This implements a node alias cache that automatically refreshes and adds new nodes when needed. Change-Id: I4af121f7307b7b7ac4f87ad465f02d4eeb17d42f
We need to keep an inmemory cache to avoid lookups into aliases table. This adds the inmemory state of the cache. Change-Id: Ief2b9bb19e10b46839b9208472dfc3035eb49af3