How to set up a VPS 512MB 1GHz server so that it does not go to reboot?

Question

Apache HTTP Server

There is a VPS server with this configuration CPU 1GHz RAM 512MB
Apache/2.2.15 (CentOS) + nginx, MySQL 5.5.40, PHP 5.4.34
Prestashop store installed The store
works relatively fast, but sometimes the server goes to reboot, for example, when rebuilding indexes for search
If you load the server with the Load Impact or Apache Bench test, it goes to reboot. Load Impact - through time and from Apache Bench - immediately
my httpd.conf

ServerTokens OS
ServerRoot "/etc/httpd"
PidFile run/httpd.pid
Timeout 60
KeepAlive Off
MaxKeepAliveRequests 100
KeepAliveTimeout 10

<IfModule prefork.c>
    StartServers       1
    MinSpareServers    1
    MaxSpareServers    3
    ServerLimit        10
    MaxClients         10
    MaxRequestsPerChild  3000
</IfModule>

<IfModule worker.c>
    StartServers         1
    MinSpareThreads     5
    MaxSpareThreads     15
  ThreadLimit			25
    ThreadsPerChild     5
  MaxClients         25
    MaxRequestsPerChild  200
</IfModule>

<IfModule itk.c>
    StartServers       1
    MinSpareServers    1
    MaxSpareServers   3
    ServerLimit      10
    MaxClients       10
    MaxRequestsPerChild  1000
</IfModule>

#LoadModule auth_basic_module modules/mod_auth_basic.so
LoadModule auth_digest_module modules/mod_auth_digest.so
LoadModule authn_file_module modules/mod_authn_file.so
LoadModule authn_alias_module modules/mod_authn_alias.so
LoadModule authn_anon_module modules/mod_authn_anon.so
#LoadModule authn_dbm_module modules/mod_authn_dbm.so
LoadModule authn_default_module modules/mod_authn_default.so
LoadModule authz_host_module modules/mod_authz_host.so
LoadModule authz_user_module modules/mod_authz_user.so
LoadModule authz_owner_module modules/mod_authz_owner.so
LoadModule authz_groupfile_module modules/mod_authz_groupfile.so
#LoadModule authz_dbm_module modules/mod_authz_dbm.so
LoadModule authz_default_module modules/mod_authz_default.so
#LoadModule ldap_module modules/mod_ldap.so
#LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
LoadModule include_module modules/mod_include.so
LoadModule log_config_module modules/mod_log_config.so
LoadModule logio_module modules/mod_logio.so
LoadModule env_module modules/mod_env.so
LoadModule ext_filter_module modules/mod_ext_filter.so
LoadModule mime_magic_module modules/mod_mime_magic.so
LoadModule expires_module modules/mod_expires.so
LoadModule deflate_module modules/mod_deflate.so
LoadModule headers_module modules/mod_headers.so
LoadModule usertrack_module modules/mod_usertrack.so
LoadModule setenvif_module modules/mod_setenvif.so
LoadModule mime_module modules/mod_mime.so
LoadModule dav_module modules/mod_dav.so
LoadModule status_module modules/mod_status.so
LoadModule autoindex_module modules/mod_autoindex.so
#LoadModule info_module modules/mod_info.so
#LoadModule dav_fs_module modules/mod_dav_fs.so
LoadModule vhost_alias_module modules/mod_vhost_alias.so
LoadModule negotiation_module modules/mod_negotiation.so
LoadModule dir_module modules/mod_dir.so
LoadModule actions_module modules/mod_actions.so
#LoadModule speling_module modules/mod_speling.so
#LoadModule userdir_module modules/mod_userdir.so
LoadModule alias_module modules/mod_alias.so
LoadModule rewrite_module modules/mod_rewrite.so
LoadModule proxy_module modules/mod_proxy.so
#LoadModule proxy_balancer_module modules/mod_proxy_balancer.so
#LoadModule proxy_ftp_module modules/mod_proxy_ftp.so
#LoadModule proxy_http_module modules/mod_proxy_http.so
#LoadModule proxy_connect_module modules/mod_proxy_connect.so
LoadModule cache_module modules/mod_cache.so
LoadModule suexec_module modules/mod_suexec.so
#LoadModule disk_cache_module modules/mod_disk_cache.so
#LoadModule file_cache_module modules/mod_file_cache.so
#LoadModule mem_cache_module modules/mod_mem_cache.so
LoadModule cgi_module modules/mod_cgi.so
LoadModule version_module modules/mod_version.so

Include conf.d/*.conf

ExtendedStatus On

User apache
Group apache

ServerAdmin [email protected]
UseCanonicalName Off
DocumentRoot "/var/www/html"
<Directory />
    Options SymLinksIfOwnerMatch
    AllowOverride None
</Directory>

<Directory "/var/www/html">
    Options Indexes SymLinksIfOwnerMatch
    AllowOverride None
    Order allow,deny
    Allow from all
</Directory>

<IfModule mod_userdir.c>
    UserDir public_html
</IfModule>

DirectoryIndex index.php index.htm index.html

AccessFileName .htaccess
<Files ~ "^\.ht">
    Order allow,deny
    Deny from all
</Files>
TypesConfig /etc/mime.types

