Redis 6 compatibility

[The Old Man]

Hello,

I was asked to post this in the feedback section in response to my support ticket...

Please could you update the Redis configuration settings in Advanced Configuration, to include a USERNAME field for compatibility with the latest stable release of Redis (currently v6.2.5).

https://redis.io/download

IPS needs to be able to pass the username as part of the configuration, whereas previous it was just an optional password (due to changes that came about with the improved security and ACL feature).

https://redis.io/topics/acl
 

Many thanks.

[The Old Man]

IPS are looking at compatibility. It looks like a workaround by switching back to using a port and IP address instead of my usual Unix Socket.

IPS 4.5.4.2 still reports caching isn't working but it seems to be according to the increasing keys. Perhaps the red banner goes away after a while.

 

 

[Afrodude]

8 minutes ago, The Old Man said:

Perhaps the red banner goes away after a while.

Yes it will. I am using latest version of Redis 6.2.5, and it works jus fine using IP address and port. 

[The Old Man]

Thanks!

I  just tried it on a 4.6.3 site and switching to IP 127.0.0.1, my Port No. and no password works on that too.

[Afrodude]

@The Old Man have you noticed any slowness in your site using redis 6.2.5? 

[The Old Man]

Hi Afro,

Hard to say, I haven't done any specific benchmarking either with v6.2.5 or prior but I've found in my particular usage cases (site traffic, DB size, VPS specs etc) that it seems to be snappier and more responsive experience having it enabled for data store and reducing Mysql overhead enabled, but disabling Redis to cache pages, that definitely seemed to make things more sluggish. As Brandon once said, it make cost more in efficiency and resources to cache all the pages if you don't have that much traffic.

[The Old Man]

I have noticed that using the new Clear System Caches button in 4.6 doesn't clear stored data from Redis 6.2.5.

[Afrodude]

14 hours ago, The Old Man said:

I have noticed that using the new Clear System Caches button in 4.6 doesn't clear stored data from Redis 6.2.5.

Are using a prefix for your database ? If yes, I have found a bug related to this, and it's the one causing this with Redis no matter what version. IPS staff said that it will be fixed with the up coming release which I hope they do it before.  

[The Old Man]

Thanks. Do you mean table prefixes in the MySQL database, if so yes. 

[Afrodude]

6 minutes ago, The Old Man said:

Thanks. Do you mean table prefixes in the MySQL database, if so yes. 

Yes table prefix. This is what causing the issue, and I have already reported it as I mentioned above. Hopefully IPS fixing this issue soon.  

[The Old Man]

Thanks for highlighting this!

[Afrodude]

Just now, The Old Man said:

Thanks for highlighting this!

it wasn't easy find trust me I have made many things to find this issue. Hopefully @Stuart Silvester will release a patch to fix the issue because it causing many other issues. 

[Stuart Silvester]

I'm slightly confused because there issue you reported is related to pagination in the SQL toolbox. It isn't related in any way to Redis.

I would recommend submitting a ticket if you're having an issue.

[Daniel F]

6 hours ago, Afrodude said:

Yes table prefix. This is what causing the issue, and I have already reported it as I mentioned above. Hopefully IPS fixing this issue soon.  

Yes, the SQL Toolbox bug was fixed for an upcoming release  and as Stu said, this isn’t related to Redis at all. 

[Afrodude]

6 hours ago, Stuart Silvester said:

I'm slightly confused because there issue you reported is related to pagination in the SQL toolbox. It isn't related in any way to Redis.

I would recommend submitting a ticket if you're having an issue.

 

5 hours ago, Daniel F said:

Yes, the SQL Toolbox bug was fixed for an upcoming release  and as Stu said, this isn’t related to Redis at all. 

Well the Redis is a cache for the database, and if the database queries aren't running for other pages. How you are expecting Redis to work fine ? I am sure after you guys release the fix it will fix this issue. I might be mistaken, but we will wait this upcoming release. 

Edited August 1, 2021 by Afrodude

[Matt]

Redis is not a cache for the database in the literal sense.

We use Redis as a cache for data that is otherwise stored in the database to allow us to retrieve it quickly, but it doesn't assist queries directly like that.

[The Old Man]

Hi Matt,

Thanks. Do you consider it necessary that Clear System Caches in 4.6 should clear stored objects from Redis? I realise you do add expiry to them, but to flush the object cache at the same time as other system caches?

[Afrodude]

45 minutes ago, Matt said:

We use Redis as a cache for data that is otherwise stored in the database to allow us to retrieve it quickly, but it doesn't assist queries directly like that.

In this case then we are running into another issue.

 

 

[Matt]

14 minutes ago, The Old Man said:

Hi Matt,

Thanks. Do you consider it necessary that Clear System Caches in 4.6 should clear stored objects from Redis? I realise you do add expiry to them, but to flush the object cache at the same time as other system caches?

It should already clear out Redis. If it doesn't, that's a bug.

Although to be clear, it "clears" the Redis cache by changing the prefix used for all Redis keys. So you will still have a lot of data in Redis just after you cleared caches, but the Redis TTL will clear them out eventually because Invision Community will no longer ready/write to those specific keys.

So if you spot lots of data still in Redis after hitting "Clear Caches" then that's not a bug.

If you clear caches and Redis is still returning 'old' data to Invision Community directly, that is a bug.

[The Old Man]

Thanks Matt, as I understand it then, clearing the Redis cache in this manner would effectively mean the Redis cache size should visibly increase, since the existing data isn't purged, it could potentially double in size. Depending on the size of the cache and how full it is prior to clearing, it should be very noticeable. However it stays the same according to the Dashboard. 

Monitoring it live in real-time with Netdata, it should show a sudden influx of new keys, but I don't think I've seen that. I'll have to check again to be sure, but certainly the Redis data size in AdminCP stays the same, it should at least change which confused me.

[Afrodude]

@The Old Man have you opened a ticket with IPS staff about it yet? 

[The Old Man]

No, not yet. A lot going on, sorry. To be honest a lot of bugs IPS could verify for themselves, creating tickets for bugs is so time consuming for both parties so I try to limit to priority issues.

Edited August 5, 2021 by The Old Man

[Afrodude]

On 8/5/2021 at 11:08 AM, The Old Man said:

No, not yet. A lot going on, sorry. To be honest a lot of bugs IPS could verify for themselves, creating tickets for bugs is so time consuming for both parties so I try to limit to priority issues.

After recent patch I have noticed improvement using Redis because before that the site was like it's not been cached at all and very slow. 

[David..]

10 hours ago, Afrodude said:

After recent patch I have noticed improvement using Redis because before that the site was like it's not been cached at all and very slow. 

There was nothing mentioned in the patch about Redis though.

[Afrodude]

22 minutes ago, David.. said:

There was nothing mentioned in the patch about Redis though.

I know. Also, I don't know if you had issues with it before, but me and @The Old Man notice some issues. I disabled it because IPS staff are working on huge amount of bugs, yet they released this patch. I decided to enable it back after this patch, and I noticed that it's working fine again.

Edited August 14, 2021 by Afrodude