One of my GAE task-queue requests exceeded the soft memory limit (log below). My understanding of the soft memory limit is that it lets the request complete and then after it finishes, it shuts down the instance.
However, from the logs, it looks like when I hit the soft memory limit, execution stops. I see no more logging code after the memory limit message and I’ve inspected my state and it does not look like the request is completing. I’m not sure if it matters, but this request is executing in within a deferred library TaskQueue.
So, if a TaskQueue hits a soft private memory limit, does execution continue until the request completes or does it immediately halt? Is it possible that only logging code is no longer recorded?
Log:
2012-04-11 23:45:13.203
Exceeded soft private memory limit with 145.848 MB after servicing 3 requests total
W 2012-04-11 23:45:13.203
After handling this request, the process that handled this request was found to be using too much memory and was terminated. This is likely to cause a new process to be used for the next request to your application. If you see this message frequently, you may have a memory leak in your application.
What happens here is that handler at the end checks the memory status, if it is above the limit it will log an error and will shutdown the instance.
Since the task has completed successfully (you can see it terminates will status 200) it will not retry it.
When during handler execution the memory status is way above the memory limit, the handler will shutdown the instance and will return error 500, at this case the task will retry.