Blocking queries responding on the coordinate endpoint, even when there is no change in the response

[johncowen]

Overview of the Issue

I have a single node test setup and when request a blocking query on /v1/coordinate/nodes, it seems to respond roughly every 5-10 seconds even though the payload/response is exactly the same.

Consul info for both Client and Server

Client info

1.4.0, 1.3.0 and 1.2.* at least

Operating system and Environment details

All versions using the official docker image to run.

[pearkes]

@johncowen if you have time it might be great to post a quick repro -- curl commands to run and what the necessary node count etc. should be.

[johncowen]

Doh, sorry yeah of course.

I have a single consul server set up that I am using for development using the official docker image. But I'm assuming it will be the same just running against the binary.

I normally use consul agent -bootstrap -server -ui to start this up.

If you run:

curl -i http://localhost:8500/v1/coordinate/nodes?dc=dc-1 (via docker exec in my case)

Notice the X-Consul-Index number, and I get a payload like:

[{"Node":"consul","Segment":"","Coord":{"Vec":[0,0,0,0,0,0,0,0],"Error":1.5,"Adjustment":0,"Height":0.00001}}]

Wait ~30 seconds and re-run the curl command and you'll notice the X-Consul-Index has changed but the payload hasn't. I'm guessing something has changed and hence the blocking query responds, but whatever it is that has changed has no effect on the payload.

Thanks,

John