Skip to main content

500 errors on Google appengine / SarathOnline

Java on Google appengine has always been an matter of concern, especially with low traffic. People have expressed their anxiety with their application's performance. This site/blog runs on blogger. However the images and JavaScript are dynamically served from Google's Big table.

 

This site was earlier on Google appengine  - Py. A much performant environment. It has its owns issues. However, relatively it was a more worry free environment for small applications. But as an enterprise language, java was to be used for this site. The migration was finally done after three unsuccessful attempts. And eventually, with an extremely slim home grown framework – smvc, a simple mvc with dependency injection, the site is run on java.

 

Initially there were resource intensive cold startups. The smvc framework was an answer to it. But lately it appears that the appengine java is plaguing the site with a bunch of 500 errors, more frequently. This behavior started around Oct 27 and persists till today. It is being monitored.

 

image

 

p/s: if you are visiting this site and are having issues, please help by dropping a comment in the feedback form. Every possible improvement to get the site working without issues, is being worked on. Your feedback will help to improve it further.

Labels:

Popular posts from this blog

Powered By

As it goes, We ought to give thanks to people who power us. This page will be updated, like the version page , to show all the tools, and people this site is Powered By! Ubuntu GIMP Firebug Blogger Google [AppEngine, Ajax and other Apis] AddtoAny Project Fondue jQuery
Read More >>

Decorator for Memcache Get/Set in python

I have suggested some time back that you could modularize and stitch together fragments of js and css to spit out in one HTTP connection. That makes the page load faster. I also indicated that there ways to tune them by adding cache-control headers. On the server-side however, you could have a memcache layer on the stitching operation. This saves a lot of Resources (CPU) on your server. I will demonstrate this using a python script I use currently on my site to generate the combined js and css fragments. So My stitching method is like this @memize(region="jscss") def joinAndPut(files, ext): res = files.split("/") o = StringIO.StringIO() for f in res: writeFileTo(o, ext + "/" + f + "." + ext) #writes file out ret = o.getvalue() o.close() return ret; The method joinAndPut is * decorated * by memize. What this means is, all calls to joinAndPut are now wrapped (at runtime) with the logic in memize. All you wa...
Read More >>

Faster webpages with fewer CSS and JS

Its easy, have lesser images, css and js files. I will cover reducing number of images in another post. But If you are like me, You always write js and css in a modular fashion. Grouping functions and classes into smaller files (and Following the DRY rule, Strictly!). But what happens is, when you start writing a page to have these css and js files, you are putting them in muliple link rel=style-sheet or script tags. Your server is being hit by (same) number of HTTP Requests for each page call. At this point, its not the size of files but the number server roundtrips on a page that slows your page down. Yslow shows how many server roundtrips happen for css and js. If you have more than one css call and one js call, You are not using your server well. How do you achieve this? By concatinating them and spitting out the content as one stream. So Lets say I have util.js, blog.js and so.js. If I have a blog template that depends on these three, I would call them in three script tags. Wh...
Read More >>