Disable failpoints by default

.github/workflows/build_and_test.yml

@@ -94,15 +94,17 @@ jobs:
       # CARGO_FEATURES is passed to "cargo metadata". It is separate from CARGO_FLAGS,
       #   because "cargo metadata" doesn't accept --release or --debug options
       #
+      # We run tests with addtional features, that are turned off by default (e.g. in release builds), see
+      # corresponding Cargo.toml files for their descriptions.
       - name: Set env variables
         run: |
           if [[ $BUILD_TYPE == "debug" ]]; then
             cov_prefix="scripts/coverage --profraw-prefix=$GITHUB_JOB --dir=/tmp/coverage run"
-            CARGO_FEATURES=""
+            CARGO_FEATURES="--features failpoints"
             CARGO_FLAGS="--locked --timings"
           elif [[ $BUILD_TYPE == "release" ]]; then
             cov_prefix=""
-            CARGO_FEATURES="--features profiling"
+            CARGO_FEATURES="--features failpoints,profiling"
             CARGO_FLAGS="--locked --timings --release $CARGO_FEATURES"
           fi
           echo "cov_prefix=${cov_prefix}" >> $GITHUB_ENV

pageserver/Cargo.toml

@@ -4,12 +4,12 @@ version = "0.1.0"
 edition = "2021"
 
 [features]
-# It is simpler infra-wise to have failpoints enabled by default
-# It shouldn't affect performance in any way because failpoints
-# are not placed in hot code paths
-default = ["failpoints"]
-profiling = ["pprof"]
+default = []
+
+# Feature that enables a special API, fail_point! macro (adds some runtime cost)
+# to run tests on outage conditions
 failpoints = ["fail/failpoints"]
+profiling = ["pprof"]
 
 [dependencies]
 async-stream = "0.3"

test_runner/README.md

@@ -6,6 +6,7 @@ Prerequisites:
 - Correctly configured Python, see [`/docs/sourcetree.md`](/docs/sourcetree.md#using-python)
 - Neon and Postgres binaries
     - See the root [README.md](/README.md) for build directions
+      If you want to test tests with failpoints, you would need to add `--features failpoints` to Rust code build commands.
     - Tests can be run from the git tree; or see the environment variables
       below to run from other directories.
 - The neon git repo, including the postgres submodule