Examples with JdbcLockRegistry org.springframework.integration.jdbc.lock.JdbcLockRegistry used on opensource projects

Example 1 with JdbcLockRegistry

use of org.springframework.integration.jdbc.lock.JdbcLockRegistry in project spring-integration by spring-projects.

the class JdbcLockRegistryLeaderInitiatorTests method testDistributedLeaderElection.

@Test
public void testDistributedLeaderElection() throws Exception {
    CountDownLatch granted = new CountDownLatch(1);
    CountingPublisher countingPublisher = new CountingPublisher(granted);
    List<LockRegistryLeaderInitiator> initiators = new ArrayList<LockRegistryLeaderInitiator>();
    for (int i = 0; i < 2; i++) {
        DefaultLockRepository lockRepository = new DefaultLockRepository(dataSource);
        lockRepository.afterPropertiesSet();
        LockRegistryLeaderInitiator initiator = new LockRegistryLeaderInitiator(new JdbcLockRegistry(lockRepository), new DefaultCandidate("foo", "bar"));
        initiator.setLeaderEventPublisher(countingPublisher);
        initiators.add(initiator);
    }
    for (LockRegistryLeaderInitiator initiator : initiators) {
        initiator.start();
    }
    assertThat(granted.await(10, TimeUnit.SECONDS), is(true));
    LockRegistryLeaderInitiator initiator1 = countingPublisher.initiator;
    LockRegistryLeaderInitiator initiator2 = null;
    for (LockRegistryLeaderInitiator initiator : initiators) {
        if (initiator != initiator1) {
            initiator2 = initiator;
            break;
        }
    }
    assertNotNull(initiator2);
    assertThat(initiator1.getContext().isLeader(), is(true));
    assertThat(initiator2.getContext().isLeader(), is(false));
    final CountDownLatch granted1 = new CountDownLatch(1);
    final CountDownLatch granted2 = new CountDownLatch(1);
    CountDownLatch revoked1 = new CountDownLatch(1);
    CountDownLatch revoked2 = new CountDownLatch(1);
    final CountDownLatch acquireLockFailed1 = new CountDownLatch(1);
    final CountDownLatch acquireLockFailed2 = new CountDownLatch(1);
    initiator1.setLeaderEventPublisher(new CountingPublisher(granted1, revoked1, acquireLockFailed1) {

        @Override
        public void publishOnRevoked(Object source, Context context, String role) {
            try {
                // It's difficult to see round-robin election, so block one initiator until the second is elected.
                assertThat(granted2.await(20, TimeUnit.SECONDS), is(true));
            } catch (InterruptedException e) {
            // No op
            }
            super.publishOnRevoked(source, context, role);
        }
    });
    initiator2.setLeaderEventPublisher(new CountingPublisher(granted2, revoked2, acquireLockFailed2) {

        @Override
        public void publishOnRevoked(Object source, Context context, String role) {
            try {
                // It's difficult to see round-robin election, so block one initiator until the second is elected.
                assertThat(granted1.await(20, TimeUnit.SECONDS), is(true));
            } catch (InterruptedException e) {
            // No op
            }
            super.publishOnRevoked(source, context, role);
        }
    });
    initiator1.getContext().yield();
    assertThat(revoked1.await(20, TimeUnit.SECONDS), is(true));
    assertThat(initiator2.getContext().isLeader(), is(true));
    assertThat(initiator1.getContext().isLeader(), is(false));
    initiator2.getContext().yield();
    assertThat(revoked2.await(20, TimeUnit.SECONDS), is(true));
    assertThat(initiator1.getContext().isLeader(), is(true));
    assertThat(initiator2.getContext().isLeader(), is(false));
    // Stop second initiator, so the first one will be leader even after yield
    initiator2.stop();
    CountDownLatch granted11 = new CountDownLatch(1);
    initiator1.setLeaderEventPublisher(new CountingPublisher(granted11));
    initiator1.getContext().yield();
    assertThat(granted11.await(20, TimeUnit.SECONDS), is(true));
    assertThat(initiator1.getContext().isLeader(), is(true));
    initiator1.stop();
}