not serving cached/optimized content

[Lefteris Skoulas]

I am trying to take advantage of the pagespeed module in my apache webserver for my wordpress ecommerce shop.

Its a dedicated server with root access.

Centos7.9 OS with plesk controlpanel installed.

using php7.4.x version.

Stackpath cdn is enabled and configured.

My structure is :

Apache directory root for WP: /var/www/vhosts/mydomain.tld/httpdocs

My wordpress image directory is via cdn https://mycdnurl.tld/wp-content' );

My plugins directory is loaded via a seperate subdomain hosted on the same server.

All related domains/subdomains are authorised in my httpd.conf

My problem is that in order to serve the optimized webp images/css/js i have to refresh the browser 2-3 times.

sometimes colors, background or even simple html elements are disappearing and appearing immediately after, very quick

What do i have to do in order to always serve the optimized pagespeed files?

Based on my pagespeed.conf or the existance of the cdn, am i doing anything wrong?

My config:

# Attempt to load mod_version if it wasn't loaded or compiled in (eg on Debian)

<IfModule !mod_version.c>

  LoadModule version_module /usr/lib64/httpd/modules/mod_version.so

</IfModule>

<IfVersion < 2.4>

  LoadModule pagespeed_module /usr/lib64/httpd/modules/mod_pagespeed.so

</IfVersion>

<IfVersion >= 2.4.2>

  # As default pagespeed.conf configuration uses old-style ACLs using

  # 'allow' and 'deny', we load mod_access_compat in Apache 2.4. If that's a

  # problem, the blocks using that can be converted to the newer 'Require'

  # syntax.

  <IfModule !access_compat_module>

    LoadModule access_compat_module /usr/lib64/httpd/modules/mod_access_compat.so

  </IfModule>

  LoadModule pagespeed_module /usr/lib64/httpd/modules/mod_pagespeed_ap24.so

</IfVersion>

# Only attempt to load mod_deflate if it hasn't been loaded already.

<IfModule !mod_deflate.c>

 LoadModule deflate_module /usr/lib64/httpd/modules/mod_deflate.so

</IfModule>

<IfModule pagespeed_module>

    # Turn on mod_pagespeed. To completely disable mod_pagespeed, you

    # can set this to "off".

    ModPagespeed on

    # Direct Apache to send all HTML output to the mod_pagespeed

    # output handler.

    AddOutputFilterByType MOD_PAGESPEED_OUTPUT_FILTER text/html

    # If you want mod_pagespeed process XHTML as well, please uncomment this

    # line.

    AddOutputFilterByType MOD_PAGESPEED_OUTPUT_FILTER application/xhtml+xml

    # The ModPagespeedFileCachePath directory must exist and be writable

    # by the apache user (as specified by the User directive).

    ModPagespeedFileCachePath            "/var/cache/mod_pagespeed/"

    # LogDir is needed to store various logs, including the statistics log

    # required for the console.

    ModPagespeedLogDir "/var/log/pagespeed"

    # The locations of SSL Certificates is distribution-dependent.

    ModPagespeedSslCertDirectory "/etc/pki/tls/certs"

    ModPagespeedSslCertFile /etc/pki/tls/cert.pem

    # If you want, you can use one or more memcached servers as the store for

    # the mod_pagespeed cache.

    # ModPagespeedMemcachedServers localhost:11211

       #ModPagespeedRedisServer "127.0.0.1:6379"

    # A portion of the cache can be kept in memory only, to reduce load on disk

    # (or memcached) from many small files.

    ModPagespeedCreateSharedMemoryMetadataCache "/var/cache/mod_pagespeed/" 51200

<VirtualHost mydomain.tld.com:80>

  ModPagespeedFileCachePath "/var/cache/pagespeed/"

</VirtualHost>

<VirtualHost mydomain.tld.com:443>

  ModPagespeedFileCachePath "/var/cache/pagespeed/"

