Experimental Physics and
Industrial Control System

"Wang, Lin" <[email protected]> · Fri, 14 Apr 2017 09:17:09 +0800 (GMT+08:00)

Hi Michael,
Thanks for replying my question.
Actually, the default 10 TCP CA connections are acceptable and not the problem for us. The problem is that for example we have 366 channels in one IOC to be archived, as reported by casr() on IOC shell, Channel Archiver established one CA connection and accessed 366 channels in total, whereas Archiver Appliance established 10 CA connections (fine for us) BUT accessed ~1692 channels in total, which I cannot understand.

epics> casr
TCP 10.1.204.12:49088(carchiver): User="histdata", V4.11, 366 Channels, Priority=20  (This line is for Channel Archiver)
TCP 10.1.204.41:39671(archappl): User="control", V4.13, 216 Channels, Priority=0
TCP 10.1.204.41:39672(archappl): User="control", V4.13, 192 Channels, Priority=0
TCP 10.1.204.41:39674(archappl): User="control", V4.13, 164 Channels, Priority=0
TCP 10.1.204.41:39677(archappl): User="control", V4.13, 164 Channels, Priority=0
TCP 10.1.204.41:39679(archappl): User="control", V4.13, 136 Channels, Priority=0
TCP 10.1.204.41:39681(archappl): User="control", V4.13, 198 Channels, Priority=0
TCP 10.1.204.41:39684(archappl): User="control", V4.13, 180 Channels, Priority=0
TCP 10.1.204.41:39688(archappl): User="control", V4.13, 108 Channels, Priority=0
TCP 10.1.204.41:39694(archappl): User="control", V4.13, 164 Channels, Priority=0
TCP 10.1.204.41:39696(archappl): User="control", V4.13, 170 Channels, Priority=0

When I reproduced it in a VM on my laptop, I have only 3 channels to be archived in the IOC and there is actually no any other channel in the IOC, Archiver Appliance established 3 CA connections (fine as well) BUT accessed 3*8=24 channels in total.

epics> casr
TCP 127.0.0.1:33826(debian-8): User="wanglin", V4.13, 8 Channels, Priority=0
TCP 127.0.0.1:33827(debian-8): User="wanglin", V4.13, 8 Channels, Priority=0
TCP 127.0.0.1:33828(debian-8): User="wanglin", V4.13, 8 Channels, Priority=0

