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Kestra Integration: Declarative Spark Orchestration

केस्ट्रा का मुख्य पृष्ठ

विहंगावलोकन

केस्ट्रा is an open-source data orchestration platform that enables the definition of complex pipelines through a declarative YAML syntax. By integrating Kestra with Ilum, engineering teams can combine Kestra's orchestration capabilities with Ilum's Spark-on-Kubernetes execution engine to build robust, scalable data workflows.

This integration allows for the decoupling of workflow logic from execution logic: Kestra manages the dependencies, scheduling, and triggers, while Ilum manages the Spark lifecycle, resource allocation, and Kubernetes pod orchestration.

Architectural Interaction

The integration relies on the native स्पार्क-सबमिट protocol proxied through Ilum's control plane. The communication flow for a Spark job submission is as follows:

  1. Workflow Trigger: Kestra initiates a task based on a schedule, API call, or external event.
  2. Task Execution: The Kestra Worker executes the SparkCLI plugin task.
  3. Submission: The Spark Client initiates a REST request to Ilum's Core component (इलम-कोर: 9888), which emulates a Spark Master interface.
  4. वाद्यवृंदकरण: Ilum translates the request into a Kubernetes SparkApplication or manages the driver pod directly, applying resource quotas and scaling policies.
  5. निगरानी: Kestra polls the execution status while Ilum provides real-time logs and metrics.

Installation & Prerequisites

Kestra is packaged as an optional module within the Ilum platform.

चेतावनी

Kestra is not enabled by default in Ilum. Check out the Production Deployment guide for detailed installation instructions.

Additionally, if you want to use any Ilum features from inside Kestra, make sure your Kestra worker has access to the इलम कोर service.

When the Kestra module is enabled, you should be able to access the Kestra UI from Ilum’s sidebar menu.

You can also use the direct port-forwarding method to access the Kestra UI:

kubectl port-forward svc/ilum-kestra 8080:8080

After issuing the command, navigate to http://localhost:8080/external/kestra.


Configuring Spark Workflows

Defining a Spark job in Kestra involves creating a flow that uses the io.kestra.plugin.spark.SparkCLI task. This task wraps the standard Spark submission process.

Basic Workflow Structure

The following YAML definition demonstrates a standard Spark batch job submission.

परिचय: उत्तेजक गुण-डाटा-ingestion
Namespace: com.enterprise.data
या क़िस्‍म: "Daily ingestion pipeline utilizing Ilum Spark cluster"

inputs:
- परिचय: jar_location
प्रकार: तार
defaults: "s3a://data-lake-artifacts/jobs/spark-job-1.0.jar"
- परिचय: main_class
प्रकार: तार
defaults: "com.enterprise.data.IngestionJob"

कार्य:
- परिचय: submit-उत्तेजक गुण-job
प्रकार: io.kestra.plugin.spark.SparkCLI
आदेश:
- |
स्पार्क-सबमिट \
--मास्टर spark://ilum-core:9888 \
--deploy-mode क्लस्टर \
--conf spark.master.rest.enabled=true \
--conf spark.executor.instances=2 \
--conf spark.executor.memory=4g \
--conf spark.executor.cores=2 \
--class {{ inputs.main_class }} \
{{ inputs.jar_location }}

Configuration Parameters Explained

  • --master spark://ilum-core:9888: This targets Ilum’s virtual Spark Master. Unlike a standard standalone master, this endpoint is backed by Ilum’s orchestration logic, which handles the Kubernetes scheduling.
  • --deploy-mode क्लस्टर: Critical. This instructs the client to launch the driver program inside the cluster (managed by Ilum). Using ग्राहक mode would attempt to run the driver within the Kestra worker pod, which is not recommended for production due to resource contention and network isolation.
  • --conf spark.master.rest.enabled=true: Enables the REST submission protocol required for communicating with the Ilum control plane.
Artifact Management

The Spark JAR file specified in {{ inputs.jar_location }} must be accessible by the Spark Driver pod spawned by Ilum. Recommended storage backends include S3 (MinIO), HDFS, or GCS. Local file paths from the Kestra worker are नहीं accessible to the Spark cluster.

Alternatively, you can use Kestra’s object storage upload - e.g. io.kestra.plugin.aws.s3.Upload task to upload the JAR to some accessible S3 bucket.

The workflow implemented Visual representation of the workflow DAG in Kestra


Advanced Workflow Patterns

1. Dynamic Parameter Injection

Pass runtime variables such as execution dates or upstream data paths into your Spark application arguments.

