private void RunChangeTrackerTransientError(
ChangeTrackerMode mode,
Int32 errorCode,
string statusMessage,
Int32 numExpectedChangeCallbacks)
{
var changeTrackerFinishedSignal = new CountdownEvent(1);
var changeReceivedSignal = new CountdownEvent(numExpectedChangeCallbacks);
var client = new ChangeTrackerTestClient(changeTrackerFinishedSignal, changeReceivedSignal);
MockHttpRequestHandler.HttpResponseDelegate sentinal = RunChangeTrackerTransientErrorDefaultResponder();
var responders = new List <MockHttpRequestHandler.HttpResponseDelegate>();
responders.Add(RunChangeTrackerTransientErrorDefaultResponder());
responders.Add(MockHttpRequestHandler.TransientErrorResponder(errorCode, statusMessage));
MockHttpRequestHandler.HttpResponseDelegate chainResponder = (request) =>
{
if (responders.Count > 0)
{
var responder = responders[0];
responders.RemoveAt(0);
return(responder(request));
}
return(sentinal(request));
};
var handler = client.HttpRequestHandler;
handler.SetResponder("_changes", chainResponder);
var testUrl = GetReplicationURL();
var scheduler = new SingleTaskThreadpoolScheduler();
var remoteSession = new RemoteSession(new RemoteSessionContructorOptions {
WorkExecutor = new TaskFactory(scheduler),
BaseUrl = testUrl
});
remoteSession.SetupHttpClientFactory(client.HttpClientFactory, database);
remoteSession.Setup(new ReplicationOptions());
var changeTracker = ChangeTrackerFactory.Create(new ChangeTrackerOptions {
DatabaseUri = testUrl,
Mode = mode,
IncludeConflicts = false,
Client = client,
RetryStrategy = new ExponentialBackoffStrategy(2),
WorkExecutor = new TaskFactory(scheduler),
RemoteSession = remoteSession
});
changeTracker.Start();
var success = changeReceivedSignal.Wait(TimeSpan.FromSeconds(30));
Assert.IsTrue(success);
changeTracker.Stop(ErrorResolution.Ignore);
success = changeTrackerFinishedSignal.Wait(TimeSpan.FromSeconds(30));
Assert.IsTrue(success);
}
private void TestChangeTrackerBackoff(MockHttpClientFactory httpClientFactory)
{
var changeTrackerFinishedSignal = new CountdownEvent(1);
var client = new ChangeTrackerTestClient(changeTrackerFinishedSignal, null);
client.HttpClientFactory = httpClientFactory;
var testUrl = GetReplicationURL();
var scheduler = new SingleTaskThreadpoolScheduler();
var opts = new RemoteSessionContructorOptions {
BaseUrl = testUrl,
WorkExecutor = new TaskFactory(scheduler)
};
var remoteSession = new RemoteSession(opts);
remoteSession.SetupHttpClientFactory(client.HttpClientFactory, database);
remoteSession.Setup(new ReplicationOptions());
var changeTracker = ChangeTrackerFactory.Create(new ChangeTrackerOptions {
DatabaseUri = testUrl,
Mode = ChangeTrackerMode.LongPoll,
IncludeConflicts = true,
Client = client,
RetryStrategy = new ExponentialBackoffStrategy(2),
WorkExecutor = new TaskFactory(scheduler),
RemoteSession = remoteSession
});
changeTracker.Continuous = true;
changeTracker.Start();
// sleep for a few seconds
Sleep(5 * 1000);
// make sure we got less than 10 requests in those 8 seconds (if it was hammering, we'd get a lot more)
var handler = client.HttpRequestHandler;
Assert.Less(handler.CapturedRequests.Count, 10);
handler.ClearResponders();
handler.AddResponderReturnEmptyChangesFeed();
handler.ResponseDelayMilliseconds = 100;
// at this point, the change tracker backoff should cause it to sleep for about 3 seconds
// and so lets wait 3 seconds until it wakes up and starts getting valid responses
Sleep(10 * 1000);
// now find the delta in requests received in a 2s period
int before = handler.CapturedRequests.Count;
Sleep(2 * 1000);
int after = handler.CapturedRequests.Count;
changeTracker.Stop(ErrorResolution.Ignore);
// assert that the delta is high, because at this point the change tracker should
// be hammering away
Assert.Greater((after - before), 10);
// the backoff numAttempts should have been reset to 0
Assert.IsTrue(changeTracker.Backoff.NumAttempts == 0);
var success = changeTrackerFinishedSignal.Wait(TimeSpan.FromSeconds(30));
Assert.IsTrue(success);
}
