Non blocking io about mongo-php-library

[jmikola]

We currently have no plans to develop an async PHP driver. While I'd personally find the work very interesting, it's not something we can justify with the current staffing on the PHP team.

Since the underlying PHP extension depends on libmongoc, we do not have the flexibility to delegate internal IO to an event loop (or something like fibers in PHP 8.1+). An async PHP driver would likely need to be an entirely new project. At best, we may be able to avoid duplicating the library package if we could standardize on a lower level API between the async and libmongoc-based sync driver.

Some previous discussions beyond what you might be able to search up in GitHub issues on both projects:

• PHPC-160 is a very old ticket where we considered some API to dispatch asynchronous queries.
• PHPC-2072 is a recent question from a developer at Appwrite.io about supporting Swoole specifically. I didn't have much context for their use case, but in a separate Reddit thread I mentioned that many Swoole users had previously requested an API to disable client persistence, which we implemented in PHPC-1645. That functionality makes it possible to maintain a pool of MongoDB\Driver\Manager objects, each with their own libmongoc client and network connections, and share them among async workers. That is admittedly more a mitigation strategy than a solution, but it seemed sufficient for the needs of those Swoole users.