Backends¶
Wagtailsearch has support for multiple backends, giving you the choice between using the database for search or an external service such as Elasticsearch. The database backend is enabled by default.
You can configure which backend to use with the WAGTAILSEARCH_BACKENDS
setting:
WAGTAILSEARCH_BACKENDS = {
'default': {
'BACKEND': 'wagtail.wagtailsearch.backends.db',
}
}
AUTO_UPDATE
¶
New in version 1.0.
By default, Wagtail will automatically keep all indexes up to date. This could impact performance when editing content, especially if your index is hosted on an external service.
The AUTO_UPDATE
setting allows you to disable this on a per-index basis:
WAGTAILSEARCH_BACKENDS = {
'default': {
'BACKEND': ...,
'AUTO_UPDATE': False,
}
}
If you have disabled auto update, you must run the update_index command on a regular basis to keep the index in sync with the database.
ATOMIC_REBUILD
¶
New in version 1.1.
By default (when using the Elasticsearch backend), when the update_index
command is run, Wagtail deletes the index and rebuilds it from scratch. This causes the search engine to not return results until the rebuild is complete and is also risky as you can’t rollback if an error occurs.
Setting the ATOMIC_REBUILD
setting to True
makes Wagtail rebuild into a separate index while keep the old index active until the new one is fully built. When the rebuild is finished, the indexes are swapped atomically and the old index is deleted.
Warning
Experimental feature
This feature is currently experimental. Please use it with caution.
BACKEND
¶
Here’s a list of backends that Wagtail supports out of the box.
Database Backend (default)¶
wagtail.wagtailsearch.backends.db
Changed in version 1.1: Before 1.1, the full path to the backend class had to be specified: wagtail.wagtailsearch.backends.db.DBSearch
The database backend is very basic and is intended only to be used in development and on small sites. It cannot order results by relevance, severely hampering its usefulness when searching a large collection of pages.
It also doesn’t support:
- Searching on fields in subclasses of
Page
(unless the class is being searched directly)- Indexing callables and other attributes
- Converting accented characters to ASCII
If any of these features are important to you, we recommend using Elasticsearch instead.
Elasticsearch Backend¶
wagtail.wagtailsearch.backends.elasticsearch
Changed in version 1.1: Before 1.1, the full path to the backend class had to be specified: wagtail.wagtailsearch.backends.elasticsearch.ElasticSearch
Prerequisites are the Elasticsearch service itself and, via pip, the elasticsearch-py package:
Note
Wagtail doesn’t support Elasticsearch 2.0 yet; please use 1.x in the meantime. Elasticsearch 2.0 support is scheduled for a future release.
pip install elasticsearch
The backend is configured in settings:
WAGTAILSEARCH_BACKENDS = {
'default': {
'BACKEND': 'wagtail.wagtailsearch.backends.elasticsearch',
'URLS': ['http://localhost:9200'],
'INDEX': 'wagtail',
'TIMEOUT': 5,
}
}
Other than BACKEND
, the keys are optional and default to the values shown. In addition, any other keys are passed directly to the Elasticsearch constructor as case-sensitive keyword arguments (e.g. 'max_retries': 1
).
If you prefer not to run an Elasticsearch server in development or production, there are many hosted services available, including Bonsai, who offer a free account suitable for testing and development. To use Bonsai:
- Sign up for an account at Bonsai
- Use your Bonsai dashboard to create a Cluster.
- Configure
URLS
in the Elasticsearch entry inWAGTAILSEARCH_BACKENDS
using the Cluster URL from your Bonsai dashboard - Run
./manage.py update_index
Rolling Your Own¶
Wagtail search backends implement the interface defined in wagtail/wagtail/wagtailsearch/backends/base.py
. At a minimum, the backend’s search()
method must return a collection of objects or model.objects.none()
. For a fully-featured search backend, examine the Elasticsearch backend code in elasticsearch.py
.