Отношения между процессами apache и загрузками / просмотрами / обращениями страниц

Когда я запускаю команду ps aux, Я вижу много записей /usr/sbin/apache2 -k start (На машине Ubuntu) и /usr/sbin/httpd -k start (В Centos). Я где-то читал, что каждая из этих записей представляет собой процесс apache, который создается заранее, чтобы быть готовым к будущему запросу к серверу.

Итак, насколько я понимаю, каждый из этих процессов apache должен обслуживать HTTP-запрос, и он умирает после выполнения задания, и другие процессы будут созданы для подготовки к другим будущим запросам.

Что я не понимаю, каждый процесс apache будет обслуживать загрузку страницы или попадание? (Поскольку каждая загрузка страницы может иметь несколько десятков обращений).

Я задаю этот вопрос, потому что вижу два разных поведения Ubuntu и Centos. Я более знаком с Ubuntu, и мои машины с Ubuntu никогда не сталкивались с проблемами высокой нагрузки, когда у меня было много обращений к несуществующим страницам (когда я говорю о несуществующих страницах, это означает, что файлы не существуют на сервере, и он не перезаписывается в файл php файлом .htaccess)

Однако в последнее время мне приходится управлять сервером Centos. Я вижу, что некоторые плохие боты просто бросают 20-30 обращений к несуществующим страницам в течение 1-2 секунд, и каждый раз, когда это происходит, средняя нагрузка резко возрастает, и я также вижу много /usr/sbin/httpd -k start записи из ps aux команда.

Итак, я предполагаю, что Centos использует один процесс httpd для каждого обращения, а в ubuntu каждый процесс apache может использоваться для нескольких обращений. Это правильное предположение? Если это правильно, я думаю, что Centos очень неэффективен по сравнению с Ubuntu.

Может ли кто-нибудь прояснить эти моменты, чтобы я мог видеть, что мне не хватает?

Большое спасибо!

Обновление 1:

Я также вижу еще одно отличие: когда я открываю URL-адрес с компьютеров ubuntu, /usr/bin/php5-cgi процесс создается, и этот процесс все еще существует в течение очень долгого времени (часов), даже если загрузка страницы завершается в течение 1-2 секунд. Итак, я предполагаю, что этот php-процесс хранит некоторую информацию о кеше, чтобы ее можно было использовать для обслуживания следующего запроса страницы (я не вижу нового /usr/bin/php5-cgi процесс, когда я продолжаю переходить на другую страницу)

Но в машине Centos, когда я посещаю страницу, если мне повезет, я вижу /opt/cpanel/ea-php56/root/usr/bin/php-cgi процесс, и этот процесс практически исчезает сразу через 1-2 секунды

Обновление 2

Вот содержимое /etc/apache2/apache2.conf (Ubuntu)

# This is the main Apache server configuration file.  It contains the
# configuration directives that give the server its instructions.
# See http://httpd.apache.org/docs/2.4/ for detailed information about
# the directives and /usr/share/doc/apache2/README.Debian about Debian specific
# hints.
#
#
# Summary of how the Apache 2 configuration works in Debian:
# The Apache 2 web server configuration in Debian is quite different to
# upstream's suggested way to configure the web server. This is because Debian's
# default Apache2 installation attempts to make adding and removing modules,
# virtual hosts, and extra configuration directives as flexible as possible, in
# order to make automating the changes and administering the server as easy as
# possible.

