server: Set a pprof label on new stream goroutines (#9082)

Fixes #9010

To make stack-traces and some profiles more useful, change sets
goroutine labels indicating which gRPC method is being handled.

Goroutine labels are inherited by child goroutines, so this provides
useful context in profiles and traces for work that's been farmed out to
child goroutines.

These currently show up in three places:
 - trace labels in pprof CPU profiles
- trace labels in runtime/pprof (and http/pprof) debug=0 goroutine
profiles (which are pprof format)
 - debug=1 aggregated text-format goroutine profiles

For Go 1.27, golang/go#76349 adds goroutine labels to tracebacks and by
extension debug=2 pprof text-based profiles for go 1.27+ modules.

The naming of the goroutine label currently matches the opentelemetry
RPC method tag, and has some similarities to the current proposal for
goroutine tag naming for tests in golang/go#75047. I.e. this uses
`grpc.method`.

This change avoids setting anything on the client side due to the lower
utility and goroutine lifetime issues.

Include a `GRPC_GO_SERVER_GOROUTINE_LABELS` environment variable to
allow users to easily opt-in of setting these goroutine labels. The
value the form `grpc.method=true` to enable a specific goroutine label,
and has special values of `all` and `none` which enable and disable all
registered goroutine labels respectively.

RELEASE NOTES:
* server: Set runtime/pprof goroutine labels for incoming method
streams. This may be enabled with the
`GRPC_GO_SERVER_GOROUTINE_LABELS=grpc.method=true` environment variable
for just the new goroutine label or
`GRPC_GO_SERVER_GOROUTINE_LABELS=all` to enable all goroutine labels
that might be added later. `none` is available for blanket disabling, as
well.
4 files changed
tree: 0d90d77ebd6b783abdf2e12a74ea9229c564c45a
  1. .gemini/
  2. .github/
  3. admin/
  4. attributes/
  5. authz/
  6. backoff/
  7. balancer/
  8. benchmark/
  9. binarylog/
  10. channelz/
  11. cmd/
  12. codes/
  13. connectivity/
  14. credentials/
  15. Documentation/
  16. encoding/
  17. examples/
  18. experimental/
  19. gcp/
  20. grpclog/
  21. health/
  22. internal/
  23. interop/
  24. keepalive/
  25. mem/
  26. metadata/
  27. orca/
  28. peer/
  29. profiling/
  30. reflection/
  31. resolver/
  32. scripts/
  33. security/
  34. serviceconfig/
  35. stats/
  36. status/
  37. tap/
  38. test/
  39. testdata/
  40. xds/
  41. AUTHORS
  42. backoff.go
  43. balancer_wrapper.go
  44. balancer_wrapper_test.go
  45. call.go
  46. clientconn.go
  47. clientconn_authority_test.go
  48. clientconn_parsed_target_test.go
  49. clientconn_test.go
  50. CODE-OF-CONDUCT.md
  51. codec.go
  52. codec_test.go
  53. CONTRIBUTING.md
  54. default_dial_option_server_option_test.go
  55. dial_test.go
  56. dialoptions.go
  57. doc.go
  58. go.mod
  59. go.sum
  60. GOVERNANCE.md
  61. grpc_test.go
  62. interceptor.go
  63. LICENSE
  64. MAINTAINERS.md
  65. Makefile
  66. NOTICE.txt
  67. picker_wrapper.go
  68. picker_wrapper_test.go
  69. preloader.go
  70. producer_ext_test.go
  71. README.md
  72. resolver_balancer_ext_test.go
  73. resolver_test.go
  74. resolver_wrapper.go
  75. rpc_util.go
  76. rpc_util_test.go
  77. SECURITY.md
  78. server.go
  79. server_ext_test.go
  80. server_test.go
  81. service_config.go
  82. service_config_test.go
  83. stream.go
  84. stream_interfaces.go
  85. stream_test.go
  86. trace.go
  87. trace_notrace.go
  88. trace_test.go
  89. trace_withtrace.go
  90. version.go
README.md

gRPC-Go

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The Go implementation of gRPC: A high performance, open source, general RPC framework that puts mobile and HTTP/2 first. For more information see the Go gRPC docs, or jump directly into the quick start.

Prerequisites

Installation

Simply add the following import to your code, and then go [build|run|test] will automatically fetch the necessary dependencies:

import "google.golang.org/grpc"

Note: If you are trying to access grpc-go from China, see the FAQ below.

Learn more

FAQ

I/O Timeout Errors

The golang.org domain may be blocked from some countries. go get usually produces an error like the following when this happens:

$ go get -u google.golang.org/grpc
package google.golang.org/grpc: unrecognized import path "google.golang.org/grpc" (https fetch: Get https://google.golang.org/grpc?go-get=1: dial tcp 216.239.37.1:443: i/o timeout)

To build Go code, there are several options:

  • Set up a VPN and access google.golang.org through that.

  • With Go module support: it is possible to use the replace feature of go mod to create aliases for golang.org packages. In your project's directory:

    go mod edit -replace=google.golang.org/grpc=github.com/grpc/grpc-go@latest
    go mod tidy
    go mod vendor
    go build -mod=vendor
    

    Again, this will need to be done for all transitive dependencies hosted on golang.org as well. For details, refer to golang/go issue #28652.

Compiling error, undefined: grpc.SupportPackageIsVersion

Please update to the latest version of gRPC-Go using go get google.golang.org/grpc.

How to turn on logging

The default logger is controlled by environment variables. Turn everything on like this:

$ export GRPC_GO_LOG_VERBOSITY_LEVEL=99
$ export GRPC_GO_LOG_SEVERITY_LEVEL=info

The RPC failed with error "code = Unavailable desc = transport is closing"

This error means the connection the RPC is using was closed, and there are many possible reasons, including:

  1. mis-configured transport credentials, connection failed on handshaking
  2. bytes disrupted, possibly by a proxy in between
  3. server shutdown
  4. Keepalive parameters caused connection shutdown, for example if you have configured your server to terminate connections regularly to trigger DNS lookups. If this is the case, you may want to increase your MaxConnectionAgeGrace, to allow longer RPC calls to finish.

It can be tricky to debug this because the error happens on the client side but the root cause of the connection being closed is on the server side. Turn on logging on both client and server, and see if there are any transport errors.