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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

5490.0. "%MCC-E-INSEVTPOOLMEM" by KETJE::PACCO (Horum omnium fortissimi sunt Belgae) Tue Aug 17 1993 07:00

    After I got no notifications any more, and a lot of errors, I found
    out that I have a "event memory pool" error. (ULTRIX DECmcc V1.3).
    
    I wanted to clear this problem, in the usual way : mcc_kill,
    but there was no sufficient event pool for this.
    
    I decided to "kill" all processes individually.
    
    Now I even cannot restart DECmcc any more: both the FCL-PM and ICMP-PM
    gives the error:
    MCC> Failure in kernel event receipt. Thread terminating
     %MCC-E-INSEVTPOOLMEM, insufficient event pool memory to post event
    
    This happens in the FCL-PM, at initialization, where even no
    notifications or events are enabled !
    
    What can I do to solve this problem ?
    
    	Regards,
    	Dominique.
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5490.1Problem disappeared after reboot.KETJE::PACCOHorum omnium fortissimi sunt BelgaeTue Aug 17 1993 10:355
    The event pool file resides on /tmp
    
    After a reboot of the system, the problem disappeared.
    
    Dominique.
5490.2%MCC-E-INSEVTPOOLMEM problem.KETJE::PACCOHorum omnium fortissimi sunt BelgaeMon Oct 11 1993 10:2031
    MCC> Failure in kernel event receipt. Thread terminating
     %MCC-E-INSEVTPOOLMEM, insufficient event pool memory to post event
    This happens alfter a few days of operation.
    I get this error more and more.
    
    From then on "mcc_kill" even does not work any more.
    
    Even after a kill of ALL mcc processes a restart DECmcc (both the
    FCL-PM and ICMP-PM) is not possible any more.
    The only possibility is a complete shutdown/restart of ULTRIX.
    This becomes very annoying.
    
    QUESTION:
    	How is the event pool be sized.
    	Which parameters are responsible
    		- to allocate space?
    		- to use that space?
    
    	Regards,
    	Dominique.
================================================================================
Note 5490.1                   %MCC-E-INSEVTPOOLMEM                        1 of 1
KETJE::PACCO "Horum omnium fortissimi sunt Belgae"    5 lines  17-AUG-1993 09:35
                     -< Problem disappeared after reboot. >-
--------------------------------------------------------------------------------
    The event pool file resides on /tmp
    
    After a reboot of the system, the problem disappeared.
    
    Dominique.
    
5490.3Some answersTAEC::FLAUWTue Oct 12 1993 04:5064
Dominique,

We have seen what look like a smilar problem in TeMIP and have studied quite a 
lot the Event Manager. 

First a few answers to your questions :
    
>>    QUESTION:
>>        How is the event pool be sized.
The Event Pool is controlled through a set of environment variables :
    - MCC_EVENT_POOL_SIZE : this variable determines the size of the event
      pool available for containing event data. This variable should be in
      multiples of 1024 bytes. the default is 524288 (1/2 MB), the minimum
      262144 (1/4 MB) and the maximum 8192000 (8000 KB). In TeMIP, we
      recommand and define in our temip_login.csh MCC_EVENT_POOL_SIZE
      2097152 (2 MB)
    - MCC_EVENT_EDQ_SIZE_LIMIT : this variable determines the maximum
      number of events that can be queued up (in the event pool) for a
      given event "get" if the fullness of the event pool has exceeded a
      threshold.  Events for an event "get" that exceed this queue size are
      lost and are returned as "lost" events for that event "get".  The
      event pool fullness threshold is a varying percentage of the total
      event pool size, and is the larger of 32K bytes or 1/16th of the
      event pool size.
      The default value is 25 events for an event "get" queue.  Units are
      in number of events in the queue.  Note that if this variable is set
      high enough (say, 100000), there is no queue size limit. In TeMIP, we
      recommand a value of 2500, as it corresponds to our requirements
      
    There are also other environment variables, but these 2 are the most
    important ones as far as event pool size is concerned. 

>>        Which parameters are responsible
>>                - to allocate space?
See above

>>                - to use that space?
I will try to summarize it for you. It might not be 100% accurate, but it
should be close enough.   Each time an mcc_event_get is made, space for the
get structure is allocated in the pool. If the process exits nicely, this
structure is cleaned. If it exits abruptly, then this structure is left in
this event pool and a specific sweeper mechanism running either every hour
or when the event pool starts to be full removes these structures.  



>>    MCC> Failure in kernel event receipt. Thread terminating
>>     %MCC-E-INSEVTPOOLMEM, insufficient event pool memory to post event
>>    This happens alfter a few days of operation.
>>    I get this error more and more.
    
Regarding your problem, we found a problem linked to a bad clean-up of some
event get structures when they were empty. I don't know if your problem is
the same, but we found it in a similar way : receiving "insufficient event
pool" messages after a few days of operation. Further analysis of the event
pool behaviour has shown us that in our case it was getting filled up with
dead event get structures

If you have access to the QAR database, it is QAR #560, entered
12-MAY-1993. It is marked as closed, fixed in V1.3 MUP and OSF/1 code stream.

Hope this helps,

Marc.
5490.4No DECnet events any more ...KETJE::PACCOHorum omnium fortissimi sunt BelgaeFri Oct 15 1993 12:3517
    Marc,
    
    	After I modified (added) the following 2 variables in mcc_login.csh
    
    setenv MCC_EVENT_POOL_SIZE 2097152
    setenv MCC_EVENT_EDQ_SIZE_LIMIT 2500
    
    	and after I have rebooted the system, DECmcc seemed to work fine,
    except for one item:  I do not get any DECnetV events any more.
    
    removing these two lines (and restart of DECmcc) permitted to have
    DECnetV events again !
    
    Is the choice of these two assignments wrong ?
    
    Kind regards,
    	Dominique.
5490.5TAEC::FLAUWFri Oct 15 1993 13:0214
	Dominique,

	Your environment variables seem right. One thing to watch for is that 
	*all* processes that use the Event Manager should have the same value for 
	these variables. 

	I am not familiar enough with the way Phase V events are collected, but 
	the only direction I can think of might be that there is a sink process
	somewhere that does not use these variables. 

	Best regards,

	Marc.