মূল বিষয়বস্তুতে যান

Orchestrate dbt with Airflow on Spark: A Complete Guide

This guide demonstrates how to orchestrate scalable dbt pipelines on Ilum's অ্যাপাচি স্পার্ক cluster using Apache Airflow এবং Astronomer Cosmos. You will learn how to build a robust medallion architecture (Bronze → Silver → Gold) utilizing Kubernetes-native compute for efficient data transformation. We will cover automatic DAG generation, data quality testing, and incremental processing strategies.

টিপ

For a comprehensive deep-dive into the architecture, benefits, and strategic considerations of running dbt on Spark with Airflow, see our detailed blog post: Orchestrate dbt on Spark with Airflow: A Guide to Modern Data Engineering on Ilum.

Prerequisites for Airflow and dbt on Ilum

  • Ilum version 6.6.2 or later
  • Airflow enabled with the 3.1.1-dbtপ্রতিচ্ছবি
  • Spark SQL (Thrift Server) or স্পার্ক কানেক্ট সক্ষম
  • Basic familiarity with dbt and Airflow concepts

dbt-Airflow-Spark Architecture Overview

The integration combines four key components:

ComponentTechnology
Compute EngineApache Spark on Ilum (Kubernetes-native)
Data Modelingdbt-spark (dbt-core + Spark adapter)
অর্কেস্ট্রেশন Apache Airflow 3.1 with KubernetesExecutor
DAG GenerationAstronomer Cosmos

Workflow: Git repository → gitSync → Airflow → Cosmos (auto-generates DAG) → Spark SQL / Spark Connect → Ilum Spark Cluster

স্থাপত্য
┌──────────────────────────────────────────────────────────────────┐
│ Gitea Repository │
│ airflow.git/ilum_dbt_project/ │
│ ├── dbt_project.yml │
│ ├── seeds/crypto_prices_raw.csv │
│ └── models/{bronze,silver,gold}/*.sql │
└──────────────────────────────────────────────────────────────────┘
│ gitSync

┌──────────────────────────────────────────────────────────────────┐
│ Airflow 3.1 (Kubernetes) │
│ ┌─────────────────────────────────────────────────────────────┐ │
│ │ Astronomer Cosmos │ │
│ │ - Parses dbt project │ │
│ │ - Generates DAG with tasks for each model + test │ │
│ │ - Maintains dbt ref() dependencies │ │
│ └─────────────────────────────────────────────────────────────┘ │
└──────────────────────────────────────────────────────────────────┘

┌───────────────────┴───────────────────┐
▼ ▼
┌─────────────────────┐ ┌─────────────────────┐
│ Thrift Server │ │ Spark Connect │
│ (ilum-sql-thrift) │ │ (job-xxx-driver) │
│ Port: 10009 │ │ Port: 15002 │
└─────────────────────┘ └─────────────────────┘
│ │
└───────────────────┬───────────────────┘

┌──────────────────────────────────────────────────────────────────┐
│ Ilum Spark Cluster │
│ Executes SQL queries, creates managed tables │
└──────────────────────────────────────────────────────────────────┘

Quick Start: Deploying dbt Pipelines

1. Enable Airflow with dbt Support

Install Ilum with Airflow and dbt pre-configured:

helm install
Helm installation il and ile/el \ 
--সেট ilum-Hive-metastore.enabled=true \
--set ilum-core.metastore.enabled=true \
--set ilum-core.metastore.type=hive \
--সেট ilum-core.sql.সক্ষম=সত্য \
--সেট ilum-sql.enabled=true \
--set airflow.enabled=true \
--set airflow.images.airflow.tag=3.1.1-dbt
Pre-loaded Example

When using the 3.1.1-dbt image tag, the complete dbt project and DAG described in this guide are automatically pre-loaded into the internal Gitea repository and synced to Airflow. You can trigger the example pipeline immediately after installation.

2. Access Airflow

Navigate to the Airflow UI via the Ilum console. The default credentials are typically অ্যাডমিন:অ্যাডমিন .

3. Verify the Connection

Starting from Ilum 6.6.2, ঐ spark_thrift_default connection is automatically configured. Verify it exists:

AdminConnections → Search for spark_thrift_default

If missing, create it manually:

Fieldমান
Connection IDspark_thrift_default
Connection Typeস্ফুলিঙ্গ বা spark_sql
Hostilum-sql-thrift-binary.<NAMESPACE>.svc.cluster.local
Port10009

4. Trigger the DAG

Find ilum_dbt_thrift_pipeline in the Airflow UI and trigger it manually. Monitor the Graph View to see the auto-generated task dependencies.

