Memcached - no add instance Button

Memcached - no add instance Button

by Heather P -
Number of replies: 9

Hello

I'm on a Moodle 4.0 and Windows server 2019 with SQL

I'm trying to configure Memcache as my site is just slow doing anything.

I'm on admin / plugins / caching / configuration page. 
Next to Memcached there is no 'Add Instance' button.

I've been to the Moodle php info page and memcache is definitely there - says it is enabled. I've restarted IIS just to be sure.

What am I missing? How do I get that button to appear please.

Thank you 

Heather

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In reply to Heather P

Re: Memcached - no add instance Button

by Justin Hunt -
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Heather

I think you maybe dont want memcached.
Memcached is really for enterprise or multi server configurations.
If your site is not such a large one, its going to be a more complex solution than you need. And probably wont make much of a difference.

It can be hard to diagnose slow server problems.
What are the server specs? (CPU, memory, PHP version, Moodle version, free disk space etc )
Is the database server on the same machine?
??
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In reply to Justin Hunt

Re: Memcached - no add instance Button

by Howard Miller -
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This started because it looks like the file subsystem is slow. I suggested this as maybe the simplest solution.
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In reply to Justin Hunt

Re: Memcached - no add instance Button

by Heather P -
Hi
Currently we are a multi server site. One in the dmz and one internal. Moodle usage has gone right down since the pandemic so we were just speculating on losing the internal and just having the one web front end in the DMZ. (Although currently I'm just on a test system -internal only). Our ISP has become much better at defending us from DDoS which was one of the original reasons for splitting internal and external, so less of a need there now.
Windows server 2019 Virtual machine.
Moodle version 4 is the one I'm testing and it seems slower than the version 3.10 that we are running as live, although that has become a bit less responsive than our students like.
The database is on SQL server - not the same device. (3.10 is our live site with a view to upgrading soon).
The data folder is also not on the same device (although for the test rig it is).
PHP is 7.4
16 GB of RAM
Intel Xeon (R) CPU E5
Plenty of spare disk space.

If Memcached isn't going to do a lot then I think I might abandon the wrestling match as I think it is winning.

Thank you
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In reply to Heather P

Re: Memcached - no add instance Button

by Ken Task -
Picture of Particularly helpful Moodlers

Pardon this dumb question ...

understood that you are testing a 3.x to 4.x upgrade on an internal only setup ... so to do that, you are using a "Windows server 2019 Virtual machine"?    That's the guest OS but the VM server ... what is that?   Azure? Other?

Granted you've already said your entity has flipped-flopped and at one point in time your entity did have Linux (you didn't say which flavor) but couldn't support it - or should I say you 'felt' you couldn't support it?

Since you are in a testing mode, is it time to revisit a Linux VM - same specs as other?  Ubuntu LTS with LetsEncrypt and throw in the mix there CloudFlare - would assume that CloudFlare would be OK with your cyber insurance and equal to if not surpasses such services offered by JANET.

Ok, am probably not being very helpful ... more like upsetting the apple cart ... but ...

'SoS', Ken



Average of ratings: Useful (1)
In reply to Heather P

Re: Memcached - no add instance Button

by Justin Hunt -
Picture of Particularly helpful Moodlers Picture of Plugin developers
Sorry Heather, I had not know about the other thread until alerted. And had not know you were running more than one server.
Memcached might indeed be meaningful since the data folder is on a different device.

I checked my own notes, and the option to add an instance did not appear until the php memcached extension had been installed.
Installing that on ubuntu (php8) looked like this:

sudo apt-get install -y php8.0-memcached
sudo service apache2 restart

Once the PHP extension is set up it looks like this:
 
I cant say what the right thing for you to do is. But if you are just running a single Moodle server then its a lot simpler to store the data dir on a local drive (not a mapped networked drive). If you have a cluster of Moodle servers, you probably do need a caching server

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In reply to Heather P

Re: Memcached - no add instance Button

by Howard Miller -
Picture of Core developers Picture of Documentation writers Picture of Particularly helpful Moodlers Picture of Peer reviewers Picture of Plugin developers
memcache and memcached are completely different cache servers. You seem to be mentioning them both interchangably. They are definitely not.
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In reply to Howard Miller

Re: Memcached - no add instance Button

by Heather P -
Hi
I had no idea they were different and now I don't know what I've got going on.
This isn't helped by the http://pecl.php.net/package/memcache/4.0.5.2/windows as it mentions Memcache in the title and then further down says memcached extension.
That page is definitely where I got the php dll file from so that's what php is looking for. I've got php_memcache.dll. php info in Moodle says that memcache is running.
It looks like I installed Memcached on the server.
So if they aren't the same that probably explains the lack of button to press etc.

So I need a new dll. I think.
Thank you
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