Inconsistent label cardinality

[panchiz]

Once the service is runnig after 2 or 4 requests to the /metrics endpoint I get:

Attaching to beanstalkdexporter_beanstalkd_1, beanstalkdexporter_beanstalkd_exporter_1
beanstalkd_exporter_1  | 2017/10/09 20:53:17 main.go:216: Listening on port :8080 .
beanstalkd_exporter_1  | 2017/10/09 20:53:17 main.go:217: Polling beanstalkd:11300 for stats every 30 seconds
beanstalkd_exporter_1  | panic: inconsistent label cardinality
beanstalkd_exporter_1  |
beanstalkd_exporter_1  | goroutine 16 [running]:
beanstalkd_exporter_1  | github.com/prometheus/client_golang/prometheus.(*MetricVec).With(0xc42017bc20, 0xc42017b890, 0xc42017bc20, 0x0)
beanstalkd_exporter_1  | 	/go/src/github.com/messagebird/beanstalkd_exporter/vendor/src/github.com/prometheus/client_golang/prometheus/vec.go:143 +0x76
beanstalkd_exporter_1  | github.com/prometheus/client_golang/prometheus.(*GaugeVec).With(0xc42017bc20, 0xc42017b890, 0x88f740, 0xc42017bc20)
beanstalkd_exporter_1  | 	/go/src/github.com/messagebird/beanstalkd_exporter/vendor/src/github.com/prometheus/client_golang/prometheus/gauge.go:119 +0x37
beanstalkd_exporter_1  | main.statTube(0xc4200ec140, 0x7ffcac2dff27, 0x10, 0xc42014f860, 0x7)
beanstalkd_exporter_1  | 	/go/src/github.com/messagebird/beanstalkd_exporter/src/beanstalkd_exporter/main.go:162 +0x7c5
beanstalkd_exporter_1  | main.poll(0x7ffcac2dff27, 0x10)
beanstalkd_exporter_1  | 	/go/src/github.com/messagebird/beanstalkd_exporter/src/beanstalkd_exporter/main.go:97 +0x44e
beanstalkd_exporter_1  | created by main.main.func1
beanstalkd_exporter_1  | 	/go/src/github.com/messagebird/beanstalkd_exporter/src/beanstalkd_exporter/main.go:222 +0xba
beanstalkdexporter_beanstalkd_exporter_1 exited with code 2

I'm running this using docker-compose (see #9)

[dbendelman]

@samwierema @marcelcorso I'm hitting this too. Launched beanstalkd_exporter next to a freshly launched and totally empty beanstalkd v1.10:

/ # time beanstalkd_exporter -poll 5 -log.level debug
2017/10/17 19:40:44 main.go:216: Listening on port :8080 .
2017/10/17 19:40:44 main.go:217: Polling localhost:11300 for stats every 5 seconds
2017/10/17 19:40:49 main.go:44: Debug: Calling localhost:11300 stats()
2017/10/17 19:40:49 main.go:85: Debug: Calling localhost:11300 ListTubes()
2017/10/17 19:40:49 main.go:104: Debug: Calling localhost:11300 Tube{name: default}.Stats()
panic: inconsistent label cardinality

goroutine 27 [running]:
github.com/prometheus/client_golang/prometheus.(*MetricVec).With(0xc4201cf170, 0xc4201cede0, 0xc4201cf170, 0x0)
	/go/src/github.com/messagebird/beanstalkd_exporter/vendor/src/github.com/prometheus/client_golang/prometheus/vec.go:143 +0x76
github.com/prometheus/client_golang/prometheus.(*GaugeVec).With(0xc4201cf170, 0xc4201cede0, 0x8c4a80, 0xc4201cf170)
	/go/src/github.com/messagebird/beanstalkd_exporter/vendor/src/github.com/prometheus/client_golang/prometheus/gauge.go:119 +0x37
main.statTube(0xc42014a640, 0x74b64c, 0xf, 0xc42013ad60, 0x7)
	/go/src/github.com/messagebird/beanstalkd_exporter/src/beanstalkd_exporter/main.go:162 +0x793
main.poll(0x74b64c, 0xf)
	/go/src/github.com/messagebird/beanstalkd_exporter/src/beanstalkd_exporter/main.go:97 +0x7bc
created by main.main.func1
	/go/src/github.com/messagebird/beanstalkd_exporter/src/beanstalkd_exporter/main.go:222 +0x96
Command exited with non-zero status 2
real	0m 5.09s
user	0m 0.00s
sys	0m 0.00s

As you can see from the above, no need to request the /metrics endpoint as the OP mentioned; the panic happens right after the first poll.

Based on this comment, it seems beanstalkd_exporter is giving the Prometheus client library the same metric multiple times but with a different number of labels, which is not allowed.

[marcelcorso]

@panchiz @dbendelman thanks for the report! I'll take a look.