Console: Report workers active with any interesting activity.

web-console/src/druid-models/stages/stages.spec.ts

@@ -422,6 +422,63 @@ describe('Stages', () => {
       // Worker 1 has output/shuffle data, so it's active even though input is zero
       expect(inactiveCount).toBe(1);
     });
+
+    it('counts worker as active if it has wall time but no channel activity yet', () => {
+      const customStages = new Stages(
+        [
+          {
+            stageNumber: 0,
+            definition: {
+              id: 'test-stage',
+              input: [
+                {
+                  type: 'external',
+                  inputSource: { type: 'http', uris: [] },
+                  inputFormat: { type: 'json' },
+                  signature: [],
+                },
+              ],
+              processor: { type: 'scan' },
+              signature: [],
+              maxWorkerCount: 2,
+            },
+            phase: 'READING_INPUT',
+            workerCount: 2,
+            partitionCount: 1,
+          },
+        ],
+        {
+          '0': {
+            '0': {
+              // Worker 0 has wall time but no channel activity yet
+              input0: {
+                type: 'channel',
+                rows: [0],
+              },
+              cpu: {
+                type: 'cpus',
+                main: {
+                  type: 'cpu',
+                  cpu: 500000,
+                  wall: 1000000,
+                },
+              },
+            },
+            '1': {
+              // Worker 1 is truly inactive - no wall time, no channel activity
+              input0: {
+                type: 'channel',
+                rows: [0],
+              },
+            },
+          },
+        },
+      );
+
+      const inactiveCount = customStages.getInactiveWorkerCount(customStages.stages[0]);
+      // Worker 0 has wall time, so only worker 1 is inactive
+      expect(inactiveCount).toBe(1);
+    });
   });
 
   describe('#getByPartitionCountersForStage', () => {

web-console/src/druid-models/stages/stages.ts

@@ -644,18 +644,30 @@ export class Stages {
 
     const channelCounters = this.getChannelCounterNamesForStage(stage);
 
-    // Calculate and return the number of workers that have zero count across all inputChannelCounters
+    // Calculate and return the number of workers that have zero interesting counters
     return sum(
-      Object.values(forStageCounters).map(stageCounters =>
-        Number(
+      Object.values(forStageCounters).map(stageCounters => {
+        // Check if the worker has any wall time recorded
+        const { cpu } = stageCounters;
+        if (cpu) {
+          const totalWall = sum(CPUS_COUNTER_FIELDS, field => cpu[field]?.wall || 0);
+          if (totalWall > 0) return 0;
+        }
+
+        // Check if the worker has any channel activity
+        return Number(
           channelCounters.every(channel => {
             const c = stageCounters[channel];
             if (!c) return true;
-            const totalRows = sum(c.rows || []);
-            return totalRows === 0;
+            return (
+              sum(c.rows || []) === 0 &&
+              sum(c.files || []) === 0 &&
+              sum(c.bytes || []) === 0 &&
+              sum(c.frames || []) === 0
+            );
           }),
-        ),
-      ),
+        );
+      }),
     );
   }
 

web-console/src/views/workbench-view/execution-stages-pane/execution-stages-pane.tsx

@@ -985,7 +985,7 @@ ${title} uncompressed size: ${formatBytesCompact(
                   <div>{formatInteger(value)}</div>
                   <div
                     className="detail-line"
-                    data-tooltip="Workers are counted as inactive until they report starting to read rows from their input."
+                    data-tooltip="Workers are counted as active once they report any activity."
                   >{`${formatInteger(inactiveWorkers)} inactive`}</div>
                 </div>
               );