AWS operators (S3, Redshift, EMR) in Apache Airflow - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an S3ToRedshiftOperator that copies data from S3 to Redshift.

Apache Airflow

copy_to_redshift = S3ToRedshiftOperator(
    task_id='copy_s3_to_redshift',
    redshift_conn_id='redshift_default',
    aws_conn_id='aws_default',
    schema='public',
    table='users',
    s3_bucket='my-bucket',
    s3_key=[1],
    copy_options=['csv']
)

Drag options to blanks, or click blank then click option'

A'data/users.csv'

B's3://my-bucket/data/users.csv'

C'users.csv'

D'/data/users.csv'

Attempts:

3 left

💡 Hint

Common Mistakes

Using full s3 URI instead of just the key path.

Using an absolute file path starting with '/'.

The s3_key parameter expects the path inside the bucket, not the full s3 URI.

2fill in blank

medium

Complete the code to define an EMRCreateJobFlowOperator with the correct job flow name.

Apache Airflow

create_emr_cluster = EMRCreateJobFlowOperator(
    task_id='create_emr_cluster',
    job_flow_overrides={
        'Name': [1],
        'ReleaseLabel': 'emr-6.3.0',
        'Instances': {
            'InstanceGroups': [
                {
                    'Name': 'Master nodes',
                    'Market': 'ON_DEMAND',
                    'InstanceRole': 'MASTER',
                    'InstanceType': 'm5.xlarge',
                    'InstanceCount': 1
                }
            ],
            'KeepJobFlowAliveWhenNoSteps': True
        }
    }
)

Drag options to blanks, or click blank then click option'

A'EMR Cluster'

BMyEMRCluster

C'emr_cluster'

D'MyEMRCluster'

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around the cluster name.

Using a variable name without defining it.

The 'Name' value must be a string literal, so it needs quotes.

3fill in blank

hard

Fix the error in the RedshiftToS3Operator by completing the parameter for unloading data.

Apache Airflow

unload_to_s3 = RedshiftToS3Operator(
    task_id='unload_redshift_to_s3',
    redshift_conn_id='redshift_default',
    aws_conn_id='aws_default',
    schema='public',
    table='sales',
    s3_bucket='my-bucket',
    s3_key='exports/sales/',
    unload_options=[[1]]
)

Drag options to blanks, or click blank then click option'

A'parallel=off'

B'parallel off'

C'PARALLEL OFF'

D'PARALLEL=OFF'

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase or equals sign in unload options.

Missing quotes around the option string.

Unload options are case sensitive and must be uppercase with spaces, not equals sign.

4fill in blank

hard

Fill both blanks to configure an EMRAddStepsOperator that adds a Spark step to the cluster.

Apache Airflow

add_spark_step = EMRAddStepsOperator(
    task_id='add_spark_step',
    job_flow_id=[1],
    aws_conn_id='aws_default',
    steps=[{
        'Name': 'Spark application',
        'ActionOnFailure': 'CONTINUE',
        'HadoopJarStep': {
            'Jar': 'command-runner.jar',
            'Args': ['spark-submit', [2]]
        }
    }]
)

Drag options to blanks, or click blank then click option'

A'j-2AXXXXXXGAPLF'

B'--deploy-mode',

C's3://my-bucket/scripts/spark_app.py'

D'--master'

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong format for job_flow_id.

Passing incorrect spark-submit arguments.

job_flow_id is the cluster id string; the spark-submit argument is the script path in S3.

5fill in blank

hard

Fill all three blanks to define an S3CreateBucketOperator with region and ACL settings.

Apache Airflow

create_bucket = S3CreateBucketOperator(
    task_id='create_bucket',
    bucket_name=[1],
    region_name=[2],
    acl=[3],
    aws_conn_id='aws_default'
)

Drag options to blanks, or click blank then click option'

A'my-new-bucket-12345'

B'us-west-2'

C'private'

D'public-read'

Attempts:

3 left

💡 Hint

Common Mistakes

Using invalid region names.

Using ACL values not supported by S3.

Bucket name is a string, region is a valid AWS region string, and ACL is usually 'private' or 'public-read'.

Practice

1. What is the primary purpose of the S3CreateObjectOperator in Airflow?

easy

A. To delete an S3 bucket

B. To list all objects in an S3 bucket

C. To create or upload an object (file) to an S3 bucket

D. To move objects between two S3 buckets

Solution

1. Step 1: Understand the operator's name and function

   The name S3CreateObjectOperator suggests it creates or uploads an object to S3.

2. Step 2: Match the operator to its main action

   This operator is designed to create or upload files to an S3 bucket, not delete or list buckets.

3. Final Answer:

   To create or upload an object (file) to an S3 bucket -> Option C

4. Quick Check:

   S3CreateObjectOperator = Upload file to S3 [OK]

Hint: Operator names usually describe their main action clearly [OK]

Common Mistakes:

• Confusing object creation with bucket deletion
• Thinking it lists objects instead of creating
• Assuming it moves objects between buckets

2. Which of the following is the correct way to instantiate an RedshiftSQLOperator in Airflow?

easy

A. RedshiftSQLOperator(sql='SELECT * FROM table', aws_conn_id='my_conn')

B. RedshiftSQLOperator(query='SELECT * FROM table', aws_conn_id='my_conn')

C. RedshiftSQLOperator(command='SELECT * FROM table', redshift_conn='my_conn')

D. RedshiftSQLOperator(sql='SELECT * FROM table', redshift_conn_id='my_conn')

Solution

1. Step 1: Identify correct parameter names for RedshiftSQLOperator

   The operator expects sql for the query and redshift_conn_id for the connection ID.

