"Error processing mdm request, returning 400" flooding JamfSoftwareServer.log

@Sonic84 , question. By any chance, on your Jamf Pro server, is this link accessible? http://www.apple.com/DTDs/PropertyList-1.0.dtd

We had to open our FireWall up to allow it to pass after we upgraded to JP10. We had something similar and Jamf Support provided this nugget:
>>The product issue I was referencing is PI-004915, where the server needs to be able to reference a particular file on port 80 here: http://www.apple.com/DTDs/PropertyList-1.0.dtd. We can either whitelist www.apple.com on port 80 or we can assist with pointing the server communication to another webserver internally by editing the /etc/hosts file on the Jamf Pro server box. Let us know how you would like to proceed, this should be fixed in Jamf Pro version 10.2 however.<<

Not sure this is due to this...? but I thought I'd toss it your way and see if it offered any help.
Good luck.

We have had this same issue and are cloud hosted. I had a case open with the senior engineer at jamf and they said there is an issue on our network. When we had our logs in debug, they took a look and came back with:

"MDMController.process -> IOUtils.toByteArray -> IOUtils.copyLarge -> SocketInputStream.socketRead -> SocketTimeoutException: Read timed out

so it was an MDM request... with a large byte array... we were reading it... and then the reading of the data timed out"

Since this is coming from the device, we believe that due to the slowness of the network, the device is unable to respond in a timely manner, in turn, causes it to time out and not complete.

We're seeing the same thing with the flooding on all of our Tomcat frontends. We're locally hosted and on 10.2. About to call our Jamf Buddy to see what he says.

So, we upgraded to 10.2 and continued to see the error for two more days. However, today, the errors seem to be gone. I don't know what changed, but ours seemed to have corrected itself.

@luke.reagor - you're so lucky. i continue to see this daily...

We are Jamf hosted, and i am seeing this also. Also having some major issue with clients not checking in and inventory not running on machines. Starting to think this is related.

Curious to hear what Jamf has to say for others. I put in an email to my biddy but no response all yesterday...

Wonder if Blizzard Quinn is causing this for us ;)

-Peter

After upgrading to 10.3 we're still seeing it. I even put the hosts file workaround back in place, even though thats supposed to be fixed now. All web nodes can curl down http://www.apple.com/DTDs/PropertyList-1.0.dtd just fine.

@lashomb Can you share the changes on the hosts file?

The changes were just to point to an internal web server hosting that same folder and file structure for that www.apple.com link.

I just started seeing this error in my log this morning. It wasn't there yesterday afternoon, but today it's hammering the log every couple of seconds and the thousands of errors are filling my log.