Experimental Physics and
Industrial Control System

"Kasemir, Kay" <[email protected]> · Fri, 01 Oct 2010 08:37:04 -0400

Hi:

Are these 'scanned' channels?

What can happen is this:

Your PV never changes, it's timestamp is T0.
The archive engine scans the channel.

Every time, the sample engine gets the same value, so it doesn't write
anything to the archive.
But once upon a time there were users who then complained:
Why is there nothing in my archive?
How do I know if
a) The value really didn't change
b) The engine stopped functioning.
So after N repetitions of the same value, the engine _does_ write another
sample with the current host time stamp.
N = max repeat count
Read section 3.1.6 of the manual:
http://ics-web.sns.ornl.gov/kasemir/archiver/manual.pdf

If you now restart the engine, it'll first store the "real" sample with time
T0 in the new sub-archive, and then add those ARCH_REPEAT samples again.

Thanks,
-Kay

On 10/1/10 05:54 , "[email protected]"
<[email protected]> wrote:

> Hi
> 
> Does anyone have experience with overlapping blocks appearing in the
> Rtree Channel Archiver?
> 
> Our archive engine restarts each week. For a channel, sometimes the
> first sample in the new week's archive has the same timestamp and value
> as the first sample in the previous week's archive, after that the
> samples are correct. This is not related to the IOC timestamps as it
> happens across many channels. We do connect through the gateway but I'm
> not aware of a gateway bug that could cause this.
> 
> Previous week  SSSSSSSSSSS
> New week       S____________SSSSSSSSS
> 
> James
> 
> [jr76@pc0053 archiver_indexer]$
> ~/archiver/trunk/bin/linux-x86/ArchiveDataTool -verbose \
> 3 /extra1/index/archiver1/raid1/PS/2010/06_09/index -blocks -channel
> LI-PS-VAULT-01:SRCH\
> COUNT
> RTree M for channel 'LI-PS-VAULT-01:SRCHCOUNT': 50
> Datablocks for channel 'LI-PS-VAULT-01:SRCHCOUNT':
> '20100609' @ 0xB4E6ED: Indexed range 06/08/2010 09:46:37.516254210 -
> 06/16/2010 07:15:30\
> .669380000
> 
> 1 data blocks, 0 hidden blocks, 1 total
> 
> [jr76@pc0053 archiver_indexer]$
> ~/archiver/trunk/bin/linux-x86/ArchiveDataTool -verbose \
> 3 /extra1/index/archiver1/raid1/PS/2010/06_16/index -blocks -channel
> LI-PS-VAULT-01:SRCH\
> COUNT
> RTree M for channel 'LI-PS-VAULT-01:SRCHCOUNT': 50
> Datablocks for channel 'LI-PS-VAULT-01:SRCHCOUNT':
> '20100616' @ 0xBC0B10: Indexed range 06/08/2010 09:46:37.516254210 -
> 06/17/2010 10:26:40\
> .334905070
> 
> 1 data blocks, 0 hidden blocks, 1 total
> 
> 
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System