question: public boolean stop ( ) { logger . info ( "Stopping Gondola instance for host {}..." , hostId ) ; boolean status = network . stop ( ) ; status = Utils . stopThreads ( threads ) && status ; threads . clear ( ) ; for ( Shard shard : shards ) { status = shard . stop ( ) && status ; } shards . clear ( ) ; shardMap . clear ( ) ; status = storage . stop ( ) && status ; status = clock . stop ( ) && status ; try { mbs . unregisterMBean ( objectName ) ; inited = false ; } catch ( InstanceNotFoundException | MBeanRegistrationException e ) { logger . error ( "Unregister MBean failed" , e ) ; } catch ( Exception e ) { logger . error ( e . getMessage ( ) , e ) ; } return status ; }
target:  Stops all threads and releases all resources. After this call, start() can be called again.