Fix: event multi-execution

[Meldiron]

What does this PR do?

With this PR, if multiple functions execute with an event, they will all attempt to be executed instead of stopping when one execution fails. Use case explained well in the issue linked below.

I believe this is the correct behavior, as we don't have a function chaining feature in Appwrite.

Test Plan

• Manual QA

Related PRs and Issues

#3666

Have you read the Contributing Guidelines on issues?

Yes 😇

[eldadfux]

Why is this even causing the issue? shouldn't it be handled by our default error handler for workers?

[Meldiron]

@eldadfux The problem is that if an event comes into a function worker, and there are multiple functions that need to be executed for this event... Well, if the first execution fails, then no other will run. It could fail, for instance, when a function does not have deployment yet.

Sooo yes, the worker will handle the error and work on the next task in the queue. But in one task, it was supposed to execute 5 functions, but it only executed one and stopped due to an exception.

Function worker receives info that "this event occurred", and it then (as a part of one task) executes multiple functions. So one execution request failing means all the others are skipped.

Does it make sense?

[eldadfux]

Do we have 5 tasks in a single task because or our new event model? Have we considered pushing 5 tasks for 5 events instead of running 5 events in one task? What is the max amount of events we can have in the same task?

[stnguyen90]

@eldadfux, when an event comes in for the function worker to process, it loops through each function to check execute the event. If one function throws an exception, the for loop fails to finish iterating over all functions.

appwrite/app/workers/functions.php

Lines 70 to 88 in e658457

	foreach ($functions as $function) {
	if (!array_intersect($events, $function->getAttribute('events', []))) {
	continue;
	}
	Console::success('Iterating function: ' . $function->getAttribute('name'));
	$this->execute(
	project: $project,
	function: $function,
	dbForProject: $database,
	trigger: 'event',
	// Pass first, most verbose event pattern
	event: $events[0],
	eventData: $payload,
	user: $user
	);
	Console::success('Triggered function: ' . $events[0]);

And it's possible for the $this->execute() to throw an exception:

appwrite/app/workers/functions.php

Line 208 in e658457

throw new Exception('Deployment not found. Create deployment before trying to execute a function', 404);

[Meldiron]

@eldadfux Regarding maximum executions under one event, that is limited as far as I am concerned. For instance, document create: databases.*.collections.*.documents.*

There are 3 dynamic parts that can either be specific ID or wildcard. That makes a combination of 8 options if I am not mistaken. For 4 dynamic parts it would be 16, for 5 it would be 32.

[christyjacob4]

Let's change the target branch to master