taskFaker.sleep(100.µs)
      log += "red:finishing@${taskFaker.nanoTime}"
    }
    assertThat(taskFaker.executeCallCount).isEqualTo(1)

    // Enqueueing the blue task doesn't start a thread because the red one is still starting.
    blueQueue.execute("blue task") {
      log += "blue:starting@${taskFaker.nanoTime}"
      taskFaker.sleep(100.µs)

                dataCrawlingThreadStatusList.set(startedCrawlerNum, Constants.RUNNING);
                startedCrawlerNum++;
                activeCrawlerNum++;
                ThreadUtil.sleep(crawlingExecutionInterval);
                continue;
            }

            // check status
            for (int i = 0; i < startedCrawlerNum; i++) {

}

@AfterClass
public static void afterClass() {
    runner.close();
    runner.clean();
}
```

### Testing Best Practices

- Minimize `Thread.sleep()` - use only when absolutely necessary
- For timestamp tests: use minimal delays (50-100ms)
- Clean only test-specific indices (not `_all` unless needed)
- Use `runner.refresh()` after index operations

                            session.release();
                        } else {
                            session.acquire();
                            // Hold for a bit
                            Thread.sleep(1);
                            session.release();
                        }
                    }
                } catch (Exception e) {

            while (!isInterrupted() && !stopIfLeisure()) {
                for (final TimeoutTask task : getExpiredTask()) {
                    processTask(executorService, task);
                }
                Thread.sleep(1000L);
            }
        } catch (final InterruptedException e) {
            if (logger.isDebugEnabled()) {
                logger.debug("Interrupted.", e);
            }
        } finally {

        IOException error = new IOException("Connection failed");
        failover.handleFailure(failedChannel, error);

        // Wait a bit for recovery attempt
        Thread.sleep(100);

        verify(mockChannelManager).createTransport(failedChannel.getLocalInterface(), failedChannel.getRemoteInterface());
    }

    @Test
    void testMultipleFailuresExceedRetryLimit() {

        // Start indexer in separate thread
        indexUpdater.start();

        // Let it run briefly
        ThreadUtil.sleep(100);

        // Stop the indexer
        indexUpdater.setFinishCrawling(true);

        // Wait for completion with longer timeout
        indexUpdater.join(3000);

    final int millis;
    volatile boolean completed;

    SleepingRunnable(int millis) {
      this.millis = millis;
    }

    @Override
    public void run() {
      try {
        Thread.sleep(millis);
      } catch (InterruptedException wontHappen) {
        throw new AssertionError();
      }
      completed = true;
    }
  }

			<-ctx.Done()
			return
		}
		duration := max(time.Duration(r.Float64()*float64(time.Minute)),
			// Make sure to sleep at least a second to avoid high CPU ticks.
			time.Second)
		time.Sleep(duration)
	}
}

// Loads bucket replication resync statuses into memory.

    override fun writeTo(sink: BufferedSink) {
      try {
        var i = 0
        while (i < contentLength()) {
          sink.write(chunk!!)
          sink.flush()
          Thread.sleep(100)
          i += chunk.size
        }
      } catch (e: IOException) {
        ioe = e
      } catch (e: InterruptedException) {
        throw RuntimeException(e)
      }
    }
  }