I read this sentences in the Hadoop definitive guide book.
*Multiple writers, arbitrary file modifications*
Files in HDFS may be written to by a single writer. Writes are always made
at the end of the file. There is no support for multiple writers, or for
modifications at arbitrary offsets in the file.(*These might be supported in
the future, but they are likely to be relatively inefficient.*)
So, are you working to support for modifications at arbitarary offsets in
the file now?
What if some modifications succeed, but other's replicas modifications fail?
How do I do?
To support modification feature and to guarantee file system integrity at
the moment, what are the matters that require attention for the developer.
Please give me some ideas.