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From "Zhenhua (Gerald) Guo" <jen...@gmail.com>
Subject Replication is done synchronously or asynchronously?
Date Thu, 26 Jan 2012 18:57:28 GMT
I have two questions regarding creation of replicas.
- When a user uploads a file to HDFS, it returns whenever the first
replica is created? or the client needs wait until all replicas are
created?
- When the output of MapReduce jobs is written to HDFS (by reduce
tasks), the writing of output returns when the first replica is
created? or wait until all replicas are created?

Thanks

Gerald

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