Hello everyone,
I’m developing a Tango service, and I’ve encountered a weird behaviour when subscribing to certain events. Let’s say I have a Tango device running on a server (Ubuntu 20.04 LTS) and I use pytango.DeviceProxy to subscribe to different events. When subscribing to most events, like “CHANGE_EVENT” on a certain attribute, everything works fine:
>>> dm.subscribe_event("dishMode", tango.EventType.CHANGE_EVENT, EM())
2024-09-16 17:24:30.802752
change
35
>>> dm.subscribe_event("dishMode", tango.EventType.CHANGE_EVENT, EM())
2024-09-16 17:24:32.197378
change
36
>>> dm.subscribe_event("dishMode", tango.EventType.CHANGE_EVENT, EM())
2024-09-16 17:24:33.627955
change
37
However, when I subscribe to “INTERFACE_CHANGE_EVENT” specifically, the reported timestamp becomes erratic, often displaying random dates: sometimes in the past, sometimes in the future, as you can see below.
>>> dsm.subscribe_event(tango.EventType.INTERFACE_CHANGE_EVENT, tango.utils.EventCallback())
utils::_get_value()
[b]1970-09-18 23:52:16[/b] MID_DSH_0119/LMC/DS_MANAGER <UNKNOWN> INTR_CHANGE None
1
>>> dsm.subscribe_event(tango.EventType.INTERFACE_CHANGE_EVENT, tango.utils.EventCallback())
utils::_get_value()
[b]1970-09-17 09:52:32[/b] MID_DSH_0119/LMC/DS_MANAGER <UNKNOWN> INTR_CHANGE None
2
>>> dsm.subscribe_event(tango.EventType.INTERFACE_CHANGE_EVENT, tango.utils.EventCallback())
utils::_get_value()
[b]1970-09-19 04:38:40[/b] MID_DSH_0119/LMC/DS_MANAGER <UNKNOWN> INTR_CHANGE None
3
I am using Tango v9.3.4, python3.8 and pytango 9.4.1. The issue occurs when subscribing locally (from the same host where the service is running) and also when subscribing from remote hosts. We are not sure if this is related to some synchronization issues / timeouts we are having, but it is definitely annoying.
Any idea into what might be causing this?
Thanks in advance,
Cristobal