Application is down for several hours / days

[Daniel Florey]

Since a few days I am getting this error for almost every request. I reverted back to an old version that has been running fine for the last year, but this is what I get. Many users are asking for a refund, so please have a look at

floreysoftucm

Thanks

1. /_ah/channel/disconnected/ 500 3338ms 0kb module=default version=5

   0.1.0.10 - - [26/Nov/2013:01:08:56 -0800] "POST /_ah/channel/disconnected/ HTTP/1.1" 500 0 - - "floreysoftucm.appspot.com" ms=3338 cpu_ms=692 loading_request=1 pending_ms=1396 exit_code=121 app_engine_release=1.8.8 instance=00c61b117c38da138127333d5b3a7f9d2e19b17c

2. I2013-11-26 10:08:56.154

   This request caused a new process to be started for your application, and thus caused your application code to be loaded for the first time. This request may thus take longer and use more CPU than a typical request for your application.

3. W2013-11-26 10:08:56.154

   A problem was encountered with the process that handled this request, causing it to exit. This is likely to cause a new process to be used for the next request to your application. (Error code 121)

[Nico Verwer]

At the moment my app is having the same problem. Does anyone from Google care to respond?

[Daniel Florey]

After being completely down for 3 days the app seems to work again.

Googlers, did you find anything at your end?

[Julien Marchal]

Same problem since 4 hours but my backend instance works fine (strange !)

[Nico Verwer]

Earlier this year, this issue occurred because of a bug in appengine's memory estimation: http://stackoverflow.com/questions/17259928/randomly-121-error-on-google-app-engine.
There are several other mentions of this problem on stackoverflow (http://stackoverflow.com/search?q=121+appengine), on google code and google groups. In these posts I have not found any response from Google indicating what this error means or how it can be prevented. It happens both in Java and Python applications.

This blog posting indicates that the problem would be minimized by having a paid subscription. But my app runs under a paid subscription, and the 121 error still occurred. It caused a lot of stress for my customer, and for myself.

For other reasons I was already looking at alternatives to appengine, and the "121 issue" is even more reason to look for better cloud options. Since my app was written for appengine, Appscale might be viable. It runs on Amazon EC2, but I have no data on its reliability compared to Google appengine. Heroku is also interesting, but I would have to / want to rewrite my application. Even Microsoft Azure looks good, since it allows you to use node.js which is far better than the limited Java (or Python) implementation on appengine.