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High consumption of memory in Zimbra + Centos 7

Posted: Mon May 20, 2019 7:33 am
by elderf
Hello greetings ...

The installation of zimbra triggers a high consumption of memory in the server even on non-working days such as weekends.

The server has Centos 7 and Zimbra 8.8.12 Opensource and 24GB of ram memory installed. It is running 200 email accounts approximately and even without being in use the consumption reaches 16GB of memory ... the option we got was to restart with zmcontrol restart and the consumption went down ...

Can someone please help us and tell us the reason why this is happening? and how can we correct it so as not to be restarting services every time?

Thank you

Re: High consumption of memory in Zimbra + Centos 7

Posted: Mon May 20, 2019 9:40 am
by phoenix
How do you know ZCS is the culprit? What diagnostic steps have you taken to find out what's happening on your server? Is this a new install of ZCS?

Re: High consumption of memory in Zimbra + Centos 7

Posted: Mon May 20, 2019 9:57 am
by elderf
Thanks for answering...

Execute htop ... there it is seen that the user zimbra is the one that consumes more resources ...

20 minutes ago we restarted the zimbra service at this moment there is only 1 user with session started and it has already increased 2 GB consumption

Watch

http://prntscr.com/nqv8rc

You can also see memory consumption by free -m

http://prntscr.com/nqv6hs

as the time elapses after executing zmcontrol restart the consumption of memory increases by the user zimbra whether or not users with session started via web

It's a new installation with 200 users migrated last week from gmail apps with imapsync

Re: High consumption of memory in Zimbra + Centos 7

Posted: Tue May 21, 2019 9:30 am
by elderf
Hello..
I still do not understand this behavior of zimbra ...

The memory assigned to the server is "frozen" in some way and is not released when the users close the web sessions.

Yesterday during working hours 114 sessions were open and the consumption of memory rose to 14GB of 24 installed .. I understand that as a normal behavior ..

Outside of working hours there were only 19 open sessions and yet the memory consumption was 15GB of 24 installed, and on weekends no one connected has reached 16GB of RAM consumed ...

Can someone give me an idea of what is happening and how can I correct it?

Thank you

Re: High consumption of memory in Zimbra + Centos 7

Posted: Tue May 21, 2019 11:06 am
by L. Mark Stone
Java and MariaDB are allocated pools of memory based on how much RAM was present during the installation. Other components like Lucene will also use RAM irrespective of the number of users logged in.

What you report seems neither unusual nor worrisome.

Perhaps I missed something; why are you concerned?

Mark

Re: High consumption of memory in Zimbra + Centos 7

Posted: Tue May 21, 2019 11:06 am
by elderf
I'm worried that I'll be neglected and that peak will reach the 24 GB installed and the server will collapse ... or will it run out of memory

Re: High consumption of memory in Zimbra + Centos 7

Posted: Tue May 21, 2019 11:13 am
by L. Mark Stone
elderf wrote:I'm worried that I'll be neglected and that peak will reach the 24 GB installed and the server will collapse ... or will it run out of memory


Always good to have a swap file for exactly that reason, but I think you’ll find the Zimbra installer sets things to use all the RAM you have, so a little swapping periodically isn’t necessarily bad.

24GB for 200 mailboxes is a fine amount of RAM for good performance, even with heavy imap users and users logged in from multiple devices/clients simultaneously.

Hope that helps,
Mark

Re: High consumption of memory in Zimbra + Centos 7

Posted: Tue May 21, 2019 11:16 am
by elderf
This is my current memory consumption ...

http://prntscr.com/nrd2am

The maximum peak I've had is 16GB of consumption which does not drop even when users close session or disconnect ....

That is normal?' that is to say with 110 users with a session started, I understand that the consumption will be triggered ... but that same memory consumption does not decrease when the session is closed ??

Re: High consumption of memory in Zimbra + Centos 7

Posted: Tue May 21, 2019 11:25 am
by elderf
In the image you see swap ... how do I use it for zimbra? alerts are set

Thank you

Re: High consumption of memory in Zimbra + Centos 7

Posted: Tue May 21, 2019 11:26 am
by L. Mark Stone
I’m not seeing anything there that gives me pause.

The two biggest consumers of RAM are MariaDB and the Java mailbox app. Neither “release” memory as users log off.

Make sure you have a swap file and some memory alerting configured and you should rest easy.

Mark