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Bug
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Resolution: Fixed
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Minor
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4.1.5, 4.2.2, 4.3
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MOODLE_401_STABLE, MOODLE_402_STABLE, MOODLE_403_STABLE
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MOODLE_401_STABLE, MOODLE_402_STABLE
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MDL-79285_401 -
Copied from
MDL-76397Important note
While looking to this issue I detected that there are some problems with this extension and PHP 8.0 and up (see https://github.com/tideways/php-xhprof-extension/issues/107). To workaround that, you can:
- Use the PECL xhprof extension instead of tideways one (not tested here!)
- Alternatively, use any of our php docker images that come with PECL xhprof installed (via moodle-docker or similar solution).
Requirements
- To have some of the 2 xhprof extensions (tideways or PECL) enabled.
- To have "dot" (that comes with the Graphviz package) installed.
- Add the path to "dot" in the config.php
$CFG->pathtodot = '/opt/local/bin/dot';
Install the tideways_xhprof PHP extension
Install the tideways extension for PHP7, see https://github.com/tideways/php-profiler-extension for Installation instructions. Or if you're on Ubuntu/LinuxMint, follow the instructions below
Ubuntu/LinuxMint install instructions
- Update your system
sudo apt update && sudo apt upgrade -y - Download the precompiled tideways_xhprof extension installer for Debian-based systems:
wget https://github.com/tideways/php-xhprof-extension/releases/download/v5.0.4/tideways-xhprof_5.0.4_amd64.deb - Install the package
sudo dpkg -i tideways-xhprof_5.0.4_amd64.deb - Check your PHP version
php -v - Check the contents of /usr/lib/tideways_xhprof
ls /usr/lib/tideways_xhprof - Make sure that there is a .so file that matches your current PHP version. For example, if you're on PHP 7.4, then confirm that tideways_xhprof-7.4.so is available in that folder.
- Using your favourite editor, create a "tideways_xhprof.ini" under /etc/php/[YOUR_PHPVERSION]/mods-available. e.g. if you're on PHP 7.4 on LinuxMint with xed as the editor:
sudo xed /etc/php/7.4/mods-available/tideways_xhprof.ini - Paste the following line in tideways_xhprof.ini pointing to the path of the tideways_xhprof extension file matching your PHP version.
extension=/usr/lib/tideways_xhprof/tideways_xhprof-7.4.so - Enable the tideways_xhprof extension
sudo phpenmod tideways_xhprof - Install Graphviz. (This is required for generating the callgraph of the profiling run)
sudo apt install graphviz - Restart your webserver
sudo service apache2 restart - Check your phpinfo() page. Search for tideways_xhprof and confirm that it is present.
Mac install instructions
- Start the apple font if you encounter error regarding apple font
sudo launchctl load -w /System/Library/LaunchAgents/com.apple.fontd.useragent.plist - Restart your webserver
brew services restart httpd - Make sure xhprof is enabled by going to "admin/phpinfo.php"
Enabling xhprof
- Make sure "Developer mode" is turned on.
- Go to "Site administration / Development / Profiling"
- Tick "Enable profiling".
- Under "Profile these", enter "/index.php"
- Save changes
Test export & graphs performance
- Go to the "Site home".
- Scroll down to the bottom of the page. Confirm that there is a link named "This script has been profiled"
- Click the "This script has been profiled" link.
- Confirm that it loads okay.
- Click "Export this profiling run"
- Confirm that a .mpr file archive is downloaded containing XML files is generated (rename it to .zip and uncompress if needed).
- Click "View profiling details".
- Confirm that a table of function calls is displayed.
- Click on "View Full Callgraph"
- Confirm that the call graph is generated.
- Confirm that it's quick (1-2 seconds at most, not minutes/hours/crashing anymore).
Test the new "reducedata" parameter.
- Go to the "Site home".
- Scroll down to the bottom of the page. Confirm that there is a link named "This script has been profiled"
- Click the "This script has been profiled" link.
- Confirm that it loads okay.
- Click "View profiling details".
- Confirm that a table of function calls is displayed.
- Confirm that you can see a lot of "__Mustache_xxxxxx" entries in the table, with long hexadecimal suffixes. Some of them are shown together.
- On separate tabe Edit the URL of the page and add (without the quotes): "&reducedata=1"
- Press enter.
- Confirm that now there are a lot less of "__Mustache_xxxx" entries in the table. Easiest was to verify is to click 'display all' link in the bottom and sort table by function name
- Confirm that all the links in the page have that "&reducedata=1" added to them.
- Navigate following various links to entries in the table.
- Confirm that the "&reducedata=1" persists in the URL all the time.
- Click on the "View Top Level Run Report" link.
- Confirm that the "&reducedata=1" is part of it.
- Edit the URL of the page and add (without the quotes): "&reducedata=0"
- Press enter.
- Confirm that all the links in the page don't have any "reducedata" any more.
- Confirm that the table is again showing a lot of "__Mustache" entries, like it was in step 7.
