Too many open files

Every process in Linux runs with limits. One of these limits is the number of files and network sockets a process can open at the same time. When the limit is too low, you may see the error Too many open files.

Astra and Open File Limits

In Astra, this error may appear when the system limit is not set high enough. By default, if you installed Astra with the command astra init (as described in our Quick Start guide), the limit is set to 65536 open files. This value is usually enough for most use cases.

If you start Astra in a different way, you need to make sure the open file limit is set correctly. Below are the common cases.

Starting with init.d

When using an init.d script, you must increase the limit before starting Astra. Add the ulimit -n 65536 line before the command that launches Astra.

Example script:

if [ "$1" = "start" ]; then
  /usr/bin/astra -c /etc/astra/astra.conf -p 8000 --pid /var/run/astra.pid --log /var/log/astra.log --daemon
elif [ "$1" = "stop" ]; then
  if [ -f /var/run/astra.pid ]; then
    kill $(cat /var/run/astra.pid)
  fi
elif [ "$1" = "restart" ]; then
  $0 stop
  sleep 1
  $0 start
fi

Starting with systemd

For systemd services, you should set the limit inside the service file. In the [Service] section, add:

[Service]
Type=simple
LimitNOFILE=65536
ExecStart=/usr/bin/astra -c /etc/astra/astra.conf -p 8000 --log /var/log/astra.log --no-stdout

This ensures Astra can open enough files and sockets without hitting the error.

Checking the Current Limit

You can check the current open file limit for a running process using the ulimit or cat commands.

If you are inside the same shell where Astra is running, run:

ulimit -n

This shows the maximum number of open files for that shell (and any processes started from it).

If Astra is already running as a daemon, find its process ID (PID) and check directly:

pidof astra

This returns the PID of the Astra process. Then run:

cat /proc/<PID>/limits | grep "open files"

Example output:

Max open files            65536                65536                files