Troubleshooting

When something goes wrong.

Logging

In most cases, you will find the answer to your problem in the logs.Watermill offers a significant amount of logs on different severity levels.

If you are using StdLoggerAdapter, just change debug, and trace options to true:

  2. logger := watermill.NewStdLogger(true, true)

I have a deadlock

When running locally, you can send a SIGQUIT to the running process:

  • CTRL + \ on Linux
  • kill -s SIGQUIT [pid] on other UNIX systemsThis will kill the process and print all goroutines along with lines on which they have stopped.
  1. SIGQUIT: quit
  2. PC=0x45e7c3 m=0 sigcode=128
  4. goroutine 1 [runnable]:
  5. github.com/ThreeDotsLabs/watermill/pubsub/gochannel.(*GoChannel).sendMessage(0xc000024100, 0x7c5250, 0xd, 0xc000872d70, 0x0, 0x0)
  6.     /home/example/go/src/github.com/ThreeDotsLabs/watermill/pubsub/gochannel/pubsub.go:83 +0x36a
  7. github.com/ThreeDotsLabs/watermill/pubsub/gochannel.(*GoChannel).Publish(0xc000024100, 0x7c5250, 0xd, 0xc000098530, 0x1, 0x1, 0x0, 0x0)
  8.     /home/example/go/src/github.com/ThreeDotsLabs/watermill/pubsub/gochannel/pubsub.go:53 +0x6d
  9. main.publishMessages(0x7fdf7a317000, 0xc000024100)
  10.     /home/example/go/src/github.com/ThreeDotsLabs/watermill/docs/src-link/_examples/pubsubs/go-channel/main.go:43 +0x1ec
  11. main.main()
  12.     /home/example/go/src/github.com/ThreeDotsLabs/watermill/docs/src-link/_examples/pubsubs/go-channel/main.go:36 +0x20a
  14. // ...

When running in production and you don’t want to kill the entire process, a better idea is to use pprof.

You can visit http://localhost:6060/debug/pprof/goroutine?debug=1on your local machine to see all goroutines status.

  1. goroutine profile: total 5
  2. 1 @ 0x41024c 0x6a8311 0x6a9bcb 0x6a948d 0x7028bc 0x70260a 0x42f187 0x45c971
  3. #    0x6a8310    github.com/ThreeDotsLabs/watermill.LogFields.Add+0xd0                            /home/example/go/src/github.com/ThreeDotsLabs/watermill/log.go:15
  4. #    0x6a9bca    github.com/ThreeDotsLabs/watermill/pubsub/gochannel.(*GoChannel).sendMessage+0x6fa    /home/example/go/src/github.com/ThreeDotsLabs/watermill/pubsub/gochannel/pubsub.go:75
  5. #    0x6a948c    github.com/ThreeDotsLabs/watermill/pubsub/gochannel.(*GoChannel).Publish+0x6c        /home/example/go/src/github.com/ThreeDotsLabs/watermill/pubsub/gochannel/pubsub.go:53
  6. #    0x7028bb    main.publishMessages+0x1eb                                        /home/example/go/src/github.com/ThreeDotsLabs/watermill/docs/src-link/_examples/pubsubs/go-channel/main.go:43
  7. #    0x702609    main.main+0x209                                                /home/example/go/src/github.com/ThreeDotsLabs/watermill/docs/src-link/_examples/pubsubs/go-channel/main.go:36
  8. #    0x42f186    runtime.main+0x206                                            /usr/lib/go/src/runtime/proc.go:201
  10. // ...