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<== Date ==> <== Thread ==>

Subject: RE: alarm hook
From: "Liyu, Andrei" <liyua@ornl.gov>
To: Andrew Johnson <anj@aps.anl.gov>, "Dalesio, Leo `Bob`" <dalesio@slac.stanford.edu>
Cc: Matthias Clausen <Matthias.Clausen@desy.de>, Geoff Savage <savage@fnal.gov>, EPICS core-talk <core-talk@aps.anl.gov>, Fritz Bartlett <bartlett@fnal.gov>, Bernd Schoeneburg <Bernd.schoeneburg@desy.de>
Date: Fri, 23 Jun 2006 16:59:57 -0400
Andrew,

Could you, please, explain better about local CA client? 

How can it subscribe to local records automatically? Or will it have
list?
How standard CA client will send to log server? Or it is special CA
application?

I also see that String or waveform record types can be used.
String has restriction 40 symbols(?). CA queue has restriction too
(10-20 in the queue ?).
Waveform queue is 1.

==========
Any,

I was absent couple days. I will re-read all messages. I like George's
approach with list. Maybe he or Matthias can collect variants in Wiki? I
will write some variants for items in George's list. 

At last, I see that Bob wrote very interesting notice about archive :) 

Have a great weekend, Andrei.
 

-----Original Message-----
From: Andrew Johnson [mailto:anj@aps.anl.gov] 
Sent: Friday, June 23, 2006 4:27 PM
To: Dalesio, Leo `Bob`
Cc: Matthias Clausen; Geoff Savage; EPICS core-talk; Fritz Bartlett;
Liyu, Andrei; Bernd Schoeneburg
Subject: Re: alarm hook

I suggested:
> It occurs to me that another model you could consider would be to run
> a local CA client on each IOC that subscribes to alarm events for all
> local records, and forwards them to the log server; this would then
> make use of CA's queue/ cache mechanism, and would mean this CA
> client doesn't need to keep its own queue of messages going to the
> log server, all that queueing would be done for you by CA.  This
> would avoid having to add the hook at all... 

Dalesio, Leo `Bob` wrote:
> ------ This has a lot of
> appeal. It could cache the last alarm monitor for every record.

Actually it wouldn't even need to do that itself if its job is just to 
pass the alarm changes on to the log server -- CA will automatically 
queue and cache the most changes for every channel on the clients 
behalf, until it finally manages to deliver them to the client.

- Andrew
-- 
Not everything that can be counted counts,
and not everything that counts can be counted.
   -- Albert Einstein


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Re: alarm hook Andrew Johnson

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