Оптимизация для Wordpress: SSD VDS 4GB RAM 4 Core для сетки сайтов

Нужна помощь сообщества, в следующем вопросе - можно ли что-то "подшаманить", чтобы всё "летало" и MySQL не умирал, или надо переезжать на конфигурацию с лучшими характеристиками.

Пациент: VDS

• 4 Core
• 4 GB RAM
• 40 GB SSD

Сайты проксируются через CloudFlare

my.cnf:

datadir=/var/lib/mysql

socket=/var/lib/mysql/mysql.sock

user=mysql

symbolic-links=0

max_connections=256

max_user_connections=128

wait_timeout=1024

query-cache-type=1

query-cache-size=128M

query-cache-limit=8M

interactive_timeout=1024

max_heap_table_size = 128M

tmp_table_size = 128M

thread_cache_size = 32

long_query_time=1

#log-queries-not-using-indexes

#log-slow-queries=/var/log/mysql/log-slow-queries.log



#innodb_use_native_aio = 0

innodb_file_per_table=1



[mysqld_safe]

log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid

nginx.conf:

# Server globals

user                    nginx;

worker_processes        auto;

error_log               /var/log/nginx/error.log;

pid                     /var/run/nginx.pid;





# Worker config

events {

        worker_connections  4096;

        use                 epoll;

}





http {

    # Main settings

    sendfile                        on;

    tcp_nopush                      on;

    tcp_nodelay                     on;

    client_header_timeout           1m;

    client_body_timeout             10;

    client_header_buffer_size       2k;

    client_body_buffer_size         256k;

    client_max_body_size            10m;

    large_client_header_buffers     4   8k;

    send_timeout                    2;

    keepalive_timeout               30;

	keepalive_requests              100;

    reset_timedout_connection       on;

    server_tokens                   off;

    server_name_in_redirect         off;

    server_names_hash_max_size      8192;

    server_names_hash_bucket_size   512;





    # Log format

    log_format  main    '$remote_addr - $remote_user [$time_local] $request '

                        '"$status" $body_bytes_sent "$http_referer" '

                        '"$http_user_agent" "$http_x_forwarded_for"';

    log_format  bytes   '$body_bytes_sent';

    #access_log          /var/log/nginx/access.log  main;

    access_log off;

    error_log /var/log/nginx/error.log crit;





    # Mime settings

    include             /etc/nginx/mime.types;

    default_type        application/octet-stream;





    # Compression

    gzip                on;

    gzip_comp_level     9;

    gzip_min_length     1024;

    gzip_buffers        8 64k;

	gzip_disable "msie6";

    gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript application/javascript;

    gzip_proxied        any;





    # Proxy settings

    proxy_redirect      off;

    proxy_set_header    Host            $host;

    proxy_set_header    X-Real-IP       $remote_addr;

    proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;

    proxy_pass_header   Set-Cookie;

    proxy_connect_timeout   90;

    proxy_send_timeout  90;

    proxy_read_timeout  90;

    proxy_buffers       32 4k;





    # SSL PCI Compliance

    ssl_ciphers                 RC4:HIGH:!aNULL:!MD5:!kEDH;

    ssl_session_cache           shared:SSL:10m;

    ssl_prefer_server_ciphers   on;





    # Error pages

    error_page          403          /error/403.html;

    error_page          404          /error/404.html;

    error_page          502 503 504  /error/50x.html;





    # Cache

    proxy_cache_path /var/cache/nginx levels=2 keys_zone=cache:10m inactive=60m max_size=512m;

    proxy_temp_path  /var/cache/nginx/temp;

    proxy_cache_key "$host$request_uri $cookie_user";

    proxy_ignore_headers Expires Cache-Control;

    proxy_cache_use_stale error timeout invalid_header http_502;

    proxy_cache_valid any 3d;



    map $http_cookie $no_cache {

        default 0;

        ~SESS 1;

        ~wordpress_logged_in 1;

    }





    # Wildcard include

    include             /etc/nginx/conf.d/*.conf;

}

mysqltuner.pl

 >>  MySQLTuner 1.4.0 - Major Hayden <major@mhtx.net>

 >>  Bug reports, feature requests, and downloads at http://mysqltuner.com/

 >>  Run with '--help' for additional options and output filtering

[OK] Currently running supported MySQL version 5.5.37

[OK] Operating on 64-bit architecture



-------- Storage Engine Statistics -------------------------------------------

[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MRG_MYISAM

[--] Data in MyISAM tables: 13M (Tables: 87)

[--] Data in InnoDB tables: 80M (Tables: 258)

[--] Data in PERFORMANCE_SCHEMA tables: 0B (Tables: 17)

