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Recovering from "shutdown" takes long due to compression

Question asked by Shchurd on Dec 16, 2019
Latest reply on Feb 21, 2020 by gregor

Hello,

 

I have the shutdown attribute = 1.  I find this helpful because it allows me to instantly know when there is a data loss.  I can use this along with the badval calculation in AF to send notifications when data flow has stopped.

 

Sometimes I only have momentary loss of data.  This leads to "shutdown" being written to the tag which is fine.  The problem is that even though data flow resumes after only a few minutes, certain tags take hours to recover from this.  I believe this is due to my compression settings.  Basically it takes many hours to get a value that meets the compdev requirements and stores a new value (at least I believe this is the issue).  This is a huge nuisance to me because it ruins all of my analysis and trends during that time period.  One minute of data loss appears as 8 hour of data loss in Pi.

 

In my opinion, if the previous data archive value is shutdown, then there should be no compression applied to the next value.  Does anyone have any suggestions on how I can solve this?

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