From 37cf676063d07aef9d674f7e99910031b4d13175 Mon Sep 17 00:00:00 2001
From: Simon Tokumine <simon@japancentre.com>
Date: Tue, 6 Dec 2011 01:46:02 +0000
Subject: [PATCH] set last modified and cache control for varnish

---
 lib/cartodb/cartodb_windshaft.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/cartodb/cartodb_windshaft.js b/lib/cartodb/cartodb_windshaft.js
index 26e84eed..fb424400 100644
--- a/lib/cartodb/cartodb_windshaft.js
+++ b/lib/cartodb/cartodb_windshaft.js
@@ -9,6 +9,8 @@ var CartodbWindshaft = function(serverOptions) {
     // set the cache chanel info to invalidate the cache on the frontend server
     serverOptions.afterTileRender = function(req, res, tile, headers, callback) {
         res.header('X-Cache-Channel', req.params.dbname);
+        res.header('Last-Modified','Wed, 30 Aug 1978 00:00:00 GMT'); // special date in the past. 
+        res.header('Cache-Control','no-cache,must-revalidate, public');
         callback(null, tile, headers);
     };