Tracking performance issues for clients

[ajgdls]

Links to the issue raised on each of the client repositories

DiamondLightSource/aioca#30
pyepics/pyepics#240
caproto/caproto#802
epics-base/p4p#94
epics-base/pvaPy#78
DiamondLightSource/cothread#33

[mdavidsaver]

wrt. PVA clients, I think it would be a good idea to explicitly give the same pvRequest for both, including subscription queueSize. eg. record[queueSize=4]field() or record[queueSize=10]field(value,alarm,timeStamp) or something.

EPICSPyClientPerformance/src/EPICSPyClientPerformance/p4p_monitor.py

Line 17 in 8d54401

self._subscriptions.append(self._ctxt.monitor(pv_name, cb))

with p4p, pass request='...' to monitor().

fyi. If not provided, P4P defaults to 'field()', which selects all fields, and the server default queueSize. For QSRV, this is 4.

EPICSPyClientPerformance/src/EPICSPyClientPerformance/pvapy_monitor.py

Line 18 in 8d54401

c.startMonitor("field(value,alarm,timeStamp)")