redis cache for SMF (predis)

[danielrichter]

Link to the mod

redis mod for SMFsss

[FrizzleFried]

What benefit does redis bring to the table for the typical SMF forum?

[Arantor]

So caching in general is about reducing server load.

Different cache systems handle the load differently, file based vs memcache vs Redis vs other options.

That said if you're not on a VPS you almost certainly don't have access to a Redis instance to have it store the data for you...

[PrimalPrime]

Any chance of it being compatible with 2.13 or 2.14?

[Diego Andrés]

Did you have issues with it?
Should probably work fine, it's using hooks.

[PrimalPrime]

No, I'm kind of coward with this stuff. Even to try it on the test site will scare me to death, even with your seeming assurance. I'll probably work up the guts though. Thank you.

[PrimalPrime]

So, no go. After install,the option for redis doesn't appear.

[danielrichter]

So, no go. After install,the option for redis doesn't appear.

Please make sure the Hook is activated, you can find the activated hooks under the hooks section in ACP.

[PrimalPrime]

Hi, thank you for the assistance. There are two entries and both are listed as active but still the redis option doesn't appear in the caching options. Thank you

integrate_helpadmin   Function: SMF\Cache\APIs\Redis::integrate_helpadmin
Included file: $sourcedir/Cache/APIs/Redis.php   ./Sources/Cache/APIs/Redis.php      

integrate_update_settings_file   Function: SMF\Cache\APIs\Redis::integrate_update_settings_file
Included file: $sourcedir/Cache/APIs/Redis.php   ./Sources/Cache/APIs/Redis.php

[Massl]

Unfortunately I confirm... SMF 2.1.4 and there is no option to activate Redis
Thanks

EDIT: Sorry, I see now that the option is visible only if a Redis server is available.

There is a way to use a socket connection instead TCP?

[spiros]

I am trying to test this mod but I have no idea what one should enter in "Cache Directory". My Redis is using sockets as described here https://www.simplemachines.org/community/index.php?msg=4183007

[Chen Zhen]

As per the other thread, I'm not familiar with having it use a Unix socket (as Arantor pointed out) but I have successfully used this mod with a localhost : TCP port connection.

After some searching in the Redis docs & other resources, I have found that Redis allows connections for TCP ports AND Unix sockets simultaneously if you comment out the bind parameter in its settings.
This should allow SMF to use the TCP port & your WP to use the Unix socket if I understand correctly.

This mod may allow a connection via the socket but I'm not sure because I never configured & tested a socket connection for it. It's up to you for trying to configure Redis to do both connection types which might work for your scenario.

ref.
https://serverfault.com/questions/591193/single-redis-instance-with-local-redis-connections-via-unix-socket-and-remote-vi

[spiros]

Thank you so much for your reply. Interesting thread you point out to (although since then many things may have changed). Redis is managed by directadmin (hosting panel) so I do not think interfering with it is straightforward.

So, the standard text for "Cache Directory" would be "127.0.0.1:6379"?

[Chen Zhen]

As per the author's example, yes that is correct. It works for me but that is a TCP host:port.
I don't know if you have a hosted VPS or maybe just shared. Shared is limited & usually without cmd line access but I ask you...

As for DirectAdmin.. does it provide a terminal interface OR possibly a way to configue Redis? Are you using a VPS that would allow you to access it via a terminal (command line)?

If you have access to the command line then you can configure Redis files to have it behave the way you want.
You can always do a snapshot (temp. backup) before any changes in case something is misconfigured.

If you have shared hosting & your DirectAdmin panel doesn't have a way to configure Redis then this mod may not work by entering the socket path. At least not without modifying its files.

[Chen Zhen]

I did find a DirectAdmin plugin for Redis configuration that may help:
https://github.com/kbentlage/da-redis-management?tab=readme-ov-file

As I said before, just do a snapshot before making changes just in case you can't fix something.
It works for RHEL but hasn't been updated in 5 years though and the current DirectAdmin may have something for it now.
I only use CPanel & Webmin so you're more familiar with that panel than myself.

[Chen Zhen]

Ignore the link I previously posted as it's a bad idea to open Redis on all ports.
It will give you this warning right in the Redis config file within the comments.
If you edit the config file, leave it so it uses only the ipv4 & ipv6 local ports.
To have both work at the same time you just need to uncomment a few options in the Redis config file.
I can post those changes if anyone asks, but you previously stated that DirectAdmin already configured it for Unix Socket support so I assume you don't need that info.


You piqued my curiosity about running the cache on a unix socket so I've done some testing & came up with positive results for running both simultaneuosly, only Unix socket or only TCP port on SMF and Wordpress.

I was successful at running the Redis cache on the same domain for:

• WP cache on a Unix socket (using Redis Object Cache)
• WP cache on a TCP port (using Redis Object Cache)
• SMF 2.1 on a Unix Socket (using this mod)
• SMF 2.1 on a TCP port (using this mod)

v1.0 of this modification will only support a TCP connection out of the box.
You'll need to edit one of its files to make it use the Unix Socket if that's what you prefer or are using an environment that doesn't allow changes to that effect.


