Hi Randall,
a. We are running 2 servers on AWS, we sync our datasets to Amazon S3 bucket that we have mounted to each host using NFS4.
b. Correct, this is shape file data
c. There is nothing unusual in the records of those particular layers that have issues
d. We have a registered data store on the server, so that the services can be updated with out dynamic data (it is frequently updated weather forecast information).
As a side note -- ESRI tech support thinks it may have something to do with caching related to the mounted file store, but nothing we've done (e.g. turn on the automated caching 'noac' NFS mount option) as resulted in any fix.
Thanks for your response!
Sean