public override void OnSendingRequest(HttpPipelineMessage message)
{
if (message.Request.Method != RequestMethod.Get && message.Request.Method != RequestMethod.Head)
{
return;
}
// Look up what the alternate host is set to in the message properties. For the initial request, this will
// not be set.
string alternateHost =
message.TryGetProperty(
Constants.GeoRedundantRead.AlternateHostKey,
out var alternateHostObj)
? alternateHostObj as string
: null;
if (alternateHost == null)
{
// queue up the secondary host for subsequent retries
message.SetProperty(Constants.GeoRedundantRead.AlternateHostKey, _secondaryStorageHost);
return;
}
// Check the flag that indicates whether the resource has not been propagated to the secondary host yet.
// If this flag is set, we don't want to retry against the secondary host again for any subsequent retries.
// Also, the flag being set implies that the current request must already be set to the primary host, so we
// are safe to return without checking if the current host is secondary or primary.
var resourceNotReplicated =
message.TryGetProperty(Constants.GeoRedundantRead.ResourceNotReplicated, out var value) &&
(bool)value;
if (resourceNotReplicated)
{
return;
}
// If alternateHost was not null that means the message is being retried. Hence what is stored in the Host
// property of UriBuilder is actually the host from the last try.
var lastTriedHost = message.Request.Uri.Host;
// If necessary, set the flag to indicate that the resource has not yet been propagated to the secondary host.
if (message.HasResponse &&
message.Response.Status == Constants.HttpStatusCode.NotFound &&
lastTriedHost == _secondaryStorageHost)
{
message.SetProperty(Constants.GeoRedundantRead.ResourceNotReplicated, true);
}
// Toggle the host set in the request to use the alternate host for the upcoming attempt, and update the
// the property for the AlternateHostKey to be the host used in the last try.
message.Request.Uri.Host = alternateHost;
message.SetProperty(Constants.GeoRedundantRead.AlternateHostKey, lastTriedHost);
}
public void TryGetPropertyIsCaseSensitive()
{
HttpPipelineMessage message = new HttpPipelineMessage(new MockRequest(), new ResponseClassifier(), CancellationToken.None);
message.SetProperty("someName", "value");
Assert.False(message.TryGetProperty("SomeName", out object value));
}
public void TryGetPropertyIsCaseSensitive()
{
HttpPipelineMessage message = new HttpPipelineMessage(CancellationToken.None);
message.SetProperty("someName", "value");
Assert.False(message.TryGetProperty("SomeName", out object value));
}
public void TryGetPropertyReturnsValueIfSet()
{
HttpPipelineMessage message = new HttpPipelineMessage(new MockRequest(), new ResponseClassifier());
message.SetProperty("someName", "value");
Assert.True(message.TryGetProperty("someName", out object value));
Assert.AreEqual("value", value);
}
public void TryGetPropertyReturnsValueIfSet()
{
HttpPipelineMessage message = new HttpPipelineMessage(CancellationToken.None);
message.SetProperty("someName", "value");
Assert.True(message.TryGetProperty("someName", out object value));
Assert.AreEqual("value", value);
}
public void OnSendingRequest_FirstTry_ShouldUsePrimary_ShouldSetAlternateToSecondary()
{
var message = new HttpPipelineMessage(
CreateMockRequest(MockPrimaryUri),
new StorageResponseClassifier(MockSecondaryUri));
var policy = new GeoRedundantReadPolicy(MockSecondaryUri);
policy.OnSendingRequest(message);
Assert.AreEqual(MockPrimaryUri.Host, message.Request.Uri.Host);
Assert.IsTrue(message.TryGetProperty(Constants.GeoRedundantRead.AlternateHostKey, out object val) &&
(string)val == MockSecondaryUri.Host);
}
public void OnSendingRequest_PutRequest_ShouldIgnore()
{
MockRequest request = CreateMockRequest(MockPrimaryUri);
request.Method = RequestMethod.Put;
var message = new HttpPipelineMessage(
request,
new StorageResponseClassifier(MockSecondaryUri));
var policy = new GeoRedundantReadPolicy(MockSecondaryUri);
policy.OnSendingRequest(message);
Assert.AreEqual(MockPrimaryUri.Host, message.Request.Uri.Host);
Assert.IsFalse(message.TryGetProperty(Constants.GeoRedundantRead.AlternateHostKey, out object val) &&
(string)val == MockSecondaryUri.Host);
}
public void OnSendingRequest_404onSecondary_ShouldSetNotFoundFlag_ShouldUsePrimary()
{
var message = new HttpPipelineMessage(
CreateMockRequest(MockSecondaryUri),
new StorageResponseClassifier(MockSecondaryUri))
{
Response = new MockResponse(Constants.HttpStatusCode.NotFound)
};
message.SetProperty(Constants.GeoRedundantRead.AlternateHostKey, MockSecondaryUri.Host);
var policy = new GeoRedundantReadPolicy(MockSecondaryUri);
policy.OnSendingRequest(message);
Assert.AreEqual(MockSecondaryUri.Host, message.Request.Uri.Host);
Assert.IsTrue(message.TryGetProperty(Constants.GeoRedundantRead.ResourceNotReplicated, out object val) &&
(bool)val);
}
public void TryGetPropertyReturnsFalseIfNotExist()
{
HttpPipelineMessage message = new HttpPipelineMessage(new MockRequest(), new ResponseClassifier());
Assert.False(message.TryGetProperty("someName", out _));
}
public void TryGetPropertyReturnsFalseIfNotExist()
{
HttpPipelineMessage message = new HttpPipelineMessage(CancellationToken.None);
Assert.False(message.TryGetProperty("someName", out _));
}
