eZ Publish Performance Optimization Part 2 of 3: Identifying Trouble Spots by Debugging

eZ Publish's site.ini.append.php configuration file contains some useful debug settings to customize the debug output's behavior:

SQLOutput

• Block: [DatabaseSettings]
• Description: When SQLOutput is enabled, eZ debug output displays the SQL queries used in processing the current view.

QueryAnalysisOutput

• Block: [DatabaseSettings]
• Description: This controls whether the queries should be analyzed for the debug output. It requires SQLOutput to be enabled. This setting is used as a way to obtain information about how MySQL executes a SELECT statement. It is useful for identifying slow queries.

Note: Currently this only works for MySQL, and not other types of database such as Oracle.

SlowQueriesOutput

• Block: [DatabaseSettings]
• Description: When this setting is larger than 0, queries are only shown in SQLOutput if the execution time takes more than the specified number of milliseconds. It is useful for identifying slow queries.

DebugByIP

• Block: [DebugSettings]
• Description: This setting controls whether the debug output is shown only to certain IP addresses. If enabled, it uses DebugIPList to determine which IPs are shown the debug output. IP ranges can be used in addition to individual IPs. This setting is very useful on "live" sites where you don't want every user to see the debug output.

DebugByUser

• Block: [DebugSettings]
• Description: This setting controls whether the debug output is shown only to certain users, similar to DebugByIP. If enabled, it uses DebugUserIDList to determine which users are shown the debug output. DebugUserIDList is an array of UserIDs.

Debug

• Block: [TemplateSettings]
• Description: When this setting is enabled, the debug output shows which template files are loaded. This option is useful when used in conjunction with the ShowXHTMLCode setting.

ShowXHTMLCode

• Block: [TemplateSettings]
• Description: If enabled, the template names are displayed as shown below.

The Administration Interface with ShowXHTMLCode and Debug enabled

When ShowXHTMLCode is set to disabled and Debug is enabled, the template names appear as XHTML comments, which can still be viewed in the page source code as shown below:

<!-- START: including template: design/standard/templates/page_head.tpl (design/standard/templates/page_head.tpl) -->

ShowUsedTemplates

• Block: [TemplateSettings]
• Description: When Debug and ShowUsedTemplates are enabled, the debug output shows a list of all templates used to render the current view.

DebugRedirection

• Block: [DebugSettings]
• Description: If DebugRedirection is enabled, whenever an internal page redirection occurs within eZ Publish, a redirection page with the debug output is displayed. This is especially useful for debugging workflows for custom extensions.

AlwaysLog

• Block: [DebugSettings]
• Description: By default, only major errors are stored in the error.log file under the path/to/ez_publish/var/log/ directory. You can specify which debug types to log with the AlwaysLog setting. error is the default value; warning, debug and notice are the other available values, in decreasing order of debug message severity. Using notice will log general notices and can fill up the log files quickly.