feat: use Redis read replicas

.cargo/nextest.toml

@@ -0,0 +1,8 @@
+[test-groups]
+redis = { max-threads = 6 }
+
+[[profile.default.overrides]]
+# number of tests running with 'redis' in the name should be up to 6 at any given time to prevent
+# overloading the redis instances
+test-group = "redis"
+filter = "test(redis)"

.changesets/feat_caroline_redis_replicas.md

@@ -0,0 +1,8 @@
+### Support Redis read replicas ([PR #8405](https://github.com/apollographql/router/pull/8405))
+
+Read-only queries will now be sent to replica nodes when using clustered Redis. Previously, all commands would be sent
+to the master nodes.
+
+This change applies to all Redis caches, including the query plan cache and the response cache.
+
+By [@carodewig](https://github.com/carodewig) in https://github.com/apollographql/router/pull/8405

.circleci/config.yml

@@ -253,9 +253,7 @@ commands:
                 command: |
                   curl https://mise.jdx.dev/install.sh | sh
                   mise activate bash >> "$BASH_ENV"
-                  # --raw disables the terminal timer/progress bars, so if mise gets stuck,
-                  # it will not continue to produce output preventing CCI from timing it out
-                  mise install --yes --raw
+                  mise install --yes --quiet
       - when:
           condition:
             or:
@@ -271,9 +269,7 @@ commands:
                 name: Install mise
                 command: |
                   scoop install mise@${MISE_VERSION#v}
-                  # --raw disables the terminal timer/progress bars, so if mise gets stuck,
-                  # it will not continue to produce output preventing CCI from timing it out
-                  mise install --yes --raw
+                  mise install --yes --quiet
   fetch_dependencies:
     steps:
       - run:

.config/mise/config.toml

@@ -17,3 +17,4 @@ helm = "3.19.2"
 helm-docs = "1.14.2"
 yq = "4.48.2"
 jq = "1.8.1"
+redis = "7.4.7"

.gitignore

@@ -42,4 +42,6 @@ dhat-heap.json
 # generated fuzz/ files
 fuzz/crash-*
 fuzz/slow-unit-*
-fuzz/timeout-*
+fuzz/timeout-*
+
+.config/mise/mise.local.toml

DEVELOPMENT.md

@@ -9,7 +9,7 @@ The **Apollo Router Core** is a configurable, high-performance **graph router**
 
 ## Development
 
-We use [`mise`](https://mise.jdx.dev/) to manage toolchain dependencies.
+We use [`mise`](https://mise.jdx.dev/) to manage toolchain and test dependencies.
 Example commands in this document assume that mise shims are available in the environment.
 If you do not use `mise activate`, you can use `mise x -- <COMMAND>` in place of the commands below, for example `mise x -- cargo build`.
 
@@ -28,15 +28,16 @@ docker compose up -d
 ```
 
 This starts:
-- **Redis** (port 6379-7005) - Required for entity caching, response caching, and Redis-related integration tests
-- **PostgreSQL** (port 5432) - Used by database integration tests
+- **Redis** (port 6379, 7000-7005) - Required for entity caching, response caching, and Redis-related integration tests
 - **Zipkin** (port 9411) - For distributed tracing tests
 - **Datadog Agent** (port 8126) - For Datadog telemetry integration tests
 
 Some tests that use the features above are configured with `required_to_start: true`. The router won't start if these services aren't available, causing test failures.
 
 **Note:** `-d` runs services in the background. Remove `-d` if you want to see logs or run in foreground.
 
+Several tests also require the `redis-cli` binary; this is installed by default if you use `mise`.
+
 #### Enterprise feature testing
 
 Some tests require Apollo GraphOS credentials to test enterprise features like licensing, reporting, and Apollo Studio integration.
@@ -53,7 +54,8 @@ export TEST_APOLLO_GRAPH_REF="your-graph-ref@variant"
 
 ### Testing
 
-Tests on this repository are run using [nextest](https://nexte.st/). nextest is installed automatically when you use `mise`.
+Tests on this repository are run using [nextest](https://nexte.st/). nextest is installed automatically when you use
+`mise`.
 
 #### Test environment setup
 

apollo-router/Cargo.toml

@@ -98,6 +98,7 @@ fred = { version = "10.1.0", features = [
     "i-cluster",
     "tcp-user-timeouts",
     "metrics",
+    "replicas",
     "serde-json"
 ] }
 futures = { version = "0.3.30", features = ["thread-pool"] }
@@ -310,6 +311,7 @@ fred = { version = "10.1.0", features = [
     "mocks",
     "i-cluster",
     "tcp-user-timeouts",
+    "replicas"
 ] }
 futures-test = "0.3.30"
 insta.workspace = true