possible improvement to compaction invocation

[Ted Yu]

Hi,
I was looking at how compaction is invoked from HBaseAdmin (line 1460 in
trunk code)

        final String tableName = tableNameString(tableNameOrRegionName, ct);

        List<Pair<HRegionInfo, ServerName>> pairs =

          MetaReader.getTableRegionsAndLocations(ct,

              tableName);

        for (Pair<HRegionInfo, ServerName> pair: pairs) {

          if (pair.getFirst().isOffline()) continue;

          if (pair.getSecond() == null) continue;

          try {

            compact(pair.getSecond(), pair.getFirst(), major, columnFamily);

We issue one compaction request per region.

Looks like we can group regions which reside on the same server and make
one network trip per region server.


Your comment on this would be appreciated.