Examples of org.lilyproject.util.hbase.LocalHTable

org.lilyproject.util.hbase.LocalHTable

This is a threadsafe solution for the non-threadsafe HTable.

Be careful/considerate when using autoflush.

The problems with HTable this tries to solve is that HTable:

HTable is not threadsafe
It needs to be closed when you're done with it (cfr. HConnection refcounting). And closing as soon as you're done might actually not be efficient because when the refcount reaches zero, the connection is closed but maybe a second later you'll need it again.
it is best not to instantiate a new HTable for each use for performance reasons (though according to HBASE-4805, if you pass an executorservice & hconnection yourself, this isn't true).

Note that HTable doesn't represent a connection, but uses a HConnection managed by the HConnectionManager.

The first implementation was based on caching HTable instances in threadlocal variables, now it is based on HTablePool. The reason for changing this was that HTable now contains an ExecutorService instance, which is better exploited if we reduce the number of HTable instances. And now this implementation even changes it by a shared ExecutorService instance, since otherwise still very many very short-lived threads were created. So in fact we could return to the thread-local approach, but maybe that's less efficient when threads are not reused (which would actually be an efficiency problem by itself, so this is maybe not an argument).

        System.out.println("Using index meta table " + metaTable);


        Configuration conf = HBaseConfiguration.create();
        conf.set("hbase.zookeeper.quorum", zkConnect);


        HTableInterface table = new LocalHTable(conf, metaTable);


        HBaseAdmin admin = new HBaseAdmin(conf);


        ResultScanner scanner = table.getScanner(Bytes.toBytes("meta"));


        Result result;
        while ((result = scanner.next()) != null) {
            byte[] tableName = result.getRow();
            String tableNameString = Bytes.toString(result.getRow());

     * @throws IndexNotFoundException if the index does not exist
     */
    public Index getIndex(String name) throws IOException, IndexNotFoundException {
        HTableInterface table;
        try {
            table = new LocalHTable(hbaseConf, name);
        } catch (RuntimeException e) {
            if (e.getCause() != null && e.getCause() instanceof TableNotFoundException) {
                throw new IndexNotFoundException(name);
            } else {
                throw e;

Examples of org.lilyproject.util.hbase.LocalHTable

Related Classes of org.lilyproject.util.hbase.LocalHTable