template changes take some seconds to recompile with PHP5 opcache enabled. #72

calguy1000 · 2015-07-16T16:42:40Z

Problem:

With Smarty opcache enabled (PHP 5.5+) template changes take some seconds to be recompiled.  This can cause problems when using caching of varying sorts to cache the rendered output from a compiled page

Severity: MAJOR

Symptoms:

Making a small change to a smarty template, and then browsing to the page has no effect.  You must wait for a few seconds or continuously reload in order to see the change.

How to reproduce:

1.  Ensure that the PHP 5.5+ opcache is enabled in the php.ini (default settings otherwise)
    opcache.enable=1

2.  Browse to the supplied testcase script with a browser, and see the rendered page

3.  Save a small change in the templates/index.tpl file

4.  Immediately reload the browser page.

Problem Area:

sysplugins/smarty_template_compiled.php smarty_template_compiled::process()
on line 174 the compiled template is 'included' to check for validity and wether it must be 'recompiled'
if it must be recompiled it is recompiled and 'included' again (line 179)
because this is within the opcache revalidate frequency, even though the timestamp on the php file has changed
the include has no effect (the opcache optimizes this out).

Sample code

<?php
include_once('smarty-3.1.27/libs/Smarty.class.php');
define('SMARTY_COMPILE_DIR',getcwd().'/tmp/templates_c');
define('SMARTY_CACHE_DIR',getcwd().'/tmp/cache');

ini_set('opcache.revalidate_freq',10); // by default this is 2

$smarty = new Smarty();
$smarty->setCompileDir(SMARTY_COMPILE_DIR);
$smarty->setCacheDir(SMARTY_CACHE_DIR);
$smarty->addTemplateDir(getcwd().'/templates');
$smarty->addConfigDir(getcwd().'/configs');

$data = [];
$data['title'] = 'Test Smarty and PHP 5.5 opcache';
$data['subtitle'] = 'Template changes have no effect for some seconds.';
$smarty->assign('data',$data);
$conf = opcache_get_configuration();
$smarty->assign('conf',$conf['directives']);
$smarty->display('index.tpl');

Test template

<html>
<head>
  <title>{$data.title}</title>
</head>
<body>
  <h1 style="text-align: center;">{$data.title}</h1>
  <h2 style="text-align: center;">{$data.subtitle}</h2>
  <h3 style="color: orange; text-align: center;">Make a small change to {$smarty.template} and immediately reload this page.</h3>
  <p>some text aa</p>
  <p>some text bb</p>
  <p>some text cc</p>
  <p>some text</p>
  <p>some text</p>
  <p>some text</p>
  <p>some text</p>
  <fieldset>
    <legend>Opcache configuration</legend>
    <table style="width: 100%;">
    {foreach $conf as $key => $val}
      <tr>
        <td>{$key}</td>
    <td>{$val}</td>
      </tr>
    {/foreach}
    </table>
  </fieldset>
</body>
</html>

The text was updated successfully, but these errors were encountered:

uwetews · 2015-07-19T16:58:10Z

I think the problem is the opcache.revalidate_freq parameter which controls how often opcache does check for modifications. It should be

opcache.revalidate_freq=0

which means always revalidate.

calguy1000 · 2015-07-19T17:39:13Z

I think that your solution is short sighted. The factory default setting of php 5.5 for the opcache is
opcache.revalidate_freq=2. changing it to 0 would result in a sub-optimal use of the opcode cache. Infact for sites that don't change often increasing this value is probably a good performance boost.

Which means that every person using smarty with PHP5 would need to adjust their php settings. This is not good for publicly distributed software applications using smarty.

A better solution would be to change the code such that this file does not get included twice.

A fallback solution would be to call opcache_invalidate on the file before including it.
something like: if( function_exists('opcache_invalidate') ) opcache_invalidate($filename);

Which should solve the problem without making every smarty user using PHP 5.5 adjust their PHP settings and would still take advantage of the opcode cache for repeated requests when the template does not need to be recompiled.

…mplates #72

uwetews · 2015-07-20T02:04:33Z

The patch is now in dev-master

…e-php5-to-php7-diagnostic-code-for-note-42 Redmine-#5313:[レスポンス改善] サーバーサイドをPHP5→PHP7にアップグレードする

uwetews closed this as completed Jul 19, 2015

uwetews added a commit that referenced this issue Jul 20, 2015

- improvement invalidate PHP 5.5 opcache for recompiled and cached te…

8cbe51a

…mplates #72

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template changes take some seconds to recompile with PHP5 opcache enabled. #72

template changes take some seconds to recompile with PHP5 opcache enabled. #72

calguy1000 commented Jul 16, 2015

uwetews commented Jul 19, 2015

calguy1000 commented Jul 19, 2015

uwetews commented Jul 20, 2015

template changes take some seconds to recompile with PHP5 opcache enabled. #72

template changes take some seconds to recompile with PHP5 opcache enabled. #72

Comments

calguy1000 commented Jul 16, 2015

Problem:

Severity: MAJOR

Symptoms:

How to reproduce:

Problem Area:

Sample code

Test template

uwetews commented Jul 19, 2015

calguy1000 commented Jul 19, 2015

uwetews commented Jul 20, 2015