Hi Emmanuel,
You asked about SLAC - we're using the PV part
of IRMIS at SLAC. Our rdb is Oracle, and we're running the PV
crawler, along with client crawlers for alh, Channel Watcher, Channel Archiver,
and some sequence programs. Please let me know if you'd like more
info.
cheers,
Judy
Emmanuel
First, IRMIS consists of various parts - PVs,
hardware and cabling. This discussion only concerns the IRMIS PV
part.
Emmanuel Mayssat wrote:
IRMIS is definitely one of the solution I am looking for.
But how difficult is it to implement?
You have to install a relational database management
system, and then make the appropriate PERL crawlers work (usually this is an NFS
issue: providing network access for IRMIS to the .db and.dbd files that the IOC
uses to reboot). It really helps to have a standard ioc build structure, to
help the PV crawler find the associated resource files.
is IRMIS for Oracle databases only?
We use MySQL at APS, SNS and SLAC use Oracle, the Canadian
Light Source uses Microsoft Sequel Server, for example. I think that
there is also some work on PostGreSQL
Are simple crawlers easy to program?
It depends on the domain. The pv crawler is the most
complicated since it is trying to emulate the IOC boot process. In spite
of this complexity, we have had valuable contributions/fixes to the PV crawler
code. For PV client crawlers, again it depends on how sophisticated the
client handles nested macro substitution, etc A lot of these crawlers have
also been written.
It will be an interesting challenge for the hardware
part of IRMIS to handle the plug-and-play aspects (that you were discussing in
another thread). That is another topic.
Don
is there any other solution out there?
Is anybody on this list at SLAC and using IRMIS?
I definitely would like to have a short demo in the near future.
Thanks,
--
Emmanuel
On Fri, 2007-08-24 at 14:08 -0500, Don Dohan wrote:
Emmanuel
This is one of the features of the IRMIS relational database.
IRMIS consists of, in part, all of the PVs in your system. A pv crawler
(a perl program) detects when an IOC reboots, then scans and expands
that IOC's st.cmd file to load the IRMIS database with that IOCs PVs.
This scanning is unobtrusive to the IOC.
Other crawlers have been written to scan CA clients. At the APS, we
crawl for MEDM, ALH, and SDDS clients, and we are testing the SNL
crawler written at SLAC. We intend to crawl save/restore files as well
(future). For each CA client instance, a list of resolved PVs is
generated, and inserted into the IRMIS database.
Taking the MEDM client as an example, the crawler resolves the macro
substitutions for nested MEDM screens, so that it tells you which .adl
file in the chain needs to be fixed if a given PV is removed.
Crawlers for other CA clients have been written at other facilities -
EDM, DM/2K for example.
Don Dohan
Emmanuel Mayssat wrote:
Another question about software upgrade...
Let's say that I change the name of PV in my epics database.
Potentially with this change, I could break epics extensions.
Medm of course, but also feedback system, PV backup, etc.
Is there a way to know which extensions will break if I change a PV
name? (may keeping track for each extension of the used PVs in a flat
file is the solution, but is there any other, smarter ones?)
--
Emmanuel
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