You are correct. It will flush the commits after 12MB of data has been
written to the write buffer. However, it doesn't take the last batch into
account...
On 9 March 2010 07:03, Bob Jacoby <b...@cabsmail.com> wrote:
> I'm using HBase 0.20.3. I'm trying to calculate some performance numbers
> for our Hbase setup. I'm using the test suite included with HBase as a
> starting point. However, looking at the test code, the timer showing how
> long the test took is stopped prior to performing an explicit flush of the
> table. This would appear to mean that the contents of the write buffer at
> the end of the test will never be written to HBase, which would
> significantly affect the results of the test if the buffer is only filled a
> small number of times (or never filled).
>
> Shouldn't the flush occur after the loop in the test() method, but before
> the elapsedTime is calculated? Am I missing something in how these tests are
> run?
>
> org.apache.hadoop.hbase.PerformanceEvaluation$Test test() method is the
> following:
>
> long test() throws IOException {
> long elapsedTime;
> testSetup();
> long startTime = System.currentTimeMillis();
> try {
> int lastRow = this.startRow + this.perClientRunRows;
> // Report on completion of 1/10th of total.
> for (int i = this.startRow; i < lastRow; i++) {
> testRow(i);
> if (status != null && i > 0 && (i % getReportingPeriod()) == 0) {
> status.setStatus(generateStatus(this.startRow, i, lastRow));
> }
> }
> elapsedTime = System.currentTimeMillis() - startTime;
> } finally {
> testTakedown();
> }
> return elapsedTime;
> }
>
> void testTakedown() throws IOException {
> this.table.flushCommits();
> }
>
> The sequentialWrite testRow method is as following:
> void testRow(final int i) throws IOException {
> Put put = new Put(format(i));
> put.add(FAMILY_NAME, QUALIFIER_NAME, generateValue(this.rand));
> table.put(put);
> }
>
> Thanks,
> Bob
>
