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The following page has been changed by PatrickHunt: http://wiki.apache.org/hadoop/ZooKeeper/Tao New page: = The Tao of ZooKeeper = !ZooKeepers are dedicated to the animals they are in charge of as well as the people that visit those animals. They are guided by a code, until now known only to those of their craft, that keep the both the animals and their visitors safe. * '''!ZooKeepers keep order''' - There are schedules to be kept, procedures that need to be followed. Total order is needed for changes to avoid confusion among !ZooKeepers; however, individual !ZooKeepers may answer questions from memory unless explicitly asked not to. Even these answers are consistent with the total ordering of changes to procedures or policies. * '''!ZooKeepers are reliable''' - The Zoo is a dangerous place. Changes agreed upon by ZooKeeper survive even the deaths of individual !ZooKeepers. If a ZooKeeper is asked to make a change that it can't make a durability guarantee for, it will inform the requester of a problem. * '''!ZooKeepers are efficient''' - !ZooKeepers have a big job and Zoos are getting larger everyday. They do their jobs efficiently without flair. They let visitors and animals have the bells and whistles and focus on their jobs. * '''!ZooKeepers are timely''' - There are time constraints that !ZooKeepers have: animals must be fed on schedule, visitors have questions, fences mended, etc. If feeding the elephant took 5 mins yesterday, it better take 5 mins today. * '''!ZooKeepers avoid contention''' - !ZooKeepers don't want animals and visitors to get angry at each other, so they never make an animal or a visitor they are currently helping wait on another visitor or animal. (For example, a ZooKeeper if one guest on a tour requests to visit the elephants first and later another guest asks to visit the pigs, a ZooKeeper should never check with the first guest before responding to the second. The first guest could have fallen asleep or may take a while to decide. Ancient !ZooKeepers wasted a lot of time trying to satisfy a request by consulting others. So, in this example, the ZooKeeper will simply announce to the first guest that "the plans have changed, we are seeing the pigs".) * '''!ZooKeepers are ambition free''' - !ZooKeepers consider their job to be a great honor and have dedicated their lives to it. Sometimes they are presented with ways to enhance their careers, doing some mail delivery on the side or serving as an event announcer, but they know that such things will distract them from their important role of keeping the Zoo safe and organized.
