AWS Big Data Blog

In-stream anomaly detection with Amazon OpenSearch Ingestion and Amazon OpenSearch Serverless

Unsupervised machine learning analytics has emerged as a powerful tool for anomaly detection in today’s data-rich landscape, especially with the growing volume of machine-generated data. In-stream anomaly detection offers real-time insights into data anomalies, enabling proactive response. Amazon OpenSearch Serverless focuses on delivering seamless scalability and management of search workloads; Amazon OpenSearch Ingestion complements this by providing a robust solution for anomaly detection on indexed data.

In this post, we provide a solution using OpenSearch Ingestion that empowers you to perform in-stream anomaly detection within your own AWS environment.

In-stream anomaly detection with OpenSearch Ingestion

OpenSearch Ingestion makes the process of in-stream anomaly detection straightforward and at less cost. In-stream anomaly detection helps you save on indexing and avoids the need for extensive resources to handle big data. It lets organizations apply the appropriate resources at the appropriate time, managing large data efficiently and saving money. Using peer forwarders and aggregate processors can make things more complex and expensive; OpenSearch Ingestion reduces these issues.

Let’s look at a use case showing an OpenSearch Ingestion configuration YAML for in-stream anomaly detection.

Solution overview

In this example, we walk through the setup of OpenSearch Ingestion using a random cut forest anomaly detector for monitoring log counts within a 5-minute period. We also index the raw logs to provide a comprehensive demonstration of the incoming data flow. If your use case requires the analysis of raw logs, you can streamline the process by bypassing the initial pipeline and focus directly on in-stream anomaly detection, indexing only the identified anomalies.

The following diagram illustrates our solution architecture.

The configuration outlines two OpenSearch Ingestion pipelines. The first, non-ad-pipeline, ingests HTTP data, timestamps it, and forwards it to both ad-pipeline and an OpenSearch index, non-ad-index. The second, ad-pipeline, receives this data, performs aggregation based on the ID within a 5-minute window, and conducts anomaly detection. Results are stored in the index ad-anomaly-index. This setup showcases data processing, anomaly detection, and storage within OpenSearch Service, enhancing analysis capabilities.

Implement the solution

Complete the following steps to set up the solution:

  1. Create a pipeline role.
  2. Create a collection.
  3. Create a pipeline in which you specify the pipeline role.

The pipeline assumes this role in order to sign requests to the OpenSearch Serverless collection endpoint. Specify the values for the keys within the following pipeline configuration:

  • For sts_role_arn, specify the Amazon Resource Name (ARN) of the pipeline role that you created.
  • For hosts, specify the endpoint of the collection that you created.
  • Set serverless to true.
version: "2"
# 1st pipeline
      path: "/${pipelineName}/test_ingestion_path"
    - date:
        from_time_received: true
        destination: "@timestamp"
    - pipeline:
        name: "ad-pipeline"
    - opensearch:
        index: "non-ad-index"
          sts_role_arn: "arn:aws:iam::{account-id}:role/pipeline-role"
          region: "us-east-1"
          serverless: true
# 2nd pipeline
      name: "non-ad-pipeline"
    - aggregate:
        identification_keys: ["id"]
        group_duration: "300s"
    - anomaly_detector:
        keys: ["value"] # value will have sum of logs
            output_after: 200 
    - opensearch:
          sts_role_arn: "arn:aws:iam::{account-id}:role/pipeline-role"
          region: "us-east-1"
          serverless: true
        index: "ad-anomaly-index"

For a detailed guide on the required parameters and any limitations, see Supported plugins and options for Amazon OpenSearch Ingestion pipelines.

  1. After you update the configuration, confirm the validity of your pipeline settings by choosing Validate pipeline.

A successful validation will display a message stating Pipeline configuration validation successful.” as shown in the following screenshot.

If validation fails, refer to Troubleshooting Amazon OpenSearch Service for troubleshooting and guidance.

Cost estimation for OpenSearch Ingestion

You are only charged for the number of Ingestion OpenSearch Compute Units (Ingestion OCUs) that are allocated to a pipeline, regardless of whether there’s data flowing through the pipeline. OpenSearch Ingestion immediately accommodates your workloads by scaling pipeline capacity up or down based on usage. For an overview of expenses, refer to Amazon OpenSearch Ingestion.

The following table shows approximate monthly costs based on specified throughputs and compute needs. Let’s assume that operation occurs from 8:00 AM to 8:00 PM on weekdays, with a cost of $0.24 per OCU per hour.

The formula would be: Total Cost/Month = OCU Requirement * OCU Price * Hours/Day * Days/Month.

Throughput Compute Required (OCUs) Total Cost/Month (USD)
1 Gbps 10 576
10 Gbps 100 5760
50 Gbps 500 28800
100 Gbps 1000 57600
500 Gbps 5000 288000

Clean up

When you are done using the solution, delete the resources you created, including the pipeline role, pipeline, and collection.


With OpenSearch Ingestion, you can explore in-stream anomaly detection with OpenSearch Service. The use case in this post demonstrates how OpenSearch Ingestion simplifies the process, achieving more with fewer resources. It showcases the service’s ability to analyze log rates, generate anomaly notifications, and empower proactive response to anomalies. With OpenSearch Ingestion, you can improve operational efficiency and enhance real-time risk management capabilities.

Leave any thoughts and questions in the comments.

About the Authors

Rupesh Tiwari, an AWS Solutions Architect, specializes in modernizing applications with a focus on data analytics, OpenSearch, and generative AI. He’s known for creating scalable, secure solutions that leverage cloud technology for transformative business outcomes, also dedicating time to community engagement and sharing expertise.

Muthu Pitchaimani is a Search Specialist with Amazon OpenSearch Service. He builds large-scale search applications and solutions. Muthu is interested in the topics of networking and security, and is based out of Austin, Texas.