Copied from MDL-76397 Important note While looking to this issue I detected that there are some problems with this extension and PHP 8.0 and up (see https://github.com/tideways/php-xhprof-extension/issues/107 ). To workaround that, you can: Use the PECL xhprof extension instead of tideways one (not tested here!) Alternatively, use any of our php docker images that come with PECL xhprof installed (via moodle-docker or similar solution). Requirements To have some of the 2 xhprof extensions (tideways or PECL) enabled. To have "dot" (that comes with the Graphviz package) installed. Add the path to "dot" in the config.php $CFG->pathtodot = '/opt/local/bin/dot'; Install the tideways_xhprof PHP extension Install the tideways extension for PHP7, see https://github.com/tideways/php-profiler-extension for Installation instructions. Or if you're on Ubuntu/LinuxMint, follow the instructions below Ubuntu/LinuxMint install instructions Update your system sudo apt update && sudo apt upgrade -y Download the precompiled tideways_xhprof extension installer for Debian-based systems: wget https://github.com/tideways/php-xhprof-extension/releases/download/v5.0.4/tideways-xhprof_5.0.4_amd64.deb Install the package sudo dpkg -i tideways-xhprof_5.0.4_amd64.deb Check your PHP version php -v Check the contents of /usr/lib/tideways_xhprof ls /usr/lib/tideways_xhprof Make sure that there is a .so file that matches your current PHP version. For example, if you're on PHP 7.4, then confirm that tideways_xhprof-7.4.so is available in that folder. Using your favourite editor, create a " tideways_xhprof.ini " under /etc/php/ [YOUR_PHPVERSION] /mods-available. e.g. if you're on PHP 7.4 on LinuxMint with xed as the editor: sudo xed /etc/php/7.4/mods-available/tideways_xhprof.ini Paste the following line in tideways_xhprof.ini pointing to the path of the tideways_xhprof extension file matching your PHP version. extension=/usr/lib/tideways_xhprof/tideways_xhprof-7.4.so Enable the tideways_xhprof extension sudo phpenmod tideways_xhprof Install Graphviz. (This is required for generating the callgraph of the profiling run) sudo apt install graphviz Restart your webserver sudo service apache2 restart Check your phpinfo() page. Search for tideways_xhprof and confirm that it is present. Mac install instructions Start the apple font if you encounter error regarding apple font sudo launchctl load -w /System/Library/LaunchAgents/com.apple.fontd.useragent.plist Restart your webserver brew services restart httpd Make sure xhprof is enabled by going to "admin/phpinfo.php" Enabling xhprof Make sure " Developer mode " is turned on. Go to " Site administration / Development / Profiling " Tick " Enable profiling ". Under " Profile these ", enter " /index.php " Save changes Test export & graphs performance Go to the " Site home ". Scroll down to the bottom of the page. Confirm that there is a link named " This script has been profiled " Click the " This script has been profiled " link. Confirm that it loads okay. Click " Export this profiling run " Confirm that a .mpr file archive is downloaded containing XML files is generated (rename it to .zip and uncompress if needed). Click " View profiling details ". Confirm that a table of function calls is displayed. Click on " View Full Callgraph " Confirm that the call graph is generated. Confirm that it's quick (1-2 seconds at most, not minutes/hours/crashing anymore). Test the new "reducedata" parameter. Go to the " Site home ". Scroll down to the bottom of the page. Confirm that there is a link named " This script has been profiled " Click the " This script has been profiled " link. Confirm that it loads okay. Click " View profiling details ". Confirm that a table of function calls is displayed. Confirm that you can see a lot of "__Mustache_xxxxxx" entries in the table, with long hexadecimal suffixes. Some of them are shown together. On separate tabe Edit the URL of the page and add (without the quotes): "&reducedata=1" Press enter. Confirm that now there are a lot less of "__Mustache_xxxx" entries in the table. Easiest was to verify is to click 'display all' link in the bottom and sort table by function name Confirm that all the links in the page have that "&reducedata=1" added to them. Navigate following various links to entries in the table. Confirm that the "&reducedata=1" persists in the URL all the time. Click on the "View Top Level Run Report" link. Confirm that the "&reducedata=1" is part of it. Edit the URL of the page and add (without the quotes): "&reducedata=0" Press enter. Confirm that all the links in the page don't have any "reducedata" any more. Confirm that the table is again showing a lot of "__Mustache" entries, like it was in step 7.
Detected @ MDL-76397, and also when trying to use XHProf here and there...
The complexity of our requests has grown enormously, with way more code involved on each (aka, super big stack traces, basically).
Also, more specifically, the use of Mustache templates, with all their partials, nested... have made XHProf profiling runs to near double in size.
While the visualisation in table mode of those profiling runs in "table mode" is still acceptable (no matter the enormous noise that the Mustache templates add), right now it's impossible to render a "callgraph" with the critical paths and other useful information.
So, this issue is about to:
Introduce some way to "reduce" the information available in XHProf profiling runs.- Apply such a reduction specifically to the Mustache templates calls.
- By default, use that "reduced" information when displaying call-graphs.
- By default, use the "full" information when displaying in table mode.
- Optional: Be able to pick between full and reduced in table mode.
This has some requirements, namely:
- The backed (database) always will store the full runs.
- The "reduction" will happen on demand when presenting the information (table or graph).
- The "reduction" needs to be consistent, not leading to "orphaned" data that can lead to misleading information.
- The need of hacking the xhprof library needs to be the smallest possible. Ideally zero (although I bet we'll need to add some line here and there).
- Covered with tests as much as possible.
And the goals are:
- General: To have a working system in place to "reduce" profiling runs information.
- Specific: To be able to get the call-graphs back to work, right now it's virtually impossible because of the complexity added by the Mustache templates.
Ciao 
