Question

What is the correct usage pattern of HTablePool? I mean, assume that I have my DAO which is initialised with an instance of HTablePool. This DAO is a member instance of a Stateless Session Bean so it is reused between invocations.

What is the correct usage beween the following?

private HTableInterface aTable;

public XYZDAO(final HTablePool pool)
{
    this.aTable = pool.getTable(...);
}

public void doSomething(...)
{
    aTable.get(...)
}

or HTablePool should be used like a Datasource and therefore is more appropriate a usage like this

private HTablePool datasource;

public XYZDAO(final HTablePool pool)
{
    this.datasource = pool;
}

public void doSomething(...)
{
    HTableInterface aTable = datasource.getTable(...);
    aTable.get(...);
    aTable.close();
}

Answer 1

The second approach is the best, you should use HTablePool like it was a Datasource since the HTable class is not thread safe. A call to the close method of HTableInterface will automatically return the table to the pool.

Note that there is HConnection interface that replaces the deprecated HTablePool in newer HBase versions.