Should the snap offer the option to use APCu for local cache?

[pachulo]

After reading the Recommendations based on type of deployment on the Memory caching page of the nextcloud manual, I was wondering:

• Should the snap come with the PHP APCu extension so that it can be used for memcache.local instead of Redis?

I haven't found any real benchmarks or anything, just that it should be faster but consume more RAM, but as it is also the official recommendation, I just wanted to understand better why we use Redis instead.

[scubamuc]

@pachulo we have a large user base running "limited memory" devices (SBC's) so this should definitely be optional.

I haven't found any real benchmarks or anything, just that it should be faster but consume more RAM, but as it is also the official recommendation, I just wanted to understand better why we use Redis instead.

According to the recommendation, it could increase performance on "enhanced memory" machines. That would be desirable.

[kyrofa]

Yeah, it makes sense that we'd be using redis given our start on the Nextcloud box. However, while I agree with @scubamuc that continuing to support such users is important, I just checked the metrics this morning: literally 95% of our users are amd64. If this would enhance performance for those users, it might be worth investigating as long as we can figure out a way for it to not hurt the other 5%.

[pachulo]

OK, I found more information:

• In this nextcloud tunning guide from 2019 they talk about 2GB of RAM as the baseline for this:

  If you are running on a small cloud instance (say, less than 2GB RAM), or a resource-constrained device such as Raspberry Pi, Redis can be used for both local caching and file locking.

• And they also reference a (very old) benchmark from @oparoz :

  If you have the memory overhead to run both PHP APCu and Redis, you would enjoy better performance by running APCu as the local cache, and Redis as the file locking cache based on a user benchmark on GitHub.

• In this issue it's also discussed if there's a lot difference between using Redis and APCu: Reconsider memory cache warning / recommendation nextcloud/documentation#6729

Could we configure this based on available RAM?🤔

P.D.
Should we also look to move to NGINX based on this comment @kyrofa ? 😝

[kyrofa]

Should we also look to move to NGINX based on this comment @kyrofa ? 😝

No, only Apache is supported:

Please note that webservers other than Apache 2.x are not officially supported.

That's the reason we went this direction in the first place. NGINX is definitely lighter-weight. That's one of the reasons we've been so careful about not opening up Apache configs: we can switch to NGINX in the future with no one being the wiser if we feel it necessary/worthwhile.

[scubamuc]

checked the metrics this morning: literally 95% of our users are amd64

Only 5% running "limited memory" devices (SBC's), interesting...

we have a large user base running "limited memory" devices (SBC's)

I would be remiss if I hadn't mentioned these users?

[pachulo]

@pachulo we have a large user base running "limited memory" devices (SBC's) so this should definitely be optional.

I'm one of such users, so I can't agree more! 😄

Could we configure this based on available RAM?🤔

What do you think would make more sense @kyrofa :

1. to make it an autoconfig, depending on the amount of RAM?;
2. or to create a manual knob?

[alfi4000]

Um I am a bit confused I am totally unfamiliar with those stuff so is there a way to tune the server performance because I have 256gb ram 24 core but I had closely a crash on my device that was accessing the Nextcloud instance that is on the high performance server it were looking for me that the access device loads the hole stuff not the server where Nextcloud were running on especially when I uploaded 361 images at once my device from where I was uploading were stuck for 20sec! That was mind blowing for me ! :/
Is there something misconfigured on my instance or what is there going on any advice what I can do to improve the performance I have currently 400gb storage in Use and plan to add 1.5tb of data!

[alfi4000]

Any advice would be great! :)

[scubamuc]

@alfi4000, you have a powerful machine by the sounds of it...

this PR is a development discussion and is not the right PR for your issue... I guess. @pachulo is considering some default memory cache changes for the Snap.

as far as your performance issues are concerned, its not as simple as tuning here or there... you'd have to study your system logs and performance monitors carefully to pinpoint the bottleneck. That's admin stuff and not necessarily a Nextcloud snap issue. there may be some knobs to turn if we knew more about your system. but we're trying to make Nextcloud snap work for everyone "out of the box". So we're more concerned with stability than performance... especially since we don't know what device is being used.

basically advice for system tuning your machine would be going way beyond what we're trying to do here... also this PR would be wrong for questions about your device. So I'd suggest you make a new PR with your performance issue.

[alfi4000]

Ok