</VirtualHost>

    # Override the mod_pagespeed 'rewrite level'. The default level

    # "CoreFilters" uses a set of rewrite filters that are generally

    # safe for most web pages. Most sites should not need to change

    # this value and can instead fine-tune the configuration using the

    # ModPagespeedDisableFilters and ModPagespeedEnableFilters

    # directives, below. Valid values for ModPagespeedRewriteLevel are

    # PassThrough, CoreFilters and TestingCoreFilters.

    #

    ModPagespeedRewriteLevel PassThrough

    # Explicitly disables specific filters. This is useful in

    # conjuction with ModPagespeedRewriteLevel. For instance, if one

    # of the filters in the CoreFilters needs to be disabled for a

    # site, that filter can be added to

    # ModPagespeedDisableFilters. This directive contains a

    # comma-separated list of filter names, and can be repeated.

    #

    # ModPagespeedDisableFilters rewrite_images

    # Explicitly enables specific filters. This is useful in

    # conjuction with ModPagespeedRewriteLevel. For instance, filters

    # not included in the CoreFilters may be enabled using this

    # directive. This directive contains a comma-separated list of

    # filter names, and can be repeated.

    #

    ModPagespeedEnableFilters rewrite_javascript,rewrite_css

    ModPagespeedEnableFilters collapse_whitespace,elide_attributes

    # Explicitly forbids the enabling of specific filters using either query

    # parameters or request headers. This is useful, for example, when we do

    # not want the filter to run for performance or security reasons. This

    # directive contains a comma-separated list of filter names, and can be

    # repeated.

    #

    # ModPagespeedForbidFilters rewrite_images

    # How long mod_pagespeed will wait to return an optimized resource

    # (per flush window) on first request before giving up and returning the

    # original (unoptimized) resource. After this deadline is exceeded the

    # original resource is returned and the optimization is pushed to the

    # background to be completed for future requests. Increasing this value will

    # increase page latency, but might reduce load time (for instance on a

    # bandwidth-constrained link where it's worth waiting for image

    # compression to complete). If the value is less than or equal to zero

    # mod_pagespeed will wait indefinitely for the rewrite to complete before

    # returning.

    #

    # ModPagespeedRewriteDeadlinePerFlushMs 10

    # ModPagespeedDomain

    # authorizes rewriting of JS, CSS, and Image files found in this

    # domain. By default only resources with the same origin as the

    # HTML file are rewritten. For example:

    #

    #   ModPagespeedDomain cdn.myhost.com

    #

    # This will allow resources found on http://cdn.myhost.com to be

    # rewritten in addition to those in the same domain as the HTML.

    #

    # Other domain-related directives (like ModPagespeedMapRewriteDomain

    # and ModPagespeedMapOriginDomain) can also authorize domains.

    #

    # Wildcards (* and ?) are allowed in the domain specification. Be

    # careful when using them as if you rewrite domains that do not

    # send you traffic, then the site receiving the traffic will not

    # know how to serve the rewritten content.

    # If you use downstream caches such as varnish or proxy_cache for caching

    # HTML, you can configure pagespeed to work with these caches correctly

    # using the following directives. Note that the values for

    # ModPagespeedDownstreamCachePurgeLocationPrefix and

    # ModPagespeedDownstreamCacheRebeaconingKey are deliberately left empty here

    # in order to force the webmaster to choose appropriate value for these.

    #

    # ModPagespeedDownstreamCachePurgeLocationPrefix

    # ModPagespeedDownstreamCachePurgeMethod PURGE

    # ModPagespeedDownstreamCacheRewrittenPercentageThreshold 95

    # ModPagespeedDownstreamCacheRebeaconingKey

       ModPagespeedEnableCachePurge on

    # Other defaults (cache sizes and thresholds):

    #

    ModPagespeedFileCacheSizeKb          102400

    ModPagespeedFileCacheCleanIntervalMs 3600000

    ModPagespeedLRUCacheKbPerProcess     1024

    ModPagespeedLRUCacheByteLimit        16384

    ModPagespeedCssFlattenMaxBytes       102400

    ModPagespeedCssImageInlineMaxBytes   0

    ModPagespeedImageInlineMaxBytes      100000

    ModPagespeedCssOutlineMinBytes       100000

    ModPagespeedJsOutlineMinBytes        100000

    ModPagespeedMaxCombinedCssBytes      -1

