Move ocsp_response_cache:delete after certificate_data:set

rootfs/etc/nginx/lua/configuration.lua

@@ -101,13 +101,19 @@ local function handle_servers()
   end
 
   for uid, cert in pairs(configuration.certificates) do
+    -- don't delete the cache here, certificate_data[uid] is not replaced yet.
+    -- there is small chance that nginx worker still get the old certificate,
+    -- then fetch and cache the old OCSP Response
     local old_cert = certificate_data:get(uid)
-    if old_cert ~= nil and old_cert ~= cert then
-        ocsp_response_cache:delete(uid)
-    end
+    local is_renew = (old_cert ~= nil and old_cert ~= cert)
 
     local success, set_err, forcible = certificate_data:set(uid, cert)
-    if not success then
+    if success then
+        -- delete ocsp cache after certificate_data:set succeed
+        if is_renew then
+            ocsp_response_cache:delete(uid)
+        end
+    else
       local err_msg = string.format("error setting certificate for %s: %s\n",
         uid, tostring(set_err))
       table.insert(err_buf, err_msg)