High RAM memory usage I'm currently testing a new MySQL server, but I'm new in this so I'm not sure about my parameters, because the RAM is always above 90% of usage.

The server will be setup for a CRM environment of 100 people.

Server specs:


MySQL version 5.7.28-0ubuntu0.18.04.4-log
16GB of RAM


Changes to mysqld.conf:

key_buffer_size     = 16M
max_allowed_packet  = 16M
thread_stack        = 192K
thread_cache_size   = 8

# My changes

innodb_buffer_pool_instances = 12
innodb_buffer_pool_size     = 12G
innodb_flush_method         = O_DIRECT
innodb_log_file_size        = 1G
innodb_page_cleaners        = 4
innodb_purge_threads        = 4
max_connections             = 151
open_files_limit            = 112274
table_open_cache            = 56137

log_output                  = FILE
default-storage-engine      = INNODB
character-set-server        = utf8
innodb_lock_wait_timeout    = 300
read_buffer_size            = 64K


# Recommendations [mysqltuner]

long_query_time         = 10
query_cache_size        = 0
query_cache_type        = 0
query_cache_limit       = 2M
join_buffer_size        = 512K
table_definition_cache  = 28468
log_bin                 = /var/log/mysql/mysql-bin.log


What mysqltuner says in InnoDB Metrics:

-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 0
[OK] InnoDB File per table is activated
[!!] InnoDB buffer pool / data size: 12.0G/22.2G
[!!] Ratio InnoDB log file size / InnoDB Buffer pool size (66.6666666666667 %): 4.0G * 2/12.0G should be equal to 25%
[!!] InnoDB buffer pool instances: 8
[--] Number of InnoDB Buffer Pool Chunk : 96 for 8 Buffer Pool Instance(s)
[OK] Innodb_buffer_pool_size aligned with Innodb_buffer_pool_chunk_size &amp; Innodb_buffer_pool_instances
[OK] InnoDB Read buffer efficiency: 99.99% (5004553901 hits/ 5004951598 total)
[OK] InnoDB Write log efficiency: 96.96% (8250637 hits/ 8509152 total)
[OK] InnoDB log waits: 0.00% (0 waits / 258515 writes)


Can you help me with this? Should I change anything else in the conf file? Should I upgrade the hardware?

EDIT:

GLOBAL STATUS: https://pastebin.com/1kbHTGkL

GLOBAL VARIABLES: https://pastebin.com/KUrBh9wr

FULL PROCESSLIST: https://pastebin.com/39GZdeWB

MySQLTuner report: https://pastebin.com/Khdgf7GP

EDIT 2:

I'm using SSD Storage

ulimit: https://pastebin.com/aUAtjnUN

iostat: https://pastebin.com/kjr9GaLB
In general, you want to utilize as much RAM as possible (leaving enough for the O/S, etc), since that means data is in-memory instead of being on disk.  

For a CRM system serving 100 people, you may find 16GB of RAM dedicated to the server is not enough.  My phone has 8GB of RAM, for instance, and it's just a phone.  

In-memory access times for data is a couple of orders of magnitude faster than accessing data on disk.