How to manually change version 1.0 of this modification to allow a Unix Socket connection...

Change the socket path ($redisConnection), unique prefix (different for each site) & db# (0 - 15).
The socket path I'm using here is the default value from the Redis config file.
If your DirectAdmin configured a different path just sub in the change to my instruction (after the unix: prefix).

Edit file: ./Sources/Cache/APIs/Redis.php

find:

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$this->client = new \Predis\Client($redisConnection, ['prefix' => 'smf:']);

replace with:

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$redisConnection = 'unix:/run/redis/redis-server.sock';
$this->client = new \Predis\Client($redisConnection, ['prefix' => 'translatum:', 'database' => 15]);

You can likely add a user name & password if your Unix Socket is secured.
Here is a chart containing data that can be added to the array in the edit:
https://github.com/predis/predis/wiki/Connection-Parameters


Tested & working for either type of connection.

[spiros]

Thank you so much! Maybe you could add such an option in a next version of your mod, given the rising popularity of Directadmin it could be useful!

Checking my Directadmin panel for the specific user (the specific user has many domains underneath) I am testing your mod with, I get

Path to redis socket file: /home/<user>/.redis/redis.sock
Please make sure you specify different database IDs for your applications, so that there would be no key conflicts.

So I guess I would need to use

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/home/<user>/.redis/redis.sock somehow in your mod?

This is the reply from Directadmin:

Our Redis that is included into DA does not listen on any Port, but it uses Socket:

  https://docs.directadmin.com/other-hosting-services/mariadb-mysql/redis.html#how-to-use-redis-with-wordpress

Redis service can be enabled for every DA user separately and on the server you will see separate Redis services running for every of those users. Yo ucan also manage it for every DA user using SYSTEMCTL command:

  systemctl status redis@[USER].service

You can connect to Redis CLI of your DA user using any of these commands:

  redis-cli -p 0 -s "/home/[USER]/.redis/redis.sock" -h 127.0.0.1
or
  redis-cli -s "/home/[USER]/.redis/redis.sock" -h 127.0.0.1
or
  redis-cli -s "/home/[USER]/.redis/redis.sock"

In case if you need to have Redis installed and listen on Port like for default Redis Server installation, then you need to make such installation and configuration manually without DA.

[Chen Zhen]

Yes, just change the path to what they set up for you which appears to be unique for each user/domain on the system.

Obviously change <user> to your name on the system..

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$redisConnection = 'unix:/home/<user>/.redis/redis.sock';
$this->client = new \Predis\Client($redisConnection, ['prefix' => 'translatum:', 'database' => 15]);


Command line:
From what you posted, you should be able to ping it for a test like this (change [USER] to your user name):

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redis-cli -s "/home/[USER]/.redis/redis.sock" ping


To see if it's caching data, you should be able to use this:

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redis-cli -s "/home/[USER]/.redis/redis.sock" keys "*"


To manually empty the cache use this:

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redis-cli -s "/home/[USER]/.redis/redis.sock" FLUSHALL


[spiros]

Thanks, so what do I do with "Cache Directory" on the settings? When I enable Redis this becomes active "127.0.0.1:6379".

I tested on cli, I can see output relevant to the Wordpress site (same user). Perhaps there is a way to limit the output based on prefix/dB?

This is my code as it stands now:

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{
global $cache_redis;

//on first install it would fail otherwise?!
if(is_null($cache_redis))
$cache_redis = '127.0.0.1:6379';

$redisConnection = 'tcp://' . $cache_redis;

$redisConnection = 'unix:/home/admin/.redis/redis.sock';
$this->client = new \Predis\Client($redisConnection, ['prefix' => 'non:', 'database' => 15]);
}
Aren't the two "$redisConnection" instances overlapping somehow?

Tried again I see:

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# redis-cli -s "/home/admin/.redis/redis.sock" keys "*"
 1) "non:permissions:-1:14"
 2) "non:board_parents-0"
 3) "non:log_online-update"
 4) "non:modSettings"
 5) "non:user_settings-1"
 6) "non:spider_search"
 7) "non:posting_smileys_default"
 8) "non:parsing_smileys_default"
 9) "non:theme_settings-1:1"
10) "non:response_prefix"
11) "non:verificationQuestions"
12) "non:menu_buttons--1-english"
13) "non:moderator_group_info"
14) "non:known_languages"
15) "non:permissions:-1"
16) "non:theme_settings-1:-1"
17) "non:menu_buttons-1_7-english"


[Chen Zhen]

The edit overrides anything you enter for the setting in the admin.
It's just temporary until another version of this mod is available that has more options.

You appear to be familiar with editing files but I'll remind you to make sure the file is saved with Unix line endings.

The license for this modification allows me to edit & distribute it as I see fit (leaving credit to the author of this mod & Predis).
Since the author hasn't been active for more than a year and I use the mod myself, I'm going to add the appropriate changes & put it in my download section.
Personally, I'd rather configure it to have password support so I'm going to add that as well.
For now just use the manual edit I gave you which should allow it to connect to your socket.

Use a different prefix for any other installation of WP, SMF, etc.