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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

6341.0. "Notify ...,to file x.x writes in 8192 byte lumps" by BAHTAT::LZOPCB::bond () Mon Jul 10 1995 17:30

My customer (BT) is trying to send some events from DECmcc to another system 
for more processing.  They decided to use

	notify domain xxx, to file file.dat

and then tail -f file.dat and pipe the events into their application.

However, it seems that file.dat is only written to when there are 8192 bytes 
of data in the buffer to be written to the file.  (I have tried this myself 
and it isn't the tail command that is the problem - it really is that the 
file has nothing in it until >= 8192 bytes are available and they are 
flushed.  Then nothing more until the next 8192 bytes.)

Notify domain to the screen works fine - events get displayed as they occur 
so I tried doing a manage do notify_xxx >file.dat rather than using the ",to 
file file.dat" syntax but the same thing happens.  I guess it must be 
something to do with the ULTRIX file system?

Can anybody think of a way round this?  My suggestion was to create some 
'noise' (dummy events) every so often such that the real events get flushed 
through within a reasonable time period but then the other application has to 
extract the noise.

chris

T.R	Title	User	Personal Name	Date	Lines
6341.1		KERNEL::EVANSN	Neal Evans - UK CSC, Comms 833-3701	`Thu Jul 13 1995 17:08`	6
	Can anybody shed some light on this ?? I have taken this issue now and am getting hassled by the customer (British Telecom) for a quick reply. Neal Evans - UK CSC, Comms 833-3701
6341.2	Can you use alarms instead of notification for doing the job ?	AZUR::DURIF		`Mon Jul 17 1995 14:26`	33
	Hi Neal and Chris, I have no specific MCC information. > I guess it must be something to do with the ULTRIX file system? I agree with you. If you know some file creation option please ley me know. This problem using the "to file" qualifier may be present with other commands. >My customer (BT) is trying to send some events from DECmcc to >another system for more processing. They decided to use > > notify domain xxx, to file file.dat I do not know in depth what the customer wants to do but i have a suggestion. Is it possible to use existing alarms rules or setup specific ones. Write a specific alarm fire procedure using mcc_evc_send procedure to send MCC events. If "another system" is not runnig MCC you can put commands in the specific alarm fire procedure. The alarms functional module is designed for this purpose not the notification FM. An event is generated when an alarm fires not when a notification fires. Hope this helps. Benoit DURIF
6341.3	May not be easy to do...	BAHTAT::LZOPCB::bond		`Fri Aug 04 1995 15:54`	18
	Hello Benoit, I don't think what you suggest would be very easy to implement because the customer would have to produce an Alarm rule for every event that he is interested in seeing in every domain so this really wouldn't work very well. The idea of using notify is that he can issue this at the top level domain and pick up events from the whole heirarchy (it is a very large hierarchy!). My feeling is that the buffering is the default behaviour of whatever routines are being used to write out the notifications from DECmcc. Are they C routines 'write' or 'put' or something? If so, would it be possible to call a 'flush' routine after doing the write? I suspect that would fix the problem. Alternatively, the customer will just have to have a dummy event occuring every few minutes to keep flushing the pipe! cb
6341.4		AZUR::DURIF		`Mon Aug 07 1995 12:12`	28
	Hi Chris, >>My customer (BT) is trying to send some events from DECmcc to another system Maybe it is not for all entities in a domain. With Iconic Map in "Polycenter notification", Options menu, "Notification logging" you can set parameter "New version of logfile every xx hour". This may help creating new files. We do not plan to change the code as buffering is required for performance. You can create a domain only with entities on which you need to collect events to send to other node. Then create rules against these entities and do the processing you need. I guess to do not need to forward all events. This is the way other customer do the job. By scanning the logging files you may use some cpu and memory usefull for MCC processing. Hope this helps, Benoit