RAM Usage Builds Up Over Time

[HappyWorld]

Hello.

In my dedicated server, i notice that RAM usage builds up over time.

For example 2 days ago after running for several months, RAM usage was constantly around 250 GB almost every time (i monitored using script every minute).

But yesterday when i decided to upgrade my RAM (i added 128 GB more memory), and my server was rebooted, until now RAM usage is only around 40-45 GB.

So i thought there must be something runs in my server which seems to use RAM constantly.
Some processes which run are :

• PHP opcache
• redis
• elasticsearch
• mysql query cache (query cache size is 5 GB).

At this point i think that my latest RAM upgrade was useless , and i could just rebooted my server to gain free RAM again.

What do you think may cause RAM usage 250 GB over time?

Thank you.

 

[eva2000]

Might want to read http://www.linuxatemyram.com/

 

[HappyWorld]

Might want to read http://www.linuxatemyram.com/

Thank you, that link teaches me something new about linux

 

[eva2000]

yeah #1 misunderstood item about linux memory usage for noobs

 

[rainmotorsports]

yeah #1 misunderstood item about linux memory usage for noobs

It's Linux's fault for not displaying "usable" ram. Sure you can ALSO show cached. But no point in making that the primary number if its dumpable at a moments notice.

I was never a fan of this. I ran into it prior to SSD's and the thought is this extra gb of crap was loaded from a piece of crap hard drive. Tell me that doesn't have any performance penalty when none of those processes are getting launched today

 

[eva2000]

CentOS 7 is at least a bit better now

free -m
              total        used        free      shared  buff/cache   available
Mem:           2048         193        1441         269         413        1479
Swap:          2048          54        1993