/// <summary>
/// Processes HTTP request.
/// </summary>
private static void ProcessHTTPRequest(Object sender, EventArgs e)
{
var context = ((HttpApplication)sender).Context;
string ruleName = null;
var request = context.Request;
TraceHeader traceHeader = GetTraceHeader(context);
var segmentName = GetSegmentNamingStrategy().GetSegmentName(request);
// Make sample decision
if (traceHeader.Sampled == SampleDecision.Unknown || traceHeader.Sampled == SampleDecision.Requested)
{
SamplingResponse response = MakeSamplingDecision(request, traceHeader, segmentName);
ruleName = response.RuleName;
}
var timestamp = context.Timestamp.ToUniversalTime(); // Gets initial timestamp of current HTTP Request
SamplingResponse samplingResponse = new SamplingResponse(ruleName, traceHeader.Sampled); // get final ruleName and SampleDecision
_recorder.BeginSegment(segmentName, traceHeader.RootTraceId, traceHeader.ParentId, samplingResponse, timestamp);
if (!AWSXRayRecorder.Instance.IsTracingDisabled())
{
Dictionary <string, object> requestAttributes = new Dictionary <string, object>();
ProcessRequestAttributes(request, requestAttributes);
_recorder.AddHttpInformation("request", requestAttributes);
}
}
public static void ContinueFrom(this AWSXRayRecorder recorder, string serviceName, Message message)
{
var traceHeader = message?.GetTraceHeader() ?? new TraceHeader
{
RootTraceId = TraceId.NewId(),
ParentId = null,
Sampled = SampleDecision.Unknown
};
string ruleName = null;
if (traceHeader.Sampled == SampleDecision.Unknown || traceHeader.Sampled == SampleDecision.Requested)
{
var samplingInput = new SamplingInput(serviceName);
var sampleResponse = recorder.SamplingStrategy.ShouldTrace(samplingInput);
traceHeader.Sampled = sampleResponse.SampleDecision;
ruleName = sampleResponse.RuleName;
}
var samplingResponse = new SamplingResponse(ruleName, traceHeader.Sampled);
recorder
.BeginSegment
(
serviceName,
traceHeader.RootTraceId,
traceHeader.ParentId,
samplingResponse
);
}
private static SamplingResponse MakeSamplingDecision(HttpRequest request, TraceHeader traceHeader, string name)
{
string host = request.Headers.Get("Host");
string url = request.Url.AbsolutePath;
string method = request.HttpMethod;
SamplingInput samplingInput = new SamplingInput(host, url, method, name, _recorder.Origin);
SamplingResponse sampleResponse = _recorder.SamplingStrategy.ShouldTrace(samplingInput);
traceHeader.Sampled = sampleResponse.SampleDecision;
return(sampleResponse);
}
public void TestDefaultRuleWithRequest()
{
var request = new HttpRequestMessage
{
RequestUri = new Uri(@"http://www.amazon.com/api/product"),
Method = HttpMethod.Post
};
request.Headers.Add("Host", "www.amazon.com");
var strategy = new LocalizedSamplingStrategy();
string host = request.Headers.Host;
string url = request.RequestUri.AbsolutePath;
string method = request.Method.Method;
SamplingInput samplingInput = new SamplingInput(host, url, method, "", "");
SamplingResponse samplingResponse = strategy.ShouldTrace(samplingInput);
Assert.AreEqual(SampleDecision.Sampled, samplingResponse.SampleDecision);
Assert.IsTrue(string.IsNullOrEmpty(samplingResponse.RuleName));
}
private static void GetSamplingDetails(
IAWSXRayRecorder xRayRecorder, string serviceName, string traceHeader, out string traceId, out SamplingResponse samplingResponse,
out string parentId)
{
if (TraceHeader.TryParse(traceHeader, out TraceHeader header))
{
traceId = header.RootTraceId;
samplingResponse = new SamplingResponse {
SampleDecision = header.Sampled
};
parentId = header.ParentId;
}
else
{
traceId = TraceId.NewId();
samplingResponse = xRayRecorder.SamplingStrategy.ShouldTrace(new SamplingInput {
ServiceName = serviceName
});
parentId = null;
}
}
/// <summary>
/// Processes HTTP request.
/// </summary>
private void ProcessHTTPRequest(HttpContext context)
{
HttpRequest request = context.Request;
string headerString = null;
if (request.Headers.TryGetValue(TraceHeader.HeaderKey, out StringValues headerValue))
{
if (headerValue.ToArray().Length >= 1)
{
headerString = headerValue.ToArray()[0];
}
}
// Trace header doesn't exist, which means this is the root node. Create a new traceId and inject the trace header.
