Moped::Errors::QueryFailure: The operation: #<Moped::Protocol::Query @length=210 @request_id=88981 @response_to=0 @op_code=2004 @flags=[] @full_collection_name="comments-loadtest.contents" @skip=24800 @limit=100 @selector={"$query"=>{"_type"=>"CommentThread", "course_id"=>"BerkeleyX/ColWri2.2x/1T2014", "context"=>:course}, "$orderby"=>{"pinned"=>-1, "last_activity_at"=>-1}} @fields=nil>failed with error 17144: "Runner error: Overflow sort stage buffered data usage of 33556783 bytes exceeds internal limit of 33554432 bytes"See https://github.com/mongodb/mongo/blob/master/docs/errors.mdfor details about this error.
Hitting the 32MB limit for in-memory sort.
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