Examples with RetryAction org.apache.hadoop.io.retry.RetryPolicy.RetryAction used on opensource projects

Example 1 with RetryAction

use of org.apache.hadoop.io.retry.RetryPolicy.RetryAction in project hadoop by apache.

the class TestWebHDFS method testReadRetryExceptionHelper.

private void testReadRetryExceptionHelper(WebHdfsFileSystem fs, Path fn, final IOException ex, String msg, boolean shouldAttemptRetry, int numTimesTried) throws Exception {
    // Ovverride WebHdfsInputStream#getInputStream so that it returns
    // an input stream that throws the specified exception when read
    // is called.
    FSDataInputStream in = fs.open(fn);
    // Connection is made only when the first read() occurs.
    in.read();
    final WebHdfsInputStream webIn = (WebHdfsInputStream) (in.getWrappedStream());
    final InputStream spyInputStream = spy(webIn.getReadRunner().getInputStream());
    doThrow(ex).when(spyInputStream).read((byte[]) any(), anyInt(), anyInt());
    final WebHdfsFileSystem.ReadRunner rr = spy(webIn.getReadRunner());
    doReturn(spyInputStream).when(rr).initializeInputStream((HttpURLConnection) any());
    rr.setInputStream(spyInputStream);
    webIn.setReadRunner(rr);
    // Override filesystem's retry policy in order to verify that
    // WebHdfsInputStream is calling shouldRetry for the appropriate
    // exceptions.
    final RetryAction retryAction = new RetryAction(RetryDecision.RETRY);
    final RetryAction failAction = new RetryAction(RetryDecision.FAIL);
    RetryPolicy rp = new RetryPolicy() {

        @Override
        public RetryAction shouldRetry(Exception e, int retries, int failovers, boolean isIdempotentOrAtMostOnce) throws Exception {
            attemptedRetry = true;
            if (retries > 3) {
                return failAction;
            } else {
                return retryAction;
            }
        }
    };
    fs.setRetryPolicy(rp);
    // If the retry logic is exercised, attemptedRetry will be true. Some
    // exceptions should exercise the retry logic and others should not.
    // Either way, the value of attemptedRetry should match shouldAttemptRetry.
    attemptedRetry = false;
    try {
        webIn.read();
        fail(msg + ": Read should have thrown exception.");
    } catch (Exception e) {
        assertTrue(e.getMessage().contains(msg));
    }
    assertEquals(msg + ": Read should " + (shouldAttemptRetry ? "" : "not ") + "have called shouldRetry. ", attemptedRetry, shouldAttemptRetry);
    verify(rr, times(numTimesTried)).getResponse((HttpURLConnection) any());
    webIn.close();
    in.close();
}

Example 2 with RetryAction

use of org.apache.hadoop.io.retry.RetryPolicy.RetryAction in project hadoop by apache.

the class RetriableCommand method execute.

/**
   * The execute() method invokes doExecute() until either:
   *  1. doExecute() succeeds, or
   *  2. the command may no longer be retried (e.g. runs out of retry-attempts).
   * @param arguments The list of arguments for the command.
   * @return Generic "Object" from doExecute(), on success.
   * @throws Exception
   */
public Object execute(Object... arguments) throws Exception {
    Exception latestException;
    int counter = 0;
    while (true) {
        try {
            return doExecute(arguments);
        } catch (Exception exception) {
            LOG.error("Failure in Retriable command: " + description, exception);
            latestException = exception;
        }
        counter++;
        RetryAction action = retryPolicy.shouldRetry(latestException, counter, 0, true);
        if (action.action == RetryPolicy.RetryAction.RetryDecision.RETRY) {
            ThreadUtil.sleepAtLeastIgnoreInterrupts(action.delayMillis);
        } else {
            break;
        }
    }
    throw new IOException("Couldn't run retriable-command: " + description, latestException);
}