Hi,
Ah, I see Ted has that also questioned in HBASE-4010. Good.
And I was slightly wrong below, as there is a .logs and .oldlogs for the newly
created regions. I agree that when there is no chance for the region to take
edits before it gets the proper log, then we should drop this. Those dangling
dirs do not harm, but also do not help either.
Lars
On Jul 5, 2011, at 8:39 AM, Lars George wrote:
> Hi,
>
> Could someone confirm that we dropped the replay of the .oldlogs in the
> region directory because it is not needed anymore? Before the master rewrite
> we were, just as now, creating the region and for a brief period it had its
> own log directory, the .oldlogs under the region directory. The
> HRegion.initialize() would replay it in case an edit to the region arrived in
> between. It would then also remove it:
>
> public void initialize(Path initialFiles, final Progressable reporter)
> throws IOException {
> Path oldLogFile = new Path(regiondir, HREGION_OLDLOGFILE_NAME);
> ...
> // Play log if one. Delete when done.
> doReconstructionLog(oldLogFile, minSeqIdToRecover, maxSeqId, reporter);
> if (fs.exists(oldLogFile)) {
> if (LOG.isDebugEnabled()) {
> LOG.debug("Deleting old log file: " + oldLogFile);
> }
> fs.delete(oldLogFile, false);
> }
> ...
>
> Now we still create that directory, but the above code has been dropped. Only
> the recovered.edits is replayed instead while the .oldlogs now hang around. I
> am not even sure when they may contain an entry, but if they don't then we
> can either do not use "<regiondir>/.oldlogs", but point it to the new
> "<regiondir>/.tmp" - or we can add a unconditional delete in the initialize
> as before.
>
> Create a JIRA for this?
>
> Lars
