hadoop常见问题wikiFAQ

最新推荐文章于 2017-04-12 20:47:03 发布

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本文介绍了HDFS如何处理两个客户端尝试同时写入同一文件的情况。HDFS仅支持独占写入，当第一个客户端请求写入文件时，名称节点会授予该客户端文件租约。如果第二个客户端尝试写入同一个文件，名称节点将拒绝其请求。

http://wiki.apache.org/hadoop/FAQ

3.10. What happens when two clients try to write into the same HDFS file?

HDFS supports exclusive writes only. 
When the first client contacts the name-node to open the file for writing, the name-node grants a lease to the client to create this file. When the second client tries to open the same file for writing, the name-node will see that the lease for the file is already granted to another client, and will reject the open request for the second client.