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Tsz Wo (Nicholas), SZE commented on HDFS-3154: ---------------------------------------------- > ... Generally guarantees of immutability has use cases in the legal/SEC > environments. This is a good point! I did not think of it before. The immutability indeed is a useful feature. > Add a notion of immutable/mutable files > --------------------------------------- > > Key: HDFS-3154 > URL: https://issues.apache.org/jira/browse/HDFS-3154 > Project: Hadoop HDFS > Issue Type: New Feature > Components: name-node > Reporter: Tsz Wo (Nicholas), SZE > Assignee: Tsz Wo (Nicholas), SZE > > The notion of immutable file is useful since it lets the system and tools > optimize certain things as discussed in [this email > thread|http://mail-archives.apache.org/mod_mbox/hadoop-hdfs-dev/201203.mbox/%3CCAPn_vTuZomPmBTypP8_1xTr49Sj0fy7Mjhik4DbcAA+BLH53=g...@mail.gmail.com%3E]. > Also, many applications require only immutable files. Here is a proposal: > - Immutable files means that the file content is immutable. Operations such > as append and truncate that change the file content are not allowed to act on > immutable files. However, the meta data such as replication and permission > of an immutable file can be updated. Immutable files can also be deleted or > renamed. > - Users have to pass immutable/mutable as a flag in file creation. This is > an unmodifiable property of the created file. > - If users want to change the data in an immutable file, the file could be > copied to another file which is created as mutable. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira