(defprotocol ClusterState
 (set-ephemeral-node [this path data])
 (delete-node [this path])
 (create-sequential [this path data])
 (set-data [this path data]) ;; if node does not exist, create persistent with this data 
 (get-data [this path watch?])
 (get-children [this path watch?])
 (mkdirs [this path])
 (close [this])
 (register [this callback])
 (unregister [this id])
 )

(defprotocol StormClusterState
 (assignments [this callback])
 (assignment-info [this storm-id callback])
 (active-storms [this])
 (storm-base [this storm-id callback])
 (get-worker-heartbeat [this storm-id node port])
 (executor-beats [this storm-id executor->node+port])
 (supervisors [this callback])
 (supervisor-info [this supervisor-id]) ;; returns nil if doesn't exist
 (setup-heartbeats! [this storm-id])
 (teardown-heartbeats! [this storm-id])
 (teardown-topology-errors! [this storm-id])
 (heartbeat-storms [this])
 (error-topologies [this])
 (worker-heartbeat! [this storm-id node port info])
 (remove-worker-heartbeat! [this storm-id node port])
 (supervisor-heartbeat! [this supervisor-id info])
 (activate-storm! [this storm-id storm-base])
 (update-storm! [this storm-id new-elems])
 (remove-storm-base! [this storm-id])
 (set-assignment! [this storm-id info])
 (remove-storm! [this storm-id])
 (report-error [this storm-id task-id error])
 (errors [this storm-id task-id])
 (disconnect [this])
 )

(def ASSIGNMENTS-ROOT "assignments")
(def CODE-ROOT "code")
(def STORMS-ROOT "storms")
(def SUPERVISORS-ROOT "supervisors")
(def WORKERBEATS-ROOT "workerbeats")
(def ERRORS-ROOT "errors")

(def ASSIGNMENTS-SUBTREE (str "/" ASSIGNMENTS-ROOT))
(def STORMS-SUBTREE (str "/" STORMS-ROOT))
(def SUPERVISORS-SUBTREE (str "/" SUPERVISORS-ROOT))
(def WORKERBEATS-SUBTREE (str "/" WORKERBEATS-ROOT))
(def ERRORS-SUBTREE (str "/" ERRORS-ROOT))

/-{storm-zk-root}      -- storm在zookeeper上的根目錄(默認為/storm)
 |
 |-/assignments      -- topology的任務分配信息
 |  |
 |  |-/{topology-id}   -- 這個目錄保存的是每個topology的assignments信息包括：對應的nimbus上
 |             -- 的代碼目錄,所有task的啟動時間,每個task與機器、端口的映射。操作為
 |             -- (assignments)來獲取所有assignments的值；以及(assignment-info storm-id)
 |             -- 來得到給定的storm-id對應的AssignmentInfo信息
 |             -- 在AssignmentInfo中存儲的內容有:
 |             -- :executor->node+port :executor->start-time-secs :node->host
 |             -- 具體定義在common.clj中的
 |             -- (defrecord Assignment[master-code-dir node->host executor->node+port                  executor->start-time-secs])            
 |
 |-/storms         -- 這個目錄保存所有正在運行的topology的id
 |  |
 |  |
 |  |-/{topology-id}   -- 這個文件保存這個topology的一些信息，包括topology的名字，topology開始運行
 |             -- 的時間以及這個topology的狀態(tài)。操作(active-storms),獲得當前路徑活躍的下
 |             -- topology數據。保存的內容參考類StormBase；(storm-base storm-id)得到給定的
 |             -- storm-id下的StormBase數據,具體定義在common.clj中的
 |   -- (defrecord StormBase [storm-name launch-time-secs status num-workers component->executors])
 |
 |-/supervisors      -- 這個目錄保存所有的supervisor的心跳信息
 |  |            
 |  |
 |  |-/{supervisor-id}  -- 這個文件保存supervisor的心跳信息包括:心跳時間，主機名，這個supervisor上
 |             -- worker的端口號，運行時間(具體看SupervisorInfo類)。操作(supervisors)得到
 |             -- 所有的supervisors節(jié)點；(supervisor-info supervisor-id)得到給定的
 |             -- supervisor-id對應的SupervisorInfo信息；具體定義在common.clj中的
 |              
 |    -- (defrecord SupervisorInfo [time-secs hostname assignment-id used-ports meta scheduler-meta       uptime-secs])
 |
 |-/workerbeats          -- 所有worker的心跳
 |  |
 |  |-/{topology-id}       -- 這個目錄保存這個topology的所有的worker的心跳信息
 |    |
 |    |-/{supervisorId-port}  -- worker的心跳信息，包括心跳的時間，worker運行時間以及一些統(tǒng)計信息
 |                    
 |                 -- 操作(heartbeat-storms)得到所有有心跳數據的topology，
 |                 -- (get-worker-heartbeat storm-id node port)得到具體一個topology下
 |                 -- 的某個worker(node:port)的心跳狀況，
 |             -- (executor-beats storm-id executor->node+port)得到一個executor的心跳狀況
 |
 |-/errors         -- 所有產生的error信息
 |
 |-/{topology-id}      -- 這個目錄保存這個topology下面的錯誤信息。操作(error-topologies)得到出錯
   |           -- 的topology；(errors storm-id component-id)得到
   |           -- 給定的storm-id component-id下的出錯信息
   |-/{component-id}