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<== Date ==> <== Thread ==>
Subject: Re: write to a single element of an array field
From: "Johnson, Andrew N. via Core-talk" <core-talk at aps.anl.gov>
To: Ben Franksen <benjamin.franksen at helmholtz-berlin.de>
Cc: EPICS core-talk <core-talk at aps.anl.gov>
Date: Tue, 24 Mar 2020 17:14:35 +0000
Hi Ben,

On Mar 24, 2020, at 12:02 PM, Ben Franksen via Core-talk <core-talk at aps.anl.gov> wrote:

What if I want my database to process some counter or debug record via
CPP input link? I may not care at all for the value, only the fact that
an event happens. IMO this is valid use case and it will be hard to make
it work reliable if events are dropped in this way.

Channel Access has always been allowed to throw away monitor updates if the client can’t keep up with the rate that the server is sending them, so a counter implemented like that isn’t reliable anyway. Ralph's change might make dropping updates more common, but IIUC it only happens when your client is monitoring an array field through a filter. Maybe that’s more likely if you use a filter to only return the first element in order to reduce bandwidth needed say, but you still can’t guarantee to get all the events, even with a scalar.

- Andrew

-- 
Complexity comes for free, simplicity you have to work for.

References:
Re: write to a single element of an array field Ben Franksen via Core-talk
Re: write to a single element of an array field Ben Franksen via Core-talk
Re: write to a single element of an array field Ben Franksen via Core-talk
Re: write to a single element of an array field Ralph Lange via Core-talk
Re: write to a single element of an array field Ben Franksen via Core-talk
Re: write to a single element of an array field Ralph Lange via Core-talk
Re: write to a single element of an array field Ben Franksen via Core-talk
Re: write to a single element of an array field Ben Franksen via Core-talk
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