FWIW, Stack has already done the work needed to make sure that Hbase works with Hadoop 0.22 branch, and I suppose if https://issues.apache.org/jira/browse/MAPREDUCE-2767 is committed, it removes the last blocker from 0.22.0, so that it can be released.
I am cc'ng hbase-dev, since this is relevant to them as well. - Milind On 8/31/11 11:41 AM, "sanjay Radia" <[email protected]> wrote: > >I propose that the 20-append patches (details below) be included in >20.205 which will become the first official Apache >release of Hadoop that supports Append and HBase. > >Background: >There hasn't been a official Apache release that supports HBase. >The HBase community have instead been using the 20-append branch; the >patches were contributed by the HBase community including Facebook. The >Cloudera distribution has also included these patches. >Andrew Purtell has ported these patches to 20-security branch. > >Risk Level: >These patches have been used and tested on large HBase clusters by FB , >by those who use 20-append branch directly (various users including a 500 >node HBase cluster at Yahoo) and by those that use the Cloudera >distribution. We have reviewed the patches and have conducted further >tests; testing and validation continues. > > >Patches: >HDFS-200. Support append and sync for hadoop 0.20 branch. >HDFS-142. Blocks that are being written by a client are stored in the >blocksBeingWritten directory. >HDFS-1057. Concurrent readers hit ChecksumExceptions if following a >writer to very end of file >HDFS-724. Use a bidirectional heartbeat to detect stuck pipeline. >HDFS-895. Allow hflush/sync to occur in parallel with new writes to the >file. >HDFS-1520. Lightweight NameNode operation recoverLease to trigger lease >recovery. >HDFS-1555. Disallow pipelien recovery if a file is already being lease >recovered. >HDFS-1554. New semantics for recoverLease. >HDFS-988. Fix bug where savenameSpace can corrupt edits log. >HDFS-826. Allow a mechanism for an application to detect that datanode(s) >have died in the write pipeline. >HDFS-630. Client can exclude specific nodes in the write pipeline. >HDFS-1141. completeFile does not check lease ownership. >HDFS-1204. Lease expiration should recover single files, not entire lease >holder >HDFS-1254. Support append/sync via the default configuration. >HDFS-1346. DFSClient receives out of order packet ack. >HDFS-1054. remove sleep before retry for allocating a block. > >
