My instance of Server 11.2 running on Windows Server 2019 logs these error messages periodically.
This is from the "server" log file.
<Msg time="2024-05-16T16:11:16,512" type="SEVERE" code="9001" source="Rest" process="12700" thread="1" methodName="" machine="CC-GISSERVER.CLATSOP.CO.CLATSOP.OR.US" user="" elapsed="" requestID="6d383ec7-900f-4538-b620-9ec315e01283">Response already committed. Cannot forward to error page.</Msg>
<Msg time="2024-05-16T16:11:16,512" type="SEVERE" code="9001" source="Rest" process="12700" thread="1" methodName="" machine="CC-GISSERVER.CLATSOP.CO.CLATSOP.OR.US" user="" elapsed="" requestID="6d383ec7-900f-4538-b620-9ec315e01283">Response already committed. Cannot forward to error page.</Msg>
<Msg time="2024-05-16T16:11:16,512" type="SEVERE" code="9002" source="Rest" process="12700" thread="1" methodName="" machine="CC-GISSERVER.CLATSOP.CO.CLATSOP.OR.US" user="" elapsed="" requestID="6d383ec7-900f-4538-b620-9ec315e01283">This exception was thrown after the response was committed. Access to this resource is not allowed</Msg>
<Msg time="2024-05-16T16:11:16,512" type="INFO" code="9000" source="Rest" process="12700" thread="1" methodName="" machine="CC-GISSERVER.CLATSOP.CO.CLATSOP.OR.US" user="" elapsed="" requestID="8e56cc1d-4f45-4abf-be2d-28e6a5cba1c2">RHandler is null, Access to this resource is not allowed</Msg>
<Msg time="2024-05-16T16:11:16,512" type="SEVERE" code="9001" source="Rest" process="12700" thread="1" methodName="" machine="CC-GISSERVER.CLATSOP.CO.CLATSOP.OR.US" user="" elapsed="" requestID="8e56cc1d-4f45-4abf-be2d-28e6a5cba1c2">Response already committed. Cannot forward to error page.</Msg>
I turned up the log level to INFO from the default of WARNING. Now I can see normal requests coming through too so it's not as dismal (opening a log and seeing it packed with a continuous stream of SEVERE errors is disturbing.)
I have looked at the 'code' field, it's described here: https://enterprise.arcgis.com/en/server/latest/administer/windows/core-server-log-codes.htm and it's the same as the text in the log, for example, code 9001 means "Response already committed. Cannot forward to error page." There is no further information.
The "INFO" level message shown above is interesting too, it's a code 9000 "Internal Server Error" even though it's only logged as an INFO (information only message) it appears to be an error. Does anyone know what an "RHandler" is??
I spent a few hours trying to correlate the IIS log file with the ArcGIS Server server log file but nothing popped out, I don't think the errors are tied to any particular service, they just "happen" from time to time.
I am looking for suggestions on how to chase this down and fix it.
Over the years each time we do something like upgrade the OS, move Server to a separate VM, add memory, migrate to a new release, etc etc, nothing has changed, we still get these errors. (I live in hope, ever)
Like the "boy who cried wolf", when we see SEVERE messages now, we have learned to shrug them off, "that's normal!" I am always afraid we'll miss something buried in the noise.
Happy Wednesday all! --Brian