Notes client pegs one logical processor at 15%
by Richard Pajerski
Posted on Friday June 18, 2021 at 03:38PM in Technology
Having recently installed a Notes/Designer/Admin 12 client on Windows 8.1 Pro on an aging Intel i7 Quad-Core (with eight logical processors), I was surprised to see that after startup, Notes was consistently grabbing one logical processor and pegging it at around 15%. Windows Task Manager showed that nlnotes.exe was the process and it wouldn't let go of that processor until Notes was closed:
Notes, Designer and Admin clients all worked fine and interaction with local- and server-based applications was normal. Without giving it too much thought, I tried a few things like removing cache.ndk, stopping a couple Notes-related services and making sure the preference "Enable scheduled local agents" was disabled.
But none of that worked and strangely, Disk and Network utilization were both at 0%:
The client was set up in the normal way by connecting to a Domino server with an existing mail file on the server. However, this workstation needed to use a Location that sends and receives mail from a POP3 server instead of Domino. For that purpose I used an existing names.nsf that already had Account and Locations documents in place. All of that connectivity worked and the mail flowed normally.
The next step was internet search but nothing obvious jumped out and most references to similar problems ended with Notes client crashes which I was not experiencing.
The Location document for this POP3 configuration kicks off replication and runs it every 10 minutes. I noticed that after starting the client, there was a gap of a few seconds where the nlnotes.exe process was at 0% and didn't go up to 15% until replication started (and then stayed there). Thinking the culprit was the Replicator, I disabled replication and restarted Notes... but nlnotes.exe was back to 15%!
But this time I could clearly see that process spiked when "Notes configuration settings have been refreshed" scrolled across the Status bar:
Based on that message and the fact that a POP3 configuration like this is not commonly used, I kept pursuing the Location document as the source of the problem. And the problem was indeed there.
When you configure the Notes client for POP3 mail retrieval, only the "Mail" tab of the Location document needs to be filled out:
The "Servers" tab can remain empty -- and that was the problem! At a minimum, the "Home/mail server" field MUST have some value in it to calm down the processor:
It doesn't matter if the server is down or the value entered isn't even a Domino server -- nlnotes.exe will report that the server is not responding but it leaves the processor alone after that:
Ok, problem solved, back to work. 
