From 49551b07bfa09fcc801e6c69c136ee03ea89c191 Mon Sep 17 00:00:00 2001
From: Tobias Grieger <tobias.b.grieger@gmail.com>
Date: Mon, 2 May 2022 09:03:36 +0000
Subject: [PATCH] build: race-test only `pkg/server` on master/bors

Having a highly variable race build on the merge path is not useful,
especially since these tests may time out when too many of them are
selected. Instead, run only a canary package under `stressrace` while
merging and on master.

The PR build continues its old behavior of racing changed packages. The
nightly builds continue to run `stressrace` on the entire unit test
suite.

See [internal discussion].

[internal discussion]: https://cockroachlabs.slack.com/archives/C023S0V4YEB/p1651171505172649

Release note: None
---
 build/teamcity-support.sh                     |  3 +++
 build/teamcity-testrace.sh                    |  6 +++---
 build/teamcity/cockroach/ci/tests/testrace.sh | 13 +++++++++++--
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/build/teamcity-support.sh b/build/teamcity-support.sh
index 70b0afa0317a..6f62897fb1da 100755
--- a/build/teamcity-support.sh
+++ b/build/teamcity-support.sh
@@ -286,6 +286,9 @@ tc_release_branch() {
   [[ "$TC_BUILD_BRANCH" == master || "$TC_BUILD_BRANCH" == release-* || "$TC_BUILD_BRANCH" == provisional_* ]]
 }
 
+tc_bors_branch() {
+  [[ "$TC_BUILD_BRANCH" == staging ]]
+}
 
 if_tc() {
   if [[ "${TC_BUILD_ID-}" ]]; then
diff --git a/build/teamcity-testrace.sh b/build/teamcity-testrace.sh
index cae8220d526a..42f3095411c8 100755
--- a/build/teamcity-testrace.sh
+++ b/build/teamcity-testrace.sh
@@ -10,9 +10,9 @@ export TMPDIR=$PWD/artifacts/testrace
 mkdir -p "$TMPDIR"
 
 tc_start_block "Determine changed packages"
-if tc_release_branch; then
-  pkgspec=./pkg/...
-  echo "On release branch ($TC_BUILD_BRANCH), so running testrace on all packages ($pkgspec)"
+if tc_release_branch || tc_bors_branch; then
+  pkgspec=./pkg/server
+  echo "On release or bors branch ($TC_BUILD_BRANCH), so running testrace canary only ($pkgspec)"
 else
   pkgspec=$(changed_go_pkgs)
   if [[ $(echo "$pkgspec" | wc -w) -gt 10 ]]; then
diff --git a/build/teamcity/cockroach/ci/tests/testrace.sh b/build/teamcity/cockroach/ci/tests/testrace.sh
index 5e3ec7c98ee2..9c78bd8ea8a4 100755
--- a/build/teamcity/cockroach/ci/tests/testrace.sh
+++ b/build/teamcity/cockroach/ci/tests/testrace.sh
@@ -7,10 +7,19 @@ dir="$(dirname $(dirname $(dirname $(dirname $(dirname "${0}")))))"
 source "$dir/teamcity-support.sh"  # For $root, changed_go_pkgs
 source "$dir/teamcity-bazel-support.sh"  # For run_bazel
 
+# The full race suite takes >4h and is only suitable for nightlies. On master
+# and staging, run just the `server` package which (at the time of writing)
+# takes <30m to run and exercises most of the code in the system at least
+# rudimentarily. This (hopefully) causes obvious races to fail in bors,
+# before spraying failures over the nightly stress suite.
+canaryspec=./pkg/server
 tc_start_block "Determine changed packages"
 if tc_release_branch; then
-  pkgspec=./pkg/...
-  echo "On release branch ($TC_BUILD_BRANCH), so running testrace on all packages ($pkgspec)"
+  pkgspec="${canaryspec}"
+  echo "On release branch ($TC_BUILD_BRANCH), so running canary testrace ($pkgspec)"
+elif tc_bors_branch; then
+  pkgspec="${canaryspec}"
+  echo "On bors branch ($TC_BUILD_BRANCH), so running canary testrace ($pkgspec)"
 else
   pkgspec=$(changed_go_pkgs)
   if [[ $(echo "$pkgspec" | wc -w) -gt 10 ]]; then