Metrics updates (#26348)

Co-authored-by: gemini-cli[bot] <gemini-cli[bot]@users.noreply.github.com>

tools/gemini-cli-bot/metrics/index.ts

@@ -133,7 +133,7 @@ async function run() {
   writeFileSync(OUTPUT_FILE, results.join('\n'));
   console.log(`Saved metrics to ${OUTPUT_FILE}`);
 
-  // Update timeseries with rolling window (keep last 100 lines)
+  // Update timeseries with rolling window (keep last 5000 lines)
   const timestamp = new Date().toISOString();
   let timeseriesLines: string[] = [];
   if (existsSync(TIMESERIES_FILE)) {
@@ -146,10 +146,10 @@ async function run() {
   if (newRows.length > 0) {
     timeseriesLines.push(...newRows);
 
-    // Keep header + last 100 data rows
-    if (timeseriesLines.length > 101) {
+    // Keep header + last 5000 data rows
+    if (timeseriesLines.length > 5001) {
       const header = timeseriesLines[0];
-      timeseriesLines = [header, ...timeseriesLines.slice(-100)];
+      timeseriesLines = [header, ...timeseriesLines.slice(-5000)];
     }
 
     writeFileSync(TIMESERIES_FILE, timeseriesLines.join('\n') + '\n');

tools/gemini-cli-bot/metrics/scripts/backlog_age.ts

@@ -0,0 +1,59 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { GITHUB_OWNER, GITHUB_REPO } from '../types.js';
+import { execSync } from 'node:child_process';
+
+/**
+ * Calculates the average age of the oldest 100 open issues in days.
+ */
+function run() {
+  try {
+    const query = `
+    query($owner: String!, $repo: String!) {
+      repository(owner: $owner, name: $repo) {
+        issues(first: 100, states: OPEN, orderBy: {field: CREATED_AT, direction: ASC}) {
+          nodes {
+            createdAt
+          }
+        }
+      }
+    }
+    `;
+    const output = execSync(
+      `gh api graphql -F owner=${GITHUB_OWNER} -F repo=${GITHUB_REPO} -f query='${query}'`,
+      { encoding: 'utf-8', stdio: ['ignore', 'pipe', 'ignore'] },
+    ).trim();
+    const data = JSON.parse(output).data.repository;
+    const issues = data.issues.nodes;
+
+    if (issues.length === 0) {
+      process.stdout.write('backlog_age_days,0\n');
+      return;
+    }
+
+    const now = new Date().getTime();
+    const totalAgeDays = issues.reduce(
+      (acc: number, issue: { createdAt: string }) => {
+        const created = new Date(issue.createdAt).getTime();
+        return acc + (now - created) / (1000 * 60 * 60 * 24);
+      },
+      0,
+    );
+
+    const avgAgeDays = totalAgeDays / issues.length;
+    process.stdout.write(
+      `backlog_age_days,${Math.round(avgAgeDays * 100) / 100}\n`,
+    );
+  } catch (error) {
+    process.stderr.write(
+      error instanceof Error ? error.message : String(error),
+    );
+    process.exit(1);
+  }
+}
+
+run();