Configurable elasticsearch boosting

course_discovery/apps/edx_haystack_extensions/admin.py

+from django.contrib import admin
+from solo.admin import SingletonModelAdmin
+from course_discovery.apps.edx_haystack_extensions.models import ElasticsearchBoostConfig
+
+
+admin.site.register(ElasticsearchBoostConfig, SingletonModelAdmin)

course_discovery/apps/edx_haystack_extensions/backends.py

 from haystack.backends.elasticsearch_backend import ElasticsearchSearchBackend, ElasticsearchSearchEngine
 
+from course_discovery.apps.edx_haystack_extensions.models import ElasticsearchBoostConfig
+
 
 class SimpleQuerySearchBackendMixin(object):
     """
@@ -34,10 +36,21 @@ class SimpleQuerySearchBackendMixin(object):
             'auto_generate_phrase_queries': True,
         }
 
-        if search_kwargs['query'].get('filtered', {}).get('query', {}).get('query_string'):
-            search_kwargs['query']['filtered']['query']['query_string'] = simple_query
+        # https://www.elastic.co/guide/en/elasticsearch/reference/1.7/query-dsl-function-score-query.html
+        function_score_config = ElasticsearchBoostConfig.get_solo().function_score
+
+        function_score_config['query'] = {
+            'query_string': simple_query
+        }
+
+        function_score = {
+            'function_score': function_score_config
+        }
+
+        if search_kwargs['query'].get('filtered', {}).get('query'):
+            search_kwargs['query']['filtered']['query'] = function_score
         elif search_kwargs['query'].get('query_string'):
-            search_kwargs['query']['query_string'] = simple_query
+            search_kwargs['query'] = function_score
 
         return search_kwargs
 

course_discovery/apps/edx_haystack_extensions/migrations/0001_initial.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import jsonfield.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='ElasticsearchBoostConfig',
+            fields=[
+                ('id', models.AutoField(serialize=False, auto_created=True, verbose_name='ID', primary_key=True)),
+                ('function_score', jsonfield.fields.JSONField(help_text='JSON string containing an elasticsearch function score config.', verbose_name='Function Score', default={'boost': 5.0, 'boost_mode': 'multiply', 'functions': [], 'score_mode': 'multiply'})),
+            ],
+            options={
+                'abstract': False,
+            },
+        ),
+    ]

course_discovery/apps/edx_haystack_extensions/models.py

+from django.utils.translation import ugettext_lazy as _
+from jsonfield.fields import JSONField
+from solo.models import SingletonModel
+
+
+class ElasticsearchBoostConfig(SingletonModel):
+    """
+    Model used to store the elasticsearch boost configuration.
+    This includes a default JSON config for the function_score.
+    """
+
+    function_score = JSONField(
+        verbose_name=_('Function Score'),
+        help_text=_('JSON string containing an elasticsearch function score config.'),
+        null=False,
+        blank=False,
+        default={
+            'functions': [],
+            'boost': 1.0,
+            'score_mode': 'multiply',
+            'boost_mode': 'multiply'
+        }
+    )

course_discovery/apps/edx_haystack_extensions/tests/mixins.py

@@ -4,6 +4,7 @@ from haystack.backends import BaseSearchBackend
 from mock import patch
 
 from course_discovery.apps.core.tests.mixins import ElasticsearchTestMixin
+from course_discovery.apps.edx_haystack_extensions.models import ElasticsearchBoostConfig
 
 
 class SearchBackendTestMixin(ElasticsearchTestMixin):
@@ -34,6 +35,17 @@ class SimpleQuerySearchBackendMixinTestMixin(SearchBackendTestMixin):
         'analyze_wildcard': True,
         'auto_generate_phrase_queries': True,
     }
+    default_function_score = {
+        'function_score': {
+            'query': {
+                'query_string': simple_query
+            },
+            'functions': [],
+            'boost': 1.0,
+            'score_mode': 'multiply',
+            'boost_mode': 'multiply'
+        }
+    }
 
     def test_build_search_kwargs_all_qs_with_filter(self):
         with patch.object(BaseSearchBackend, 'build_models_list', return_value=['course_metadata.course']):
@@ -47,7 +59,7 @@ class SimpleQuerySearchBackendMixinTestMixin(SearchBackendTestMixin):
             kwargs = self.backend.build_search_kwargs(self.specific_query_string)
 
         self.assertIsNone(kwargs['query'].get('query_string'))
-        self.assertDictEqual(kwargs['query']['filtered']['query'].get('query_string'), self.simple_query)
+        self.assertDictEqual(kwargs['query']['filtered'].get('query'), self.default_function_score)
 
