Configuration via Environment Variables

Use these environment variables to configure Zammad’s behavior at runtime.

Note

🙋 What’s an environment variable, and how do I “use” it?

Unfortunately, that question has a very long answer that goes beyond the scope of this article. How you set environment variables will depend on how you installed Zammad (e.g., source, package, or Docker).

But for package installations, here’s a short answer:

# set OPTION to "value"
$ zammad config:set OPTION=value
$ systemctl restart zammad

# unset OPTION
$ zammad config:unset OPTION
$ systemctl restart zammad

To learn more, do some googling on environment variables and the shell environment (or execution environment) in Unix.

General Options

APP_RESTART_CMD

The command Zammad will use to automatically restart the server after changes have been made in the Object Manager. (E.g., "systemctl restart zammad")

If this is undefined, you will have to restart manually after making changes in the Object Manager.

Default: unset

RAILS_LOG_TO_STDOUT

Print output directly to standard output instead of /var/log/zammad/production.log.

Warning

On package installations, ⏫ this setting can be overwritten during update.

Use enabled to turn this option on only until the next update. Use true to turn it on permanently.

Default: unset

🖧 Network Options

ZAMMAD_BIND_IP

The IP address that the web server is bound to.

Default: 0.0.0.0

ZAMMAD_RAILS_PORT

The port that the web server is exposed on.

Default: 3000

ZAMMAD_WEBSOCKET_PORT

The port that the web socket server is exposed on.

Default: 6042

Note

Remember to update your web server config to reflect any changes you make here.

🎛️ Performance Tuning

Warning

⚖️ Each of these settings comes with its own tradeoffs.

There are no “recommended values” here; the optimal configuration will depend on your system’s resources and typical application load.

Proceed with caution; when adjusting any of these settings, there is a point at which performance will begin to degrade rather than improve, or other problems will begin to crop up.

Tip

🤔 How can I find out how many users are currently on Zammad?

$ zammad run rails r "p Sessions.list.uniq.count"
WEB_CONCURRENCY

How many instances of the application server to keep open at a time.

Increasing this can reduce loading times when too many users are on Zammad at once.

Default: unset

ZAMMAD_SESSION_JOBS_CONCURRENT

How many instances of the session worker to run at a time.

Increasing this can speed up background jobs (like the scheduler) when too many users are on Zammad at once.

Generally speaking, it should only be useful to adjust this setting if you have more than 40 active users at a time.

Warning

🥵 Session workers can be extremely CPU-intensive.

In some cases, they can reach 100% CPU utilization on their own. Increasing this setting is safer on systems with more cores.

Default: unset

Warning

Above settings may consume all available database connections. Please consider the database server configuration section for more.


Note

The options listed below allow you to distribute Zammad processes over several application nodes. Even if that’s not your goal, they may provide great benefits on bigger installations.

Please note that distribution of processes on several nodes is out of the scope of this documentation for various reasons.

REDIS_URL
Store your web socket connection information within Redis.
To do so, tell Zammad where to find your Redis instance: redis://your.redis.server:6379

If not provided, Zammad falls back to file system (/opt/zammad/tmp/websocket_*).

Default: unset

MEMCACHE_SERVERS
Store your application cache files within Memcached.
To do so, tell Zammad where to find your Memcached instance: your.memcached.server:11211

If not provided, Zammad falls back to file system (/opt/zammad/tmp/cache*).

Tip

🤓 Size may be important

Memcached allows you to restrict the maximum size Zammad may store as cache. This comes in handy in terms of performance and keeping caching files small. 1 GB should be a reasonable size.