private static DefaultLoadBalancer BuildLoadBalancer() // TODO: include this in library? IOptions / IConfig object?
{
var registry = new ProviderRegistry();
var strategy = new RoundRobinStrategy();
var scheduler = new Scheduler(interval: 3000); // healthcheck scheduled every 3 seconds
var heartbeatChecker = new HeartbeatChecker(registry, scheduler);
var lb = new DefaultLoadBalancer(registry, strategy, heartbeatChecker);
return(lb);
}
public void should_report_failure_when_there_are_zero_heartbeats()
{
var now = new DateTime(2010, 1, 3, 17, 2, 0);
var repo = S <IHeartbeatRepository>();
repo.Stub(x => x.GetLatest()).Return(null);
var clock = S <ISystemClock>();
clock.Stub(x => x.Now()).Return(now);
var checker = new HeartbeatChecker(repo, clock);
checker.CheckHeartbeat(5).ShouldEqual(HeartbeatChecker.DeadNoHeartbeat);
}
public void should_report_success_when_heartbeat_is_within_the_specified_threshold()
{
var now = new DateTime(2010, 1, 3, 17, 2, 0);
var nowMinusTwoMinutes = now.AddMinutes(-2);
var heartbeat = new Heartbeat {
Date = nowMinusTwoMinutes
};
var timeout = 5;
var repo = S <IHeartbeatRepository>();
repo.Stub(x => x.GetLatest()).Return(heartbeat);
var clock = S <ISystemClock>();
clock.Stub(x => x.Now()).Return(now);
var checker = new HeartbeatChecker(repo, clock);
checker.CheckHeartbeat(timeout).ShouldEqual(HeartbeatChecker.Success);
}
public void should_report_failure_when_the_last_heartbeat_is_in_the_future()
{
var now = new DateTime(2010, 1, 3, 17, 2, 0);
var future = now.AddMinutes(2);
var heartbeat = new Heartbeat {
Date = future
};
var timeout = 5;
var failureMessage = string.Format("DEAD! Heartbeat is in the future. Now [{0}], Last Heartbeat [{1}]", now,
future);
var repo = S <IHeartbeatRepository>();
repo.Stub(x => x.GetLatest()).Return(heartbeat);
var clock = S <ISystemClock>();
clock.Stub(x => x.Now()).Return(now);
var checker = new HeartbeatChecker(repo, clock);
checker.CheckHeartbeat(timeout).ShouldEqual(failureMessage);
}
public void should_report_failure_when_the_last_heartbeat_is_too_old()
{
var now = new DateTime(2010, 1, 3, 17, 2, 0);
var nowMinusTwoMinutes = now.AddMinutes(-2);
var heartbeat = new Heartbeat {
Date = nowMinusTwoMinutes
};
var timeout = 1;
var failureMessage = string.Format("DEAD! 1 minute threshold exceeded. Now [{0}], Last Heartbeat [{1}]", now,
nowMinusTwoMinutes);
var repo = S <IHeartbeatRepository>();
repo.Stub(x => x.GetLatest()).Return(heartbeat);
var clock = S <ISystemClock>();
clock.Stub(x => x.Now()).Return(now);
var checker = new HeartbeatChecker(repo, clock);
checker.CheckHeartbeat(timeout).ShouldEqual(failureMessage);
}
