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ControlSystemStudio / cs-studio

Control System Studio is an Eclipse-based collections of tools to monitor and operate large scale control systems, such as the ones in the accelerator community.
https://controlsystemstudio.org/
Eclipse Public License 1.0
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How to reduce the wait time of CSS connection when IOC start? #2728

Open 1458861693 opened 2 months ago

1458861693 commented 2 months ago

Hi，I am using CS-Studio 4.6.4-SNAPSHOT. I want to know how to reduce the wait time of CSS connection to IOC when IOC first start or reboot? I feel the wait time of cs-studio connect to IOC is a little long. Thanks for your help.

kasemir commented 2 months ago

Re-connect times are based on the reception of beacons. See https://epics.anl.gov/base/R3-14/12-docs/CAref.html, https://controlssoftware.sns.ornl.gov/training/2022_USPAS/Presentations/10%20Channel%20Access.pdf, https://epics.anl.gov/tech-talk/2007/msg01144.php

Run cash -I 10 on the same host to see if it detects the new CA server when you start your IOC. Run camonitor in a terminal on the same host, then compare how long it takes to re-connect when you reconnect.

1458861693 commented 2 months ago

I don't find "cash" command on my computer or IOC Shell. Is a epics channel access command line tools? Maybe the Version of my epics base don't contain this command, the Version is EPICS R7.0.8.

Can I decrease the connection time between CSS and IOC server by reduce the value of "EPICS_CAS_BEACON_PERIOD"? The default value of this parameter in CS-Studio is 30s.

kasemir commented 2 months ago

Spell checker... It's casw, CA server watcher.

Changing the EPICS_CAS_BEACON_PERIOD is a bad idea. You'd have to do that for all servers and clients on your network. As you reduce the beacon period, your servers may not be able to keep up with the exact beacon period. Clients will then erroneously wake up, thinking there's a new server online, re-issue their search requests, and then you wonder why your network is flooded with UDP messages from the search requests. Ask me how I know. Also, JCA doesn't necessarily read EPICS_CAS_BEACON_PERIOD.

Instead of trying to change the beacon behavior, first check if your clients see the beacons at all (casw, camonitor).

If you do want to tweak the search behavior of the CA client, check the system properties introduced in https://github.com/epics-base/jca/pull/53