OpenSearch Serverless vs Managed Domain Cost Comparison
This document presents a direct, quantitative cost comparison between two AWS OpenSearch
deployment configurations: a Provisioned architecture utilizing a Blue/Green deployment strategy,
and an Amazon OpenSearch Serverless (AOSS) architecture. All calculations are based on
published AWS On-Demand rates for US regions, assuming an average continuous operating
baseline of 730 hours per month.
Amazon OpenSearch Service domain
Resource Specifications (Per Stack)
Dedicated Master Nodes: 3 × m6g.large.search ($0.128/hr)
Data Nodes: 2 × r6g.xlarge.search ($0.335/hr)
Attached Storage: 2 × 100 GiB gp3 volumes ($0.122/GiB-mo)
Resource Component | Unit Rate | Quantity | Monthly Hrs | Total Cost |
|---|---|---|---|---|
Master Nodes | $0.128 / hr | 6 instances | 730 | $560.64 |
Data Nodes | $0.335 / hr | 4 instances | 730 | $978.20 |
EBS Storage (gp3) | $0.122 / GiB-mo | 400 GiB total | N/A | $48.80 |
Total Provisioned Cost |
|
|
| $1,587.64 |
Amazon OpenSearch Serverless
The AOSS billing model is determined by OpenSearch Compute Units (OCUs) and managed S3-backed storage. Indexing and Search operations are scaled, metered, and billed independently. The figures below assume a sustained workload requiring 10 OCUs for indexing and 10 OCUs for search continuously.
Resource Specifications
Indexing Compute: Sustained 10 OCUs ($0.24/hr per OCU)
Search Compute: Sustained 10 OCUs ($0.24/hr per OCU)
Managed Storage: 200 GiB ($0.024/GiB-mo)
10 OCUs for Indexing and Search is real and observed in production. This is primarily due to the number of indexes created, which is mitigated in the managed domain route since more indexes can be packed into the shared server instances.
Total Serverless Monthly Cost
Resource Component | Unit Rate | Baseline OCUs | Monthly Hrs | Total Cost |
|---|---|---|---|---|
AOSS Indexing Compute | $0.24 / hr | 10 OCUs | 730 | $1,752.00 |
AOSS Search Compute | $0.24 / hr | 10 OCUs | 730 | $1,752.00 |
AOSS Managed Storage | $0.024 / GiB-mo | 200 GiB total | N/A | $4.80 |
Total Serverless Cost |
|
|
| $3,508.80 |
Conclusion
Amazon OpenSearch Service domain lowers overall cost while allowing us to tune the service for our specific Synapse workloads.