X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/cb70a2fde33e9c2455ea1cfb37ee430b00058b82..f3c557bf684a0079e4bc54b622cc5d766f3a6b56:/docs/admin/Update.md diff --git a/docs/admin/Update.md b/docs/admin/Update.md index a2323cfe..add1df5c 100644 --- a/docs/admin/Update.md +++ b/docs/admin/Update.md @@ -10,18 +10,21 @@ For a list of other methods to add or update data see the output of If you have configured a flatnode file for the import, then you need to keep this flatnode file around for updates. -#### Installing the newest version of Pyosmium +### Installing the newest version of Pyosmium -It is recommended to install Pyosmium via pip. Make sure to use python3. +The replication process uses +[Pyosmium](https://docs.osmcode.org/pyosmium/latest/updating_osm_data.html) +to download update data from the server. +It is recommended to install Pyosmium via pip. Run (as the same user who will later run the updates): ```sh pip3 install --user osmium ``` -#### Setting up the update process +### Setting up the update process -Next the update needs to be initialised. By default Nominatim is configured +Next the update process needs to be initialised. By default Nominatim is configured to update using the global minutely diffs. If you want a different update source you will need to add some settings @@ -45,12 +48,176 @@ what you expect. The `replication --init` command needs to be rerun whenever the replication service is changed. -#### Updating Nominatim +### Updating Nominatim -The following command will keep your database constantly up to date: +Nominatim supports different modes how to retrieve the update data from the +server. Which one you want to use depends on your exact setup and how often you +want to retrieve updates. + +These instructions are for using a single source of updates. If you have +imported multiple country extracts and want to keep them +up-to-date, [Advanced installations section](Advanced-Installations.md) +contains instructions to set up and update multiple country extracts. + +#### Continuous updates + +This is the easiest mode. Simply run the replication command without any +parameters: nominatim replication -If you have imported multiple country extracts and want to keep them -up-to-date, [Advanced installations section](Advanced-Installations.md) contains instructions -to set up and update multiple country extracts. +The update application keeps running forever and retrieves and applies +new updates from the server as they are published. + +You can run this command as a simple systemd service. Create a service +description like that in `/etc/systemd/system/nominatim-updates.service`: + +``` +[Unit] +Description=Continuous updates of Nominatim + +[Service] +WorkingDirectory=/srv/nominatim +ExecStart=nominatim replication +StandardOutput=append:/var/log/nominatim-updates.log +StandardError=append:/var/log/nominatim-updates.error.log +User=nominatim +Group=nominatim +Type=simple + +[Install] +WantedBy=multi-user.target +``` + +Replace the `WorkingDirectory` with your project directory. Also adapt user +and group names as required. + +Now activate the service and start the updates: + +``` +sudo systemctl daemon-reload +sudo systemctl enable nominatim-updates +sudo systemctl start nominatim-updates +``` + +#### One-time mode + +When the `--once` parameter is given, then Nominatim will download exactly one +batch of updates and then exit. This one-time mode still respects the +`NOMINATIM_REPLICATION_UPDATE_INTERVAL` that you have set. If according to +the update interval no new data has been published yet, it will go to sleep +until the next expected update and only then attempt to download the next batch. + +The one-time mode is particularly useful if you want to run updates continuously +but need to schedule other work in between updates. For example, the main +service at osm.org uses it, to regularly recompute postcodes -- a process that +must not be run while updates are in progress. Its update script +looks like this: + +```sh +#!/bin/bash + +# Switch to your project directory. +cd /srv/nominatim + +while true; do + nominatim replication --once + if [ -f "/srv/nominatim/schedule-maintenance" ]; then + rm /srv/nominatim/schedule-maintenance + nominatim refresh --postcodes + fi +done +``` + +A cron job then creates the file `/srv/nominatim/schedule-maintenance` once per night. + +##### One-time mode with systemd + +You can run the one-time mode with a systemd timer & service. + +Create a timer description like `/etc/systemd/system/nominatim-updates.timer`: + +``` +[Unit] +Description=Timer to start updates of Nominatim + +[Timer] +OnActiveSec=2 +OnUnitActiveSec=1min +Unit=nominatim-updates.service + +[Install] +WantedBy=multi-user.target +``` + +And then a similar service definition: `/etc/systemd/system/nominatim-updates.service`: + +``` +[Unit] +Description=Single updates of Nominatim + +[Service] +WorkingDirectory=/srv/nominatim +ExecStart=nominatim replication --once +StandardOutput=append:/var/log/nominatim-updates.log +StandardError=append:/var/log/nominatim-updates.error.log +User=nominatim +Group=nominatim +Type=simple + +[Install] +WantedBy=multi-user.target +``` + +Replace the `WorkingDirectory` with your project directory. Also adapt user and +group names as required. `OnUnitActiveSec` defines how often the individual +update command is run. + +Now activate the service and start the updates: + +``` +sudo systemctl daemon-reload +sudo systemctl enable nominatim-updates.timer +sudo systemctl start nominatim-updates.timer +``` + +You can stop future data updates, while allowing any current, in-progress +update steps to finish, by running `sudo systemctl stop +nominatim-updates.timer` and waiting until `nominatim-updates.service` isn't +running (`sudo systemctl is-active nominatim-updates.service`). Current output +from the update can be seen like above (`systemctl status +nominatim-updates.service`). + + +#### Catch-up mode + +With the `--catch-up` parameter, Nominatim will immediately try to download +all changes from the server until the database is up-to-date. The catch-up mode +still respects the parameter `NOMINATIM_REPLICATION_MAX_DIFF`. It downloads and +applies the changes in appropriate batches until all is done. + +The catch-up mode is foremost useful to bring the database up to speed after the +initial import. Give that the service usually is not in production at this +point, you can temporarily be a bit more generous with the batch size and +number of threads you use for the updates by running catch-up like this: + +``` +cd /srv/nominatim +NOMINATIM_REPLICATION_MAX_DIFF=5000 nominatim replication --catch-up --threads 15 +``` + +The catch-up mode is also useful when you want to apply updates at a lower +frequency than what the source publishes. You can set up a cron job to run +replication catch-up at whatever interval you desire. + +!!! hint + When running scheduled updates with catch-up, it is a good idea to choose + a replication source with an update frequency that is an order of magnitude + lower. For example, if you want to update once a day, use an hourly updated + source. This makes sure that you don't miss an entire day of updates when + the source is unexpectely late to publish its update. + + If you want to use the source with the same update frequency (e.g. a daily + updated source with daily updates), use the + continuous update mode. It ensures to re-request the newest update until it + is published.