# It is split into several files forming the configuration hierarchy outlined
# below, all located in the /etc/apache2/ directory:
#
#   /etc/apache2/
#   |-- apache2.conf
#   |   `--  ports.conf
#   |-- mods-enabled
#   |   |-- *.load
#   |   `-- *.conf
#   |-- conf-enabled
#   |   `-- *.conf
#   `-- sites-enabled
#       `-- *.conf
#
#
# * apache2.conf is the main configuration file (this file). It puts the pieces
#   together by including all remaining configuration files when starting up the
#   web server.
#
# * ports.conf is always included from the main configuration file. It is
#   supposed to determine listening ports for incoming connections which can be
#   customized anytime.
#
# * Configuration files in the mods-enabled/, conf-enabled/ and sites-enabled/
#   directories contain particular configuration snippets which manage modules,
#   global configuration fragments, or virtual host configurations,
#   respectively.
#
#   They are activated by symlinking available configuration files from their
#   respective *-available/ counterparts. These should be managed by using our
#   helpers a2enmod/a2dismod, a2ensite/a2dissite and a2enconf/a2disconf. See
#   their respective man pages for detailed information.
#
# * The binary is called apache2. Due to the use of environment variables, in
#   the default configuration, apache2 needs to be started/stopped with
#   /etc/init.d/apache2 or apache2ctl. Calling /usr/bin/apache2 directly will not
#   work with the default configuration.


# Global configuration
#

#
# ServerRoot: The top of the directory tree under which the server's
# configuration, error, and log files are kept.
#
# NOTE!  If you intend to place this on an NFS (or otherwise network)
# mounted filesystem then please read the Mutex documentation (available
# at <URL:http://httpd.apache.org/docs/2.4/mod/core.html#mutex>);
# you will save yourself a lot of trouble.
#
# Do NOT add a slash at the end of the directory path.
#
#ServerRoot "/etc/apache2"

#
# The accept serialization lock file MUST BE STORED ON A LOCAL DISK.
#
Mutex file:${APACHE_LOCK_DIR} default

#
# PidFile: The file in which the server should record its process
# identification number when it starts.
# This needs to be set in /etc/apache2/envvars
#
PidFile ${APACHE_PID_FILE}

#
# Timeout: The number of seconds before receives and sends time out.
#
Timeout 300

#
# KeepAlive: Whether or not to allow persistent connections (more than
# one request per connection). Set to "Off" to deactivate.
#
KeepAlive On

#
# MaxKeepAliveRequests: The maximum number of requests to allow
# during a persistent connection. Set to 0 to allow an unlimited amount.
# We recommend you leave this number high, for maximum performance.
#
MaxKeepAliveRequests 100

#
# KeepAliveTimeout: Number of seconds to wait for the next request from the
# same client on the same connection.
#
KeepAliveTimeout 5


# These need to be set in /etc/apache2/envvars
User ${APACHE_RUN_USER}
Group ${APACHE_RUN_GROUP}

#
# HostnameLookups: Log the names of clients or just their IP addresses
# e.g., www.apache.org (on) or 204.62.129.132 (off).
# The default is off because it'd be overall better for the net if people
# had to knowingly turn this feature on, since enabling it means that
# each client request will result in AT LEAST one lookup request to the
# nameserver.
#
HostnameLookups Off

# ErrorLog: The location of the error log file.
# If you do not specify an ErrorLog directive within a <VirtualHost>
# container, error messages relating to that virtual host will be
# logged here.  If you *do* define an error logfile for a <VirtualHost>
# container, that host's errors will be logged there and not here.
#
ErrorLog ${APACHE_LOG_DIR}/error.log

#
# LogLevel: Control the severity of messages logged to the error_log.
# Available values: trace8, ..., trace1, debug, info, notice, warn,
# error, crit, alert, emerg.
# It is also possible to configure the log level for particular modules, e.g.
# "LogLevel info ssl:warn"
#
LogLevel warn

# Include module configuration:
IncludeOptional mods-enabled/*.load
IncludeOptional mods-enabled/*.conf

# Include list of ports to listen on
Include ports.conf


# Sets the default security model of the Apache2 HTTPD server. It does
# not allow access to the root filesystem outside of /usr/share and /var/www.
# The former is used by web applications packaged in Debian,
# the latter may be used for local directories served by the web server. If
# your system is serving content from a sub-directory in /srv you must allow
# access here, or in any related virtual host.
<Directory />
    Options FollowSymLinks
    AllowOverride None
    Require all denied
</Directory>

<Directory /usr/share>
    AllowOverride None
    Require all granted
</Directory>

<Directory /var/www/>
    Options Indexes FollowSymLinks
    AllowOverride None
    Require all granted
</Directory>

