Fix Issue #22.
Fix Issue #22.
Merge commit '156038578d3e089b13f799f40ff85310ea5f570c'
Fix Issue #22. Fix performance regression of AvailabilityFilteringRule. More documentation.
Upgrade archaius version to 0.5.8.
Merge pull request #23 from allenxwang/master

Issue #22. Also some effort to reduce monitor metrics.