Back Midas Rome Roody Rootana
  Midas DAQ System  Not logged in ELOG logo
Entry  12 Dec 2024, Stefan Ritt, Suggestion, New alarm sound flag to be tested 
    Reply  19 Dec 2024, Stefan Ritt, Suggestion, New alarm count added 
       Reply  20 Mar 2025, Konstantin Olchanski, Suggestion, BINARY INCOMPATIBLE CHANGE: New alarm count added 
          Reply  21 Mar 2025, Stefan Ritt, Suggestion, BINARY INCOMPATIBLE CHANGE: New alarm count added 
             Reply  21 Mar 2025, Konstantin Olchanski, Suggestion, BINARY INCOMPATIBLE CHANGE: New alarm count added 
Message ID: 2980     Entry time: 21 Mar 2025     In reply to: 2964     Reply to this: 2994
Author: Stefan Ritt 
Topic: Suggestion 
Subject: BINARY INCOMPATIBLE CHANGE: New alarm count added 
> > ALL MIDAS CLIENTS GET RE-COMPILED after the new code is applied.
> 
> Usually we expect that it is "safe" to update to the latest version of MIDAS.
> 
> In the sense that we do not have to track down every single frontend
> and rebuild it. We have several experiments where tracking down the source code
> and rebuilding a frontend takes more than 5 seconds. In many cases these are
> 10 year old executables that worked just fine through many updates of MIDAS
> without having to rebuild them.
> 
> So any binary incompatible change is best avoided and must be clearly announced.
> 
> The present binary-incompatible change is this commit:
> https://bitbucket.org/tmidas/midas/commits/5899f1657ba31121c9f420a824b3c6c13b173988
> 
> I tagged the last commit before this change as: midas-2024-12-a

Here are my replies:

- this is not a binary incompatibility, but a incompatibility of the /Alarm record which got two more variables. Old 
frontends will complain during their structure check and remove the two variables, new frontend will then complain as 
well and add the two variables. This will go in circles, that why all frontends need to be recompiled if the new code is 
used

- I did clearly announce this change in the forum. Is there another location where I should communicate that?

- The extension is not there "just for fun" but needed by several experiments which experience spurious alarms 
triggered by some noisy signals. Requiring an value to be above a limit for a certain minimum time fixes many issues in 
many experiments here at PSI, this is why it has been implemented, even if it causes work for everybody with re-
compilation.

- If there are frontend programs which have not been re-compiled for ten years, I think it is very unlikely that these 
experiments need the latest cutting edge version of midas. The can safely stick to your tag midas-2024-12-a and not 
experience the issue of different /Alarm trees.

Stefan
ELOG V3.1.4-2e1708b5