1 Reply Latest reply on Apr 21, 2015 7:54 AM by vishwanath Pendyala

    Cache Server process in v9

    Jesse McElmury

      I posted this in the beta forum (Caching Server Process) prior to the GA release, but am still seeking a response...


      I've been investigating the new server architecture and have a few questions on the "cache server".


      1.  Since this is single-threaded, what happens if this thread is consumed when VizQL or another process is trying to call it?  Will it queue?  Bypass the cache server?  Other?


      2.  How does the job flow differ when deploying multiple cache servers?  Is there a single master or primary?  Is all data between them synchronized?


      3.  Is there still a per-process VizQL cache or does this replace that function in it's entirety?




        • 1. Re: Cache Server process in v9
          vishwanath Pendyala

          Hi Jesse


          I will try to answer best of my knowledge.


          1) If you have only one cache server its not mutli threaded so it might go to queue / or may go and fetch against database or an extract is my assumption.


          2) In a multi threaded environment each process talks with all cache server processes. Coming to Cache master, There is no primary or master ,Here cache data is not in sync but all the process have the ability to check the cache on all other cluster process before going live / or against the extract.


          Here is an example for Tableau Presentation.

          Caching in a clusterJPG.JPG


          3. Yes there is Per process Vizql  Cache , But in 9.0 as I said above it's shared so that all the process even from different cluster can talk to it and share the cache.


          Experts please correct me if my understanding is wrong.


          Tableau Server Processes