Update architecture.md

docs/sources/operator/architecture.md

@@ -138,3 +138,69 @@ Two labels are added by default to every metric:
 
 The shard number is not added as a label, as sharding is designed to be
 transparent on the receiver end.
+
+## Enable sharding and replication
+
+To enable sharding and replication, you must set the `shards` and `replicas` properties in the Grafana Agent configuration file. For example, the following configuration file would shard the data into three shards and replicate each shard to two other Grafana Agent instances:
+
+```
+shards: 3
+replicas: 2
+```
+
+You can also enable sharding and replication by setting the `shards` and `replicas` arguments when you start the Grafana Agent. 
+
+### Examples
+
+The following examples show you how to enable sharding and replication in a Kubernetes environment.
+
+* To shard the data into three shards and replicate each shard to two other Grafana Agent instances, you would use the following deployment manifest:
+
+  ```
+  apiVersion: apps/v1
+  kind: Deployment
+  metadata:
+    name: grafana-agent
+  spec:
+    replicas: 3
+    selector:
+      matchLabels:
+        app: grafana-agent
+    template:
+      metadata:
+        labels:
+          app: grafana-agent
+      spec:
+        containers:
+        - name: grafana-agent
+          image: grafana/agent:latest
+          args:
+          - "--shards=3"
+          - "--replicas=2"
+  ```
+
+* To shard the data into 10 shards and replicate each shard to three other Grafana Agent instances, you would use the following deployment manifest:
+
+  ```
+  apiVersion: apps/v1
+  kind: Deployment
+  metadata:
+    name: grafana-agent
+  spec:
+    replicas: 10
+    selector:
+      matchLabels:
+        app: grafana-agent
+    template:
+      metadata:
+        labels:
+          app: grafana-agent
+      spec:
+        containers:
+        - name: grafana-agent
+          image: grafana/agent:latest
+          args:
+          - "--shards=10"
+          - "--replicas=3"
+  ```
+