[--] Data in MEMORY tables: 0B (Tables: 3)

[!!] Total fragmented tables: 22



-------- Security Recommendations  -------------------------------------------

[OK] All database users have passwords assigned



-------- Performance Metrics -------------------------------------------------

[--] Up for: 5m 22s (1K q [3.376 qps], 28 conn, TX: 9M, RX: 201K)

[--] Reads / Writes: 96% / 4%

[--] Total buffers: 536.0M global + 2.8M per thread (256 max threads)

[OK] Maximum possible memory usage: 1.2G (66% of installed RAM)

[OK] Slow queries: 0% (1/1K)

[OK] Highest usage of available connections: 0% (2/256)

[OK] Key buffer size / total MyISAM indexes: 8.0M/3.1M

[OK] Key buffer hit rate: 98.8% (68K cached / 795 reads)

[OK] Query cache efficiency: 57.1% (560 cached / 981 selects)

[OK] Query cache prunes per day: 0

[OK] Sorts requiring temporary tables: 0% (2 temp sorts / 209 sorts)

[!!] Temporary tables created on disk: 44% (44 on disk / 98 total)

[OK] Thread cache hit rate: 92% (2 created / 28 connections)

[OK] Table cache hit rate: 84% (37 open / 44 opened)

[OK] Open file limit used: 3% (40/1K)

[OK] Table locks acquired immediately: 100% (608 immediate / 608 locks)

[!!] Connections aborted: 7%

[OK] InnoDB buffer pool / data size: 128.0M/80.6M

[OK] InnoDB log waits: 0

-------- Recommendations -----------------------------------------------------

General recommendations:

    Run OPTIMIZE TABLE to defragment tables for better performance

    MySQL started within last 24 hours - recommendations may be inaccurate

    Enable the slow query log to troubleshoot bad queries

    When making adjustments, make tmp_table_size/max_heap_table_size equal

    Reduce your SELECT DISTINCT queries without LIMIT clauses

    Your applications are not closing MySQL connections properly

Variables to adjust:

    tmp_table_size (> 128M)

    max_heap_table_size (> 128M)

httpd.conf

ServerTokens OS

ServerRoot "/etc/httpd"

PidFile run/httpd.pid

Timeout 30

KeepAlive Off

MaxKeepAliveRequests 100

KeepAliveTimeout 10



<IfModule prefork.c>

    StartServers       8

    MinSpareServers    5

    MaxSpareServers   10

    ServerLimit      256

    MaxClients       200

    MaxRequestsPerChild  4000

</IfModule>



<IfModule worker.c>

    StartServers         2

    MaxClients         200

    MinSpareThreads     25

    MaxSpareThreads     75 

    ThreadsPerChild     25

    MaxRequestsPerChild  4000

</IfModule>



<IfModule itk.c>

    StartServers       8

    MinSpareServers    5

    MaxSpareServers   20

    ServerLimit      256

    MaxClients       256

    MaxRequestsPerChild  4000

</IfModule>

Теперь про сайты:

80% - Wordpress сайтов по 100-5000 страниц

Основные плагины:

• W3 Total Cache
• WordPress SEO
• Cyr-And-Lat
• Contact Form 7
• Hide My WP - скрывает админку от брутфорса.

20% планируется использовать под разные скрипты, но сейчас они не активны.

Суммарная посещаемость у данных 20+ сайтов 1500-2500 уников и до 5000 хитов в сутки (планируем увеличить посещаемость в раз 15)

Собственно, сам VDS, точнее MySQL умирает периодически, может раз в неделю, может каждый день умирать. Оживает только ребутом по ssh. Статика отдается очень быстро, это единственное что хорошего в этом VDS.

Также MySQL можно заставить умереть краулером Screaming Frog SEO Spider. Хотя, конкуренты в моей тематике тоже используют wordpress, но прогнав их через Screaming Frog SEO Spider они живут.

P.S.

Frog'ом парсится с такой скоростью:

Мой статический сайт: ~235 URl/s

Мой сайт на Wordpress: ~15 URl/s (умирает после 2-3 страниц - "connection timeout")

Конкурент на Wordpress: ~35 URl/s

Конкурент на ModX: ~125 URl/s

P.P.S.

Результаты tools.pingdom.com:

Мой статический сайт: Perf. grade 97/100 | Requests 40 | Load time 832ms | Page size 460.1kB

Мой сайт на Wordpress: Perf. grade: 69/100 | Requests 95 | Load time 1.31s | Page size 1.3MB

Конкурент на Wordpress: Perf. grade 78/100 | Requests 158 | Load time 2.83s | Page size 1.5MB

Конкурент на ModX: Perf. grade 86/100 | Requests 83 | Load time 242ms | Page size 805.8kB