Merge pull request #94 from michaelnsj/cluster

Merged.
don't rely on postgres
Merge pull request #96 from arkxu/cluster

don't rely on postgres
Merge pull request #97 from michaelnsj/cluster

Merged.
Merge pull request #98 from michaelnsj/cluster

Merged.
Merge pull request #99 from michaelnsj/cluster

Merged.
Merge pull request #100 from michaelnsj/cluster

Merged.
Merge pull request #102 from michaelnsj/cluster

Merged.