Airflow DAG Graph generated by Astronomer Cosmos showing dbt model dependencies The Airflow DAG automatically generated by Astronomer Cosmos, reflecting the dbt model dependencies.


Project Structure

The dbt project follows a standard medallion architecture:

Directory Structure
ilum_dbt_project/
├── dbt_project.yml
├── packages.yml
├── seeds/
│ └── crypto_prices_raw.csv
└── models/
├── bronze/
│ └── crypto_prices_bronze.sql
├── silver/
│ └── crypto_prices_silver_daily.sql
├── gold/
│ └── crypto_prices_gold_latest.sql
└── schema.yml

dbt Configuration

dbt_project.yml

The central configuration file defines project metadata, paths, and layer-specific settings:

dbt_project.yml
নাম :  "ilum_dbt_project"
সংস্করণ : "1.0.0"
config-version: 2

profile: "ilum_dbt_project" # must match ProfileConfig.profile_name

model-paths: [ "models"]
seed-paths: [ "seeds"]
macro-paths: [ "macros"]
test-paths: [ "tests"]

models:
ilum_dbt_project :
+materialized: সারণী
bronze:
+tags: [ "bronze"]
silver:
+tags: [ "silver"]
gold:
+tags: [ "gold"]

seeds:
ilum_dbt_project :
+column_types:
তারিখ : তারিখ
symbol: স্ট্রিং
price_usd: double
volume_usd: double
market_cap_usd: double
crypto_prices_raw:
+pre-hook:
- "{{ drop_this_seed() }}"

Key features:

  • Tags enable selective execution: dbt run --select tag:gold
  • Column types ensure correct Spark table schemas
  • Pre-hook drop_this_seed() provides idempotent seed loading for demos

Medallion Architecture Layers

Bronze Layer: Type Normalization

File: models/bronze/crypto_prices_bronze.sql

Converts raw seed data into typed, normalized tables with incremental processing:

models/bronze/crypto_prices_bronze.sql
{{ কনফিগারেশন ( 
বাস্তবায়িত = 'incremental',
unique_key= [ 'date', 'symbol']
) }}

select
cast( তারিখ হিসেবে তারিখ ) হিসেবে তারিখ ,
upper( symbol) হিসেবে symbol,
cast( price_usd হিসেবে double) হিসেবে price_usd,
cast( volume_usd হিসেবে double) হিসেবে volume_usd,
cast( market_cap_usd হিসেবে double) হিসেবে market_cap_usd
থেকে {{ রেফ ( 'crypto_prices_raw') }}

{ % যদি is_incremental( ) % }
where তারিখ > ( select max( তারিখ ) থেকে {{ this }})
{ % এন্ডআইএফ % }

বেনিফিট:

  • Only processes new records after initial load
  • Reduces compute costs for large datasets

Silver Layer: Data Enrichment

File: models/silver/crypto_prices_silver_daily.sql

Adds 7-day moving averages using Spark window functions:

models/silver/crypto_prices_silver_daily.sql
{{ কনফিগারেশন ( বাস্তবায়িত = 'টেবিল' ) }} 

select
তারিখ ,
symbol,
price_usd,
volume_usd,
market_cap_usd,
গড় ( price_usd) over (
partition দ্বারা symbol
order দ্বারা তারিখ
rows মধ্যে 6 preceding এবং current সারি
) হিসেবে price_usd_7d_avg,
গড় ( volume_usd) over (
partition দ্বারা symbol
order দ্বারা তারিখ
rows মধ্যে 6 preceding এবং current সারি
) হিসেবে volume_usd_7d_avg
থেকে {{ রেফ ( 'crypto_prices_bronze') }}

Gold Layer: Business-Ready Views

File: models/gold/crypto_prices_gold_latest.sql

Produces analytics-ready data showing the latest 30 days per symbol:

models/gold/crypto_prices_gold_latest.sql
{{ কনফিগারেশন ( বাস্তবায়িত = 'টেবিল' ) }} 

সাথে ranked হিসেবে (
select
* ,
row_number( ) over (
partition দ্বারা symbol
order দ্বারা তারিখ desc
) হিসেবে rn
থেকে {{ রেফ ( 'crypto_prices_silver_daily') }}
)

select
তারিখ ,
symbol,
price_usd,
price_usd_7d_avg,
volume_usd_7d_avg,
market_cap_usd
থেকে ranked
where rn <= 30

Data Quality Tests

Define tests in models/schema.yml to create quality gates:

models/schema.yml
সংস্করণ :  2 

seeds:
- নাম : crypto_prices_raw
columns:
- নাম : তারিখ
tests: [ not_null]
- নাম : symbol
tests: [ not_null]
- নাম : price_usd
tests: [ not_null]

models:
- নাম : crypto_prices_bronze
বর্ণনা : "Bronze layer - typed and normalized crypto prices."
columns:
- নাম : তারিখ
tests: [ not_null]
- নাম : symbol
tests: [ not_null]
- নাম : price_usd
tests: [ not_null]

In Airflow: Cosmos converts each test into a separate task that blocks downstream models if it fails.


