Another way to calculate PHP5-FPM max_children

This is a slight update from my previous post, but I stumbled across the following command  / method to help calculate the value of "pm.max_children" for PHP5-FPM.

echo "pm.max_children = $(( $(awk '/MemTotal:/ { printf "%d\n", ($2*0.66) }' /proc/meminfo) / $(ps --no-headers -o "rss,cmd" -C php5-fpm | awk '{ sum+=$1 } END { printf ("%d\n", sum/NR) }') ))"

Now whats interesting is that the suggested value return, is a ridiculously high value, but I think what comes out of this, is that it illustrates how much more RAM you can give  PHP5-FPM.

But (un)fortunately real world exists, and there are other existing services in play (e.g. MySQL could be installed).

So if you use the above command, I highly suggest you adjust the PHP5-FPM value sparingly, and thereafter recheck your Munin / Cacti etc

HTH
Brent

Adjusting PHP5-FPM child processes (Apache)

Every now and then, on a clients server, we get the following dreaded message:


WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 16 children, there are 4 idle, and 48 total children

So we will start off, by determining the non-swapped physical memory usage by each PHP5-FPM processes (notice its in kilo Bytes)

ps -ylC php5-fpm --sort:rss
ps --no-headers -o "rss,cmd" -C php5-fpm | awk '{ sum+=$1 } END { printf ("%d%s\n", sum/NR/1024,"M") }'

Thereafter I ran the following command to give me the total memory, of my current PHP5-FPM configuration.

ps -ylC php5-fpm --sort:rss | awk '!/RSS/ { s+=$8 } END { printf "%s\n", "Total memory used by PHP-FPM child processes: "; printf "%dM\n", s/1024 }'

In my case I still had plenty of RAM left.

Remember the appropriate value for pm.max_children can be calculated as:

pm.max_children = Total RAM of your server / Max child process size - in my case it was 67MB

pm.max_children = 70
pm.start_servers = 20
pm.min_spare_servers = 20
pm.max_spare_servers = 35
pm.max_requests = 500

Debian upgrade Wheezy to Jessie

Good day Guys

Here is my tip / howto to upgrade Debian Wheezy to Jessie.

I highly recommend first ensuring that your server is update.

So run:

# apt-get update

# apt-get upgrade

# apt-get dist-upgrade 

# apt-get -f install

Fix any outstanding issues. 

If all is good. You can start by changing you sources.list to reflect Jessie

sed -i 's/wheezy/jessie/g' /etc/apt/sources.list

sed -i 's/wheezy/jessie/g' /etc/apt/sources.list.d/*

The second sed is to ensure all other third pary repos reflect Jessie too.

There after you are good to go.

Run:

# rm -rf /etc/apt/preferences.d/*

# apt-get update

# apt-get upgrade

# apt-get dist-upgrade

# apt-get -f install 

This can take awhile.

After the upgrade it is recommended to reboot your system: 

# reboot

After your server has come up, for safety sake, run another 

# apt-get update

# apt-get upgrade
# apt-get -f install

You should have a new and shiny new OS, and you can verify, by using either 
hostnamectl or 
lsb_release -a

HTH
Brent