Lin

> -----Original Messages-----
> From: "Michael Davidsaver" <[email protected]>
> Sent Time: Friday, April 14, 2017
> To: "Wang, Lin" <[email protected]>, [email protected]
> Cc: 
> Subject: Re: Archiver Appliance established multiple CA connections for one channel
> 
> On 04/11/2017 07:55 AM, Wang, Lin wrote:
> > 
> > Dear all,
> > 
> > I deployed Archiver Appliance using install_scripts/single_machine_install.sh in our test environment, however, we found that AA established multiple CA connections for 1 channel. Is it the normal behavior for AA or something went wrong in my environment? We care this because our IOCs are running on embedded systems which have limited CPU and memory resources.
> 
> The short answer is that this is a the intended behavior.  It surprised
> me the first time I noticed as well.  I believe that SLAC likes to run a
> cagateway in front of AA.  Murali also mentioned that there was a
> configuration option to control this (defaults to 10).  Unfortunately I
> can't find that option name.
> 
> 
> 
> > The following is the detailed information:
> > 
> > One of the IOCs has 366 channels to be archived (now by both Channel Archiver and AA). When AA just started, the total archived channels equaled total channels casr() displayed, which means 1 archived channel corresponds to 1 channel casr() displays, which is straightforward.
> > 
> > epics> casr
> > Channel Access Server V4.13
> > Connected circuits:
> > TCP 10.1.204.12:49088(carchiver): User="histdata", V4.11, 366 Channels, Priority=20  (This line is for Channel Archiver)
> > TCP 10.1.204.41:41089(archappl): User="control", V4.13, 37 Channels, Priority=0
> > TCP 10.1.204.41:41090(archappl): User="control", V4.13, 24 Channels, Priority=0
> > TCP 10.1.204.41:41092(archappl): User="control", V4.13, 30 Channels, Priority=0
> > TCP 10.1.204.41:41094(archappl): User="control", V4.13, 38 Channels, Priority=0
> > TCP 10.1.204.41:41096(archappl): User="control", V4.13, 47 Channels, Priority=0
> > TCP 10.1.204.41:41097(archappl): User="control", V4.13, 37 Channels, Priority=0
> > TCP 10.1.204.41:41099(archappl): User="control", V4.13, 43 Channels, Priority=0
> > TCP 10.1.204.41:41103(archappl): User="control", V4.13, 38 Channels, Priority=0
> > TCP 10.1.204.41:41105(archappl): User="control", V4.13, 38 Channels, Priority=0
> > TCP 10.1.204.41:41106(archappl): User="control", V4.13, 34 Channels, Priority=0
> > 
> > However, after several hours, casr() output changed as follows, the total channels casr() displayed became multiple times of total archived channels, which means 1 archived channel corresponds to multiple channels casr() displays.
> > 
> > epics> casr
> > Channel Access Server V4.13
> > Connected circuits:
> > TCP 10.1.204.12:49088(carchiver): User="histdata", V4.11, 366 Channels, Priority=20  (This line is for Channel Archiver)
> > TCP 10.1.204.41:39671(archappl): User="control", V4.13, 216 Channels, Priority=0
> > TCP 10.1.204.41:39672(archappl): User="control", V4.13, 192 Channels, Priority=0
> > TCP 10.1.204.41:39674(archappl): User="control", V4.13, 164 Channels, Priority=0
> > TCP 10.1.204.41:39677(archappl): User="control", V4.13, 164 Channels, Priority=0
> > TCP 10.1.204.41:39679(archappl): User="control", V4.13, 136 Channels, Priority=0
> > TCP 10.1.204.41:39681(archappl): User="control", V4.13, 198 Channels, Priority=0
> > TCP 10.1.204.41:39684(archappl): User="control", V4.13, 180 Channels, Priority=0
> > TCP 10.1.204.41:39688(archappl): User="control", V4.13, 108 Channels, Priority=0
> > TCP 10.1.204.41:39694(archappl): User="control", V4.13, 164 Channels, Priority=0
> > TCP 10.1.204.41:39696(archappl): User="control", V4.13, 170 Channels, Priority=0
> > 
> > I can also reproduce this situation on my laptop with only three channels, when AA just started, 1 archived channel corresponded to 1 channel casr() displayed, but after 30 minutes, it became 1 archived channel corresponded to 8 channels casr() displayed.
> > 
> > epics> dbl
> > aiExample
> > calcExample
> > calcExample1
> > epics> 
> > epics>
> > epics> casr
> > Channel Access Server V4.13
> > Connected circuits:
> > TCP 127.0.0.1:33826(debian-8): User="wanglin", V4.13, 1 Channels, Priority=0
> > TCP 127.0.0.1:33827(debian-8): User="wanglin", V4.13, 1 Channels, Priority=0
> > TCP 127.0.0.1:33828(debian-8): User="wanglin", V4.13, 1 Channels, Priority=0
> > epics> 
> > epics>
> > epics> casr
> > Channel Access Server V4.13
> > Connected circuits:
> > TCP 127.0.0.1:33826(debian-8): User="wanglin", V4.13, 8 Channels, Priority=0
> > TCP 127.0.0.1:33827(debian-8): User="wanglin", V4.13, 8 Channels, Priority=0
> > TCP 127.0.0.1:33828(debian-8): User="wanglin", V4.13, 8 Channels, Priority=0
> > epics> 
> > 
> > 
> > Any suggestion or hint is appreciated.
> > 
> > 
> > Thanks,
> > Lin
> > 
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System