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chromium/external/github.com/grpc/grpc-go/e80524df97599752f770e6e1bce3b9cc0240d2c1
commit
e80524df97599752f770e6e1bce3b9cc0240d2c1
[log]
author
Pranjali-2501 <87357388+Pranjali-2501@users.noreply.github.com>
Wed Apr 15 20:21:57 2026
committer
GitHub <noreply@github.com>
Wed Apr 15 20:21:57 2026
tree
40399b170ee4027d4ae9d46eab8679addbd0ae1b
parent
6b3284041849906b65f3fd77011e5294e92655f1 [diff]
transport: set default header list size to 8KB and guard behind an env variable. (#9019)

Part of: https://github.com/grpc/grpc-go/issues/2308

Follow up of PR: https://github.com/grpc/grpc-go/pull/8845 

This PR implements a change to restrict the default maximum header list
size to 8KB. The change is guarded by a new environment variable
GRPC_GO_EXPERIMENTAL_DEFAULT_HEADER_LIST_SIZE, which is disabled by
default.

When the environment variable is disabled (default), the legacy default
of 16MB is used. When enabled, RPCs with a total size of headers
exceeding 8KB will fail unless explicitly configured otherwise by the
user.

## Changes

`internal/envconfig`
* Added DefaultHeaderListSize: A boolean flag controlled by the
GRPC_GO_EXPERIMENTAL_DEFAULT_HEADER_LIST_SIZE environment variable.

`internal/transport/http2_client.go` and
`internal/transport/http2_server.go`
* Use upcomingDefaultHeaderListSize (8KB) as the default value if
`DefaultHeaderListSize` is enabled.
* If env variable is disabled and header size is greater than
upcomingDefaultHeaderListSize, log a warning.

RELEASE NOTES:
* transport: change default header list size from 16MB to 8KB and guard
it behind `GRPC_GO_EXPERIMENTAL_DEFAULT_HEADER_LIST_SIZE` env var which
is disabled by default. The env var will be enabled by default in
v1.82.0 release.
4 files changed
tree: 40399b170ee4027d4ae9d46eab8679addbd0ae1b
  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

GoDoc GoReportCard codecov

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.