Spring GraphQL WebSocket keepalive PING not emitted for all idle concurrent sessions

[KelltonTechSolutions]

I am seeing inconsistent server-side WebSocket keepalive behavior with Spring GraphQL over WebFlux.

The application is configured with:

spring.graphql.websocket.path=/graphql
spring.graphql.websocket.keep-alive=15s
spring.netty.idle-timeout=0
In a scenario with two concurrent GraphQL WebSocket clients using the graphql-transport-ws protocol, one connection receives periodic server PING frames while another concurrently active connection does not.

I reviewed the keepalive support added in commit 80ef960 and expected each idle WebSocket connection to receive server PING frames independently.

This is on my local environment, when i deploy the solution to POD. SLB, closes the connection after XX duration for session B.

Question

Is this behavior expected because Spring GraphQL suppresses keepalive when a session has had recent encoded output, or should each concurrently idle WebSocket session receive its own PING frames independently?

[KelltonTechSolutions]

Please prioritize!

[rstoyanchev]

No it is not expected. Each session should have its own pings.

We prioritize issues that come with isolated samples that help us to spend less time reproducing the issue.