#<Directory /srv/>
#   Options Indexes FollowSymLinks
#   AllowOverride None
#   Require all granted
#</Directory>




# AccessFileName: The name of the file to look for in each directory
# for additional configuration directives.  See also the AllowOverride
# directive.
#
AccessFileName .htaccess

#
# The following lines prevent .htaccess and .htpasswd files from being
# viewed by Web clients.
#
<FilesMatch "^\.ht">
    Require all denied
</FilesMatch>


#
# The following directives define some format nicknames for use with
# a CustomLog directive.
#
# These deviate from the Common Log Format definitions in that they use %O
# (the actual bytes sent including headers) instead of %b (the size of the
# requested file), because the latter makes it impossible to detect partial
# requests.
#
# Note that the use of %{X-Forwarded-For}i instead of %h is not recommended.
# Use mod_remoteip instead.
#
LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined
LogFormat "%h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%h %l %u %t \"%r\" %>s %O" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent

# Include of directories ignores editors' and dpkg's backup files,
# see README.Debian for details.

# Include generic snippets of statements
IncludeOptional conf-enabled/*.conf

# Include the virtual host configurations:
IncludeOptional sites-enabled/*.conf
SSLProtocol ALL -SSLv2
SSLCipherSuite ECDHE-RSA-AES256-SHA384:AES256-SHA256:AES256-SHA256:RC4:HIGH:MEDIUM:+TLSv1:+TLSv1.1:+TLSv1.2:!MD5:!ADH:!aNULL:!eNULL:!NULL:!DH:!ADH:!EDH:!AESGCM

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet
Include /etc/phpmyadmin/apache.conf

И вот одна часть /etc/httpd/conf/httpd.conf (Centos) (другие части - это vhost для доменов, я думаю, в нем нет никакой полезной информации)

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
#
#   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
#   DO NOT EDIT. AUTOMATICALLY GENERATED.  USE INCLUDE FILES IF YOU NEED TO MAKE A CHANGE
#   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
#
#   Direct modifications to the Apache configuration file WILL be lost upon subsequent
#   regeneration of this configuration file, or an Apache update.
#
#   To have your modifications retained, you should create/edit administrator-specific
#   include files:
#
#       /etc/apache2/conf.d/includes/pre_main_global.conf
#       /etc/apache2/conf.d/includes/pre_virtualhost_global.conf
#       /etc/apache2/conf.d/includes/post_virtualhost_global.conf
#
# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #

##################################################
##################################################
#
# cPanel & WHM controlled Apache configuration
#
##################################################
##################################################

Include "/etc/apache2/conf.modules.d/*.conf"

# Administrator locations for safely altering httpd.conf
Include "/etc/apache2/conf.d/includes/pre_main_global.conf"

# These are hard-coded values that are required by cPanel & WHM
PidFile /run/apache2/httpd.pid
User nobody
Group nobody
ExtendedStatus On
LogLevel warn
# You can change this by using WHM, and navigating to the 'Basic cPanel & WHM Setup' -> 'Contact Information' interface.
ServerAdmin root@server1.domain.com

# You can change this by using WHM, and navigating to the 'Networking Setup' => 'Change Hostname' interface.
ServerName sv1.howhubs.com

# You can change this by using WHM, and navigating to the 'Apache Configuration' -> 'Global Configuration' interface.
TraceEnable Off
ServerSignature Off
ServerTokens ProductOnly
FileETag None

<Directory "/">

      AllowOverride None

    Options 
</Directory>

StartServers 5
<IfModule prefork.c>
    MinSpareServers 5
    MaxSpareServers 10
</IfModule>

ServerLimit 256
MaxRequestWorkers 150
MaxConnectionsPerChild 10000
KeepAlive On
KeepAliveTimeout 5
MaxKeepAliveRequests 100
Timeout 300


<IfModule rewrite_module>
# Global DCV Exclude
RewriteEngine on
RewriteCond %{REQUEST_URI} ^/\.well-known/pki-validation/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$ [OR]
RewriteCond %{REQUEST_URI} ^/[0-9]+\..+\.cpaneldcv$ 

