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Conference azur::mcc

Title:DECmcc user notes file. Does not replace IPMT.
Notice:Use IPMT for problems. Newsletter location in note 6187
Moderator:TAEC::BEROUD
Created:Mon Aug 21 1989
Last Modified:Wed Jun 04 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:6497
Total number of notes:27359

374.0. "Alarms START ETHERNET DEVICE FAILURE - HELP!" by TAZBOY::ZIGLER (Tom Zigler, DTN 432-7541) Tue Oct 02 1990 18:48

I am currently running the DECmcc BMS EFT Update (T1.0.1) software on a
VAXstation 3100 model 30 running VMS V5.3.  When attempting to enable MCC
Alarms, each with a polling rate of 5 minutes, for approximately 25 LAN Bridges
(mixture of 100s, 150s, and 200s), we get the following error message
consistently whenever more than 18 Alarms are enabled interactively:

	MCC-F-STRTDEVERROR, START ETHERNET DEVICE FAILED
	SYSTEM-F-EXQUOTA, EXCEEDED QUOTA

Nothing else is running on the system except for DECelms. I have carefully
adhered to the quota limits as recommended in the release notes and cannot
understand why I am experiencing this error, especially since the DECmcc BMS
V1.0 SSB release notes indicate successful alarm testing for 100s of alarms.

Any ideas?

			\Thanks in Advance
				
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374.1Memory leaksGOSTE::CALLANDERTue Oct 02 1990 19:0212
    
    You should upgrade. My guess is that the bridge memory leaks from
    that release are getting you. A lot of work has gone into the later
    kits to plug memory leaks hit by alarms (especially in the bridge 
    commands). An upgrade to the latest kit should drastically increase
    the performance of your alarms module.
    
    Note that the SSB release notes are NOT the 1.0.1 release notes.
    The biggest difference in the kits is memory leak fixes. Sorry I
    don't know where a pointer to the ssb kit is off the top of my head.
    
    
374.2Probably NOT a memory leak.WLYWLD::BRIENENDECmcc Bridge|Station Management.Tue Oct 02 1990 20:2735
My guess is that the problem is NOT the Bridge AM leaking memory (95% certain,
based on information Tom supplied to me recently).

The problem is probably one of resource consumption on the part of:

  1. Bridge AM - The Bridge AM requires on the order of 55 pages
                 of stack per instantiation. Due to the way DECmcc handles
                 stack, the Alarms FM must pre-allocate at least that much
                 stack memory per Bridge Rule before calling the Bridge AM.
                 Multiply 55 pages by the number of rules to determine
                 how much stack memory Alarms FM requires BEFORE BRIDGE AM
                 is called. 

  2. MCC_EA Exec Common Routines - The Bridge AM uses the Exec Common Routine
                 MCC_EA_Request_Enet_Packet to access the wire. It turns
                 out that MCC_EA creates two threads per request, eack of
                 which (for V1.0) took the default stack size (64 pages!).
                 So for every poll that the Alarms FM does, touching the
                 wire consumes another 128 pages of stack memory (we have
                 cut this to something like 4 pages for X1.1.1, a V1.1
                 Base Level, but obviously you don't have V1.1). Since multiple
                 threads from the Bridge (and Ethernet) AM can stall in the
                 MCC_EA waiting for $QIOs to complete, we could be talking
                 mucho pages of memory. This fact means that active alarms
                 reduce the number of enabled alarms by something like two-
                 thirds.

The Alarms Team spent alot of time characterizing DECmcc from the standpoint
of the Alarms FM, and published some of their findings in the V1.0 Release
Notes.

Assuming that this is the problem, increasing pagefilequota for the process
running DECmcc should increase the number of Bridge Alarm Rules possible.
The other "workaround" would be to split the Alarm Rules across multiple
processes. 
374.3Try increasing the page file size...WAKEME::ANILWed Oct 03 1990 20:3825
         <<< Note 374.0 by TAZBOY::ZIGLER "Tom Zigler, DTN 432-7541" >>>
>               -< Alarms START ETHERNET DEVICE FAILURE  - HELP! >-
>
>I am currently running the DECmcc BMS EFT Update (T1.0.1) software on a
>VAXstation 3100 model 30 running VMS V5.3.  When attempting to enable MCC
>Alarms, each with a polling rate of 5 minutes, for approximately 25 LAN Bridges
>(mixture of 100s, 150s, and 200s), we get the following error message
>consistently whenever more than 18 Alarms are enabled interactively:
>
>	MCC-F-STRTDEVERROR, START ETHERNET DEVICE FAILED
>	SYSTEM-F-EXQUOTA, EXCEEDED QUOTA
>    :
>    :
>Any ideas?


I have come accross the same problem not too long ago. My page file was 10,000
blocks. I extended it to 40,000 blocks and the prblem went away. Can you again
check and let us know what is the size of your page file?

I have tried ~50 bridge rules with 1 minute interval in a VAX3800. Every thing
ran fine for atleast 1 hr. So it got to be the page file. Let us know if you
need more help.

- Anil Navkal
374.4Pagefile Size Was CauseTAZBOY::ZIGLERTom Zigler, DTN 432-7541Fri Nov 02 1990 13:224
    Yes,  I discovered that the pagefile size was indeed the problem -
    thank you!
    
    		Tom Z.