cluster-ui: skip undefined regions on database pages

This patch skips `undefined` regions on the databases pages. The
`undefined` behaviour occurs when we try to match a database's node IDs
(i.e. the nodes with ranges that contain data belong to one of the
database's tables) from the database details endpoint, to nodes' region
information from the nodes endpoint.

The nodes endpoint is authoritative and is refreshed at a regular
interval. However, the database details endpoint is only fetched once on
page load, and it's node information comes from a cache, leading to the
potential of stale data (this information is authoritative in 23.1, but
not in 22.2).

Consequently when trying to match cached node IDs with recent node
regions information, we can come across behaviour where we try to get
region information for a node ID that is no longer valid (i.e. in the
case of a decommissioned node), resulting in `undefined` and surfacing
outdated node information.

This change ensures that when we encounter such occurrences, we avoid
displaying them in the console.

Release note (bug fix): Avoid displaying `undefined` regions on the
databases pages.

pkg/ui/workspaces/cluster-ui/src/databases/util.spec.ts

@@ -54,7 +54,7 @@ describe("Getting nodes by region string", () => {
       const nodes = [1, 2, 3];
       const regions = {};
       const result = getNodesByRegionString(nodes, regions, false);
-      assert.deepStrictEqual(result, `undefined(n1,n2,n3)`);
+      assert.deepStrictEqual(result, "");
     });
 
     it("when nodes are empty", () => {

pkg/ui/workspaces/cluster-ui/src/databases/util.ts

@@ -99,6 +99,10 @@ export function createNodesByRegionMap(
 ): Record<string, number[]> {
   const nodesByRegionMap: Record<string, number[]> = {};
   nodes.forEach((node: number) => {
+    // If the node's region doesn't exist skip it.
+    if (nodeRegions[node.toString()] === undefined) {
+      return;
+    }
     const region: string = nodeRegions[node.toString()];
     if (nodesByRegionMap[region] == null) {
       nodesByRegionMap[region] = [];