Some transactions in APM UI are showing as an incomplete transaction trace.

Products

• DX Application Performance Management

Issue/Introduction

Some transactions in APM UI are showing as an incomplete transaction trace.

The customer is identifying Incomplete traces in APM UI by reviewing the transaction trace duration. It seems like some part of a transaction trace showing a duration value, but based on the review of the sub parts/components of the transaction trace, customer is unable to determine how the transaction trace duration value is being calculated. Due to this, customer finds the transaction trace to be showing up as Incomplete in APM UI.

Example: component A  duration 10 ms.

component B, C and D are subcomponent of A.

component B duration 3 ms

component C duration 1 ms

component D duration 0 ms

so, if we add component B, C and D durations, it comes as 4 ms. but note that parent component A  is showing duration of10 ms.

Since customer cannot find any component where the rest of the 6 ms spent, thus customer thinks that component A is missing components or as incomplete transaction trace.

 

 

Resolution

Depending on the setting of the transaction trace, the agent only do tracing on selected components. Agent may not do transaction trace on all components of the transaction. Thus not all the components will be listed in transaction trace for a transaction.

One example will be that a transaction have 500 components. Agent may select 200 components to do the transaction trace on and not select rest of the 300 components to do the transaction trace.

So it is quite normal that transaction trace time duration of subcomponents will not add to the parent component. There is also a possibility that the parent component itself taking up time.

Consider the following example:

Example: component A Total duration 15 ms. traced 6 ms (component A itself)

component B, C, D, E, F, G and H are subcomponents of A.

component B duration 3 ms traced

component C duration 1 ms traced

component D duration 0 ms traced

component E duration 2 ms not traced

component F duration 2 ms not traced

component G duration 1 ms not traced

component H duration 0 ms not traced

The information about the Java agent Instrumentation and .NET agent Instrumentation are explained here in guide which could also impact how much transaction trace will agent do for selected transaction.

Java agent Smart/deep Instrumentation:

Configure Smart Instrumentation

.NET agent Smart/deep Instrumentation:

Configure .NET/.NET Core Smart Instrumentation