Shard the waiting directory to scale better

Previously all the waiting tasks were stored in the same "waiting"
directory. Since most filesystems don't scale well with more than 1000
entries in a directory, shard the "waiting" directory by the first two
characters of the taskKey. This will shard the waiting entries across a
max of 256 subdirectories, potentially providing improved scalibility
for up to 256K waiting entries.

Change-Id: I4da79306cb75a868a30ed98d5b33432dc3656b19
1 file changed
tree: c35ec97c7dd4c25adb58f2ad2028c8e93a2a57aa
  1. .gitignore
  2. .mailmap
  3. .settings/
  4. BUILD
  6. src/