Fatal error Out of memory but I do have plenty of memory PHP

Question

Since my question is getting longer and longer  I decide to re-write the whole question to make it better and shorter   I run my website on dedicated server with 8GB memory  I am fully aware that I need to raise the memory limit on php ini setting  I have set it from 128M to 256M and to -1  Still the problem is persistence      Fatal error  Out of memory  allocated 786432   tried to allocate 24576   bytes  in D  www football views main php on line 81   The out of memory does not make sense because it said only 786432 bytes is allocated and it needed 24576 bytes more   786432 bytes is only 768 kilobytes and is fairly small   Hints   The error occurs on a very random line  It does not always error on line number 81  At peak time  Apache only takes around 500mb of memory  I still have 6GB to spare  There is no infinite loop  The script takes 1 042 424 bytes  Getting this number from echo memory get peak usage    The resultset from MySQL is small  at most 12 of rows  purely text  no blob data   Important  If I restart Apache once every two days  the error is gone  It usually happens when Apache is running more than 2 days  I have included the profiling the script and you can get it here  This dedicated server is purely used to run only one website  This website is a high traffic website with average of 1 000 visitors every minute  At peak time  there will be 1 700 to 2 000 visitors accessing at the same time    Server Spec     OS  Windows 2008 R2 64-Bit   CPU  Intel Core i5 - 4 cores   RAM  8 GB   Apache 2 2   PHP 5 3 1   Storage  2 x 1 TB hard drives   Bandwidth  10 TB per month   Solution  I have finally tuned up and fixed the problem and I would like to share it here what I have done to improve    favicon ico was missing which mess up with my route engine  Although my route engine is very small  but by including favicon ico  it helps reduce memory usage by not running my route engine  Most of part of my website has it and I forgot to put it for this new section  Limit MaxRequestPerChild helps  In my other dedicated server  I have my MaxRequestPerChild limited  For this server  I set it to 0  I always thought that each script is isolated  Lets say if my script takes 800kb to run  Upon its completion  Apache or PHP should free 800kb memory  It seem like it doesn t work this way  Limited MaxRequestPerChild does help to prevent memory leak by creating new process after limited MaxRequestPerChild and the old process is dying  This is my new setting   ThreadsPerChild      1500 MaxRequestsPerChild  10000   ob flush    does reduce slightly more memory  It does not help much but every bit of optimization helps  I have used xdebug which I have never used before as suggested by people who attempt to answer this question  I have to say it is great tool and I have optimized a few stuffs to make it run slightly faster  I have disable a few unnecessary Apache module  I am trying to disable it one by one and leave it a few days test to ensure it works perfectly before I disable another one  I do have all unnecessary PHP extension disable now  Most of my script in this server used traditional way  no template  no database layer  pure PHP  HTML  and legacy mysql   function   To be honest  it runs very fast and used extremely small memory  However  maintenance the script is not very easy as the website is getting longer  I have tried to convert some parts of the website into proper framework  my own tiny framework   The reason that I used my own framework because it is tiny  3kb for the whole framework and include only what I need   Switching to IIS7 5 solving this problem completely

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Please note that the error is Out of memory and is not Allowed memory size      exhausted   So the memory leak is elsewhere on the system  It s possible that mysql server use a lot of system memory after this heavy query  leaving apache php without it physical and swap   This should explain the error always on the same line  and or in the same script

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Most of the time you get such a error  problem is in code  I am not trying to say that you are writing code that is bad  I am trying to say that you need to carefully observe what s there in that is using this much amount of memory   Always remember  Garbage collection in PHP is pretty bad   it s not like Java  any other such language  there is a way to enforce garbage collection through gc collect cycle  but  in my personal opinion  that won t solve your problem  PHP free all memory used for executing a page  once request-response cycle is complete  so you may run into memory issues  if your script is long running  like a background script Gearman etc   because  memory isn t freed till script is running   If above is not the case with your scr pt  and as you said there is no code that requires such a huge amount of memory  then problem is most definitely in code it self  and upgrading to any version of PHP won t solve the problem  I was facing with one of my Gearman scripts once  and there was a problem with one of my loop where I was appending one variable to one of my array  the variable itself was very heavy  approx 110KB of data   So I would suggest  do a careful inspection of your code   Ravish

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This is a known bug in PHP v 5 2 for Windows  it is present at least to version 5 2 3  https   bugs php net bug php id 41615   None of the suggested fixes have helped for us  we re going to have to update PHP

