AnsweredAssumed Answered

PI Web API Cache with strange behavior

Question asked by jonasengedal on Apr 15, 2015
Latest reply on Feb 12, 2016 by gonmerciel

Previously I stated that:


"It appears that the PI Web API cache is acting rather strangely. differently when a request is send through Internet Explorer (11) and Chrome when Cache-Control header is not set on the request. With Chrome the request is not cached, but in IE it is cached."


I thought I had found a pattern, but now it seems that Chrome is also having troubles. I am updating an event frame through System Explorer, but sometimes the update takes affect right away in PI Web API and sometimes it takes minutes. Each request is unique to avoid caching.


Why is the data not updated right away in PI Web API? Buffering?


I have also tried to set the Cache-Control header to "no-cache" explicitly on the request but then I face this:


"Cache-Control header may not be specified on bulk data requests."


When requesting https://<webapihost>/piwebapi/streamsets/<webid>/value with a webid for an eventframe.


Is this a bug or is it just missing information in the documentation?


Best regards