From SQLServer to Dashboards with Dremio and Apache Iceberg

Moving data from source systems like SQLServer to a dashboard traditionally involves a multi-step process: transferring data to a data lake, moving it into a data warehouse, and then building BI extracts and cubes for acceleration. This process can be tedious and costly. However, this entire workflow is simplified with Dremio, the Data Lakehouse Platform. Dremio enables directly serving BI dashboards from SQLServer or leveraging Apache Iceberg tables in your data lake. This post will explore how Dremio's data lakehouse platform simplifies your data delivery for business intelligence by doing a prototype version that can run on your laptop.

Setting Up Our Environment

To run this exercise on your laptop, you will need Docker Desktop to run Docker Compose files to spin up our environment. In an empty folder, create a docker-compose.yml file with the following:

version: "3"

services:
  # Nessie Catalog Server Using In-Memory Store
  nessie:
    image: projectnessie/nessie:latest
    container_name: nessie
    networks:
      sqlserver-dremio-superset:
    ports:
      - 19120:19120
  # Minio Storage Server
  minio:
    image: minio/minio:latest
    container_name: minio
    environment:
      - MINIO_ROOT_USER=admin
      - MINIO_ROOT_PASSWORD=password
      - MINIO_DOMAIN=storage
      - MINIO_REGION_NAME=us-east-1
      - MINIO_REGION=us-east-1
    networks:
      sqlserver-dremio-superset:
    ports:
      - 9001:9001
      - 9000:9000
    command: ["server", "/data", "--console-address", ":9001"]
  # Dremio
  dremio:
    platform: linux/x86_64
    image: dremio/dremio-oss:latest
    ports:
      - 9047:9047
      - 31010:31010
      - 32010:32010
    container_name: dremio
    environment:
      - DREMIO_JAVA_SERVER_EXTRA_OPTS=-Dpaths.dist=file:///opt/dremio/data/dist
    networks:
      sqlserver-dremio-superset:
  #SQLServer
  sqlserver:
    image: mcr.microsoft.com/mssql/server:2019-latest
    container_name: sqlserver
    environment:
      SA_PASSWORD: "Yourpassword2024"
      ACCEPT_EULA: "Y"
    ports:
      - "1433:1433"
    networks:
      sqlserver-dremio-superset:
  #Superset
  superset:
    image: alexmerced/dremio-superset
    container_name: superset
    networks:
      sqlserver-dremio-superset:
    ports:
      - 8080:8088
networks:
  sqlserver-dremio-superset:

This Docker Compose file sets up a development environment for integrating SQLServer with a BI dashboard through Dremio and Apache Iceberg, leveraging additional tools like Nessie and MinIO. Here's what each service in the file represents:

• Nessie: Acts as a catalog server using an in-memory store, helping to manage and version data in the data lake. It runs on port 19120 and is part of the sqlserver-dremio-superset network, facilitating integration with Dremio and SQLServer for table cataloging and version control.
  
• MinIO: Serves as a storage server, mimicking a cloud storage environment locally. It's configured with essential security and region settings and exposes ports 9000 for API access and 9001 for the console. MinIO provides the storage layer for the data lake, where data from SQLServer can be stored and managed before processing with Dremio.
  
• Dremio: This is the core component of the data lakehouse platform, providing the ability to directly query and manage data across different sources like SQLServer and the data stored in MinIO. It exposes several ports for different purposes, such as the Dremio UI (9047), and data communication (31010 and 32010).
  
• SQLServer: Represents the source database, configured with basic credentials. Port 1433 is exposed and mapped to the host machine, allowing for database connectivity. This setup is used to create a SQL Server instance that can be accessed and managed through the specified port on the host.
  
• Superset: A business intelligence tool configured to connect with Dremio, allowing users to create and view dashboards and reports. It runs on port 8088 but is mapped to 8080 on the host machine for easy access.

The networks section defines a custom network named sqlserver-dremio-superset, ensuring these services can communicate seamlessly within this isolated network environment.

In the context of our blog, this Docker Compose setup illustrates how to create a local development environment that mirrors the process of moving data from SQLServer to a BI dashboard using Dremio and Apache Iceberg, with Nessie for table cataloging and MinIO for simulating a cloud storage environment.