if (!TraceHeader.TryParse(headerString, out TraceHeader traceHeader))
{
_logger.DebugFormat("Trace header doesn't exist or not valid : ({0}). Injecting a new one.", headerString);
traceHeader = new TraceHeader
{
RootTraceId = TraceId.NewId(),
ParentId = null,
Sampled = SampleDecision.Unknown
};
}
var segmentName = SegmentNamingStrategy.GetSegmentName(request);
bool isSampleDecisionRequested = traceHeader.Sampled == SampleDecision.Requested;
string ruleName = null;
// Make sample decision
if (traceHeader.Sampled == SampleDecision.Unknown || traceHeader.Sampled == SampleDecision.Requested)
{
string host = request.Host.Host;
string url = request.Path;
string method = request.Method;
SamplingInput samplingInput = new SamplingInput(host, url, method, segmentName, _recorder.Origin);
SamplingResponse sampleResponse = _recorder.SamplingStrategy.ShouldTrace(samplingInput);
traceHeader.Sampled = sampleResponse.SampleDecision;
ruleName = sampleResponse.RuleName;
}
if (AWSXRayRecorder.IsLambda())
{
_recorder.BeginSubsegment(segmentName);
}
else
{
SamplingResponse samplingResponse = new SamplingResponse(ruleName, traceHeader.Sampled); // get final ruleName and SampleDecision
_recorder.BeginSegment(SegmentNamingStrategy.GetSegmentName(request), traceHeader.RootTraceId, traceHeader.ParentId, samplingResponse);
}
if (!AWSXRayRecorder.Instance.IsTracingDisabled())
{
var requestAttributes = new Dictionary <string, object>();
PopulateRequestAttributes(request, requestAttributes);
_recorder.AddHttpInformation("request", requestAttributes);
}
if (isSampleDecisionRequested)
{
context.Response.Headers.Add(TraceHeader.HeaderKey, traceHeader.ToString()); // Its recommended not to modify response header after _next.Invoke() call
}
}
/// <summary>
/// Sends an HTTP request to the inner handler to send to the server as an asynchronous
/// operation.
/// </summary>
/// <param name="request">The HTTP request message to send to the server.</param>
/// <param name="cancellationToken">A cancellation token to cancel operation.</param>
/// <returns>Returns System.Threading.Tasks.Task. The task object representing the asynchronous operation.</returns>
protected async override Task <HttpResponseMessage> SendAsync(HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
{
string headerSring = null;
string ruleName = null;
if (request.Headers.TryGetValues(TraceHeader.HeaderKey, out IEnumerable <string> headerValue))
{
headerSring = headerValue.First();
}
// If Trace header doesn't exist, which means this is the root node. Create a new traceId and inject the trace header.
if (!TraceHeader.TryParse(headerSring, out TraceHeader traceHeader))
{
_logger.DebugFormat("Trace header doesn't exist or not valid. Injecting a new one. existing header = {0}", headerSring);
traceHeader = new TraceHeader
{
RootTraceId = TraceId.NewId(),
ParentId = null,
Sampled = SampleDecision.Unknown
};
}
bool isSampleDecisionRequested = traceHeader.Sampled == SampleDecision.Requested;
string segmentName = SegmentNamingStrategy.GetSegmentName(request);
// Make sample decision
if (traceHeader.Sampled == SampleDecision.Unknown || traceHeader.Sampled == SampleDecision.Requested)
{
string host = request.Headers.Host;
string url = request.RequestUri.AbsolutePath;
string method = request.Method.Method;
SamplingInput samplingInput = new SamplingInput(host, url, method, segmentName, _recorder.Origin);
SamplingResponse s = _recorder.SamplingStrategy.ShouldTrace(samplingInput);
traceHeader.Sampled = s.SampleDecision;
ruleName = s.RuleName;
}
SamplingResponse samplingResponse = new SamplingResponse(ruleName, traceHeader.Sampled); // get final ruleName and SampleDecision
_recorder.BeginSegment(segmentName, traceHeader.RootTraceId, traceHeader.ParentId, samplingResponse);
if (!AppSettings.IsXRayTracingDisabled)
{
var requestAttributes = new Dictionary <string, object>();
requestAttributes["url"] = request.RequestUri.AbsoluteUri;
requestAttributes["method"] = request.Method.Method;
string xForwardedFor = GetXForwardedFor(request);
if (xForwardedFor == null)
{
requestAttributes["client_ip"] = GetClientIpAddress(request);
}
else
{
requestAttributes["client_ip"] = xForwardedFor;
requestAttributes["x_forwarded_for"] = true;
}
requestAttributes["user_agent"] = request.Headers.UserAgent.ToString();
_recorder.AddHttpInformation("request", requestAttributes);
}
var response = await base.SendAsync(request, cancellationToken);
if (!AppSettings.IsXRayTracingDisabled)
{
var responseAttributes = new Dictionary <string, object>();
int statusCode = (int)response.StatusCode;
if (statusCode >= 400 && statusCode <= 499)
{
_recorder.MarkError();
if (statusCode == 429)
{
_recorder.MarkThrottle();
}
}
else if (statusCode >= 500 && statusCode <= 599)
{
_recorder.MarkFault();
}
responseAttributes["status"] = statusCode;
if (response.Content != null && response.Content.Headers.ContentLength != null)
{
responseAttributes["content_length"] = response.Content.Headers.ContentLength;
}
_recorder.AddHttpInformation("response", responseAttributes);
}
_recorder.EndSegment();
// If the sample decision is requested, added the trace header to response
if (isSampleDecisionRequested)
{
response.Headers.Add(TraceHeader.HeaderKey, traceHeader.ToString());
}
return(response);
}