Generating Airflow DAGs with Cosmos

File: dags/ilum_dbt_thrift.py

dags/ilum_dbt_thrift.py
থেকে তারিখের সময় আমদানি তারিখের সময় ,  timedelta
আমদানি os
থেকে airflow. configuration আমদানি কনফ
থেকে cosmos আমদানি DbtDag, ProjectConfig, ProfileConfig, ExecutionConfig
থেকে cosmos. profiles আমদানি SparkThriftProfileMapping

DAGS_FOLDER = কনফ . পান ( "core", "dags_folder")
DBT_PROJECT_PATH = os. পথ . join( DAGS_FOLDER, "ilum_dbt_project")
DBT_BIN = "/home/airflow/.local/bin/dbt"

profile_config = ProfileConfig(
profile_name= "ilum_dbt_project",
target_name= "prod",
profile_mapping= SparkThriftProfileMapping(
conn_id= "spark_thrift_default",
profile_args= {
"schema": "ডিফল্ট" ,
"threads": 4 ,
} ,
) ,
)

dbt_dag = DbtDag(
project_config= ProjectConfig(
dbt_project_path= DBT_PROJECT_PATH,
) ,
profile_config= profile_config,
execution_config= ExecutionConfig(
dbt_executable_path= DBT_BIN,
) ,
dag_id= "ilum_dbt_thrift_pipeline",
schedule= "@daily",
start_date= তারিখের সময় ( 2024, 1 , 1 ) ,
catchup= False,
default_args= {
"owner": "data-team",
"retries": 2 ,
"retry_delay": timedelta( minutes= 5 ) ,
} ,
)

How it works:

  • SparkThriftProfileMapping uses the Airflow connection spark_thrift_default
  • Cosmos scans the dbt project and auto-generates tasks for each model, seed, and test
  • Dependencies mirror dbt's ref() relationships

Thrift vs Spark Connect

AspectThrift Serverস্পার্ক কানেক্ট
EndpointCentral SQL server (shared)Per-job endpoint (isolated)
Use caseMultiple tools sharing one endpointIsolated compute per project
ProtocolJDBC/ThriftgRPC (native Spark API)
ConnectionStable service nameDynamic job-based URL

Tracking Data Lineage and Dependencies

Once the pipeline runs successfully, tables are stored in the Hive Metastore and accessible across Ilum components:

Ilum data lineage view showing medallion architecture Figure 2: The Ilum Data Lineage view visualizing the full medallion architecture (Bronze → Silver → Gold) and table dependencies.


মূল উপকারিতা

বৈশিষ্ট্য Benefit
No dbt CloudFully open-source, no subscription costs
Medallion patternClean data architecture (bronze → silver → gold)
Incremental modelsProcess only new data, reduce compute costs
Quality gatesdbt tests block downstream if data fails
KubernetesExecutorEach task isolated in separate pod
gitSyncCode changes auto-deployed from Gitea
Auto DAG generationCosmos creates tasks from dbt models automatically
Full lineageTrack model dependencies in Airflow UI and Ilum

সমস্যা সমাধান

Click to view troubleshooting steps

Connection Errors

If you see failed to resolve sockaddr errors in dbt logs:

[Errno -2] Name or service not known

সমাধান: Verify the Thrift service exists:

Verify Thrift Service
kubectl get svc -n <NAMESPACE> | grep thrift

Ensure the connection host matches the service name exactly.

DAG Not Appearing

If the DAG doesn't show up in Airflow:

  1. Check gitSync logs to ensure the dbt project is synced
  2. Verify the DBT_PROJECT_PATH points to the correct directory
  3. Look for parsing errors in Airflow logs

Tests Failing

If dbt tests fail unexpectedly:

  1. Check the test task logs in Airflow
  2. Query the table directly via Ilum SQL to verify data quality
  3. Adjust test thresholds or fix upstream data issues

অতিরিক্ত রিসোর্স