Wordpress Few questions about caching methods and secure servers with Centminmod

Zend Opcache is enabled by default you can verify using these 2 commands for php version and checking if Zend Opcache is loaded

Code (Text):

php -v
php --ri 'Zend Opcache'

Code (Text):

php -v
PHP 7.2.16 (cli) (built: Mar 25 2019 04:02:10) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.2.16, Copyright (c) 1999-2018, by Zend Technologies

this next command displays same output as a phpinfo php page would just for a specific php extension that is loaded. You can replace 'Zend opcache' with the name of php extension you want to check is loaded/installed or not

listing shows 224MB memory allocated to Zend Opcache via opcache.memory_consumption setting

Code (Text):

php --ri 'Zend opcache'

Zend OPcache

Opcode Caching => Disabled
Optimization => Disabled
SHM Cache => Enabled
File Cache => Disabled
Startup Failed => Opcode Caching is disabled for CLI

Directive => Local Value => Master Value
opcache.enable => On => On
opcache.use_cwd => On => On
opcache.validate_timestamps => On => On
opcache.validate_permission => Off => Off
opcache.validate_root => Off => Off
opcache.inherited_hack => On => On
opcache.dups_fix => Off => Off
opcache.revalidate_path => Off => Off
opcache.log_verbosity_level => 1 => 1
opcache.memory_consumption => 224 => 224
opcache.interned_strings_buffer => 8 => 8
opcache.max_accelerated_files => 65407 => 65407
opcache.max_wasted_percentage => 5 => 5
opcache.consistency_checks => 0 => 0
opcache.force_restart_timeout => 180 => 180
opcache.revalidate_freq => 180 => 180
opcache.file_update_protection => 2 => 2
opcache.preferred_memory_model => no value => no value
opcache.blacklist_filename => no value => no value
opcache.max_file_size => 0 => 0
opcache.protect_memory => 0 => 0
opcache.save_comments => 1 => 1
opcache.optimization_level => 0x7FFFBFFF => 0x7FFFBFFF
opcache.opt_debug_level => 0 => 0
opcache.enable_file_override => On => On
opcache.enable_cli => Off => Off
opcache.error_log => no value => no value
opcache.restrict_api => no value => no value
opcache.lockfile_path => /tmp => /tmp
opcache.file_cache => no value => no value
opcache.file_cache_only => 0 => 0
opcache.file_cache_consistency_checks => 1 => 1
opcache.huge_code_pages => Off => Off

for checking memcache and memcached PHP extensions

Code (Text):

php --ri memcache
php --ri memcached

Code (Text):

php --ri memcache

memcache

memcache support => enabled
Version => 4.0.2
Revision => $Revision$

Directive => Local Value => Master Value
memcache.allow_failover => 1 => 1
memcache.max_failover_attempts => 20 => 20
memcache.default_port => 11211 => 11211
memcache.chunk_size => 32768 => 32768
memcache.protocol => ascii => ascii
memcache.hash_strategy => consistent => consistent
memcache.hash_function => crc32 => crc32
memcache.redundancy => 1 => 1
memcache.session_redundancy => 2 => 2
memcache.compress_threshold => 20000 => 20000
memcache.lock_timeout => 15 => 15
memcache.session_prefix_host_key => 0 => 0
memcache.session_prefix_host_key_remove_www => 1 => 1
memcache.session_prefix_host_key_remove_subdomain => 0 => 0
memcache.session_prefix_static_key => no value => no value
memcache.session_save_path => no value => no value
memcache.prefix_host_key => 0 => 0
memcache.prefix_host_key_remove_www => 1 => 1
memcache.prefix_host_key_remove_subdomain => 0 => 0
memcache.prefix_static_key => no value => no value

Code (Text):

php --ri memcached

memcached

memcached support => enabled
Version => 3.1.3
libmemcached version => 1.0.16
SASL support => yes
Session support => yes
igbinary support => no
json support => yes
msgpack support => no

