
>USERS imply maximum number of users

USERS == # sqlturbos + daemons (tbinit, tbundo, tbpgcl's) + admin processes
(tbmonitor, tbtape).

>
>Page 2-28 of Informix OnLine Administrator's Guide,
>Database Server Version 4.00 states:
>
>   " ..... Daemon and tape utilities count as users.
>    Minimum number of users is given by the equation 4 + p + m
>
>    where p is the number-of-page-cleaners
>          m is 1 if you use disk mirroring and
>          m is 0 if you are not using mirroring"
>
>My question goes if:
>
>p = 1 and m = 1 and
>I want five "people-users" (one each for isql, esql/c, forms, Wingz, Ace) 
>to use the engine what should be my setting for USERS ?
>
>If your answer is  5 + daemon + (p=1) + (m=1) = 8 ... You are wrong !!

Correct, but for the wrong reason: two deamons are allocated, so the answer
should be 9, not 8.  That assumes, based on what you have described, that
you will have 1 user running isql with one open database, one user running
an esql/c program with only one open database (and a single process appli-
cation at that)... Read on...

>On calling Informix Tech Support I was told that for five people user the
>setting should be (5 * 4) + p + m = 22 !!

Whoever told you this did not know what they were talking about, I'm
sorry to say.  By no means are 4 sqlturbos required per "user".

Now this can get a bit complicated, because a license "user" != OnLine
"user".  Consider the case of I4gl.  When you start up I4GL, the database
syspgm4gl is opened.  This requires one sqlturbo (sqlturbo is the primary
OnLine "user").  If you run a 4gl program from I4GL, that 4GL program
will open its own database, requiring another sqlturbo.  SO you have
2 sqlturbos, or 2 OnLine "users" running, yet this only constitutes ONE
license "user".  I just checked, and the official "stance" is that a
license "user" is a single userid on the same physical device (i.e.
terminal) with up to 5 database "sessions" (read "sqlturbos"). So, I 
could, sitting at my X-terminal, have several window open, with a different
Informix-based app running in each, having up to 5 sqlturbos running
(i.e. 5 OnLine "users") and still be considered one license "user".

>
>My license being for 16-users I was not sure if this was OK, so I called
>again to confirm USERS setting of 22 and queried some other Support
>engineer. He not only refused to confirm the setting but seemed upset at 
>the previous engineer for giving me the **REAL** formula !!

No, he was upset that another engineer had given you bogus info.  Look
(and this is to the whole forum, not just Bharat), we at Informix are
not the CIA, or All the President's Men.  We are not trying to hide
info from our users.  I try my utmost on this forum to "tell all" as
it were, even sometimes getting into details that the typical user
doesn't "need" to know.  ANd I am not alone in this effort, as I can say 
from off the top of my head that Alan Denny, Dave Cortesi, and others 
all mak ethe same effort here.  This paranoia that we at Informix are trying
to keep info out of the hands of our users is really quite misguided.
Now people make mistakes.  It is sad, but true, that support engineers
sometime give out the wrong info (typically either because they are
new or were told, by some bonehead, wrong info and are simply
passing it along).  The **REAL** formula is the one in the Admin Guide.

>Some simple experiments showed that a value of 10 would suffice for my needs.
>
>MY GRIPE HERE IS WITH DOCUMENTATION and WITH INFORMIX TECH SUPPORT !! 
>
>IF ONLINE REQUIRES MAX USERS SETTING WHY NOT DOCUMENT A FORMULA TO
>COMPUTE MAX ? WHY BOTHER TO GIVE A FORMULA FOR MINIMUM SETTING ?

I was prepared to take you to task for your comments about the doc, when
I reread that you were using version 4.00.  I must, therefore, agree
with you that the documentation is abysmal.  Let me assure you that we
have improved this dramatically in 5.00, and in fact most of what you
request has come to pass.  For example, regarding:

>WHY NOT BE FORTHCOMING AND SAY THAT **USERS** SETTING IS THE NUMBER OF
>PROCESSES (This though could be found out by reading the tbconfig file which 
>states that users = max number of concurrent processes). I guess I had better 
>read all Informix provided scripts & files to to understand the product!

I quote from  the 5.00 manual (pg 1-31):

	"To arrive at a value for USERS, specify the highest likely
	value for the number of user processes active at any one time
                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
	plus the value of CLEANERS plus 4."

BTW, Chapter 1 of the 5.00 manual was SPECIFICALLY designed to guide an 
admin through the setup procedure, with each step explicitly described, all 
the parameters explained, etc.  

So take what comfort you can in knowing that things are getting better.
Tech Pubs now looks to the field for input on new documentation (after all,
we are in pretty much the same boat as our users), and I believe that is
reflected in much of the 5.00 docs (though I still haven't manage to
convince them that Unix man pages would be a great addition..).  I am
truly sorry that you have had so much difficulty with what should be
a simple matter.  I am also sorry that tech support gave you erroneous
info.

Dave
-- 
Disclaimer: These opinions are not those of Informix Software, Inc.
**************************************************************************
"I look back with some satisfaction on what an idiot I was when I was 25,
 but when I do that, I'm assuming I'm no longer an idiot." - Andy Rooney