fix: OpenSearch-3.x SQL stopped supporting DSL-format SQL JSON

integrations/opensearch/docker-compose.yml

@@ -1,13 +1,14 @@
 services:
   opensearch:
-    image: "opensearchproject/opensearch:2.11.0"
+    image: "opensearchproject/opensearch:3.5.0"
     ports:
       - 9200:9200
       - 9600:9600
     restart: on-failure
     environment:
       - discovery.type=single-node
       - "ES_JAVA_OPTS=-Xms1024m -Xmx1024m"
+      - "OPENSEARCH_INITIAL_ADMIN_PASSWORD=SecureHaystack!2026"
     healthcheck:
         test: curl --fail https://localhost:9200/_cat/health -ku admin:admin || exit 1
         interval: 10s

integrations/opensearch/src/haystack_integrations/document_stores/opensearch/document_store.py

@@ -2003,12 +2003,9 @@ def _query_sql(self, query: str, fetch_size: int | None = None) -> dict[str, Any
             if fetch_size is not None:
                 body["fetch_size"] = fetch_size
 
-            params = {"format": "json"}
-
             response_data = self._client.transport.perform_request(
                 method="POST",
                 url="/_plugins/_sql",
-                params=params,
                 body=body,
             )
 
@@ -2039,12 +2036,9 @@ async def _query_sql_async(self, query: str, fetch_size: int | None = None) -> d
             if fetch_size is not None:
                 body["fetch_size"] = fetch_size
 
-            params = {"format": "json"}
-
             response_data = await self._async_client.transport.perform_request(
                 method="POST",
                 url="/_plugins/_sql",
-                params=params,
                 body=body,
             )
 

integrations/opensearch/tests/conftest.py

@@ -28,11 +28,11 @@ def document_store():
     store = OpenSearchDocumentStore(
         hosts=hosts,
         index=index,
-        http_auth=("admin", "admin"),
+        http_auth=("admin", "SecureHaystack!2026"),
         verify_certs=False,
         embedding_dim=768,
         return_embedding=True,
-        method={"space_type": "cosinesimil", "engine": "nmslib", "name": "hnsw"},
+        method={"space_type": "cosinesimil", "engine": "lucene", "name": "hnsw"},
     )
     store._ensure_initialized()
     yield store
@@ -52,11 +52,11 @@ def document_store_2():
     store = OpenSearchDocumentStore(
         hosts=hosts,
         index=index,
-        http_auth=("admin", "admin"),
+        http_auth=("admin", "SecureHaystack!2026"),
         verify_certs=False,
         embedding_dim=768,
         return_embedding=False,
-        method={"space_type": "cosinesimil", "engine": "nmslib", "name": "hnsw"},
+        method={"space_type": "cosinesimil", "engine": "lucene", "name": "hnsw"},
     )
     yield store
 
@@ -81,10 +81,10 @@ def document_store_readonly():
     store = OpenSearchDocumentStore(
         hosts=hosts,
         index=index,
-        http_auth=("admin", "admin"),
+        http_auth=("admin", "SecureHaystack!2026"),
         verify_certs=False,
         embedding_dim=768,
-        method={"space_type": "cosinesimil", "engine": "nmslib", "name": "hnsw"},
+        method={"space_type": "cosinesimil", "engine": "lucene", "name": "hnsw"},
         create_index=False,
     )
     store._ensure_initialized()
@@ -109,11 +109,11 @@ def document_store_embedding_dim_4_no_emb_returned():
     store = OpenSearchDocumentStore(
         hosts=hosts,
         index=index,
-        http_auth=("admin", "admin"),
+        http_auth=("admin", "SecureHaystack!2026"),
         verify_certs=False,
         embedding_dim=4,
         return_embedding=False,
-        method={"space_type": "cosinesimil", "engine": "nmslib", "name": "hnsw"},
+        method={"space_type": "cosinesimil", "engine": "lucene", "name": "hnsw"},
     )
     yield store
 
@@ -133,7 +133,7 @@ def document_store_embedding_dim_4_no_emb_returned_faiss():
     store = OpenSearchDocumentStore(
         hosts=hosts,
         index=index,
-        http_auth=("admin", "admin"),
+        http_auth=("admin", "SecureHaystack!2026"),
         verify_certs=False,
         embedding_dim=4,
         method={"space_type": "innerproduct", "engine": "faiss", "name": "hnsw"},

integrations/opensearch/tests/test_document_store.py

@@ -164,12 +164,24 @@ def document_store(self, document_store):
 
     def assert_documents_are_equal(self, received: list[Document], expected: list[Document]):
         """
-        The OpenSearchDocumentStore.filter_documents() method returns a Documents with their score set.
-        We don't want to compare the score, so we set it to None before comparing the documents.
+        The OpenSearchDocumentStore.filter_documents() method returns documents with their score set.
+
+        We don't want to compare the score, so we set it to None before comparing.
+
+        Embeddings are not exactly the same when retrieved from OpenSearch (float round-trip),
+        so we compare them approximately and then set both to None for the final equality check.
         """
-        for doc in received:
-            doc.score = None
-        assert received == expected
+        assert len(received) == len(expected)
+        received = sorted(received, key=lambda x: x.id)
+        expected = sorted(expected, key=lambda x: x.id)
+        for received_doc, expected_doc in zip(received, expected, strict=True):
+            received_doc.score = None
+            if received_doc.embedding is None:
+                assert expected_doc.embedding is None
+            else:
+                assert received_doc.embedding == pytest.approx(expected_doc.embedding)
+            received_doc.embedding, expected_doc.embedding = None, None
+            assert received_doc == expected_doc
 
     def test_write_documents(self, document_store: OpenSearchDocumentStore):
         docs = [Document(id="1")]
@@ -983,24 +995,15 @@ def test_query_sql(self, document_store: OpenSearchDocumentStore):
 
