Repository: hadoop Updated Branches: refs/heads/branch-3.0 2821edf6d -> 0191a862a
HDFS-12927. Update erasure coding doc to address unsupported APIs. (Contributed by Lei (Eddy) Xu) (cherry picked from commit 949be14b0881186d76c3b60ee2f39ce67dc1654c) Project: http://git-wip-us.apache.org/repos/asf/hadoop/repo Commit: http://git-wip-us.apache.org/repos/asf/hadoop/commit/0191a862 Tree: http://git-wip-us.apache.org/repos/asf/hadoop/tree/0191a862 Diff: http://git-wip-us.apache.org/repos/asf/hadoop/diff/0191a862 Branch: refs/heads/branch-3.0 Commit: 0191a862a36453170358726da114b6bf7ec3e169 Parents: 2821edf Author: Lei Xu <[email protected]> Authored: Fri Dec 15 10:20:29 2017 -0800 Committer: Lei Xu <[email protected]> Committed: Fri Dec 15 10:29:08 2017 -0800 ---------------------------------------------------------------------- .../hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/hadoop/blob/0191a862/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md ---------------------------------------------------------------------- diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md index a884ed8..4459c94 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md +++ b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md @@ -220,11 +220,14 @@ Below are the details about each command. Limitations ----------- -Certain HDFS file write operations, i.e., `hflush`, `hsync` and `append`, +Certain HDFS operations, i.e., `hflush`, `hsync`, `concat`, `setReplication`, `truncate` and `append`, are not supported on erasure coded files due to substantial technical challenges. -* `append()` on an erasure coded file will throw `IOException`. +* `append()` and `truncate()` on an erasure coded file will throw `IOException`. +* `concat()` will throw `IOException` if files are mixed with different erasure +coding policies or with replicated files. +* `setReplication()` is no-op on erasure coded files. * `hflush()` and `hsync()` on `DFSStripedOutputStream` are no-op. Thus calling `hflush()` or `hsync()` on an erasure coded file can not guarantee data being persistent. --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
