While working on Orthanc over the weekend, I created a Lua plugin that made a call to my Orthanc C++ plugin via the HttpGet function. This ended up deadlocking Orthanc in MyIncomingHttpRequestFilter::IsAllowed() while attempting to get the Lua Context Lock (since the LuaContextLock was obtained and held by the call to my plugin). While Orthanc may not be designed for my use case, it occurred to me that no HTTP or CSTORE requests can complete while a Lua plugin is running since both of those require the LuaContextLock. A Lua plugin that makes a call to a web server via HttpGet can therefore have adverse affects on Orthanc’s performance for DICOM and web requests as such processing will be blocked for the duration of the Lua plugin web request. The Lua plugin web request could potentially take a look time to complete if the server is busy or down (network timeout). You may want to think about alternative designs for this or at least document this as something to take into consideration.