Default to two dedicated automation writer replicas

braintrust/ci/values-aws.yaml

@@ -46,6 +46,8 @@ api:
   affinity: {}
 
 brainstore:
+  automationwriter:
+    replicas: 0
   serviceAccount:
     name: "brainstore"
     awsRoleArn: "arn:aws:iam::123456789012:role/test-role"

braintrust/ci/values-azure.yaml

@@ -88,6 +88,7 @@ brainstore:
     volume:
       size: "100Gi"
   automationwriter:
+    replicas: 0
     volume:
       size: "200Gi"
   writer:

braintrust/ci/values-google.yaml

@@ -48,6 +48,8 @@ api:
   affinity: {}
 
 brainstore:
+  automationwriter:
+    replicas: 0
   serviceAccount:
     name: "brainstore"
     googleServiceAccount: "test@project.iam.gserviceaccount.com"

braintrust/ci/values-minimal.yaml

@@ -39,6 +39,8 @@ api:
   affinity: {}
 
 brainstore:
+  automationwriter:
+    replicas: 0
   serviceAccount:
     name: "brainstore"
     annotations: {}

braintrust/examples/google-autopilot-cel/values.yaml

@@ -172,10 +172,10 @@ brainstore:
 
   # Brainstore Automation Writer configuration
   # Optional, dedicated automations writer pool with an internal Service when enabled.
-  # Disabled by default (replicas: 0); scale up to opt in.
+  # Defaults to two replicas; set replicas: 0 to use regular writers.
   automationwriter:
     name: "brainstore-automationwriter"
-    replicas: 0
+    replicas: 2
     service:
       name: ""
       type: ClusterIP

braintrust/examples/google-autopilot/values.yaml

@@ -152,10 +152,10 @@ brainstore:
 
   # Brainstore Automation Writer configuration
   # Optional, dedicated automations writer pool with an internal Service when enabled.
-  # Disabled by default (replicas: 0); scale up to opt in.
+  # Defaults to two replicas; set replicas: 0 to use regular writers.
   automationwriter:
     name: "brainstore-automationwriter"
-    replicas: 0
+    replicas: 2
     service:
       name: ""
       type: ClusterIP

braintrust/tests/brainstore-automationwriter-defaults_test.yaml

@@ -0,0 +1,33 @@
+suite: test default automation writer isolation
+templates:
+  - brainstore-automationwriter-deployment.yaml
+  - brainstore-automationwriter-configmap.yaml
+  - brainstore-writer-configmap.yaml
+  - api-configmap.yaml
+tests:
+  - it: should run two dedicated automation writers by default
+    template: brainstore-automationwriter-deployment.yaml
+    asserts:
+      - equal:
+          path: spec.replicas
+          value: 2
+  - it: should run only automations on the dedicated pool by default
+    template: brainstore-automationwriter-configmap.yaml
+    asserts:
+      - equal:
+          path: data.BRAINSTORE_WRITER_LOOP_CONFIG
+          value: include:automations
+  - it: should exclude automations from regular writers by default
+    template: brainstore-writer-configmap.yaml
+    asserts:
+      - equal:
+          path: data.BRAINSTORE_WRITER_LOOP_CONFIG
+          value: exclude:automations
+  - it: should route automation queries to the dedicated pool by default
+    template: api-configmap.yaml
+    release:
+      namespace: braintrust
+    asserts:
+      - equal:
+          path: data.BRAINSTORE_AUTOMATION_WRITER_URL
+          value: http://brainstore-automationwriter.braintrust:4000

braintrust/tests/brainstore-automationwriter-routing_test.yaml

@@ -5,6 +5,8 @@ templates:
   - brainstore-startup-gate-rbac.yaml
 tests:
   - it: should preserve writer fallback when the pool is disabled
+    set:
+      brainstore.automationwriter.replicas: 0
     template: api-configmap.yaml
     asserts: &fallback
       - isNull:

braintrust/tests/brainstore-automationwriter-service_test.yaml

@@ -3,6 +3,8 @@ templates:
   - brainstore-automationwriter-service.yaml
 tests:
   - it: should omit the service when the pool is disabled
+    set:
+      brainstore.automationwriter.replicas: 0
     asserts: &absent
       - hasDocuments:
           count: 0

braintrust/tests/brainstore-startup-gate_test.yaml

@@ -62,6 +62,7 @@ tests:
     set:
       api.brainstoreStartupGate.enabled: true
       api.image.tag: v2.15.0
+      brainstore.automationwriter.replicas: 0
       brainstore.image.tag: v2.15.0
     asserts:
       - equal:
@@ -113,6 +114,7 @@ tests:
       api.brainstoreStartupGate.enabled: true
       api.brainstoreStartupGate.minimumVersion: v2.15.0
       api.brainstoreStartupGate.image: registry.example/python:3.13
+      brainstore.automationwriter.replicas: 0
       brainstore.image.tag: v2.15.1
     asserts:
       - equal:
@@ -265,6 +267,7 @@ tests:
     set:
       api.brainstoreStartupGate.enabled: true
       api.image.tag: v2.15.0
+      brainstore.automationwriter.replicas: 0
       brainstore.image.tag: v2.14.0
     asserts:
       - contains:

braintrust/values.yaml

@@ -606,9 +606,7 @@ brainstore:
   # When enabled (replicas > 0), the regular writer pool is automatically
   # configured to exclude automations, and the API receives this pool's query
   # endpoint. A compatible API release decides which queries use the endpoint.
-  # Disabled by default (replicas: 0), preserving existing deployments.
-  # This option is not recommended for most
-  # deployments; enable it only with guidance from Braintrust support.
+  # Defaults to two replicas. Set replicas: 0 to run automations on regular writers.
   automationwriter:
     name: "brainstore-automationwriter"
     labels: {}
@@ -618,7 +616,7 @@ brainstore:
       deployment: {}
       service: {}
       pod: {}
-    replicas: 0
+    replicas: 2
     minReadySeconds: 0
     progressDeadlineSeconds: 600
     strategy: