Historian server lost all four of its OPC DA sources at 6.10 Monday morning. Two KEPServerEX boxes, an RSLinx Classic OPC server on the old packaging PLC and a vendor DA server on the compressor. About 8,000 tags, the lot of them bad quality from the same minute.
All four boxes ping and the DA servers show running, local clients on each one still see data. IT pushed Windows updates Sunday night to the historian box and to the two Kepware boxes and nobody thought to tell me so that is the only thing that has changed.
I restarted the collector service twice, nothing, rebooted a Kepware box, nothing, and reconnecting a link by hand gets as far as connecting and then drops.
Four vendors dying at once says it isn't the servers. Is there something in a Windows update that shuts DA out from across the network and leaves the local clients alone?
Are those four links all remote DCOM, historian box to server box? And what's in the historian's Windows event log at 6.10, System and Application? When a link drops on my remote sites it's always in the log, even when the collector says nothing.