[jackbdoughty]

Description of work

Lets users who are in manager mode, restart individual server-side processes that before they would have had to do via a whole server restart. This is done by exposing two new PVs:

• CS:BLOCKSERVER:RESTART_SERVICE_IOC (Restarts the given service list of IOCs provided to it as a compressed, hexed and jsonified string)
• CS:BLOCKSERVER:RESTART_DBSVR (Restarts the Database server when written 1 to)

All server processes (except PSCTRL) are restarted (by the frontend) by writing their ioc name to CS:BLOCKSERVER:RESTART_SERVICE_IOC. Most of which are restarted by the blockserver. The 3 that are different are:

• The blockserver itself (Does a sys.exit when pv is written to)
• Database server (Blockserver writes a 1 to CS:BLOCKSERVER:RESTART_DBSVR which in turn causes a sys.exit)
• Block gateway (Blockserver just called reload on the gateway.)

Unit tests are written at the blockserver and database server level. And there is a system test that checks that all service iocs can be restarted from the above PV.

To test, check out all linked PRs. You'll need to do a python -m pip install -e . --no-deps for server-common and just copy paste the inst-server changes to C:\instrument\apps\EPICS\ISIS\inst_servers\master. (atleast thats what I did). Make sure all tests pass and check for expected behaviour. Is their enough friction/informative enough on the front end for restarting processes?