testScaleUp() — netty Function Reference

Source Code

common/src/test/java/io/netty/util/concurrent/AutoScalingEventExecutorChooserFactoryTest.java lines 124–169

    @Test
    @Timeout(30)
    void testScaleUp() throws InterruptedException {
        TestEventExecutorGroup group = new TestEventExecutorGroup(1, 3, 50, TimeUnit.MILLISECONDS);
        try {
            startAllExecutors(group);
            Thread.sleep(200);
            assertEquals(1, group.activeExecutorCount());

            TestEventExecutor activeExecutor = null;
            for (EventExecutor exec : group) {
                if (!exec.isSuspended()) {
                    activeExecutor = (TestEventExecutor) exec;
                    break;
                }
            }
            if (activeExecutor == null) {
                fail("Could not find an active executor to stress.");
            }

            activeExecutor.setHighLoad(true);

            // The monitor will see high utilization on the active thread. After 2 cycles (100 ms),
            // it will decide to scale up.
            long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(5);
            while (group.activeExecutorCount() < 2 && System.nanoTime() < deadline) {
                Thread.sleep(50);
            }
            assertEquals(2, group.activeExecutorCount(),
                         "Should scale up to 2 after stressing one executor.");

            for (EventExecutor exec : group) {
                if (!exec.isSuspended()) {
                    ((TestEventExecutor) exec).setHighLoad(true);
                }
            }

            while (group.activeExecutorCount() < 3 && System.nanoTime() < deadline) {
                Thread.sleep(50);
            }
            assertEquals(3, group.activeExecutorCount(),
                         "Should scale up to 3 after stressing two executors.");
        } finally {
            group.shutdownGracefully().syncUninterruptibly();
        }
    }