    ModPagespeedMaxCombinedJsBytes       100000

    # Limit the number of inodes in the file cache. Set to 0 for no limit.

    # The default value if this paramater is not specified is 0 (no limit).

    ModPagespeedFileCacheInodeLimit        500000

    # Bound the number of images that can be rewritten at any one time; this

    # avoids overloading the CPU.  Set this to -1 to remove the bound.

    #

    # ModPagespeedImageMaxRewritesAtOnce      8

    # You can also customize the number of threads per Apache process

    # mod_pagespeed will use to do resource optimization. Plain

    # "rewrite threads" are used to do short, latency-sensitive work,

    # while "expensive rewrite threads" are used for actual optimization

    # work that's more computationally expensive. If you live these unset,

    # or use values <= 0 the defaults will be used, which is 1 for both

    # values when using non-threaded MPMs (e.g. prefork) and 4 for both

    # on threaded MPMs (e.g. worker and event). These settings can only

    # be changed globally, and not per virtual host.

    #

    ModPagespeedNumRewriteThreads 32

    ModPagespeedNumExpensiveRewriteThreads 32

    # Randomly drop rewrites (*) to increase the chance of optimizing

    # frequently fetched resources and decrease the chance of optimizing

    # infrequently fetched resources. This can reduce CPU load. The default

    # value of this parameter is 0 (no drops).  90 means that a resourced

    # fetched once has a 10% probability of being optimized while a resource

    # that is fetched 50 times has a 99.65% probability of being optimized.

    #

    # (*) Currently only CSS files and images are randomly dropped.  Images

    # within CSS files are not randomly dropped.

    #

    # ModPagespeedRewriteRandomDropPercentage 90

    # Many filters modify the URLs of resources in HTML files. This is typically

    # harmless but pages whose Javascript expects to read or modify the original

    # URLs may break. The following parameters prevent filters from modifying

    # URLs of their respective types.

    #

    # ModPagespeedJsPreserveURLs on

    # ModPagespeedImagePreserveURLs on

    # ModPagespeedCssPreserveURLs on

    # When PreserveURLs is on, it is still possible to enable browser-specific

    # optimizations (for example, webp images can be served to browsers that

    # will accept them).  They'll be served with Vary: Accept or Vary:

    # User-Agent headers as appropriate.  Note that this may require configuring

    # reverse proxy caches such as varnish to handle these headers properly.

    #

    ModPagespeedEnableFilters in_place_optimize_for_browser

    # Internet Explorer has difficulty caching resources with Vary: headers.

    # They will either be uncached (older IE) or require revalidation.  See:

    # http://blogs.msdn.com/b/ieinternals/archive/2009/06/17/vary-header-prevents-caching-in-ie.aspx

    # As a result we serve them as Cache-Control: private instead by default.

    # If you are using a reverse proxy or CDN configured to cache content with

    # the Vary: Accept header you should turn this setting off.

    #

    # ModPagespeedPrivateNotVaryForIE on

    # Settings for image optimization:

    #

    # Lossy image recompression quality (0 to 100, -1 just strips metadata):

    # ModPagespeedImageRecompressionQuality 85

    #

    # Jpeg recompression quality (0 to 100, -1 uses ImageRecompressionQuality):

    ModPagespeedJpegRecompressionQuality -1

    ModPagespeedJpegRecompressionQualityForSmallScreens 70

    #

    # WebP recompression quality (0 to 100, -1 uses ImageRecompressionQuality):

    ModPagespeedWebpRecompressionQuality 80

    ModPagespeedWebpRecompressionQualityForSmallScreens 70

    #

    # Timeout for conversions to WebP format, in

    # milliseconds. Negative values mean no timeout is applied. The

    # default value is -1:

    #ModPagespeedWebpTimeoutMs -1

    #

    # Percent of original image size below which optimized images are retained:

    ModPagespeedImageLimitOptimizedPercent 100

    #

    # Percent of original image area below which image resizing will be

    # attempted:

    ModPagespeedImageLimitResizeAreaPercent 100

    # Settings for inline preview images

    #

    # Setting this to n restricts preview images to the first n images found on

    # the page.  The default of -1 means preview images can appear anywhere on

    # the page (if those images appear above the fold).

    ModPagespeedMaxInlinedPreviewImagesIndex -1

