diff --git a/src/core/ranking.js b/src/core/ranking.js
index b01a855..ccc72d0 100644
--- a/src/core/ranking.js
+++ b/src/core/ranking.js
@@ -34,6 +34,7 @@ class Ranks {
   }
 
   async updateRanking() {
+    logger.info('Update pixel rankings');
     // recalculate ranking column
     await Model.query(
       // eslint-disable-next-line max-len
diff --git a/src/routes/chunks.js b/src/routes/chunks.js
index 2ba2cd2..12018a9 100644
--- a/src/routes/chunks.js
+++ b/src/routes/chunks.js
@@ -18,7 +18,7 @@ import logger from '../core/logger';
 const chunkEtags = new Map();
 RedisCanvas.setChunkChangeCallback((canvasId, cell) => {
   const [x, y] = cell;
-  const ret = chunkEtags.delete(`${canvasId}:${x}:${y}`);
+  chunkEtags.delete(`${canvasId}:${x}:${y}`);
 });
 
 /*
@@ -65,7 +65,7 @@ export default async (req: Request, res: Response, next) => {
     }
 
     res.set({
-      'Cache-Control': `public, s-maxage=${60 * 2}, max-age=${50 * 2}`, // seconds
+      'Cache-Control': `public, s-maxage=${60}, max-age=${40}`, // seconds
       'Content-Type': 'application/octet-stream',
     });