Anomaly Detection in Streaming Data with AWS Timestream

Question

Pulumi · Accepted Answer

To implement anomaly detection in streaming data using AWS and Pulumi, you'll need to first set up AWS Timestream, which is AWS's fully managed time series database designed to handle high volume data events. It scales automatically and offers fast queries. This can then be used to store and analyze streaming data.

Since anomaly detection is usually part of a larger analytics solution, you might also consider additional AWS services. For instance, AWS Kinesis can be used to handle real-time data streams, AWS Lambda for executing your anomaly detection logic, and AWS S3 for longer-term storage (if needed).

Here’s a broad overview of how such a system could work with Pulumi:
- Create a Kinesis stream to ingest the real-time data.
- Set up a Lambda function that reads from the Kinesis stream, performs anomaly detection, and writes anomalies to Timestream for further analysis or to trigger alerts.
- Create a Timestream database and table to store and index the streaming data.

Below is a simplified Pulumi Python program that creates these resources. For the anomaly detection logic, you would typically use a machine learning model or a statistical method of detecting outliers. However, this code doesn't include the specific anomaly detection logic, as that would depend on your use case and data.

```python
import pulumi
import pulumi_aws as aws

# Create a new Kinesis stream to receive real-time data.
stream = aws.kinesis.Stream("anomaly-detection-stream",
                            shard_count=1)

# Define a Timestream database to store time-series data.
timestream_database = aws.timestreamwrite.Database("anomaly-detection-database")

# Define a Timestream table within the database to store the actual time-series records.
timestream_table = aws.timestreamwrite.Table("anomaly-detection-table",
                                             database_name=timestream_database.name,
                                             retention_properties={
                                                 "MemoryStoreRetentionPeriodInHours": "24",
                                                 "MagneticStoreRetentionPeriodInDays": "7"
                                             })

# Define an IAM role for the Lambda function.
role = aws.iam.Role("lambda-role", 
                    assume_role_policy=aws.iam.get_policy_document(statements=[
                        aws.iam.get_policy_document_statement(actions=["sts:AssumeRole"],
                            principals=[aws.iam.get_policy_document_statement_principal(type="Service", identifiers=["lambda.amazonaws.com"])])
                    ]).json)

# Attach policies to the Lambda role to allow it to write to Timestream and read from Kinesis.
policy = aws.iam.Policy("lambda-policy",
                        policy=pulumi.Output.all(stream.arn, timestream_database.name, timestream_table.name).apply(lambda args: {
                            "Version": "2012-10-17",
                            "Statement": [
                                {
                                    "Effect": "Allow",
                                    "Action": [
                                        "kinesis:DescribeStream",
                                        "kinesis:GetShardIterator",
                                        "kinesis:GetRecords",
                                        "kinesis:ListShards"
                                    ],
                                    "Resource": args[0]
                                },
                                {
                                    "Effect": "Allow",
                                    "Action": [
                                        "timestream:WriteRecords",
                                        "timestream:CreateTable",
                                        "timestream:DescribeDatabase"
                                    ],
                                    "Resource": [f'arn:aws:timestream:*:*:database/{args[1]}', f'arn:aws:timestream:*:*:table/{args[1]}/{args[2]}']
                                }
                            ]
                        }).json)
policy_attachment = aws.iam.RolePolicyAttachment("lambda-policy-attachment",
                                                 role=role,
                                                 policy_arn=policy.arn)

# Define a Lambda function to process the records from the Kinesis stream.
# This is where you would add your anomaly detection code.
lambda_function = aws.lambda_.Function("anomaly-detection-lambda",
                                      role=role.arn,
                                      handler="index.handler",
                                      runtime="python3.8",
                                      code=pulumi.FileArchive("./lambda.zip"))  # Replace './lambda.zip' with the path to your Lambda function's deployment package.

# Create an event source mapping to invoke the Lambda function for records placed into Kinesis.
event_source_mapping = aws.lambda_.EventSourceMapping("anomaly-detection-event-source",
                                                      event_source_arn=stream.arn,
                                                      function_name=lambda_function.name,
                                                      starting_position="LATEST")

# Export useful output that you might need for other resources.
pulumi.export("stream_name", stream.name)
pulumi.export("timestream_database_name", timestream_database.name)
pulumi.export("timestream_table_name", timestream_table.name)
```

To run this Pulumi program, you will need to have the AWS and Pulumi CLIs installed and configured with the necessary access keys.

After the creation of your AWS resources via this script, the final step is to implement the code that goes into `lambda.zip`. This package would contain the logic for processing stream data, detecting anomalies, and writing results to Timestream. The nature of this logic is highly dependent on your specific use case and data characteristics.

An important aspect of anomaly detection systems is their ability to scale with the volume of data, and to process and analyze data in near real-time. AWS Kinesis scales by adjusting the number of shards in the stream, and AWS Lambda scales automatically to the number of events in the stream.

Keep in mind that Timestream tables have TTL policies for the data in memory and magnetic storage (editable in the `retention_properties` in the `timestream_table` resource), so you'll need to set these according to your needs for data retention and querying.

Finally, this is a basic setup for streaming data and anomaly detection; if you need to build a more complex or robust system, you may need to introduce additional services or logic to your Pulumi program.