Directive => Local Value => Master Value
memcached.sess_locking => On => On
memcached.sess_lock_wait_min => 150 => 150
memcached.sess_lock_wait_max => 150 => 150
memcached.sess_lock_retries => 5 => 5
memcached.sess_lock_expire => 0 => 0
memcached.sess_binary_protocol => Off => Off
memcached.sess_consistent_hash => Off => Off
memcached.sess_consistent_hash_type => ketama => ketama
memcached.sess_number_of_replicas => 0 => 0
memcached.sess_randomize_replica_read => Off => Off
memcached.sess_remove_failed_servers => Off => Off
memcached.sess_server_failure_limit => 0 => 0
memcached.sess_connect_timeout => 3000 => 3000
memcached.sess_sasl_username => no value => no value
memcached.sess_sasl_password => no value => no value
memcached.sess_persistent => Off => Off
memcached.sess_prefix => memc.sess.key. => memc.sess.key.
memcached.sess_lock_wait => not set => not set
memcached.sess_lock_max_wait => not set => not set
memcached.compression_type => fastlz => fastlz
memcached.compression_factor => 1.3 => 1.3
memcached.compression_threshold => 2000 => 2000
memcached.serializer => php => php
memcached.store_retry_count => 2 => 2
memcached.default_consistent_hash => Off => Off
memcached.default_binary_protocol => Off => Off
memcached.default_connect_timeout => 0 => 0

checking if memcached server is running

Code (Text):

service memcached status

output

Code (Text):

service memcached status
Memcached server is running 

or filter grep the process list output for memcached - if blank output returns, that means memcached server not running

Code (Text):

ps aufxw | grep memcached | grep -v grep

output

Code (Text):

ps aufxw | grep memcached | grep -v grep
memcach+  3275  0.0  0.0 449776  1728 ?        Ssl  Mar25   1:22 /usr/local/bin/memcached -d -m 8 -l 127.0.0.1 -p 11211 -c 2048 -b 2048 -R 200 -t 4 -n 72 -f 1.25 -u memcached -o modern -P /var/run/memcached/memcached1.pid

more details on Centmin Mod's memcached server on official site at https://centminmod.com/memcached.html i.e. how to change memory size allocation to memcached server etc.

for adjusting Zend Opcache memory allocation add a custom php .ini settings file instead of editing php.ini directly as explained at https://centminmod.com/phpfpm.html#customphpini

use command php --ini to list all the custom .ini settings files first

Code (Text):

php --ini
Configuration File (php.ini) Path: /usr/local/lib
Loaded Configuration File:         /usr/local/lib/php.ini
Scan for additional .ini files in: /etc/centminmod/php.d
Additional .ini files parsed:      /etc/centminmod/php.d/a_customphp.ini,
/etc/centminmod/php.d/curlcainfo.ini,
/etc/centminmod/php.d/fileinfo.ini,
/etc/centminmod/php.d/geoip.ini,
/etc/centminmod/php.d/igbinary.ini,
/etc/centminmod/php.d/imagick.ini,
/etc/centminmod/php.d/mailparse.ini,
/etc/centminmod/php.d/mcrypt.ini,
/etc/centminmod/php.d/memcache.ini,
/etc/centminmod/php.d/memcached.ini,
/etc/centminmod/php.d/redis.ini,
/etc/centminmod/php.d/zendopcache.ini

Then as the order of .ini loaded is alphabetically, custom ini files need to be after the existing default

for Zend Opcache and memcached stats pages see in Centmin Mod Insight's forum sticky thread at https://community.centminmod.com/threads/php-opcode-and-memcached-statistics-pages.1513/ so to override settings in /etc/centminmod/php.d/zendopcache.ini, create a new ini file named /etc/centminmod/php.d/z-zendopcache.ini

here i piped in opcache.memory_consumption with 256MB memory allocated to Zend Opcache into /etc/centminmod/php.d/zz-zendopcache.ini settings file

