@Test
public void testEmptyMembership() throws Exception {
ZooKeeperClient zkClient1 = createZkClient(TIMEOUT);
final CandidateImpl candidate1 = new CandidateImpl(createGroup(zkClient1));
Reign candidate1Reign = new Reign("1", candidate1);
candidate1.offerLeadership(candidate1Reign);
assertSame(candidate1, candidateBuffer.takeLast());
candidate1Reign.abdicate();
assertFalse(candidate1.getLeaderData().isPresent());
}
@Test
public void testOfferLeadership() throws Exception {
ZooKeeperClient zkClient1 = createZkClient(TIMEOUT);
final CandidateImpl candidate1 =
new CandidateImpl(createGroup(zkClient1)) {
@Override
public String toString() {
return "Leader1";
}
};
ZooKeeperClient zkClient2 = createZkClient(TIMEOUT);
final CandidateImpl candidate2 =
new CandidateImpl(createGroup(zkClient2)) {
@Override
public String toString() {
return "Leader2";
}
};
ZooKeeperClient zkClient3 = createZkClient(TIMEOUT);
final CandidateImpl candidate3 =
new CandidateImpl(createGroup(zkClient3)) {
@Override
public String toString() {
return "Leader3";
}
};
Reign candidate1Reign = new Reign("1", candidate1);
Reign candidate2Reign = new Reign("2", candidate2);
Reign candidate3Reign = new Reign("3", candidate3);
Supplier<Boolean> candidate1Leader = candidate1.offerLeadership(candidate1Reign);
Supplier<Boolean> candidate2Leader = candidate2.offerLeadership(candidate2Reign);
Supplier<Boolean> candidate3Leader = candidate3.offerLeadership(candidate3Reign);
assertTrue(
"Since initial group join is synchronous, candidate 1 should be the first leader",
candidate1Leader.get());
shutdownNetwork();
restartNetwork();
assertTrue(
"A re-connect without a session expiration should leave the leader elected",
candidate1Leader.get());
candidate1Reign.abdicate();
assertSame(candidate1, candidateBuffer.takeLast());
assertFalse(candidate1Leader.get());
// Active abdication should trigger defeat.
candidate1Reign.expectDefeated();
CandidateImpl secondCandidate = candidateBuffer.takeLast();
assertTrue(
"exactly 1 remaining candidate should now be leader: "
+ secondCandidate
+ " "
+ candidateBuffer,
candidate2Leader.get() ^ candidate3Leader.get());
if (secondCandidate == candidate2) {
expireSession(zkClient2);
assertSame(candidate3, candidateBuffer.takeLast());
assertTrue(candidate3Leader.get());
// Passive expiration should trigger defeat.
candidate2Reign.expectDefeated();
} else {
expireSession(zkClient3);
assertSame(candidate2, candidateBuffer.takeLast());
assertTrue(candidate2Leader.get());
// Passive expiration should trigger defeat.
candidate3Reign.expectDefeated();
}
}