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I had a similar problem with PHP   1  Check your error logs  Eliminate EVERY error before continuing  2  Consider modifying your apache configuration to eliminate unused modules - this will reduce the footprint needed by PHP - here s a great link for this - it s specific to Wordpress but should still be very useful http   thethemefoundry com blog optimize-apache-wordpress   To give you an idea of the kind of bug I found  I had some code that was trying to post content to Facebook  Facebook then modified their API so this broke  I also used a  content expirator  which basically meant that it kept retrying to post this content to Facebook and leaving loads of objects lying in memory

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Try to run php over fcgid  this may help      These are the classic errors you will see when running PHP as an   Apache module  We struggled with these errors for months  Switching to   using PHP via mod fcgid  as James recommends  will fix all of these   problems  Be sure you have the latest Visual C   Redistributable   package installed        http   support microsoft com kb 2019667       Also  I recommend switching to the 64-bit version of MySQL  No real   reason to run the 32-bit version anymore    Source  Apache 2 4 6 0 crash due to a problem in php5ts dll 5 5 1 0

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For my case  this error was triggered because of a huge select query  hundreds of thousands of returned results     It arose immediately after adding millions of records in my Database to test the scalability of WordPress  so it was the only probable reason for me

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From the profiler output file I ve noticed a couple of things which I did not like trust much and would look into these   Apart from not knowing the meaning of the output numbers to detect an anomaly or how PHP scripts work     Is this not a problem  Having an include to the same main ph file  which looks like a recursive thing   2121 fl D  www football views main php 2122 fn include  D  www football views main php   Noticed the file D  www football views main php is making use of some string functions several times  I guess it is calling these functions on the data returned by your query   strlen substr strtotime   If  like in the C language  these functions require strings be null terminated or some other end of string terminator to avoid memory problems  I would look at the strings returned by your query    Can you post the url of your website

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I know it s an old thread  but here s my experience getting it resolved  My server is a hosted service running Apache  My script crashed with out of memory at 6Mb  when my limit Was 256Mb - crazy  yeah  It is being called synchronously via an http callback  from javascript running on my client  and crashed after around 550 calls  After much time wasted with incompetent  quot Escalated Support quot  guys  my script now magically runs  They said all they did was to reset php ini  but I checked the differences   No changes there that I can see that could have a bearing on an Out of Memory error  I suspect a memory leak in the web server which my  quot Escalated Support quot  guy is hiding under the guise of resetting the php ini  And  really  I m not a conspiracy theorist

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this happened to me a few days ago  I did a fresh installation and it still happened  as far as everyone sees and based on your server specs  most likely it is an infinite loop  it could be not on the PHP code itself but on the requests made to Apache   lets say when you access this url http   localhost mysite page with multiple requests  Check your Apache s access log if it receives multiple requests  trace that request and check out the code that might cause a  bottleneck  to the system  mine s exec   when using sendmail   The bottleneck im talking about doesn t need to be an  infinite loop   It could be a function that takes sometime to finish  or maybe some of php s  program execution functions   You might need to check ajax requests too  the ones that execute when the page loads   if that ajax request redirects to the same url   e g  httpx   localhost mysite page with multiple requests  it would  redo  the requests all over again  it would help if you post the random lines or the code itself where the script ends maybe there is a  loop  code somewhere there  imho php won t just call random lines for nothing   http   blog piratelufi com 2012 08 browser-sending-multiple-requests-at-once

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Hey I also got the same problem on my server  I just changed the following things    change php ini to     memory limit   128M   and add to httpd conf  RLimitMEM 1073741824 2147483648   and restart apache  amp  i removed the error

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I would say the server is running out of physical swap memory  so PHP can t allocate enough memory   Can you paste the output of free here

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I would start by upgrading PHP to 5 4  as it s up to 50  faster for some applications  They fixed a large number of memory leaks  Please see becnhamrks  http   news php net php internals 57760

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Just to recap  I m adding this answer quite a distance from the original question     PHP is unable to allocate what appears to be a small amount of memory the current memory usage at the time the error occrs   the requested amount is less than the memory limit currently in force the system has 6Gb available for use by PHP when this occurs since the problem is resolved by restarting apache - it s apache which is preventing the memory from beig available to PHP   If these are all valid then the only possible explanation is that the 6Gb is very fragmented - which I think is a little unlikely  You didn t say how PHP is invoked from Apache - mod php  fpm  Fcgi   I would start by examining each of the above predicates - particularly the free memory one  How do you know that there s 6Gb free when the error occurs  A more likely cause is that there s a memory leak occurring which you re not spotting   You ve not provided any details of how apache is configured  I d also have a look at reducing MaxRequestsPerChild and MaxMemFree   I m not very familiar with worker apache where this will apply per thread - really you need a limit per process   If you provided the core setting from the apache config then maybe we could make further suggestions   Unless you are using Ajax extensively  make sure your keepalive time is 2 or less