To spin up the environment, simply run the command:

docker compose up

Populating Data in Our SQLServer Database

To access the SQLServer database shell and populate it with data to simulate data in operational databases, run the following command in another terminal window or tab:

docker exec -it sqlserver /bin/bash

Then, once you are in the container’s bash shell run the following command:

/opt/mssql-tools/bin/sqlcmd -S localhost -U SA -P 'Yourpassword2024'

From the SQLServer shell, run the following queries, make sure to run “GO” after each query:

CREATE TABLE DashboardData (RecordID INT PRIMARY KEY, Category NVARCHAR(50), Value INT, DateRecorded DATE);

GO

INSERT INTO DashboardData (RecordID, Category, Value, DateRecorded) VALUES (1, 'Category A', 100, '2023-01-01'), (2, 'Category B', 150, '2023-01-02'), (3, 'Category C', 200, '2023-01-03'), (4, 'Category A', 110, '2023-01-04'), (5, 'Category B', 120, '2023-01-05'), (6, 'Category C', 130, '2023-01-06'), (7, 'Category A', 140, '2023-01-07'), (8, 'Category B', 160, '2023-01-08'), (9, 'Category C', 170, '2023-01-09'), (10, 'Category A', 180, '2023-01-10');

GO

To quit the SQLServer shell run the following command:

# Exit SQLShell
EXIT
# Exit Container Bash Shell
exit

Connecting SQLServer, Nessie, and Minio to Dremio

Open MinIO in the browser at localhost:9000 and log in with username “admin” and password “password”. Once you log in, create a new bucket called “warehouse”. Keep in mind that Nessie is always running in the background and is accessed by a REST API which is how the Dremio connector communicates with the catalog.

Now, head over to localhost:9047 in your browser to set up your Dremio admin account. Once that is set up, click “add a Source” and select a “Nessie” as the source. Enter in the following settings:

• General settings tab
  • Source Name: nessie
  • Nessie Endpoint URL: http://nessie:19120/api/v2
  • Auth Type: None
• Storage settings tab
  • AWS Root Path: warehouse
  • AWS Access Key: admin
  • AWS Secret Key: password
  • Uncheck “Encrypt Connection” Box (since we aren’t using SSL)
  • Connection Properties
    • Key: fs.s3a.path.style.access | Value: true
    • Key: fs.s3a.endpoint | Value: minio:9000
    • Key: dremio.s3.compat | Value: true

Click on “Save,” and the source will now be added to Dremio, against which you can run full DDL and DML SQL. Dremio turns your data lake into a data warehouse, a data lakehouse!

Now let’s add an SQLServer source with the following settings:

• Name: sqlserver
• Host: sqlserver
• Port: 1433
• Username: SA
• Password: Yourpassword2024

Once you save the source you can see both sources on the Dremio dashboard and begin working with them.

Moving Our SQLServer Data to Our Data Lake

Historically, moving data from our databases into our data lake as Apache Iceberg tables would require spinning up an Apache Spark cluster and writing complex jobs in Python, Java, or Scala. But with Dremio, we can move our data to our data lake with some simple SQL.

Head over to the SQL Runner in the Dremio UI and run the following query to ingest the table in SQLServer as an Apache Iceberg table in our Nessie source:

CREATE TABLE nessie.dashboard_data AS SELECT * FROM sqlserver.master.dbo.DashboardData;

This is a great way to move the table to your data lake initially. To update the table, you can use the INSERT INTO SELECT statement, adding all records with a higher ID value to the highest ID value in the destination. This will ensure only new records are added to the table.

INSERT INTO nessie.dashboard_data
SELECT *
FROM sqlserver.master.dbo.DashboardData
WHERE RecordID > (SELECT COALESCE(MAX(RecordID), 0) FROM nessie.dashboard_data);

Now we have the data in our data lakehouse. While we could choose to not move the data and operate with the data directly from SQLServer, we could possibly run into competition for resources as the growing number of analytical queries compete with existing operational queries being sent to our SQLServer database. To avoid this, we can either create a data reflection, which creates a Dremio-managed materialization on your data lake that Dremio substitutes when the table is queried, or ingest the data into our data lakehouse like we did above. Either option allows analytical queries to fully utilize Dremio’s infinite horizontal and vertical scaling capabilities.

Connecting Superset to Dremio

Dremio can be used with most existing BI tools, with one-click integrations in the user interface for tools like Tableau and Power BI. We will use an open-source option in Superset for this exercise, but any BI tool would have a similar experience. 

We need to initialize Superset, so open another terminal and run this command:

docker exec -it superset superset init

This may take a few minutes to finish initializing but once it is done you can head over to localhost:8080 and log in to Superset with the username “admin” and password “admin”. Once you are in, click on “Settings” and select “Database Connections”.

• Add a New Database
• Select “Other”
• Use the following connection string (make sure to include Dremio username and password in URL):
  
  dremio+flight://USERNAME:PASSWORD@dremio:32010/?UseEncryption=false

• Test connection
• Save connection

The next step is to add a dataset by clicking on the + icon in the upper right corner and selecting “create dataset”. From here, select the table you want to add to Superset, in this case our sales_data table.

We can then click the + to add charts based on the datasets we’ve added. Once we create the charts we want we can add them to a dashboard, and that’s it! You’ve now taken data from an operational database, ingested it into your data lake, and served a BI dashboard using the data.

Consider deploying Dremio into production to make delivering data for analytics easier for your data engineering team.