DefaultType text/plain

<IfModule mod_mime_magic.c>
    MIMEMagicFile conf/magic
</IfModule>

HostnameLookups Off

ErrorLog logs/error_log
LogLevel warn

LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%h %l %u %t \"%r\" %>s %b" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent
LogFormat "%b" bytes
CustomLog logs/access_log combined

ServerSignature On

Alias /icons/ "/var/www/icons/"

<Directory "/var/www/icons">
    Options Indexes MultiViews
    AllowOverride None
    Order allow,deny
    Allow from all
</Directory>

<Directory "/var/www/html">
    AllowOverride None
    Order allow,deny
    Allow from all
</Directory>

ScriptAlias /cgi-bin/ "/var/www/cgi-bin/"

<Directory "/var/www/cgi-bin">
    AllowOverride None
    Options ExecCGI
    Order allow,deny
    Allow from all
</Directory>

IndexOptions FancyIndexing VersionSort NameWidth=* HTMLTable

AddIconByEncoding (CMP,/icons/compressed.gif) x-compress x-gzip
AddIconByType (TXT,/icons/text.gif) text/*
AddIconByType (IMG,/icons/image2.gif) image/*
AddIconByType (SND,/icons/sound2.gif) audio/*
AddIconByType (VID,/icons/movie.gif) video/*
AddIcon /icons/binary.gif .bin .exe
AddIcon /icons/binhex.gif .hqx
AddIcon /icons/tar.gif .tar
AddIcon /icons/world2.gif .wrl .wrl.gz .vrml .vrm .iv
AddIcon /icons/compressed.gif .Z .z .tgz .gz .zip
AddIcon /icons/a.gif .ps .ai .eps
AddIcon /icons/layout.gif .html .shtml .htm .pdf
AddIcon /icons/text.gif .txt
AddIcon /icons/c.gif .c
AddIcon /icons/p.gif .pl .py
AddIcon /icons/f.gif .for
AddIcon /icons/dvi.gif .dvi
AddIcon /icons/uuencoded.gif .uu
AddIcon /icons/script.gif .conf .sh .shar .csh .ksh .tcl
AddIcon /icons/tex.gif .tex
AddIcon /icons/bomb.gif core
AddIcon /icons/back.gif ..
AddIcon /icons/hand.right.gif README
AddIcon /icons/folder.gif ^^DIRECTORY^^
AddIcon /icons/blank.gif ^^BLANKICON^^
DefaultIcon /icons/unknown.gif
ReadmeName README.html
HeaderName HEADER.html
IndexIgnore .??* *~ *# HEADER* README* RCS CVS *,v *,t
AddLanguage ca .ca
AddLanguage cs .cz .cs
AddLanguage da .dk
AddLanguage de .de
AddLanguage el .el
AddLanguage en .en
AddLanguage eo .eo
AddLanguage es .es
AddLanguage et .et
AddLanguage fr .fr
AddLanguage he .he
AddLanguage hr .hr
AddLanguage it .it
AddLanguage ja .ja
AddLanguage ko .ko
AddLanguage ltz .ltz
AddLanguage nl .nl
AddLanguage nn .nn
AddLanguage no .no
AddLanguage pl .po
AddLanguage pt .pt
AddLanguage pt-BR .pt-br
AddLanguage ru .ru
AddLanguage sv .sv
AddLanguage zh-CN .zh-cn
AddLanguage zh-TW .zh-tw
LanguagePriority en ca cs da de el eo es et fr he hr it ja ko ltz nl nn no pl pt pt-BR ru sv zh-CN zh-TW
ForceLanguagePriority Prefer Fallback

AddDefaultCharset UTF-8

AddType application/x-compress .Z
AddType application/x-gzip .gz .tgz
AddType image/x-icon .ico

AddType text/html .shtml
AddOutputFilter INCLUDES .shtml

ErrorDocument 403 /error/403.html
ErrorDocument 404 /error/404.html
ErrorDocument 500 /error/50x.html
ErrorDocument 501 /error/50x.html
ErrorDocument 502 /error/50x.html
ErrorDocument 503 /error/50x.html
ErrorDocument 506 /error/50x.html

BrowserMatch "Mozilla/2" nokeepalive
BrowserMatch "MSIE 4\.0b2;" nokeepalive downgrade-1.0 force-response-1.0
BrowserMatch "RealPlayer 4\.0" force-response-1.0
BrowserMatch "Java/1\.0" force-response-1.0
BrowserMatch "JDK/1\.0" force-response-1.0
BrowserMatch "Microsoft Data Access Internet Publishing Provider" redirect-carefully
BrowserMatch "MS FrontPage" redirect-carefully
BrowserMatch "^WebDrive" redirect-carefully
BrowserMatch "^WebDAVFS/1.[0123]" redirect-carefully
BrowserMatch "^gnome-vfs/1.0" redirect-carefully
BrowserMatch "^XML Spy" redirect-carefully
BrowserMatch "^Dreamweaver-WebDAV-SCM1" redirect-carefully

running the top command to find out the culprit and then loading with Load Impact showed that just before the server crashed, several (7-9) httpd (apache) processes were using 11-12% CPU and 9-10% MEM each.
I understand Do I need to change some apache settings?

Answer 1

you need a more powerful server just if you want some kind of cancarency for several users

Answer 2

Yes, is it really a very weak iron that the only option is an upgrade?