got traceId "N/A" in the class extends ZuulFilter under 6.4.0

[jadezhong]

Please answer these questions before submitting your issue.

• Why do you submit this issue?
• Question or discussion

---

Question

• What do you want to know?
  got traceId "N/A" in the class extends ZuulFilter under 6.4.0, how to solve this problem?

---

Bug

• Which version of SkyWalking, OS and JRE?
  Skywalking 6.4.0, CentOS 7.x, JDK 1.8, 8C CPU, 16G RAM

• Which company or project?

• What happen?
  upgraded from 6.3.0 to 6.4.0, our gateway using Zuul, get traceId in the class extends ZuulFilter, it is ok under 6.3.0, but get traceId "N/A" under 6.4.0, debug step into found out the segment is null, how to solve this problem?

---

Requirement or improvement

• Please describe about your requirements or improvement suggestions.

[wu-sheng]

Segment is null, meaning, there is no tracing context, so span created. Do you check wich plugin should generate span? Please check our supported list, and make sure you have the plugins you need.

[jadezhong]

@wu-sheng question is error only if i use the agent of 6.4.0, it is always ok before that version.

[wu-sheng]

N/A is not the error, it means no one created the span before you call#getTraceId, nothing more.

[jadezhong]

@wu-sheng i know, but still i don’t know why upgrade from 6.2.0/6.3.0 to 6.4.0 will cause that? Isn’t it should keep functionality consistently? or in another word “Backwards compatible”?

[jadezhong]

@wu-sheng currently we fully upgraded to 6.4.0. to make TraceContext.traceId() right, we revert the agent back to 6.3.0, but still this is very awkward.

[jadezhong]

@wu-sheng found out this problem caused by apm-sniffer/apm-sdk-plugin/undertow-plugins/undertow-2.x-plugin under 6.4.0, it is ok when i use the one under 6.3.0.

[jadezhong]

get undertow-2.x-plugin from 6.3.0, package it and upload it onto server's .../agent/plugins/, test and no conflict.

[jadezhong]

ps., we use 1.4.* undertow.

[wu-sheng]

We can't verify in every case. If you think there is an issue, I think it is better to fix and send pull request. There are too many possibilities for plugin.