FEATURE: Seamless embedding model upgrades (#1486)

app/jobs/scheduled/embeddings_backfill.rb

@@ -18,11 +18,24 @@ module Jobs
         )
       end
 
-      rebaked = 0
+      production_vector = DiscourseAi::Embeddings::Vector.instance
 
-      vector = DiscourseAi::Embeddings::Vector.instance
-      vector_def = vector.vdef
+      if SiteSetting.ai_embeddings_backfill_model.present? &&
+           SiteSetting.ai_embeddings_backfill_model != SiteSetting.ai_embeddings_selected_model
+        backfill_vector =
+          DiscourseAi::Embeddings::Vector.new(
+            EmbeddingDefinition.find_by(id: SiteSetting.ai_embeddings_backfill_model),
+          )
+      end
+
+      topic_work_list = []
+      topic_work_list << production_vector
+      topic_work_list << backfill_vector if backfill_vector
+
+      topic_work_list.each do |vector|
+        rebaked = 0
         table_name = DiscourseAi::Embeddings::Schema::TOPICS_TABLE
+        vector_def = vector.vdef
 
         topics =
           Topic
@@ -35,7 +48,7 @@ module Jobs
 
         rebaked += populate_topic_embeddings(vector, topics.limit(limit - rebaked))
 
-      return if rebaked >= limit
+        next if rebaked >= limit
 
         # Then, we'll try to backfill embeddings for topics that have outdated
         # embeddings, be it model or strategy version
@@ -47,7 +60,7 @@ module Jobs
 
         rebaked += populate_topic_embeddings(vector, relation, force: true)
 
-      return if rebaked >= limit
+        next if rebaked >= limit
 
         # Finally, we'll try to backfill embeddings for topics that have outdated
         # embeddings due to edits or new replies. Here we only do 10% of the limit
@@ -59,9 +72,7 @@ module Jobs
 
         populate_topic_embeddings(vector, relation, force: true)
 
-      return if rebaked >= limit
-
-      return unless SiteSetting.ai_embeddings_per_post_enabled
+        next unless SiteSetting.ai_embeddings_per_post_enabled
 
         # Now for posts
         table_name = DiscourseAi::Embeddings::Schema::POSTS_TABLE
@@ -85,7 +96,7 @@ module Jobs
             rebaked += batch.length
           end
 
-      return if rebaked >= limit
+        next if rebaked >= limit
 
         # Then, we'll try to backfill embeddings for posts that have outdated
         # embeddings, be it model or strategy version
@@ -102,7 +113,7 @@ module Jobs
             rebaked += batch.length
           end
 
-      return if rebaked >= limit
+        next if rebaked >= limit
 
         # Finally, we'll try to backfill embeddings for posts that have outdated
         # embeddings due to edits. Here we only do 10% of the limit
@@ -115,8 +126,7 @@ module Jobs
             vector.gen_bulk_reprensentations(Post.where(id: batch))
             rebaked += batch.length
           end
-
-      rebaked
+      end
     end
 
     private

config/settings.yml

@@ -230,6 +230,12 @@ discourse_ai:
     enum: "DiscourseAi::Configuration::EmbeddingDefsEnumerator"
     validator: "DiscourseAi::Configuration::EmbeddingDefsValidator"
     area: "ai-features/embeddings"
+  ai_embeddings_backfill_model:
+    type: enum
+    default: ""
+    allow_any: false
+    enum: "DiscourseAi::Configuration::EmbeddingDefsEnumerator"
+    hidden: true
   ai_embeddings_per_post_enabled:
     default: false
     hidden: true

lib/embeddings/schema.rb

@@ -20,8 +20,11 @@ module DiscourseAi
       MissingEmbeddingError = Class.new(StandardError)
 
       class << self
-        def for(target_klass)
-          vector_def = EmbeddingDefinition.find_by(id: SiteSetting.ai_embeddings_selected_model)
+        def for(target_klass, vector_def: nil)
+          vector_def =
+            EmbeddingDefinition.find_by(
+              id: SiteSetting.ai_embeddings_selected_model,
+            ) if vector_def.nil?
           raise "Invalid embeddings selected model" if vector_def.nil?
 