# Exclude proxy subdomains as we need rewrites to capture the DCV requests
RewriteCond %{HTTP_HOST} !^(?:autoconfig|autodiscover|cpanel|cpcalendars|cpcontacts|webdisk|webmail|whm)\.
RewriteRule ^ - [END]
</IfModule>



# You can change this by using WHM, and navigating to the 'Apache Configuration' -> 'DirectoryIndex Priority' interface.
<IfModule dir_module>
    DirectoryIndex index.php index.php5 index.php4 index.php3 index.perl index.pl index.plx index.ppl index.cgi index.jsp index.jp index.phtml index.shtml index.xhtml index.html index.htm index.wml Default.html Default.htm default.html default.htm home.html home.htm index.js
</IfModule>

# You can change this by using WHM, and navigating to the 'Apache Configuration' -> 'Memory Usage Restrictions' interface.

# This setting is required by cPanel & WHM in order to provide access to a default webpage when none exists
<Directory "/var/www/html">
    Options All
    AllowOverride None
    Require all granted
</Directory>

# Required cPanel security policy: Disallow remote access to .htaccess, .htpasswd, .user.ini, and php.ini files

<Files ~ "^error_log$">
    Order allow,deny
    Deny from all
    Satisfy All
</Files>

<FilesMatch "^(\.ht(access|passwds?)|\.user\.ini|php\.ini)$">
    Require all denied
</FilesMatch>

<IfModule alias_module>
    ScriptAliasMatch ^/?controlpanel/?$ /usr/local/cpanel/cgi-sys/redirect.cgi
    ScriptAliasMatch ^/?cpanel/?$ /usr/local/cpanel/cgi-sys/redirect.cgi
    ScriptAliasMatch ^/?kpanel/?$ /usr/local/cpanel/cgi-sys/redirect.cgi
    ScriptAliasMatch ^/?securecontrolpanel/?$ /usr/local/cpanel/cgi-sys/sredirect.cgi
    ScriptAliasMatch ^/?securecpanel/?$ /usr/local/cpanel/cgi-sys/sredirect.cgi
    ScriptAliasMatch ^/?securewhm/?$ /usr/local/cpanel/cgi-sys/swhmredirect.cgi
    ScriptAliasMatch ^/?webmail$ /usr/local/cpanel/cgi-sys/wredirect.cgi
    ScriptAliasMatch ^/?webmail/ /usr/local/cpanel/cgi-sys/wredirect.cgi
    ScriptAliasMatch ^/?whm/?$ /usr/local/cpanel/cgi-sys/whmredirect.cgi

    Alias /bandwidth /usr/local/bandmin/htdocs/
    Alias /img-sys /usr/local/cpanel/img-sys/
    Alias /java-sys /usr/local/cpanel/java-sys/
    Alias /mailman/archives /usr/local/cpanel/3rdparty/mailman/archives/public/
    Alias /pipermail /usr/local/cpanel/3rdparty/mailman/archives/public/
    Alias /sys_cpanel /usr/local/cpanel/sys_cpanel/

    ScriptAlias /cgi-sys /usr/local/cpanel/cgi-sys/
    ScriptAlias /mailman /usr/local/cpanel/3rdparty/mailman/cgi-bin/

</IfModule>

# This can be configured in the cPanel 'Leech Protection' interface.
<IfModule rewrite_module>
    RewriteEngine on
    RewriteMap LeechProtect prg:/usr/local/cpanel/bin/leechprotect
    Mutex file:/run/apache2 rewrite-map
</IfModule>

<IfModule mime_module>
    TypesConfig conf/mime.types

    AddType application/x-compress .Z
    AddType application/x-gzip .gz .tgz
    AddType text/html .shtml
    AddType application/x-tar .tgz
    AddType text/vnd.wap.wml .wml
    AddType image/vnd.wap.wbmp .wbmp
    AddType text/vnd.wap.wmlscript .wmls
    AddType application/vnd.wap.wmlc .wmlc
    AddType application/vnd.wap.wmlscriptc .wmlsc

