Autonomous diagnosis and mitigation of network anomalies may include creating a plurality of sketch matrices wherein each sketch matrix corresponds to an individual hashing function and each row in each sketch matrix corresponds to an array of hashed parameters of interest from multiple network devices for a given period of time, the parameters of interest being configurable by an administrator. A principal components analysis (PCA) input matrix is created for each of the sketch matrices by computing an entropy value for each element in the sketch matrices, and principal components analysis (PCA) is performed on each of the PCA input matrices to heuristically detect a network anomaly in real time.