/// <summary>
/// Try to inject the trace context into the Kafka message headers
/// </summary>
/// <param name="agent">The agent</param>
/// <param name="segment">The outgoing distributed tracing data to propagate</param>
/// <param name="message">The duck-typed Kafka Message object</param>
/// <typeparam name="TTopicPartitionMarker">The TopicPartition type (used optimisation purposes)</typeparam>
/// <typeparam name="TMessage">The type of the duck-type proxy</typeparam>
internal static void TryInjectHeaders <TTopicPartitionMarker, TMessage>(IApmAgent agent, IExecutionSegment segment, TMessage message)
where TMessage : IMessage
{
if (!HeadersInjectionEnabled)
{
return;
}
try
{
message.Headers ??= CachedMessageHeadersHelper <TTopicPartitionMarker> .CreateHeaders();
var adapter = new KafkaHeadersCollection(message.Headers, agent.Logger);
var distributedTracingData = segment.OutgoingDistributedTracingData;
adapter.Set(TraceContext.TraceParentBinaryHeaderName, distributedTracingData.SerializeToString());
adapter.Set(TraceContext.TraceStateHeaderName, distributedTracingData.TraceState.ToTextHeader());
}
catch (Exception ex)
{
// don't keep trying if we run into problems
HeadersInjectionEnabled = false;
agent.Logger.Warning()?.LogException(ex, "There was a problem injecting headers into the Kafka record. Disabling headers injection");
}
}
internal static ITransaction CreateConsumerTransaction(
IApmAgent agent,
string topic,
Partition?partition,
Offset?offset,
IMessage message)
{
ITransaction transaction = null;
try
{
if (agent.Tracer.CurrentTransaction is not null)
{
return(null);
}
if (agent is ApmAgent apmAgent)
{
var matcher = WildcardMatcher.AnyMatch(apmAgent.ConfigurationStore.CurrentSnapshot.IgnoreMessageQueues, topic);
if (matcher != null)
{
agent.Logger.Trace()
?.Log(
"Not tracing message from {Queue} because it matched IgnoreMessageQueues pattern {Matcher}",
topic,
matcher.GetMatcher());
return(null);
}
}
DistributedTracingData distributedTracingData = null;
if (message?.Headers != null)
{
var headers = new KafkaHeadersCollection(message.Headers, agent.Logger);
try
{
var traceParent = string.Join(",", headers.GetValues(TraceContext.TraceParentBinaryHeaderName));
var traceState = headers.GetValues(TraceContext.TraceStateHeaderName).FirstOrDefault();
distributedTracingData = TraceContext.TryExtractTracingData(traceParent, traceState);
}
catch (Exception ex)
{
agent.Logger.Error()?.LogException(ex, "Error extracting propagated headers from Kafka message");
}
}
var name = string.IsNullOrEmpty(topic)
? "Kafka RECEIVE"
: $"Kafka RECEIVE from {topic}";
transaction = agent.Tracer.StartTransaction(name, ApiConstants.TypeMessaging, distributedTracingData);
if (partition is not null)
{
transaction.SetLabel("partition", partition.ToString());
}
if (offset is not null)
{
transaction.SetLabel("offset", offset.ToString());
}
// record only queue topic name and age on context for now. capture body and headers potentially in future
transaction.Context.Message = new Message {
Queue = new Queue {
Name = topic
}
};
if (transaction is Transaction realTransaction && message is not null && message.Timestamp.Type != 0)
{
var consumeTime = TimeUtils.ToDateTime(realTransaction.Timestamp);
var produceTime = message.Timestamp.UtcDateTime;
var age = Math.Max(0, (consumeTime - produceTime).TotalMilliseconds);
if (age > 0 && age < MaxAge)
{
transaction.Context.Message.Age = new Age {
Ms = (long)age
}
}
;
}
if (message is not null && message.Value is null)
{
transaction.SetLabel("tombstone", "true");
}
}
catch (Exception ex)
{
agent.Logger.Error()?.LogException(ex, "Error creating or populating transaction.");
}
return(transaction);
}