19 documented AWS RDS cost inefficiencies, each with how to detect it and how to fix it.
AWS RDSCER-0323
Amazon RDS for SQL Server has traditionally used a License Included model where the SQL Server license cost is bundled into a single hourly instance price alongside Windows OS licensing, compute resources, and RDS management capabilities....
AWS RDSCER-0322
Amazon RDS for SQL Server uses a License Included pricing model where the hourly instance rate bundles Microsoft SQL Server licensing fees on a per-vCPU basis. When non-production workloads - such as development, testing, staging, QA, or...
AWS RDSCER-0320
Amazon RDS for SQL Server uses a License Included pricing model where SQL Server and Windows OS licensing costs are bundled into the per-instance-hour rate - and those licensing costs scale directly with the number of vCPUs on the...
AWS RDSCER-0299
An RDS database instance is deleted but its manual snapshots or retained backups remain. Unlike automated backups tied to a live instance, these backups persist independently and continue generating storage costs despite no longer...
AWS RDSCER-0206
Many organizations continue to run outdated database engines, such as MySQL 5.7 or PostgreSQL 11, beyond their support windows. Beginning in 2024, AWS automatically enrolls these into Extended Support to maintain security updates, adding...
AWS RDSCER-0055
If backup retention settings are too high or old automated backups are unnecessarily retained, costs can accumulate rapidly. RDS backup storage is significantly more expensive than equivalent storage in S3. For long-term retention or...
AWS RDSCER-0210
RDS Multi-AZ deployments are designed for production-grade fault tolerance. In non-production environments, a Multi-AZ DB instance deployment roughly doubles the cost of database instances and storage, and a Multi-AZ DB cluster runs three...
AWS RDSCER-0205
RDS reader nodes are intended to handle read-only workloads, allowing for traffic offloading from the primary (writer) node. However, in many environments, services are misconfigured or hardcoded to send all traffic - including reads-to...
AWS RDSCER-0030
RDS workloads often evolve - changing engine types, rightsizing instances, or shifting to Aurora or serverless models. When these changes occur after Reserved Instances have been purchased, the existing commitments may no longer match...
AWS RDSCER-0119
Many RDS workloads continue to run on older x86 instance types (e.g., db.m5, db.r5) even though compatible Graviton-based options (e.g., db.m6g, db.r6g) are widely available. These newer families deliver improved performance per vCPU and...
AWS RDSCER-0097
While stopping an RDS instance reduces runtime cost, AWS enforces a 7-day limit on stopped state. After this period, the instance is automatically restarted and resumes incurring compute charges - even if the database is still not needed....
AWS RDSCER-0086
An RDS instance uses a high-cost storage type such as io1 or io2 but does not require the performance benefits it provides. In many cases, provisioned IOPS are set at or below the free baseline included with gp3 (3,000 IOPS and 125 MiB/s,...
AWS RDSCER-0065
An RDS instance remains in the running state but is no longer actively serving application traffic. These instances may be remnants of retired applications, paused development environments, or workloads that were migrated elsewhere. If an...
AWS RDSCER-0015
An RDS instance is consistently operating below its provisioned capacity - for example, showing low CPU, or memory utilization over an extended period. This often results from conservative initial sizing, decreased workload demand, or...
AWS RDSCER-0082
An RDS instance is allocated significantly more storage than it consumes. For example, a 2TB volume might contain only 150GB of actual data. Since RDS does not allow reducing allocated storage on existing instances, these volumes continue...
AWS RDSCER-0064
An RDS cluster remains provisioned but is no longer serving any workloads and has no active database connections. Unlike underutilized resources, these clusters are completely idle-showing no query activity, background processing, or usage...
AWS RDSCER-0072
Manual snapshots are often created for operational tasks like upgrades, migrations, or point-in-time backups. Unlike automated backups, which are automatically deleted after a set retention period, manual snapshots remain in place until...
AWS RDSCER-0036
Read replicas are intended to improve performance for read-heavy workloads or support cross-region redundancy. However, it's common for replicas to remain in place even after their intended purpose has passed. In some cases, they were...
AWS RDSCER-0370
Production RDS and Aurora databases are among the most predictable workloads in an AWS account: they typically run 24 hours a day on the same instance class for long periods. When that usage is not covered by reserved DB instances or...
