China Mobile ECloud VectorSearch is a fully managed, enterprise-level distributed search and analysis service. China Mobile ECloud VectorSearch provides low-cost, high-performance, and reliable retrieval and analysis platform level product services for structured/unstructured data. As a vector database , it supports multiple index types and similarity distance methods.
You’ll need to install langchain-community with pip install -qU langchain-community to use this integration This notebook shows how to use functionality related to the ECloud ElasticSearch VectorStore. To run, you should have an China Mobile ECloud VectorSearch instance up and running: Read the help document to quickly familiarize and configure China Mobile ECloud ElasticSearch instance. After the instance is up and running, follow these steps to split documents, get embeddings, connect to the baidu cloud elasticsearch instance, index documents, and perform vector retrieval. 
#!pip install elasticsearch == 7.10.1
First, we want to use OpenAIEmbeddings so we have to get the OpenAI API Key. 
import getpass
import os

if "OPENAI_API_KEY" not in os.environ:
    os.environ["OPENAI_API_KEY"] = getpass.getpass("OpenAI API Key:")
Secondly, split documents and get embeddings. 
from langchain_community.document_loaders import TextLoader
from langchain_community.vectorstores import EcloudESVectorStore
from langchain_openai import OpenAIEmbeddings
from langchain_text_splitters import CharacterTextSplitter

loader = TextLoader("../../../state_of_the_union.txt")
documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
docs = text_splitter.split_documents(documents)

embeddings = OpenAIEmbeddings()

ES_URL = "http://localhost:9200"
USER = "your user name"
PASSWORD = "your password"
indexname = "your index name"
then, index documents 
docsearch = EcloudESVectorStore.from_documents(
    docs,
    embeddings,
    es_url=ES_URL,
    user=USER,
    password=PASSWORD,
    index_name=indexname,
    refresh_indices=True,
)
Finally, Query and retrieve data 
query = "What did the president say about Ketanji Brown Jackson"
docs = docsearch.similarity_search(query, k=10)
print(docs[0].page_content)
A commonly used case 
def test_dense_float_vectore_lsh_cosine() -> None:
    """
    Test indexing with vectore type knn_dense_float_vector and  model-similarity of lsh-cosine
    this mapping is compatible with model of exact and similarity of l2/cosine
    this mapping is compatible with model of lsh and similarity of cosine
    """
    docsearch = EcloudESVectorStore.from_documents(
        docs,
        embeddings,
        es_url=ES_URL,
        user=USER,
        password=PASSWORD,
        index_name=indexname,
        refresh_indices=True,
        text_field="my_text",
        vector_field="my_vec",
        vector_type="knn_dense_float_vector",
        vector_params={"model": "lsh", "similarity": "cosine", "L": 99, "k": 1},
    )

    docs = docsearch.similarity_search(
        query,
        k=10,
        search_params={
            "model": "exact",
            "vector_field": "my_vec",
            "text_field": "my_text",
        },
    )
    print(docs[0].page_content)

    docs = docsearch.similarity_search(
        query,
        k=10,
        search_params={
            "model": "exact",
            "similarity": "l2",
            "vector_field": "my_vec",
            "text_field": "my_text",
        },
    )
    print(docs[0].page_content)

    docs = docsearch.similarity_search(
        query,
        k=10,
        search_params={
            "model": "exact",
            "similarity": "cosine",
            "vector_field": "my_vec",
            "text_field": "my_text",
        },
    )
    print(docs[0].page_content)

    docs = docsearch.similarity_search(
        query,
        k=10,
        search_params={
            "model": "lsh",
            "similarity": "cosine",
            "candidates": 10,
            "vector_field": "my_vec",
            "text_field": "my_text",
        },
    )
    print(docs[0].page_content)
With filter case 
def test_dense_float_vectore_exact_with_filter() -> None:
    """
    Test indexing with vectore type knn_dense_float_vector and default model/similarity
    this mapping is compatible with model of exact and similarity of l2/cosine
    """
    docsearch = EcloudESVectorStore.from_documents(
        docs,
        embeddings,
        es_url=ES_URL,
        user=USER,
        password=PASSWORD,
        index_name=indexname,
        refresh_indices=True,
        text_field="my_text",
        vector_field="my_vec",
        vector_type="knn_dense_float_vector",
    )
    # filter={"match_all": {}} ,default
    docs = docsearch.similarity_search(
        query,
        k=10,
        filter={"match_all": {}},
        search_params={
            "model": "exact",
            "vector_field": "my_vec",
            "text_field": "my_text",
        },
    )
    print(docs[0].page_content)

    # filter={"term": {"my_text": "Jackson"}}
    docs = docsearch.similarity_search(
        query,
        k=10,
        filter={"term": {"my_text": "Jackson"}},
        search_params={
            "model": "exact",
            "vector_field": "my_vec",
            "text_field": "my_text",
        },
    )
    print(docs[0].page_content)

    # filter={"term": {"my_text": "president"}}
    docs = docsearch.similarity_search(
        query,
        k=10,
        filter={"term": {"my_text": "president"}},
        search_params={
            "model": "exact",
            "similarity": "l2",
            "vector_field": "my_vec",
            "text_field": "my_text",
        },
    )
    print(docs[0].page_content)