2. Step 2: Check each option for correct parameters

   RedshiftSQLOperator(sql='SELECT * FROM table', redshift_conn_id='my_conn') uses sql and redshift_conn_id, which is correct. Others use wrong parameter names.

3. Final Answer:

   RedshiftSQLOperator(sql='SELECT * FROM table', redshift_conn_id='my_conn') -> Option D

4. Quick Check:

   Use sql and redshift_conn_id for RedshiftSQLOperator [OK]

Hint: Remember: SQL query = sql, connection = redshift_conn_id [OK]

Common Mistakes:

• Using 'query' instead of 'sql' parameter
• Using 'aws_conn_id' instead of 'redshift_conn_id'
• Misspelling parameter names

3. Given the following Airflow task using EmrCreateJobFlowOperator:

emr_task = EmrCreateJobFlowOperator(
    task_id='start_emr_cluster',
    job_flow_overrides={
        'Name': 'TestCluster',
        'ReleaseLabel': 'emr-6.3.0',
        'Instances': {'InstanceCount': 3, 'KeepJobFlowAliveWhenNoSteps': True}
    },
    aws_conn_id='aws_default'
)

What will be the state of the EMR cluster after this task runs successfully?

medium

A. A running EMR cluster named 'TestCluster' with 3 instances, waiting for steps

B. An EMR cluster terminated immediately after creation

C. An EMR cluster with zero instances running

D. An error because 'ReleaseLabel' is missing

Solution

1. Step 1: Analyze job_flow_overrides parameters

   The cluster is named 'TestCluster', uses EMR release 6.3.0, has 3 instances, and is set to keep alive when no steps run.

2. Step 2: Understand KeepJobFlowAliveWhenNoSteps effect

   This setting keeps the cluster running after creation, waiting for steps to be added.

3. Final Answer:

   A running EMR cluster named 'TestCluster' with 3 instances, waiting for steps -> Option A

4. Quick Check:

   KeepJobFlowAliveWhenNoSteps=True means cluster stays running [OK]

Hint: KeepJobFlowAliveWhenNoSteps=True keeps cluster alive after creation [OK]

Common Mistakes:

• Assuming cluster terminates immediately
• Ignoring instance count setting
• Thinking ReleaseLabel is missing

4. You wrote this Airflow task to copy data from S3 to Redshift using RedshiftToS3Operator:

copy_task = RedshiftToS3Operator(
    task_id='copy_data',
    redshift_conn_id='redshift_default',
    s3_bucket='my-bucket',
    s3_key='data/output/',
    sql='SELECT * FROM users'
)

But the task fails with an error about missing parameters. What is the likely cause?

medium

A. The sql parameter is not supported by RedshiftToS3Operator

B. The operator name is incorrect; it should be S3ToRedshiftOperator

C. The s3_key parameter must be a full S3 URI starting with s3://

D. The redshift_conn_id must be named aws_conn_id

Solution

1. Step 1: Check operator purpose and name

   RedshiftToS3Operator copies data from Redshift to S3, but the task description says copying from S3 to Redshift.

2. Step 2: Identify correct operator for S3 to Redshift copy

   The correct operator for copying data from S3 to Redshift is S3ToRedshiftOperator.

3. Final Answer:

   The operator name is incorrect; it should be S3ToRedshiftOperator -> Option B

4. Quick Check:

   RedshiftToS3Operator copies Redshift to S3, not reverse [OK]

Hint: Check operator name matches data flow direction [OK]

Common Mistakes:

• Mixing up RedshiftToS3Operator and S3ToRedshiftOperator
• Assuming sql parameter works for all operators
• Incorrect S3 URI format

5. You want to automate a workflow where you first upload a CSV file to S3, then run a Redshift COPY command to load the data, and finally start an EMR cluster for processing. Which sequence of Airflow operators correctly implements this?

hard

A. S3CreateObjectOperator -> RedshiftSQLOperator -> EmrCreateJobFlowOperator

B. RedshiftSQLOperator -> S3CreateObjectOperator -> EmrCreateJobFlowOperator

C. EmrCreateJobFlowOperator -> S3CreateObjectOperator -> RedshiftSQLOperator

D. S3CreateObjectOperator -> EmrCreateJobFlowOperator -> RedshiftSQLOperator

Solution

1. Step 1: Identify the logical order of tasks

   First, upload the CSV to S3 using S3CreateObjectOperator.

2. Step 2: Load data into Redshift using COPY command via RedshiftSQLOperator

   After the file is in S3, run the COPY command in Redshift to load data.

3. Step 3: Start EMR cluster with EmrCreateJobFlowOperator for processing

   Finally, start the EMR cluster to process the loaded data.

4. Final Answer:

   S3CreateObjectOperator -> RedshiftSQLOperator -> EmrCreateJobFlowOperator -> Option A

5. Quick Check:

   Upload -> Load -> Process = A [OK]

Hint: Think data flow: upload, load, then process [OK]

Common Mistakes:

• Running Redshift load before uploading to S3
• Starting EMR before data is loaded
• Mixing operator order