Anecdotal: AppEngine deprecated their Master&#x2F;Slave datastore[0] in April 2012, and it was actually shutdown on July 6, 2015.  So that&#x27;s 3+ years to move to newer tech.<p>[0] <a href="http:&#x2F;&#x2F;googleappengine.blogspot.com&#x2F;2012&#x2F;04&#x2F;masterslave-datastore-thanks-for-all.html" rel="nofollow">http:&#x2F;&#x2F;googleappengine.blogspot.com&#x2F;2012&#x2F;04&#x2F;masterslave-data...</a>