小议供应链中的“牛鞭效应”

阐述了牛鞭效应的含义,指出了牛鞭效应的危害,分析了产生牛鞭效应的原因．提出了减缓牛鞭效应的办法。     

Parallel recovery method in shared-nothing spatial database cluster system

Shared-notliing spatial database cluster system provides high availability since a replicated node can continue service even if any node in cluster system was crashed. However if the failed node wouldn’t be recovered quickly,whole system performance will decrease since the other nodes must process the queries which the failed node may be processed. Therefore the recovery of cluster system is very important to provide the stable service. In most previous proposed techniques,external logs should be recorded in all nodes even if the failed node does not exist. So update transactions are processed slowly. Also reccvery time of the failed node increases since a single storage for all database is used to record external logs in each node. Therefore we propose a parallel recovery method for recovering the failed node quickly.