Error 503 Service Unavailable

I believe this tends to happen due to Varnish cache servers which is prevalent on many hosters these days. If you want to disable this feature caused by your host which possibly might be the reason for your 503 errors try putting this in your htaccess file:

Header set Cache-Control "max-age=0, private, no-cache, no-store, must-revalidate"

Cheers,
Kimberly

Hi Kimberly,

Thank you very much!! ??

After this change, i didn′t see any error…

Please, i had a code at htaccess that i took off after your suggestion, could you see if is it possible to avail some part of it? (if yes, what part…)

# ——————————————————————————
# | Web fonts access |
# ——————————————————————————

# Allow access from all domains for web fonts

<IfModule mod_headers.c>
<FilesMatch “\.(eot|font.css|otf|ttc|ttf|woff)$”>
Header set Access-Control-Allow-Origin “*”
</FilesMatch>
</IfModule>

# ##############################################################################
# # INTERNET EXPLORER #
# ##############################################################################

# ——————————————————————————
# | Better website experience |
# ——————————————————————————

# Force IE to render pages in the highest available mode in the various
# cases when it may not: https://hsivonen.iki.fi/doctype/ie-mode.pdf.

<IfModule mod_headers.c>
Header set X-UA-Compatible “IE=edge”
# mod_headers can’t match based on the content-type, however, we only
# want to send this header for HTML pages and not for the other resources
<FilesMatch “\.(appcache|crx|css|eot|gif|htc|ico|jpe?g|js|m4a|m4v|manifest|mp4|oex|oga|ogg|ogv|otf|pdf|png|safariextz|svgz?|ttf|vcf|webapp|webm|webp|woff|xml|xpi)$”>
Header unset X-UA-Compatible
</FilesMatch>
</IfModule>

# ——————————————————————————
# | Cookie setting from iframes |
# ——————————————————————————

# Allow cookies to be set from iframes in IE.

# <IfModule mod_headers.c>
# Header set P3P “policyref=\”/w3c/p3p.xml\”, CP=\”IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT\””
# </IfModule>

# ——————————————————————————
# | Screen flicker |
# ——————————————————————————

# Stop screen flicker in IE on CSS rollovers (this only works in
# combination with the ExpiresByType directives for images from below).

# BrowserMatch “MSIE” brokenvary=1
# BrowserMatch “Mozilla/4.[0-9]{2}” brokenvary=1
# BrowserMatch “Opera” !brokenvary
# SetEnvIf brokenvary 1 force-no-vary

# ##############################################################################
# # MIME TYPES AND ENCODING #
# ##############################################################################

# ——————————————————————————
# | Proper MIME types for all files |
# ——————————————————————————

<IfModule mod_mime.c>

# Audio
AddType audio/mp4 m4a f4a f4b
AddType audio/ogg oga ogg

# JavaScript
# Normalize to standard type (it’s sniffed in IE anyways):
# https://tools.ietf.org/html/rfc4329#section-7.2
AddType application/javascript js
AddType application/json json

# Video
AddType video/mp4 mp4 m4v f4v f4p
AddType video/ogg ogv
AddType video/webm webm
AddType video/x-flv flv

# Web fonts
AddType application/font-woff woff
AddType application/vnd.ms-fontobject eot

# Browsers usually ignore the font MIME types and sniff the content,
# however, Chrome shows a warning if other MIME types are used for the
# following fonts.
AddType application/x-font-ttf ttc ttf
AddType font/opentype otf

# Make SVGZ fonts work on iPad:
# https://twitter.com/FontSquirrel/status/14855840545
AddType image/svg+xml svg svgz
AddEncoding gzip svgz

# Other
AddType application/octet-stream safariextz
AddType application/x-chrome-extension crx
AddType application/x-opera-extension oex
AddType application/x-shockwave-flash swf
AddType application/x-web-app-manifest+json webapp
AddType application/x-xpinstall xpi
AddType application/xml atom rdf rss xml
AddType image/webp webp
AddType image/x-icon ico
AddType text/cache-manifest appcache manifest
AddType text/vtt vtt
AddType text/x-component htc
AddType text/x-vcard vcf

</IfModule>

# ——————————————————————————
# | UTF-8 encoding |
# ——————————————————————————

# Use UTF-8 encoding for anything served as text/html or text/plain.
AddDefaultCharset utf-8

# Force UTF-8 for certain file formats.
<IfModule mod_mime.c>
AddCharset utf-8 .atom .css .js .json .rss .vtt .webapp .xml
</IfModule>

# – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –

# Block access to backup and source files.
# These files may be left by some text editors and can pose a great security
# danger when anyone has access to them.