    # These extensions are used to redirect incoming requests to WHM
    AddHandler cgi-script .cgi .pl .plx .ppl .perl

    # This is used for custom error documents
    AddHandler server-parsed .shtml
</IfModule>

# You can change this by using WHM, and updating the 'Tweak Settings' -> 'System' -> 'Allow server-info' option.
<IfModule status_module>
    # This is used by the WHM 'Apache Status' application
    <Location /whm-server-status>
        SetHandler server-status
        Order deny,allow
        Deny from all
        Allow from 127.0.0.1 ::1
    </Location>

</IfModule>

# Required cPanel security policy: disable userdir when mod_ruid2 or mpm_itk or mod_passenger are loaded
<IfModule userdir_module>
    UserDir public_html

    <IfModule ruid2_module>
        UserDir disabled
    </IfModule>
    <IfModule mpm_itk.c>
        UserDir disabled
    </IfModule>
    <IfModule mod_passenger.c>
        UserDir disabled
    </IfModule>
</IfModule>


<IfModule log_config_module>
    LogFormat "%{Referer}i -> %U" referer
    LogFormat "%{User-agent}i" agent
    # NOTE: "combined" and "common" are required by WHM
    LogFormat "%h %l %u %t \"%r\" %>s %b" common
    LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined

    # access_log format can be set in WHM under 'Basic cPanel & WHM Setup'
    CustomLog logs/access_log combined
</IfModule>


# The Listen port can be updated using 'Tweak Settings' -> 'System',
# However, if you have any Apache Reserved IPs, then this Tweak setting will
# be ignored. Instead, each IP on your system (excluding Apache Reserved IPs)
# will be listed here.
Listen 0.0.0.0:80
Listen [::]:80

<IfModule ssl_module>
    # cipher and protocol directives can be set in WHM under 'Apache Configuration' -> 'Global Configuration'
    SSLCipherSuite ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:!DSS
    SSLProtocol All -SSLv2 -SSLv3
    SSLPassPhraseDialog  builtin

    <IfModule socache_shmcb_module>
        SSLUseStapling on
        SSLStaplingCache shmcb:/run/apache2/stapling_cache_shmcb(256000)

        # Prevent browsers from failing if an OCSP server is temporarily broken.
        SSLStaplingReturnResponderErrors off
        SSLStaplingErrorCacheTimeout 60
        SSLStaplingFakeTryLater off
        SSLStaplingResponderTimeout 3
        SSLSessionCache shmcb:/run/apache2/ssl_gcache_data_shmcb(1024000)
    </IfModule>
    <IfModule !socache_shmcb_module>
        SSLSessionCache dbm:/run/apache2/ssl_gcache_data_dbm
    </IfModule>

    SSLSessionCacheTimeout  300
    Mutex                   file:/run/apache2 ssl-cache
    SSLRandomSeed startup builtin
    SSLRandomSeed connect builtin

    # The Listen port can be updated using 'Tweak Settings' -> 'System',
    # However, if you have any Apache Reserved IPs, then this Tweak setting will
    # be ignored. Instead, each IP on your system (excluding Apache Reserved IPs)
    # will be listed here.
    Listen 0.0.0.0:443
    Listen [::]:443

    AddType application/x-x509-ca-cert .crt
    AddType application/x-pkcs7-crl .crl
</IfModule>

Include "/etc/apache2/conf.d/*.conf"

Include "/etc/apache2/conf.d/includes/account_suspensions.conf"
Include "/etc/apache2/conf.d/includes/errordocument.conf"

# Administrator locations for safely globally altering all virtualhost configurations
Include "/etc/apache2/conf.d/includes/pre_virtualhost_global.conf"

ProxyPass /___proxy_subdomain_ws_cpanel  ws://127.0.0.1:2082 max=1 retry=0
ProxyPass /___proxy_subdomain_ws_whm     ws://127.0.0.1:2086 max=1 retry=0
ProxyPass /___proxy_subdomain_ws_webmail ws://127.0.0.1:2095 max=1 retry=0