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<== Date ==> <== Thread ==>

Subject: RE: Notification of Archiver Appliance interruptions
From: <[email protected]>
To: <[email protected]>, <[email protected]>
Date: Tue, 3 Oct 2017 09:40:53 +0000
Thanks to Murali and Michael,

As far as I can tell, this is nearly as much as the Channel Archiver gives you. The one thing I can't find is notification when the connection was lost in the case of an Archiver Appliance reboot, which means that it may be unclear how much data is missing in that case.

This is possibly something that could be added in future.

Cheers,
Will

________________________________
From: Shankar, Murali [[email protected]]
Sent: 19 September 2017 00:46
To: [email protected]
Cc: Rogers, Will (DLSLtd,RAL,TEC)
Subject: Re: Notification of Archiver Appliance interruptions

Hi Will,

   Don't know if this is what you are looking for but there are a couple of extra fields available in the JSON/RAW responses. Here's some info from a couple of months back (this should be cleaned up and added to the documentation).

For example, I just started my dev appserver and asked for recent data.
You can see that the first sample is from some time ago (date -d @1497486486 = Wed Jun 14 17:28:06 PDT 2017​) and in the second sample we add these headers
--> cnxlostepsecs ​- This is the server time we lost the connection to the PV
--> cnxregainedepsecs  - The is the server time we regained connection to the PV
--> startup - This lets you know if the connection was lost because of an appliance restart. In the case of an appliance​ restart, we really do not know when we lost the connection so the cnxlost is almost always 0.

$ curl -s "http://localhost:17665/retrieval/data/getData.json?pv=mshankar:arch:sine&from=2017-07-06T20:14:46.258Z&to=2017-07-07T21:14:46.258Z";
[
{ "meta": { "name": "mshankar:arch:sine" , "EGU": "Lollipo" , "PREC": "10" },
"data": [
{ "secs": 1497486486, "val": -0.9776236311492024, "nanos": 220984002, "severity":2, "status":5 },
{ "secs": 1499375542, "val": 0.7103532724176082, "nanos": 452983690, "severity":2, "status":3, "fields": { "cnxlostepsecs": "0","startup": "true","cnxregainedepsecs": "1499375542"} },

Of course, there is nothing saved if the engine process crashed.

The same fields are there in case of an IOC reboot. For example, here I have rebooted the IOC.
{ "secs": 1499376673, "val": -0.4496474645347919, "nanos": 452668468, "severity":2, "status":5 },
{ "secs": 1499376742, "val": 0.0, "nanos": 710740321, "severity":2, "status":3, "fields": { "cnxlostepsecs": "1499376674","cnxregainedepsecs": "1499376742"} },
{ "secs": 1499376743, "val": 0.009999833334166664, "nanos": 710700442, "severity":2, "status":3 },
Since the appserver was alive during this time, it has server times for both the cnxlost and cnxregained.

Hope that helps..

Regards,
Murali






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References:
Re: Notification of Archiver Appliance interruptions Shankar, Murali

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