Google appengine: Task queue performance

Question

I currently have an application running on appengine and I am executing a few jobs using the deferred library, some of these tasks run daily, while some of them are executed

Answer 1

By placing the if more statement at the end of the addCompaniesToIndex() function you're practically serializing the task execution: the next deferred task is not created until the current deferred task completed indexing its share of docs.

What you could do is move the if more statement right after the Company.query().fetch_page() call where you obtain (most of) the variables needed for the next deferred task execution.

This way the next deferred task would be created and enqueued (long) before the current one completes, so their processing can potentially be overlapping/staggered. You will need some other modifications as well, for example handling the n_entities variable which loses its current meaning in the updated scenario - but that's more or less cosmetic/informational, not essential to the actual doc indexing operation.

If the number of deferred tasks is very high there is a risk of queueing too many of them simultaneously, which could cause an "explosion" in the number of instances GAE would spawn to handle them. In such case is not desired you can "throttle" the rate at which the deferred tasks are spawned by delaying their execution a bit, see https://stackoverflow.com/a/38958475/4495081.