bq. let's make the hbase snapshot for a conf variable. Once we decide on the new name of snapshot directory, we should still use hardcoded value. This aligns with current code base: See this snippet from HConstants:
public static final List<String> HBASE_NON_TABLE_DIRS = Collections.unmodifiableList(Arrays.asList(new String[] { HREGION_LOGDIR_NAME, HREGION_OLDLOGDIR_NAME, CORRUPT_DIR_NAME, SPLIT_LOGDIR_NAME, HBCK_SIDELINEDIR_NAME, HFILE_ARCHIVE_DIRECTORY, SNAPSHOT_DIR_NAME, HBASE_TEMP_DIRECTORY })); Cheers On Mon, Apr 15, 2013 at 8:24 PM, Jonathan Hsieh <j...@cloudera.com> wrote: > constraints: > > 1) hbase 0.94.6 is released and .snapshot is hardcoded in there. > 2) hdfs snapshots is a Hadoop 2.1 or 3.0 feature. I doubt that it will ever > make it to 1.x. This hdfs feature ideally this shouldn't affect current A > pache Hbase 0.94.x's. > 3) hbase 95/96 may default to Hadoop1 or Hadoop 2. these versions should > pick a different table snapshot name to respect fs conventions. > > proposed actions: > > 1) let's make the hbase snapshot for a conf variable. (hbase. > snapshots.dir) let's change the default for hbase 95+. (maybe > .hbase-snapshots). we'll also port this patch to 0.94.x > 2) let's publish instructions on how to update the hbase snapshot dir: > shutdown hbase, config update, rename dir, restart hbase. > 3) I lean towards leaving the current default hbase snapshot dir in 94 > since it shouldn't be affected. upgrading hbase to 95/96 will require > shutdown and update scripts so it seems like the ideal time to autoforce > this default change. > > Thoughts? > > > On Monday, April 15, 2013, lars hofhansl wrote: > > > OK. Let's try to fix that quickly, so that I can release HBase 0.94.7. > > > > -- Lars > > > > > > > > ________________________________ > > From: Ted Yu <yuzhih...@gmail.com> > > To: d...@hbase.apache.org; hdfs-dev@hadoop.apache.org > > Sent: Monday, April 15, 2013 7:13 PM > > Subject: collision in the naming of '.snapshot' directory between hdfs > > snapshot and hbase snapshot > > > > > > Hi, > > This afternoon Huned ad I discovered an issue while playing with HBase > > Snapshots on top of Hadoop's Snapshot branch ( > > http://svn.apache.org/viewvc/hadoop/common/branches/HDFS-2802/). > > > > HDFS (built from HDFS-2802 branch) doesn't allow paths with .snapshot as > a > > component while HBase tries to create paths with .snapshot as a > component. > > This leads to issues in HBase, and one of HDFS or HBase needs to give up > > the .snapshot reserved keyword. HBase released Snapshots feature in > 0.94.6 > > (quite recently) and it may not be too late to change HBase to use a > > different path component in an upcoming new release. > > > > In HBase these path names are not user visible. If there is a deployment > of > > 0.94.6, one could provide a migration tool that renames .snapshot to > > .hbase-snapshot or something to be able to move to the Snapshot release > of > > Hadoop. On the other hand, .snapshot in HDFS is a user visible name and > is > > a convention that is used by many file systems. It's a matter of > > familiarity with such path names that would help users in using HDFS > > snapshots. > > > > I am including the hdfs-dev in this email. Would appreciate if we could > > work together and come up with a solution. > > > > You can find sample output from hdfs command here: > > http://pastebin.com/bBqR4Fvr > > > > Cheers > > > > -- > // Jonathan Hsieh (shay) > // Software Engineer, Cloudera > // j...@cloudera.com >