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Fatal error  Out of memory  allocated SOLVED i had similar problem  for months no solution  finally i was checking in one of the apache folders i e  apache conf extra  i came across this file that controls the memory allocation of apache  the file name is httpd-mpm in that file you are to increase the MaxMemFree which is set 2048 to something higher  i took mine to 10000 for the first MaxMemFree  IfModule  mpm netware module  then made the second one MaxMemFree to 5000 IfModule mpm netware module   These solved my problem  hope it helps

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The following two facts definitely point to memory leaks    The error appears at different lines in your code  The error reports a relatively small memory allocation    I would first single out PDO  disabling all the other extensions and let it run overnight using something like Siege   Apache Bench  ab   You could also try running it using the cli interface  just make sure you keep the same memory limits    You could use the memory get peak usage   function at the end of your script to see how much memory PHP thinks it has been using   From your comment that s 800 kB  which is okay  definitely not the gigantic amount of memory that would cause an out-of-memory  -   Lastly  though I wouldn t recommend upgrading to 5 4 at this point  upgrading to the latest 5 3 x is probably worth it due to multiple vulnerabilities and leaks that have been addressed since 5 3 1

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I ran accross the same kind of problem with the server dying when trying to use the swap  This is because mod php does not free memory ever  So Apache processes keep growing either reaching apache or PHP s memory limit or  if there s no limit  crashing the server    Restarting apache makes it to spawn new fresh slim processes but as they run PHP scripts over time  they grow until problems arise    The solution is to make apache to kill processes after a certain number of queries served so it will create new ones   There are some questions related to that  reducing the MaxRequestsPerChild configuration option to  let s say 100  Defaults to 1000     Of course this may reduce server performances as it takes ressources to kill and spawn new processes but at least it keeps the site working  You might be tempted to raise the number of running processes to keep performances high  be sure PHP  or apache  memory limit x max number of processes do not get over your server s physical ram   Here s my experience  hope it helps

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For starters  memory get peak usage   will not be helpful here  It will only return the amount of memory which was allocated  and that is the same number which caused the error   memory get usage will return the active amount of memory which is being allocated when it is called    ini set  memory limit    256M    will set the maximum allowance of PHP s footprint on your systems Memory  If you are getting OOM at 768K  upping it will not fix the problem    There is no indication as to what version of PHP you are using  but I would suggest an upgrade immediately  There are several bugs where Zend s Memory Manager fails to deallocate memory  which would lead you exactly to the same problem   Are both your local server and your production server running the same version of OS  the same long bit and the same version of PHP  The answer will be no   If it is unrelated to the windows malloc   issue  being it is a sub domain and probably within a VirtualHost  and allocating only 768k  it almost sounds like an OS issue   Run tasklist from the command prompt when you access your script  Do you see an additional Apache thread  or Memory usage across the processes spike   One last idea is  run flush   and or ob flush    after each loop for the table row column  This should clear your buffer and save you some memory in the event this is where the issue is occurring

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Install xdebug and enable profiler trigger  Generate a profiler file  then post the cachegrind file if you still would not be able to tell the source of the problem   EDIT  profiler file of the page where the memory leak happens of course

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I would guess that you either haven t edited the right php ini or you haven t restarted PHP and or the webserver   Create a phpinfo php page in your docroot with the contents  lt  php phpinfo    to make sure you are changing the correct php ini  In addition to the location of the php ini file the webserver is using  it will also state the maximum script memory allowed   Next  I would add some stack traces to your page so you can see the chain of events that led to this  The following function will catch fatal errors and provide more information about what happened   register shutdown function function         if  error   error get last                     Should actually log this instead of printing out            var dump  error           var dump debug backtrace                 Personally  Nginx   PHP-FPM is what I have used for years since I left slow ol  Apache

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Could be an issue with MySQL and the number of open connections  hence why it sorts itself out when you restart every few days  Are they auto closing on script shutdown

[php] Fatal error: Out of memory, but I do have plenty of memory (PHP)

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