Code (Text):

echo 'opcache.memory_consumption=256' > /etc/centminmod/php.d/zz-zendopcache.ini

which is listed after default zendopcache.ini

Code (Text):

php --ini
Configuration File (php.ini) Path: /usr/local/lib
Loaded Configuration File:         /usr/local/lib/php.ini
Scan for additional .ini files in: /etc/centminmod/php.d
Additional .ini files parsed:      /etc/centminmod/php.d/a_customphp.ini,
/etc/centminmod/php.d/curlcainfo.ini,
/etc/centminmod/php.d/fileinfo.ini,
/etc/centminmod/php.d/geoip.ini,
/etc/centminmod/php.d/igbinary.ini,
/etc/centminmod/php.d/imagick.ini,
/etc/centminmod/php.d/mailparse.ini,
/etc/centminmod/php.d/mcrypt.ini,
/etc/centminmod/php.d/memcache.ini,
/etc/centminmod/php.d/memcached.ini,
/etc/centminmod/php.d/redis.ini,
/etc/centminmod/php.d/zendopcache.ini,
/etc/centminmod/php.d/zz-zendopcache.ini

then restart php-fpm service

Code (Text):

service php-fpm restart

or via command shortcut

Code (Text):

fpmrestart

Zend Opcache is fastest so ignore APC Cache for opcode caching. For data caching it's between Redis and Memcached server caching if your web app supports it. You can have Zend Opcache working for PHP opcode cachinge + either Memcached or Redis caching for data caching.

In context of Wordpress via centmin.sh menu option 22, also there's additional security setups like autoprotect.sh and wp plugin whitelisting outlined at https://community.centminmod.com/threads/wordpress-403-permission-denied-errors.11215/

But yes CSF Firewall is installed by default and has features for brute force SSHD protection and login failure so fail2ban isn't required to protect SSHD port at least see https://centminmod.com/csf_firewall.html

change SSHD port can be done via centmin.sh menu option 16 which first asks you for default SSHD port number which is 22, then asks what is the desired new SSHD port number

Code (Text):

--------------------------------------------------------
     Centmin Mod Menu 123.09beta01 centminmod.com     
--------------------------------------------------------
1).  Centmin Install
2).  Add Nginx vhost domain
3).  NSD setup domain name DNS
4).  Nginx Upgrade / Downgrade
5).  PHP Upgrade / Downgrade
6).  XCache Re-install
7).  APC Cache Re-install
8).  XCache Install
9).  APC Cache Install
10). Memcached Server Re-install
11). MariaDB MySQL Upgrade & Management
12). Zend OpCache Install/Re-install
13). Install/Reinstall Redis PHP Extension
14). SELinux disable
15). Install/Reinstall ImagicK PHP Extension
16). Change SSHD Port Number
17). Multi-thread compression: zstd,pigz,pbzip2,lbzip2
18). Suhosin PHP Extension install
19). Install FFMPEG and FFMPEG PHP Extension
20). NSD Install/Re-Install
21). Update - Nginx + PHP-FPM + Siege
22). Add Wordpress Nginx vhost + Cache Plugin
23). Update Centmin Mod Code Base
24). Exit
--------------------------------------------------------
Enter option [ 1 - 24 ] 

as to updates etc as outlined in welcome reply post at https://community.centminmod.com/threads/im-new-to-centminmod.17050/#post-72192 see keep track of Centmin Mod installed software updates

and same welcome post reply's section for

maybe start with bad bot block/rate limiting, enabling CSF firewall blocklist/advance block lists and nginx general rate limiting if you need it though centmin.sh menu option 22 already by default does rate limiting for key wordpress urls see https://community.centminmod.com/th...l-vs-centmin-sh-menu-option-22-install.15435/

 

No for most folks using centmin.sh menu option 22 wordpress installer choosing cache enabler for full page caching + autoptimize plugins mentioned at https://community.centminmod.com/th...l-vs-centmin-sh-menu-option-22-install.15435/ are enough

 

no you don't need those wordpress plugins for memcached nor do you need memcached if you choose cache enable + autoptimize for performance.

you don't need memcached for data caching as cache enabler/redis nginx level cache/wp super cache options for full page cache replaces memcached data caching purpose

 

Zend Opcache operates on php and php command line. When you run via SSH the command you are testing Zend Opcache command line cache and that is disabled. But when you run non-command line i.e. your normal PHP script usage, Zend Opcache is enabled