           case target_klass&.name

lib/embeddings/semantic_related.rb

@@ -3,6 +3,8 @@
 module DiscourseAi
   module Embeddings
     class SemanticRelated
+      CACHE_PREFIX = "semantic-suggested-topic-"
+
       def self.clear_cache_for(topic)
         Discourse.cache.delete("semantic-suggested-topic-#{topic.id}")
         Discourse.redis.del("build-semantic-suggested-topic-#{topic.id}")
@@ -79,14 +81,21 @@ module DiscourseAi
         )
       end
 
+      def self.clear_cache!
+        Discourse
+          .cache
+          .keys("#{CACHE_PREFIX}*")
+          .each { |key| Discourse.cache.delete(key.split(":").last) }
+      end
+
       private
 
       def semantic_suggested_key(topic_id)
-        "semantic-suggested-topic-#{topic_id}"
+        "#{CACHE_PREFIX}#{topic_id}"
       end
 
       def build_semantic_suggested_key(topic_id)
-        "build-semantic-suggested-topic-#{topic_id}"
+        "build-#{CACHE_PREFIX}#{topic_id}"
       end
     end
   end

lib/embeddings/vector.rb

@@ -25,7 +25,7 @@ module DiscourseAi
             idletime: 30,
           )
 
-        schema = DiscourseAi::Embeddings::Schema.for(relation.first.class)
+        schema = DiscourseAi::Embeddings::Schema.for(relation.first.class, vector_def: @vdef)
 
         embedding_gen = vdef.inference_client
         promised_embeddings =
@@ -58,7 +58,7 @@ module DiscourseAi
         text = vdef.prepare_target_text(target)
         return if text.blank?
 
-        schema = DiscourseAi::Embeddings::Schema.for(target.class)
+        schema = DiscourseAi::Embeddings::Schema.for(target.class, vector_def: @vdef)
 
         new_digest = OpenSSL::Digest::SHA1.hexdigest(text)
         return if schema.find_by_target(target)&.digest == new_digest

spec/jobs/scheduled/embeddings_backfill_spec.rb

@@ -20,6 +20,8 @@ RSpec.describe Jobs::EmbeddingsBackfill do
   end
 
   fab!(:vector_def) { Fabricate(:embedding_definition) }
+  fab!(:vector_def2) { Fabricate(:embedding_definition) }
+  fab!(:embedding_array) { Array.new(1024) { 1 } }
 
   before do
     SiteSetting.ai_embeddings_selected_model = vector_def.id
@@ -27,16 +29,14 @@ RSpec.describe Jobs::EmbeddingsBackfill do
     SiteSetting.ai_embeddings_backfill_batch_size = 1
     SiteSetting.ai_embeddings_per_post_enabled = true
     Jobs.run_immediately!
-  end
-
-  it "backfills topics based on bumped_at date" do
-    embedding = Array.new(1024) { 1 }
 
     WebMock.stub_request(:post, "https://test.com/embeddings").to_return(
       status: 200,
-      body: JSON.dump(embedding),
+      body: JSON.dump(embedding_array),
     )
+  end
 
+  it "backfills topics based on bumped_at date" do
     Jobs::EmbeddingsBackfill.new.execute({})
 
     topic_ids =
@@ -68,4 +68,19 @@ RSpec.describe Jobs::EmbeddingsBackfill do
 
     expect(index_date).to be_within_one_second_of(Time.zone.now)
   end
+
+  it "backfills embeddings for the ai_embeddings_backfill_model" do
+    SiteSetting.ai_embeddings_backfill_model = vector_def2.id
+    SiteSetting.ai_embeddings_backfill_batch_size = 100
+
+    Jobs::EmbeddingsBackfill.new.execute({})
+
+    topic_ids =
+      DB.query_single(
+        "SELECT topic_id from #{DiscourseAi::Embeddings::Schema::TOPICS_TABLE} WHERE model_id = ?",
+        vector_def2.id,
+      )
+
+    expect(topic_ids).to contain_exactly(first_topic.id, second_topic.id, third_topic.id)
+  end
 end