         # Verify raw JSON response structure
         assert isinstance(result, dict)
-        assert "hits" in result
-        assert "hits" in result["hits"]
-        assert len(result["hits"]["hits"]) == 2  # Two documents with category A
-
-        # Extract _source from each hit
-        hits = result["hits"]["hits"]
-        assert all(isinstance(hit, dict) and "_source" in hit for hit in hits)
-
-        categories = [hit["_source"].get("category") for hit in hits]
-        assert all(cat == "A" for cat in categories)
-
-        # verify all expected fields are present in _source
-        for hit in hits:
-            source = hit["_source"]
-            assert "content" in source
-            assert "category" in source
-            assert "status" in source
-            assert "priority" in source
+        assert "schema" in result
+        assert "datarows" in result
+        assert "size" in result
+        assert "status" in result
+        assert [entry["name"] for entry in result["schema"]] == ["content", "category", "status", "priority"]
+        assert len(result["datarows"]) == 2  # Two documents with category A
+
+        categories = [row[1] for row in result["datarows"]]
+        assert all(category == "A" for category in categories)
 
         # error handling for invalid SQL query
         invalid_query = "SELECT * FROM non_existent_index"

integrations/opensearch/tests/test_document_store_async.py

@@ -827,24 +827,15 @@ async def test_query_sql(self, document_store: OpenSearchDocumentStore):
 
         # Verify raw JSON response structure
         assert isinstance(result, dict)
-        assert "hits" in result
-        assert "hits" in result["hits"]
-        assert len(result["hits"]["hits"]) == 2  # Two documents with category A
+        assert "schema" in result
+        assert "datarows" in result
+        assert "size" in result
+        assert "status" in result
+        assert [entry["name"] for entry in result["schema"]] == ["content", "category", "status", "priority"]
+        assert len(result["datarows"]) == 2  # Two documents with category A
 
-        # Extract _source from each hit
-        hits = result["hits"]["hits"]
-        assert all(isinstance(hit, dict) and "_source" in hit for hit in hits)
-
-        categories = [hit["_source"].get("category") for hit in hits]
-        assert all(cat == "A" for cat in categories)
-
-        # verify all expected fields are present in _source
-        for hit in hits:
-            source = hit["_source"]
-            assert "content" in source
-            assert "category" in source
-            assert "status" in source
-            assert "priority" in source
+        categories = [row[1] for row in result["datarows"]]
+        assert all(category == "A" for category in categories)
 
         # error handling for invalid SQL query
         invalid_query = "SELECT * FROM non_existent_index"
@@ -869,9 +860,14 @@ async def test_query_sql_async_with_fetch_size(self, document_store: OpenSearchD
 
         # Should return raw JSON response (exact count depends on OpenSearch behavior)
         assert isinstance(result, dict)
-        assert "hits" in result
-        assert "hits" in result["hits"]
-        assert all(isinstance(hit, dict) and "_source" in hit for hit in result["hits"]["hits"])
+        assert "schema" in result
+        assert "datarows" in result
+        assert "size" in result
+        assert "status" in result
+        assert [entry["name"] for entry in result["schema"]] == ["content", "category", "index"]
+        assert len(result["datarows"]) > 0
+        assert len(result["datarows"]) <= 5
+        assert result.get("cursor") is not None
 
     @pytest.mark.integration
     @pytest.mark.asyncio
@@ -889,13 +885,14 @@ async def test_query_sql_async_pagination_flow(self, document_store: OpenSearchD
         # Query with small fetch_size to test pagination
         result = await document_store._query_sql_async(sql_query, fetch_size=10)
         assert isinstance(result, dict)
-        assert "hits" in result
-        assert "hits" in result["hits"]
-        assert len(result["hits"]["hits"]) > 0
-
-        # Verify all results have expected fields in _source
-        for hit in result["hits"]["hits"]:
-            source = hit["_source"]
-            assert "content" in source
-            assert "category" in source
-            assert "index" in source
+        assert "schema" in result
+        assert "datarows" in result
+        assert "size" in result
+        assert "status" in result
+        assert [entry["name"] for entry in result["schema"]] == ["content", "category", "index"]
+        assert len(result["datarows"]) > 0
+        assert len(result["datarows"]) <= 10
+
+        # Verify all results contain expected row columns
+        for row in result["datarows"]:
+            assert len(row) == 3

integrations/opensearch/tests/test_filters.py

@@ -229,9 +229,19 @@ def test_normalize_ranges():
 class TestFilters(FilterDocumentsTest):
     def assert_documents_are_equal(self, received: list[Document], expected: list[Document]):
         """
-        The OpenSearchDocumentStore.filter_documents() method returns a Documents with their score set.
-        We don't want to compare the score, so we set it to None before comparing the documents.
+        The OpenSearchDocumentStore.filter_documents() method returns documents with their score set.
+        We don't want to compare the score, so we set it to None before comparing.
+        Embeddings are not exactly the same when retrieved from OpenSearch (float round-trip),
+        so we compare them approximately and then set both to None for the final equality check.
         """
-        for doc in received:
-            doc.score = None
-        assert received == expected
+        assert len(received) == len(expected)
+        received = sorted(received, key=lambda x: x.id)
+        expected = sorted(expected, key=lambda x: x.id)
+        for received_doc, expected_doc in zip(received, expected, strict=True):
+            received_doc.score = None
+            if received_doc.embedding is None:
+                assert expected_doc.embedding is None
+            else:
+                assert received_doc.embedding == pytest.approx(expected_doc.embedding)
+            received_doc.embedding, expected_doc.embedding = None, None
+            assert received_doc == expected_doc