diff --git a/ops/monitoring/lib/cluster.libsonnet b/ops/monitoring/lib/cluster.libsonnet
index 9b64f05..511d426 100644
--- a/ops/monitoring/lib/cluster.libsonnet
+++ b/ops/monitoring/lib/cluster.libsonnet
@@ -2,8 +2,10 @@
 
 {
     // Cluster sets up all cluster-specific monitoring resources in their own namespace.
+    //
     // Currently this consists of a prometheus server that scrapes k8s nodes for kubelet
-    // and cAdvisor metrics.
+    // and cAdvisor metrics, and possibly ships over metrics to the global tier via set
+    // upstreams.
     Cluster(name):: {
         local cluster = self,
         local cfg = cluster.cfg,
@@ -18,6 +20,17 @@
             storageClasses: {
                 prometheus: error "storageClasses.prometheus must be set",
             },
+
+            // Username used to authenticate to upstreams.
+            username: error "username must be set",
+
+            // Global tier upstreams that this cluster should ship metrics off to.
+            // List of
+            //  {
+            //     remote: URL of upstream
+            //     password: password used to authenticate, in conjunction with cfg.username.
+            //  
+            upstreams: [],
         },
 
         namespace: kube.Namespace(cfg.namespace),
@@ -105,6 +118,17 @@
                         ],
                     },
                 ],
+
+                remote_write: [
+                    {
+                        url: u.remote,
+                        basic_auth: {
+                            username: cluster.cfg.username,
+                            password: u.password,
+                        },
+                    }
+                    for u in cluster.cfg.upstreams
+                ],
             },
 
             configmap: kube.ConfigMap("prometheus-cluster") {
@@ -152,9 +176,7 @@
                                         "/bin/prometheus",
                                         "--config.file=/etc/prometheus/prometheus.yml",
                                         "--storage.tsdb.path=/prometheus",
-                                        # TODO(q3k): reduce this once we have a long-term storage
-                                        # solution.
-                                        "--storage.tsdb.retention.time=120d",
+                                        "--storage.tsdb.retention.size=10GB",
                                         "--web.console.libraries=/usr/share/prometheus/console_libraries",
                                         "--web.console.templates=/usr/share/prometheus/consoles",
                                         "--web.enable-lifecycle",
@@ -198,7 +220,7 @@
                     accessModes: ["ReadWriteOnce"],
                     resources: {
                         requests: {
-                            storage: "32Gi",
+                            storage: "16Gi",
                         },
                     },
                 },