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forwarder: still having issues with PV reconnection after a gateway config change #80
Closed as duplicate
Description
I have deployed the forwarder to all 25.8.0 instruments, and they're all falling over at the first config change despite ISISComputingGroup/forwarder#5 making the release.
the forwarder, when using CA, has an issue where if you reconfigure the gateway (ie. what we do with the blockserver on a config change) a pv never reconnects and then isn't ever forwarded. this is pretty easy to reproduce.
this is a bug in caproto i believe - we tried to fix it by setting timeout=None on the pv itself but that didn't work. a normal camonitor does reconnect.
Activity
[-]still having issues with PV reconnection after a gateway[/-][+]still having issues with PV reconnection after a gateway config change[/+]rerpha commentedon Jan 12, 2026
One option here is to try and strip out the caproto contexts that are passed between objects, with pyepics/aioca instead.
Another option is to try using PVA instead, with something like https://github.com/ControlSystemStudio/pvaify which will serve blocks. This will need testing with gateway changes (ie. a blockserver config change) and has the caveat that we need to keep another process alive. If this works, we should try our best to containerise it and push upstream with a dockerfile.
We could also rewrite the forwarder as it's fundamentally not that complex. The ESS only use CA in their forwarder for ISIS' benefit so could remove it to simplify things.
[-]still having issues with PV reconnection after a gateway config change[/-][+]forwarder: still having issues with PV reconnection after a gateway config change[/+]