# Deploying the Nominatim Python frontend
-The Nominatim can be run as a Python-based web application. You have the
+The Nominatim can be run as a Python-based
+[ASGI web application](https://asgi.readthedocs.io/en/latest/). You have the
choice between [Falcon](https://falcon.readthedocs.io/en/stable/)
and [Starlette](https://www.starlette.io/) as the ASGI framework.
-This section gives a quick overview on how to configure Nginx to server
+This section gives a quick overview on how to configure Nginx to serve
Nominatim. Please refer to the documentation of
-[Nginx](https://nginx.org/en/docs/) for background information on how to configure it.
+[Nginx](https://nginx.org/en/docs/) for background information on how
+to configure it.
!!! Note
- Throughout this page, we assume that your Nominatim project directory is
- located in `/srv/nominatim-project` and that you have installed Nominatim
+ Throughout this page, we assume your Nominatim project directory is
+ located in `/srv/nominatim-project` and you have installed Nominatim
using the default installation prefix `/usr/local`. If you have put it
somewhere else, you need to adjust the commands and configuration
accordingly.
### Installing the required packages
-The recommended way to deploy Python ASGI application is to run
-the ASGI runner (uvicorn)[https://uvicorn.org/]
-together with (gunicorn)[https://gunicorn.org/] HTTP server. We use
+The recommended way to deploy a Python ASGI application is to run
+the ASGI runner [uvicorn](https://uvicorn.org/)
+together with [gunicorn](https://gunicorn.org/) HTTP server. We use
Falcon here as the web framework.
Create a virtual environment for the Python packages and install the necessary
``` sh
sudo apt install virtualenv
virtualenv /srv/nominatim-venv
-/srv/nominatim-venv/bin/pip install SQLAlchemy PyICU psycopg[binary]\
+/srv/nominatim-venv/bin/pip install SQLAlchemy PyICU psycopg[binary] \
psycopg2-binary python-dotenv PyYAML falcon uvicorn gunicorn
```
### Setting up Nominatim as a systemd job
-Next you need to set up the application that serves Nominatim. This is
+Next you need to set up the service that runs the Nominatim frontend. This is
easiest done with a systemd job.
Create the following file `/etc/systemd/system/nominatim.service`:
User=www-data
Group=www-data
WorkingDirectory=/srv/nominatim-project
-ExecStart=/srv/nominatim-venv/bin/gunicorn -b unix:/run/nominatim.sock -w 14 -k uvicorn.workers.UvicornWorker nominatim.server.falcon.server:run_wsgi
+ExecStart=/srv/nominatim-venv/bin/gunicorn -b unix:/run/nominatim.sock -w 4 -k uvicorn.workers.UvicornWorker nominatim.server.falcon.server:run_wsgi
ExecReload=/bin/kill -s HUP $MAINPID
-StandardOutput=append:/ssd/nominatim/log/gunicorn.log
+StandardOutput=append:/var/log/gunicorn-nominatim.log
StandardError=inherit
PrivateTmp=true
TimeoutStopSec=5
WantedBy=multi-user.target
```
+This sets up gunicorn with 4 workers (`-w 4` in ExecStart). Each worker runs
+its own Python process using
+[`NOMINATIM_API_POOL_SIZE`](../customize/Settings.md#nominatim_api_pool_size)
+connections to the database to serve requests in parallel.
+
Make the new service known to systemd and start it:
``` sh