कार्य:
- परिचय: daily-aggregation
प्रकार: io.kestra.plugin.spark.SparkCLI
आदेश:
- |
स्पार्क-सबमिट \
--मास्टर spark://ilum-core:9888 \
--deploy-mode क्लस्टर \
--conf spark.master.rest.enabled=true \
--class com.etl.Aggregator \
s3a://bucket/jars/etl.jar \
--date {{ execution.startDate | date("yyyy-MM-dd") }} \
--input-path s3a://raw-data/{{ execution.startDate | date("yyyy/MM/dd") }}/

2. Parallel Execution

Execute multiple independent Spark jobs concurrently to maximize cluster utilization.

कार्य:
- परिचय: parallel-संसाधन
प्रकार: io.kestra.core.tasks.flows.Parallel
कार्य:
- परिचय: job-region-eu
प्रकार: io.kestra.plugin.spark.SparkCLI
आदेश: ["spark-submit ... --class com.jobs.EUJob ..."]

- परिचय: job-region-us
प्रकार: io.kestra.plugin.spark.SparkCLI
आदेश: ["spark-submit ... --class com.jobs.USJob ..."]

Flow execution Execution triggers allow for dynamic input parameters


Performance Engineering: Optimization of Submission Latency

By default, Kestra may launch a new Docker container for each task execution. For high-frequency workflows, the overhead of spinning up a container and initializing the JVM for the Spark Client can introduce latency.

Host-Process Execution Strategy

To eliminate container startup overhead, you can configure Kestra to execute the स्पार्क-सबमिट command directly in the host process of the Kestra worker. This requires a custom worker image with Spark binaries pre-installed.

1. Build Custom Worker Image

एक बनाएँ डॉकरफ़ाइल that layers the Spark client binaries onto the Kestra base image.

# आधार के रूप में आधिकारिक केस्ट्रा छवि का उपयोग करें
से kestra/kestra:v1.3.15

उपभोक्ता root

# Install Spark Client Dependencies
RUN apt-get update && apt-get install -y curl tar openjdk-17-jre-headless && \
rm -rf /var/lib/apt/lists/*

# स्पार्क-सबमिट डाउनलोड और इंस्टॉल करें
ईएनवी SPARK_VERSION=4.1.2
RUN curl -O https://dlcdn.apache.org/spark/spark-${SPARK_VERSION}/spark-${SPARK_VERSION}-bin-hadoop3.tgz && \
tar -xzf spark-${SPARK_VERSION}-bin-hadoop3.tgz -C /opt && \
mv /opt/spark-${SPARK_VERSION}-bin-hadoop3 /opt/spark && \
rm spark-${SPARK_VERSION}-bin-hadoop3.tgz

# Configure Path
ईएनवी PATH=$PATH:/opt/spark/bin
ईएनवी SPARK_HOME=/opt/spark

# Restore Kestra user
उपभोक्ता kestra
WORKDIR /app
प्रवेश बिंदु ["docker-entrypoint.sh"]
CMD ["--help"]

2. Configure Task Runner

Modify your workflow to use the Process task runner, bypassing the Docker isolation for the submission step.

कार्य:
- परिचय: low-latency-submission
प्रकार: io.kestra.plugin.spark.SparkCLI
टास्करुनर:
प्रकार: io.kestra.plugin.core.runner.Process
आदेश:
- |
स्पार्क-सबमिट \
--मास्टर spark://ilum-core:9888 \
--deploy-mode क्लस्टर \
--conf spark.master.rest.enabled=true \
--class {{ इनपुट। YourMainClass }} \
{{इनपुट। YourSparkJar }}

Observability & Debugging

Job Correlation

When a workflow is executed:

  1. Kestra UI: Displays the स्पार्क-सबमिट logs (stdout/stderr), providing immediate feedback on the submission status.
  2. इलम यूआई: The job appears in the "Applications" view. The Spark Driver logs provide the deep execution details.

The workflow executed Kestra execution timeline showing task duration and status

Failure Handling

Spark jobs may fail due to transient cluster issues (e.g., preemption). Configure automatic retries in Kestra to handle these gracefully.

कार्य:
- परिचय: resilient-उत्तेजक गुण-job
प्रकार: io.kestra.plugin.spark.SparkCLI
retry:
प्रकार: constant
interval: PT5M
maxAttempt: 3
आदेश: ...

The job inside Ilum Verification of the job execution within the Ilum Dashboard