It seems sporadically that requests coming in (w/ or w/o parameters) will fail and the web service will return a 405 (Method Not Allowed) status code with the response. Trying the same request again moments later would succeed.
Turning on Failed Request Tracing (FRT) in IIS for the "Microsoft System Center 2012 Orchestrator Web Service" will reveal more details w/ the error.
From the site highlighted in IIS, you can enable FRT from the Actions pane. After FRT is enabled, you can create the rule to capture specific status codes (400,404,405,500 in the example below).
After the issue occurs and the request fails w/ a code of 405, a log file will be generated in the following folder if you accepted the default path - C:\inetpub\logs\FailedReqLogFiles\W3SVC2. Towards the bottom of the log file, you'll find this error information:<Data Name="Buffer"><?xml version="1.0" encoding="utf-8" standalone="yes"?>
<error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
<code></code>
<message xml:lang="en-US">The requested operation requires Publish permissions on the Runbook</message>
</error></Data>
This appears to be a bogus error since sending the same request again will succeed using the same credentials.
After a little more digging, the error occurring seems to correlate w/ the ClearAuthorizationCache maintenance task in the SQL database. Since this task computes/populates the folders, runbooks, and permissions....it theoretically make sense that while that task is running, incoming requests would fail since it thinks the user does not have permissions to the runbook (when it does!). This could technically also affect requests being sent through the Orchestration Console to stop/start jobs. By default, this task runs every 600 seconds (10 minutes). I'm not sure of the duration it takes for the ClearAuthorizationCache task to complete, but it would depend on how much data there is to process (# of runbooks, folders, etc. in the environment).
If you have seen or do experience similar issues, I'd appreciate if you left a comment. I also suggest opening a case w/ Microsoft to determine if this is a general product issue.
