Available CloudWatch Metrics

s3lim surfaces storage insights through two primary mechanisms in AWS CloudWatch: Direct Metrics and Log-Based Metrics. These metrics are automatically displayed in the CloudWatch Dashboard provided by the deployment templates.

Metric Types & Naming

Rollup vs. Direct Metrics

  • Rollup Metrics (default): Aggregate data recursively across prefix levels. For example, a rollup metric for the /data/ prefix includes all objects in /data/logs/ and /data/temp/. These are essential for high-level cost deconstruction.
  • Direct Metrics: Only include objects located exactly within that specific prefix level. These are useful for surgical analysis of a single folder’s contents.

Metric Dimensions

Most metrics are partitioned by:

  • Bucket: The name of the S3 bucket being analyzed.
  • Prefix: The specific folder path (for prefix-based metrics).

Storage Distribution

These metrics help you understand how your storage is distributed across your bucket’s hierarchy.

  • TotalSize: The aggregate size of all objects under a prefix (Rollup).
  • DirectSize: The size of objects located specifically in this prefix.
  • ObjectCount: The total count of objects under a prefix.
  • SumAgeSeconds: The cumulative age of all objects in seconds. Used to identify “cold” data that hasn’t been accessed or modified in a long time.

Cost Optimization

Metrics designed specifically to identify recoverable spend and suboptimal storage configurations.

  • DuplicatePercent: The percentage of total storage occupied by redundant data (files with identical ETags).
  • DuplicateObjectSize: Identifies the specific largest redundant files across the bucket.
  • ITCandidateBytes: Storage that meets the requirements for Intelligent Tiering but is currently in a more expensive tier (e.g., Standard).
  • SmallFileTrapCount: Identifies files that are too small to be cost-effectively moved to colder tiers (IA/Glacier) due to per-object overhead.

Metadata Insights

Deep-dive metrics into object metadata that often hides significant costs.

  • GhostVersionSize: Size occupied by non-current object versions.
  • DeleteMarkerCount: The number of expired object delete markers occupying metadata space.
  • MultipartUploadSize: The total size of incomplete multipart uploads that are still taking up space and costing money.
  • ZeroByteCount: The count of empty (0 byte) objects that may indicate application bugs or failed processing.
  • SmallFileCount: The number of objects smaller than the SMALL_FILE_THRESHOLD_KB (default 128KB).

Analysis Audit

Operational metrics for the s3lim analysis engine itself.

  • RowsProcessed: The total number of object rows successfully scanned during the run.
  • TotalBytes: The cumulative size of the inventory data processed.
  • ErrorCount: The number of inventory rows that failed to parse correctly.