The Correlation ID plugin lets you correlate requests and responses using a unique ID transmitted as HTTP headers.
Correlation ID
Related Documentation
Made by
Kong Inc.
Supported Gateway Topologies
hybrid
db-less
traditional
Supported Konnect Deployments
hybrid
cloud-gateways
serverless
Compatible Protocols
grpc
grpcs
http
https
Related Resources
How it works
When you enable this plugin, it adds a new header to all of the requests processed by Kong Gateway. This header contains the name configured in the config.header_name variable, and a unique value is generated according to config.generator.
This header is always added in calls to your upstream services, and optionally echoed back to your clients according to the config.echo_downstream setting.
If a header with the same name is already present in the client request, the plugin honors it and does not tamper with it.
Generators
Correlation ID uses a generator (config.generator) to create different headers for requests processed by Kong Gateway.
uuid
Format:
xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
This format generates a hexadecimal UUID for each request.
uuid#counter
Format:
xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx#counter
This format generates a single UUID on a per-worker basis, and the requests append a counter to the UUID after a # character. The counter value starts at 0 for each worker, and gets incremented independently of the others.
This format provides better performance, but might be harder to store or process for analyzing (due to its format and low cardinality).
tracker
Format:
ip-port-pid-connection-connection_requests-timestamp
This correlation ID contains more practical implications for each request.
The following is a detailed description of the field:
|
Form parameter |
Description |
|---|---|
ip
|
Address of the server that accepts a request. |
port
|
Port of the server that accepts a request. |
pid
|
Process ID of the Nginx worker process. |
connection
|
Connection serial number. |
connection_requests
|
Current number of requests made through a connection. |
timestamp
|
A floating-point number for the elapsed time in seconds (including milliseconds as the decimal part) from the epoch for the current timestamp from the Nginx cached time. |
FAQs
Can I see my correlation IDs in my Kong Gateway logs?
Yes, if you edit your Nginx logging parameters you can see your correlation ID in the Nginx access log. For complete instructions, see Add Correlation IDs to Kong Gateway logs.