    # Sets the minimum size in bytes of any image for which a low quality image

    # is generated.

    # ModPagespeedMinImageSizeLowResolutionBytes 3072

    # The maximum URL size is generally limited to about 2k characters

    # due to IE: See http://support.microsoft.com/kb/208427/EN-US.

    # Apache servers by default impose a further limitation of about

    # 250 characters per URL segment (text between slashes).

    # mod_pagespeed circumvents this limitation, but if you employ

    # proxy servers in your path you may need to re-impose it by

    # overriding the setting here.  The default setting is 1024

    # characters.

    #

    #ModPagespeedMaxSegmentLength 2048

    # Uncomment this if you want to prevent mod_pagespeed from combining files

    # (e.g. CSS files) across paths

    #

    # ModPagespeedCombineAcrossPaths off

    # Renaming JavaScript URLs can sometimes break them.  With this

    # option enabled, mod_pagespeed uses a simple heuristic to decide

    # not to rename JavaScript that it thinks is introspective.

    #

    # You can uncomment this to let mod_pagespeed rename all JS files.

    #

    # ModPagespeedAvoidRenamingIntrospectiveJavascript off

    # Certain common JavaScript libraries are available from Google, which acts

    # as a CDN and allows you to benefit from browser caching if a new visitor

    # to your site previously visited another site that makes use of the same

    # libraries as you do.  Enable the following filter to turn on this feature.

    #

    ModPagespeedEnableFilters canonicalize_javascript_libraries

    # The following line configures a library that is recognized by

    # canonicalize_javascript_libraries.  This will have no effect unless you

    # enable this filter (generally by uncommenting the last line in the

    # previous stanza).  The format is:

    #    ModPagespeedLibrary bytes md5 canonical_url

    # Where bytes and md5 are with respect to the *minified* JS; use

    # js_minify --print_size_and_hash to obtain this data.

    # Note that we can register multiple hashes for the same canonical url;

    # we do this if there are versions available that have already been minified

    # with more sophisticated tools.

    #

    # Additional library configuration can be found in

    # pagespeed_libraries.conf included in the distribution.  You should add

    # new entries here, though, so that file can be automatically upgraded.

    # ModPagespeedLibrary 43 1o978_K0_LNE5_ystNklf http://www.modpagespeed.com/rewrite_javascript.js

    # Explicitly tell mod_pagespeed to load some resources from disk.

    # This will speed up load time and update frequency.

    #

    # This should only be used for static resources which do not need

    # specific headers set or other processing by Apache.

    #

    # Both URL and filesystem path should specify directories and

    # filesystem path must be absolute (for now).

    #

    # ModPagespeedLoadFromFile "http://example.com/static/" "/var/www/static/"

    # Enables server-side instrumentation and statistics.  If this rewriter is

    # enabled, then each rewritten HTML page will have instrumentation javacript

    # added that sends latency beacons to /mod_pagespeed_beacon.  These

    # statistics can be accessed at /mod_pagespeed_statistics.  You must also

    # enable the mod_pagespeed_statistics and mod_pagespeed_beacon handlers

    # below.

    #

    ModPagespeedEnableFilters add_instrumentation

    # The add_instrumentation filter sends a beacon after the page onload

    # handler is called. The user might navigate to a new URL before this. If

    # you enable the following directive, the beacon is sent as part of an

    # onbeforeunload handler, for pages where navigation happens before the

    # onload event.

    #

    # ModPagespeedReportUnloadTime on

    # Uncomment the following line so that ModPagespeed will not cache or

    # rewrite resources with Vary: in the header, e.g. Vary: User-Agent.

    # Note that ModPagespeed always respects Vary: headers on html content.

    # ModPagespeedRespectVary on

    # Uncomment the following line if you want to disable statistics entirely.

    #

    # ModPagespeedStatistics off

    # These handlers are central entry-points into the admin pages.

    # By default, pagespeed_admin and pagespeed_global_admin present

    # the same data, and differ only when

    # ModPagespeedUsePerVHostStatistics is enabled.  In that case,

    # /pagespeed_global_admin sees aggregated data across all vhosts,

    # and the /pagespeed_admin sees data only for a particular vhost.

