Optimization to most-similar items -- cache item vector norms
The HTTP DIGEST hack comes back; Tomcat 7.0.35 works around only one of two bugs in the Java HTTP DIGEST auth implementation, which has now been reject from Tomcat 7.0.34
Instead of explicitly declaring number of iterations, decide number dynamically based on a convergence criterion. When (a sample of) scores' average absolute difference from previous value drops below a threshold, stop. The default will induce significantly more iterations than the previous default, because it now errs much more on the side of waiting for a stable model. model.als.iterations.convergenceThreshold can be change up from 0.001 to run fewer iterations, or down for more.
Also compute mean average precision