Hotrod api/traces displaying connecting refused

[prasad-shirodkar]

What happened?

I am trying to deploy hotrod 1.42.0 following the instructions at https://github.com/jaegertracing/jaeger/tree/v1.42.0/examples/hotrod.

Steps to reproduce

1. Run Jaeger backend
2. Run HotROD from source

git clone [email protected]:jaegertracing/jaeger.git jaeger
git checkout v.1.42.0
cd jaeger
go run ./examples/hotrod/main.go all

2023-03-30T18:22:07.301Z	INFO	[email protected]/command.go:946	Using expvar as metrics backend
2023-03-30T18:22:07.301Z	INFO	[email protected]/command.go:916	Starting all services
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:54	using jaeger trace exporter	{"service": "frontend"}
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:54	using jaeger trace exporter	{"service": "customer"}
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:54	using jaeger trace exporter	{"service": "driver"}
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:67	created OTEL->OT brige	{"service": "frontend", "service-name": "frontend"}
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:67	created OTEL->OT brige	{"service": "customer", "service-name": "customer"}
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:67	created OTEL->OT brige	{"service": "driver", "service-name": "driver"}
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:54	using jaeger trace exporter	{"service": "customer"}
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:54	using jaeger trace exporter	{"service": "driver"}
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:54	using jaeger trace exporter	{"service": "route"}
2023-03-30T18:22:07.302Z	INFO	tracing/init.go:67	created OTEL->OT brige	{"service": "driver", "service-name": "redis"}
2023-03-30T18:22:07.301Z	INFO	tracing/init.go:67	created OTEL->OT brige	{"service": "customer", "service-name": "mysql"}
2023-03-30T18:22:07.302Z	INFO	customer/server.go:55	Starting	{"service": "customer", "address": "http://0.0.0.0:8081"}
2023-03-30T18:22:07.302Z	INFO	frontend/server.go:74	Starting	{"service": "frontend", "address": "http://0.0.0.0:8080"}
2023-03-30T18:22:07.302Z	INFO	tracing/init.go:67	created OTEL->OT brige	{"service": "route", "service-name": "route"}
2023-03-30T18:22:07.302Z	INFO	route/server.go:57	Starting	{"service": "route", "address": "http://0.0.0.0:8083"}
2023/03/30 18:22:27 Post "http://localhost:14268/api/traces": dial tcp 127.0.0.1:14268: connect: connection refused

More connection refused message show up on clicking the examples in hotrod UI http://localhost:8080/

Expected behavior

No errors when using hotrod.

Relevant log output

No response

Screenshot

No response

Additional context

Similar issue has been logged as opensearch-project/data-prepper#2273

Jaeger backend version

No response

SDK

No response

Pipeline

No response

Stogage backend

No response

Operating system

Oracle Linux 7

Deployment model

No response

Deployment configs

No response

[albertteoh]

@pshirodkar-orcl, I was able to reproduce this.

I think the "Run Jaeger backend" step is missing a port mapping for 14268, so I think the command to bring up the jaeger backend should be:

docker run \
  --rm \
  --name jaeger \
  -p6831:6831/udp \
  -p16686:16686 \
  -p14268:14268 \
  jaegertracing/all-in-one:latest

I tested this command and seems to be working. I'll put together a PR to update the README doc.

[prasad-shirodkar]

Thank you - the missing port indeed solves the connection refused issue.

I noticed docker-compose only maps the port 8080. It does not map ports 8081 to 8083. Is it intentional?

[yurishkuro]

it should probably map 8083 because the blog post discusses reading expvar metrics from it curl http://127.0.0.1:8083/debug/vars

Port 8082 not need to be exposed, it's only used by Hotrod internally.