    #

    # You may insert other "Allow from" lines to add hosts you want to

    # allow to look at generated statistics.  Another possibility is

    # to comment out the "Order" and "Allow" options from the config

    # file, to allow any client that can reach your server to access

    # and change server state, such as statistics, caches, and

    # messages.  This might be appropriate in an experimental setup.

    <Location /pagespeed_admin>

        Order allow,deny

        Allow from localhost

        Allow from 127.0.0.1

        SetHandler pagespeed_admin

    </Location>

    <Location /pagespeed_global_admin>

        Order allow,deny

        Allow from localhost

        Allow from 127.0.0.1

        SetHandler pagespeed_global_admin

    </Location>

    # Enable logging of mod_pagespeed statistics, needed for the console.

    ModPagespeedStatisticsLogging on

    # Page /mod_pagespeed_message lets you view the latest messages from

    # mod_pagespeed, regardless of log-level in your httpd.conf

    # ModPagespeedMessageBufferSize is the maximum number of bytes you would

    # like to dump to your /mod_pagespeed_message page at one time,

    # its default value is 100k bytes.

    # Set it to 0 if you want to disable this feature.

    ModPagespeedMessageBufferSize 100000

    ModPagespeedImageMaxRewritesAtOnce -1

ModPagespeedEnableFilters remove_quotes

ModPagespeedEnableFilters elide_attributes

ModPagespeedEnableFilters remove_comments

ModPagespeedEnableFilters extend_cache

ModPagespeedForceCaching on

ModPagespeedEnableFilters make_google_analytics_async

ModPagespeedEnableFilters local_storage_cache

ModPagespeedEnableFilters inline_css

ModPagespeedEnableFilters inline_javascript

ModPagespeedLazyloadImagesAfterOnload off

ModPagespeedLazyloadImagesBlankUrl "https://www.gstatic.com/psa/static/1.gif"

ModPagespeedEnableFilters prioritize_critical_css

ModPagespeedEnableFilters collapse_whitespace

ModPagespeedEnableFilters recompress_images

ModPagespeedEnableFilters convert_jpeg_to_progressive

ModPagespeedEnableFilters convert_gif_to_png

ModPagespeedEnableFilters convert_to_webp_lossless

ModPagespeedEnableFilters trim_urls

ModPagespeedEnableFilters strip_image_color_profile

ModPagespeedEnableFilters strip_image_meta_data

ModPagespeedEnableFilters jpeg_subsampling

ModPagespeedEnableFilters convert_png_to_jpeg

ModPagespeedEnableFilters resize_images

ModPagespeedEnableFilters resize_rendered_image_dimensions

ModPagespeedEnableFilters convert_jpeg_to_webp

ModPagespeedEnableFilters convert_to_webp_animated

ModPagespeedEnableFilters convert_to_webp_lossless

ModPagespeedImageRecompressionQuality 85

ModPagespeedRespectXForwardedProto on

ModPagespeedEnableFilters insert_dns_prefetch

ModPagespeedEnableFilters hint_preload_subresources

ModPagespeedDomain *

ModPagespeedCssFlattenMaxBytes 100000

ModPagespeedCssInlineMaxBytes 1000000

ModPagespeedGoogleFontCssInlineMaxBytes 100000

ModPagespeedJsInlineMaxBytes 100000

ModPagespeedCssFlattenMaxBytes 100000

ModPagespeedEnableFilters lazyload_images

ModPagespeedLazyloadImagesAfterOnload off

ModPagespeedLazyloadImagesBlankUrl "https://www.gstatic.com/psa/static/1.gif"

ModPagespeedEnableFilters trim_urls

ModPagespeedFetchHttps enable

</IfModule>

pagespeed debug doesn't report anything preventing optimizing content.

[Longinos]

Can you share a url to test?

You have the VirtualHost in <IfModule pagespeed_module>block, so if the module don´t load, you have no web.

I suspect this not the whole apache config, even you need to include .htaccess file, because in this file can be rewrite rules that interfere whit pagespeed.

But, Ockham`s razor:

If the optimized resourse, the that have pagespeed in the url take times to appear and then disappear and restart the optimization process again....

What are you cache-control headers?

If you have a cache-control header for 5 mi (300 sec), some like cache-control: max-age=300, the the optimiation process must restart every 5 min.

and the optimization process take some time, to get all resources optimized take 2 or 3 hits.

Resorces need to be public cacheable aka no "private" "max-age=0" o things like it.

[George Vasiliadis]

Well, this config it's kinda complicated about the way you place the EnabledFilters but this it's not the problem. First of all you have to remove the # from     # ModPagespeedImageMaxRewritesAtOnce      8

line to allow more files for optimization at once. 

If you can share a URL to examinate!

στείλε μου σε προσωπικό αν έχεις θέμα να το δημοσιεύσεις.