     def test_build_search_kwargs_all_qs_no_filter(self):
         with patch.object(BaseSearchBackend, 'build_models_list', return_value=[]):
@@ -61,7 +73,38 @@ class SimpleQuerySearchBackendMixinTestMixin(SearchBackendTestMixin):
             kwargs = self.backend.build_search_kwargs(self.specific_query_string)
 
         self.assertIsNone(kwargs['query'].get('filtered'))
-        self.assertDictEqual(kwargs['query'].get('query_string'), self.simple_query)
+        self.assertDictEqual(kwargs['query'], self.default_function_score)
+
+    def test_build_search_kwargs_function_score(self):
+        function_score = {
+            'functions': [
+                {
+                    'filter': {
+                        'term': {
+                            'type': 'micromasters'
+                        }
+                    },
+                    'weight': 10.0
+                }
+            ],
+            'boost': 5.0,
+            'score_mode': 'multiply',
+            'boost_mode': 'sum'
+        }
+        boost_config = ElasticsearchBoostConfig.get_solo()
+        boost_config.function_score = function_score
+        boost_config.save()
+
+        with patch.object(BaseSearchBackend, 'build_models_list', return_value=[]):
+            kwargs = self.backend.build_search_kwargs(self.specific_query_string)
+
+        expected_function_score = {
+            'function_score': function_score
+        }
+        expected_function_score['function_score']['query'] = {
+            'query_string': self.simple_query
+        }
+        self.assertDictEqual(kwargs['query'], expected_function_score)
 
 
 class NonClearingSearchBackendMixinTestMixin(SearchBackendTestMixin):

course_discovery/settings/base.py

@@ -48,6 +48,7 @@ THIRD_PARTY_APPS = [
     'django_comments',
     'taggit',
     'taggit_serializer',
+    'solo',
 ]
 
 PROJECT_APPS = [

course_discovery/settings/local.py

@@ -35,6 +35,7 @@ EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'
 if os.environ.get('ENABLE_DJANGO_TOOLBAR', False):
     INSTALLED_APPS += [
         'debug_toolbar',
+        'elastic_panel',
     ]
 
     MIDDLEWARE_CLASSES += (
@@ -43,6 +44,10 @@ if os.environ.get('ENABLE_DJANGO_TOOLBAR', False):
 
     DEBUG_TOOLBAR_PATCH_SETTINGS = False
 
+    DEBUG_TOOLBAR_PANELS = [
+        'elastic_panel.panel.ElasticDebugPanel'
+    ]
+
 INTERNAL_IPS = ('127.0.0.1',)
 # END TOOLBAR CONFIGURATION
 

docs/elasticsearch.rst

@@ -32,3 +32,41 @@ We use the query string syntax to search for courses. See `the Elasticsearch doc
 query string syntax, and :doc:`course_metadata` for a list of fields which can be searched.
 
 .. _the Elasticsearch documentation: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-query-string-query.html#query-string-syntax
+
+Result Boosting
+---------------
+
+We use the `function_score` to boost relevance based on configureable factors. See `the function_score documentation`_
+for a guide to how this function can be used to provide more relevant results.
+
+Example functions:
+
+Closest to today's date
+
+.. code-block:: json
+
+    {
+      "linear":{
+        "start":{
+          "origin":"now",
+          "scale":"1d",
+          "decay":0.5
+        }
+      },
+      "weight":10.0
+    }
+
+Specific result type
+
+.. code-block:: json
+
+    {
+      "filter":{
+        "term":{
+          "type":"micromaster"
+        }
+      },
+      "weight": 5.0
+    }
+
+.. _the function_score documentation: https://www.elastic.co/guide/en/elasticsearch/reference/1.7/query-dsl-function-score-query.html

requirements/base.txt

@@ -11,6 +11,7 @@ django-guardian==1.4.5
 django-haystack==2.5.0
 django-libsass==0.7
 django-simple-history==1.8.1
+django-solo==1.1.2
 django-sortedm2m==1.3.2
 django-stdimage==2.3.3
 django-storages==1.5.0
@@ -32,6 +33,7 @@ edx-opaque-keys==0.3.1
 edx-rest-api-client==1.6.0
 elasticsearch>=1.0.0,<2.0.0
 html2text==2016.5.29
+jsonfield==1.0.3
 pillow==3.3.0
 pycountry==1.20
 python-dateutil==2.5.3

requirements/local.txt

@@ -3,7 +3,7 @@
 -r docs.txt
 
 django-debug-toolbar==1.5
-
+django-elasticsearch-debug-toolbar==1.0.4
 # i18n
 transifex-client==0.12.2
 git+https://github.com/edx/i18n-tools.git@v0.3.2#egg=i18n_tools==0.3.2