We've observed that EventLogging's Search schema is receiving around 1400 events per hour that fail validation with the following error:

u'comp_suggest' is not one of ['prefix', 'fulltext', 'prefixmergedwithfulltext']

It seems the client is sending a value that is not registered in the schema for the comp_suggest field. 1400 ev/h is probably not a big share of all Search events, but just a heads up in case you want to look into this.

You can easily analyze the error logs here:

Cheers!