Debugging, Monitoring andProfiling

Fabrizio Brancafabrizio (dot) branca (at) aoemedia (dot) de

Twitter: @fbrnc

This talk is…

• sharing some best practices

• sharing some tools with you

• an (incomplete) checklist

• a reminder (hopefully)

Fabrizio Branca

What is this all about?

• Make your website run smoothly!

• during development…

• and when the site is online

• “Smoothly” is

• No bugs (unexpected behaviour)

• Stability

• PerformanceFabrizio Branca

This talk is about

How to…

• avoid errors

• detect errors

• deal with errors

• notify yourself when errors have occurred

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It„s all about bugs

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It„s all about bugs

Everybody creates bugs. Nobody is perfect.

A high percentage of coding time goes into• searching for bugs

• fixing bugs

Increase your productivity by reducing this time!

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Automating

• Automatize error recognition

• Use proper tools

• Automatize error reporting

• Route detailed error reports into your mailbox

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Bugs

• Avoid bugs

• through programming style

• Spot bugs fast

• “Safety nets”: Unit tests, Assertions

• Detect them before the customer and/or the website user finds them

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Avoid bugs

• Use a proper IDE

• Syntax checks

• Code Completion

Coding style

• Cover all cases: No if without else!

• Use type hints wherever possible

• Stick to patterns

• Increase crearity

• Convention over configuration

• KISS

• Use object collections

• Make it easier for team members to find and fix bugs(increase the truck factor) by sticking to codingguidelines and patterns

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What does PHP offer?

• log_errors

• display_errors

• error_log

Set values in

• php.ini

• .htaccess / vhost configuration

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What does TYPO3 offer?

• devLog, sysLog, Tslog

• devIpMask

• Deprecation log

• Page not found / Page unavailable

• Exception handling

• Error handling

• Debug Console in the BEFabrizio Branca

Deal with exceptions (I)

How to react when an exception hasoccurred?

• Don„t display any details to the user!

• Send a correct HTTP status code (forsearch engines and log files)

$GLOBALS['TSFE']->pageNotFoundAndExit($errorHandlerMessage);

$GLOBALS['TSFE']->pageUnavailableAndExit($errorHandlerMessage);

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Page not found

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Page unavailable

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Deal with exceptions (II)

Handle exceptions within your controllers.

Notify yourself:

• write a message to devLog

• write a message to sysLog

• write a message to TSLog

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Exception Handler

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Bug detection

• Bugs are harder to fix the later they are detected

• Bugs become harder to diagnose the further the symptom is removed from the cause

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Bug detection with assertions

• Make sure that variables contain what youexpect at any time (e.g. after calling a function)

• E.g.: Check incoming parameters for correcttype

• Simple one line call:tx_pttools_assert::isValidUid($this->params['uid']);

• Throws an exception if assertion is not true• http://articles.sitepoint.com/article/bug-detection-php-assertions

http://debuggable.com/posts/assert-the-yummyness-of-your-cake:480f4dd6-7fe0-4113-9776-458acbdd56cb

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Bug detection with assertions

• Assertions are easy to use.

• Don„t assume anything, check it!• Example: ini_set()

• No substitute for unit tests!

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Bug detection with assertions

See EXT:pt_tools/res/staticlib/class.tx_pttools_assert.php

orbuild your own assert class

Some examples:• tx_pttools_assert::isValidUid();

• tx_pttools_assert::isNotEmptyString();

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t3lib_div::devLog()

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t3lib_div::sysLog()

Decides by configuration how to handle syslog messages

• send mail

• write to log file

• write to OS syslog

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Custom SysLog Handler

See EXT:tcaobjects/res/class.tx_tcaobjects_syslog.php

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SysLog notification mail

msg: Assertion "isValidUid" failed!extKey: pt_toolsseverity: 3exceptionClass: tx_pttools_exceptionAssertiondebugMsg:

file: /var/www/burghalle/integration/htdocs/typo3conf/ext/aoe_burg/controller/class.tx_aoeburg_controller_extranet.phpline: 78function: tx_aoeburg_controller_extranet::initassertType: isValidUidval: expected: 1

Server: TYPO3_REQUEST_URL: http://www.integration.burghalle.aoe-works.de/xtranet/uebersicht/artikel-

bearbeiten/e/typo3conf/ext/burghalle_template/i/white-75.pngHTTP_REFERER: http://www.integration.burghalle.aoe-works.de/xtranet/uebersicht/artikel-bearbeiten/e/saveContent.htmlPOST: -- none --COOKIE:

condensed: 0fe_typo_user: 6b7ccec749891321cb6e7e2fc4c685a4PHPSESSID: 4b8712f5a4c845029da1f2332cf9132b

Client: HTTP_USER_AGENT: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.4) Gecko/20100611 Firefox/3.6.4 ( .NET CLR

3.5.30729; .NET4.0C)Spider: NoREMOTE_HOST: [null]REMOTE_ADDR: 217.19.187.106

User: FE_User: aoeBE_User: -- no user --

Trace: [...]

$TYPO3_DB->debug_check_recordset()

• Check all database queries

• Debug_check_recordset takes care ofwriting log messages

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TSlog

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$TT->push() / ->pull()

Use the timetrack object to keep track of what happens in your code.

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Reports module

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Reports module

Write your own reports

Examples:• Table size

• Outdated extensions (extension manager)

• TCA Integrity

• TCA/database integrity (Like Compare tool)

• Extension integrity (dependencies, conflicts)

• Free disk space

• Server load

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Define a strong api

• Provide interfaces for hooks.

• Allow alternatives (pagerStrategy, viewClass,…)

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Keep an eye on the logs…

• Webserver

• Apache error log

• PHP error log

• TYPO3

• Log module (Core error handler…)

• Admin Panel

• RealUrl

• error log

• are all paramters encoded?

• Deprecation log

• Reports module

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Keep an eye on the logs…

• External tools

• Google Webmaster Tools

• Wget

• Piwik

• MySQL

• Slow query log

• OS (*nix)

• Syslog

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Log Module

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Google Webmaster Tools

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Let tools do the analysis

• PHP

• TSFE

• TypoScript

• jQuery code

• HTML

• CSS

• RSSFabrizio Branca

Visualizing xdebug profiling

Visualizing xdebug profiling

Visualizing pdepend xml

jQuery Lint

„Runtime Reporter“

http://james.padolsey.com/javascript/jquery-lint/

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TypoScript Check (lint)

Proof of concept!

Xclassing tslib_content:

function stdWrap($content,$conf) {

$this->getLinkChecker()->check($conf, 'stdWrap');

return parent::stdWrap($content, $conf);

}

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Tick

Tick

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Tick

Use validators

Use validators for validating

• HTML

• CSS

• RSS

Keep an eye on editor„s content

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Spot performance killers

• Use USER_INTs only if really needed.

• Create links with cHashes

• Avoid putting USER_INTs on all pages(load them via ajax)

• Cache headers

• Static publishing

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Monitoring

• Configure your TYPO3 instances to notify you when errors occur.

• Use Monitoring tools (e.g. Nagios, Caretaker?)

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Pingdom

Maintainance

• Delete old temp filesfind ../htdocs/typo3temp -type f -mtime +28 -delete

• Delete deleted records

• Delete unreferenced files

• Cleanup/check database

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