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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
|