high memory usage in php service on linux

Question

There is a 4gb memory usage per day and it does not clean at all

Have the following php script :

while(1){
    sleep(15);
    $data = // get data

    foreach ($data as $d){
        //get the db status
        // make api call in same ip to update server 
        // write log
    }
}

service linux code (via docker):

[program:cron]
command=/bin/bash -c "exec cron -f"
autostart=true
autorestart=true
startretries=3

What can be done to prevent that? it should be a sample service

@ThisGuyHasTwoThumbs because I need the service runs forever — Tuz, May 24 '18 at 06:58
then set up a cron job.. this is why you have such high memory usage xD — treyBake, May 24 '18 at 07:25
@ThisGuyHasTwoThumbs as you can see there is a cron job configured — Tuz, May 24 '18 at 08:43
then why do you need a while loop to make it run all the time? — treyBake, May 24 '18 at 08:45
So the cron starts new infinity loop every x time? So there could be like 1000 of those loops? O.o — Eakethet, May 24 '18 at 08:57
Please show your code. Since Stack Overflow hides the Close reason from you: *Questions seeking debugging help ("why isn't this code working?") must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Questions without a clear problem statement are not useful to other readers. See: [How to create a Minimal, Complete, and Verifiable example](http://stackoverflow.com/help/).* — jww, May 25 '18 at 00:52

score -1 · Answer 1 · answered May 24 '18 at 11:05

-1

It looks like you're using supervisord, why not swap the command out instead of running it through cron:

[program:phpscript]
command=/path/to/php /path/to/script.php
autostart=true
autorestart=true
startretries=3

answered May 24 '18 at 11:05

steadweb

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score -1 · Answer 2 · answered May 24 '18 at 11:13

Most likely you've got some data structure like an array which gets more data appended on each run and is never freed. There's also a chance that inside your loop, you're producing cycles in some way which are not collected immediately.

You can run a quick check by adding gc_collect_cycles(); after the foreach loop. If that solves the problem, great. You can read more about reference cycles at https://secure.php.net/manual/en/features.gc.collecting-cycles.php

Otherwise, you should have a look with a profiler to see what exactly is left allocated. See PHP memory profiling and other similar questions.

high memory usage in php service on linux

2 Answers2