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<== Date ==> <== Thread ==>
Subject: Re: Archiver appliance sampling buffer overflows after migration from Version 2018 to Version 1.1.0
From: "Shankar, Murali via Tech-talk" <tech-talk at aps.anl.gov>
To: "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>
Date: Tue, 14 Feb 2023 06:39:38 +0000
Re: Did I miss something for the migration or is there anything changed in the latest version?
The SCAN code has been reasonably stable for a couple of years now. 

Re:  For example, the process frequency of PV A:B:C:D is 25Hz, the scan period is 1 second
For a 25Hz PV; shouldn't the sampling period be somewhat smaller? With a 1 second period you will lose at least 24 of the 25 samples.

I tested with simple ai record with an external process updating at about 100Hz archiving at SCAN/0.01 and I was able to store about 100 samples per second.

$ curl -s "http://localhost:17665/retrieval/data/getData.txt?pv=mshankar:arch:static1" | grep 22:20:11 | wc -l
108
$ curl -s "http://localhost:17665/retrieval/data/getData.txt?pv=mshankar:arch:static1" | grep 22:20:12 | wc -l
108

$ curl -s "http://localhost:17665/mgmt/bpl/getPVTypeInfo?pv=mshankar:arch:static1"
...
  "samplingPeriod": "0.01",
  "samplingMethod": "SCAN",
...


Regards,
Murali



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