After upgrade to v0.9.1 only errors

[skorpy2009]

After upgrading from v0.7.1 to v0.9.1 I constantly get the following error:

time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
time="2019-05-27T15:13:16Z" level=error msg="error encoding and sending metric family: write tcp 127.0.0.1:9326->127.0.0.1:53138: write: broken pipe\n" source="log.go:172"
2019/05/27 15:13:16 http: superfluous response.WriteHeader call from github.com/prometheus/client_golang/prometheus/promhttp.httpError (http.go:305)

[timber-schroeder]

I had the same issue on a configuration scraping ~20 targets with 15 second timeouts.

The cause of this issue seems to be due to parallel scrapes no longer running at the same time. Running multiple queries now takes twice as long as before and prometheus is timing out.

I unfortunately don't know Go very well nor this project so I can't provide a root cause, but commenting out the configuration lock (configMu.Lock() in lines 266-267 in main.go) solved the problem for me since I never change the configuration while the exporter is running.

[czerwonk]

Thanks for the hint. I will have a look at it and optimize the code in respect of locking.

[skorpy2009]

Running latest fixes my errors.
Please release 0.9.2 (Docker)