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litespeed_wiki:php:slow_log_lsapi [2017/12/12 20:54]
Robert Perper
litespeed_wiki:php:slow_log_lsapi [2017/12/12 21:15] (current)
Lisa Clarke
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-====== Identify ​scripts that are slow on your server ​======+====== Identify ​Scripts That are Slow on Your Server ​======
  
-When working with php, you will notice that your site is taking longer to load then expected. ​Learning why your site is loading so slow would be great. You can do an strace but sometimes that information is not always ​the best to read.+When working with PHP, you may notice that your site is taking longer to load than expected. ​It would be useful to learn the reason why. You can do an ''​strace'' ​but sometimes that information is not the easiest ​to read.
  
-If you are a PHP programmer, you must have used PHP’s error_log function ​sometime. But PHP itself does not provide a way to identify slow scripts. ​+If you are a PHP programmer, you must have used PHP’s ​''​error_log'' ​function ​at some point. But PHP itself does not provide a way to identify slow scripts. ​
  
-Slow scripts ​are not the ones which necessarily break your site but they can be slow in themselves and slow-down your server overall as they increase CPU overhead. ​ With PHP-FPM, there is a slow_log function, by which developers can get a trace of what functions ​are running longer than a specified ​time+Slow scripts ​don'​t ​necessarily break your sitebut they can be slow by themselves ​//and// they can slow down your server overall as they increase CPU overhead. ​ With PHP-FPM, there is a ''​slow_log'' ​function, by which developers can get a trace of functions ​whose runtime exceeds ​a specified ​threshold.
  
-LiteSpeed uses the faster LiteSpeed API (LSPHP) instead of PHP-FPM.  ​What's the best way to identify slow scripts with LSWS and LSPHP?+LiteSpeed uses the faster LiteSpeed API (LSPHP) instead of PHP-FPM.  ​So, what's the best way to identify slow scripts with LSWS and LSPHP?
  
-There is a directivewhich can be placed ​at external application settings ​(WebAdmin console > Configuration > External App Environment). +There is a directive which can be placed ​in the external application settings. Navigate to **WebAdmin console > Configuration > External App** and add the following to **Environment**:
  
   LSAPI_SLOW_REQ_MSECS=10000   LSAPI_SLOW_REQ_MSECS=10000
    
-LSAPI_SLOW_REQ_MSECS: ​If set to a non-zero number, LiteSpeed Web Server will log requests into an error log file if a request takes longer than the specified number of milliseconds. This can help identify scripts that are slowing down your server.+If ''​LSAPI_SLOW_REQ_MSECS''​ is set to a non-zero number, LiteSpeed Web Server will log requests into an error log file if a request takes longer than the specified number of milliseconds. This can help to identify scripts that are slowing down your server.
  
 {{ :​litespeed_wiki:​php:​lsapi_slow_req_msecs_conf_example.png?​600 |}} {{ :​litespeed_wiki:​php:​lsapi_slow_req_msecs_conf_example.png?​600 |}}
   ​   ​
-Slow scripts are written to the stderr.log in the Litespeed ​log directory. ​ An example message would look like this:+The output of the slow script trace is written to ''​stderr.log'' ​in the LiteSpeed ​log directory. ​ An example message would look like this:
  
    ​[12/​Dec/​2017:​15:​37:​41] Slow PHP script: 10993 ms    ​[12/​Dec/​2017:​15:​37:​41] Slow PHP script: 10993 ms
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      ​Script:​ /​home/​user/​olsws/​Example/​html/​wordpress/​index.php      ​Script:​ /​home/​user/​olsws/​Example/​html/​wordpress/​index.php
  
-There may be many of these messages. ​ Note that script slow-downs tend to appear in groups around the time of highest CPU load.  You should try to identify what is slowing down the script with the script author.+There may be many of these messages. ​ Note that script slow-downs tend to appear in groups around the time of highest CPU load. When looking ​to identify what is slowing down script, a good place to start is with the script'​s ​author.
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  • Last modified: 2017/12/12 21:15
  • by Lisa Clarke