<FilesMatch “(^#.*#|\.(bak|config|dist|fla|inc|ini|log|psd|sh|sql|sw[op])|~)$”>
Order allow,deny
Deny from all
Satisfy All
</FilesMatch>

# ##############################################################################
# # WEB PERFORMANCE #
# ##############################################################################

# ——————————————————————————
# | Compression |
# ——————————————————————————

<IfModule mod_deflate.c>

# Force compression for mangled headers.
# https://developer.yahoo.com/blogs/ydn/posts/2010/12/pushing-beyond-gzipping
<IfModule mod_setenvif.c>
<IfModule mod_headers.c>
SetEnvIfNoCase ^(Accept-EncodXng|X-cept-Encoding|X{15}|~{15}|-{15})$ ^((gzip|deflate)\s*,?\s*)+|[X~-]{4,13}$ HAVE_Accept-Encoding
RequestHeader append Accept-Encoding “gzip,deflate” env=HAVE_Accept-Encoding
</IfModule>
</IfModule>

# Compress all output labeled with one of the following MIME-types
# (for Apache versions below 2.3.7, you don’t need to enable mod_filter
# and can remove the <IfModule mod_filter.c> and </IfModule> lines
# as AddOutputFilterByType is still in the core directives).
<IfModule mod_filter.c>
AddOutputFilterByType DEFLATE application/atom+xml \
application/javascript \
application/json \
application/rss+xml \
application/vnd.ms-fontobject \
application/x-font-ttf \
application/x-web-app-manifest+json \
application/xhtml+xml \
application/xml \
font/opentype \
image/svg+xml \
image/x-icon \
text/css \
text/html \
text/plain \
text/x-component \
text/xml
</IfModule>

</IfModule>

# ——————————————————————————
# | Content transformations |
# ——————————————————————————

# Prevent some of the mobile network providers from modifying the content of
# your site: https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.5.

# <IfModule mod_headers.c>
# Header set Cache-Control “no-transform”
# </IfModule>

# ——————————————————————————
# | ETag removal |
# ——————————————————————————

# Since we’re sending far-future expires headers (see below), ETags can
# be removed: https://developer.yahoo.com/performance/rules.html#etags.

# FileETag None is not enough for every server.
<IfModule mod_headers.c>
Header unset ETag
</IfModule>

FileETag None

# ——————————————————————————
# | Expires headers (for better cache control) |
# ——————————————————————————

# The following expires headers are set pretty far in the future. If you don’t
# control versioning with filename-based cache busting, consider lowering the
# cache time for resources like CSS and JS to something like 1 week.

<IfModule mod_expires.c>

ExpiresActive on
ExpiresDefault “access plus 1 month”

# CSS
ExpiresByType text/css “access plus 1 year”

# Data interchange
ExpiresByType application/json “access plus 0 seconds”
ExpiresByType application/xml “access plus 0 seconds”
ExpiresByType text/xml “access plus 0 seconds”

# Favicon (cannot be renamed!)
ExpiresByType image/x-icon “access plus 1 week”

# HTML components (HTCs)
ExpiresByType text/x-component “access plus 1 month”

# HTML
ExpiresByType text/html “access plus 0 seconds”

# JavaScript
ExpiresByType application/javascript “access plus 1 year”

# Manifest files
ExpiresByType application/x-web-app-manifest+json “access plus 0 seconds”
ExpiresByType text/cache-manifest “access plus 0 seconds”

# Media
ExpiresByType audio/ogg “access plus 1 month”
ExpiresByType image/gif “access plus 1 month”
ExpiresByType image/jpeg “access plus 1 month”
ExpiresByType image/png “access plus 1 month”
ExpiresByType video/mp4 “access plus 1 month”
ExpiresByType video/ogg “access plus 1 month”
ExpiresByType video/webm “access plus 1 month”

# Web feeds
ExpiresByType application/atom+xml “access plus 1 hour”
ExpiresByType application/rss+xml “access plus 1 hour”

# Web fonts
ExpiresByType application/font-woff “access plus 1 month”
ExpiresByType application/vnd.ms-fontobject “access plus 1 month”
ExpiresByType application/x-font-ttf “access plus 1 month”
ExpiresByType font/opentype “access plus 1 month”
ExpiresByType image/svg+xml “access plus 1 month”

</IfModule>

Regards,

Tony

I have this exact problem since yesterday. Nothing seems to have changed in my config.

Hi Kimberly,

Sorry to disturb you.

It started again… what could be?

Regards,

Tony