posthog/docs/internal/workflows/s3-query-cache-setup.md

S3 Query Cache TTL Implementation

How It Works

1 Object Tagging: Each S3 object gets tags:

ttl_days=1              # Calculated TTL in days
team_id=123            # Team identifier

2 Automatic Deletion: S3 lifecycle rules delete objects matching tag criteria

Required S3 Lifecycle Rules

Critical: You must create lifecycle rules for every ttl_days value your app generates.

AWS CLI Configuration

# Create rules for common TTL values: 1, 2, 7, 14, 30 days
cat > lifecycle-config.json << EOF
{
    "Rules": [
        {
            "ID": "query-cache-ttl-1-day",
            "Status": "Enabled",
            "Filter": {
                "And": {
                    "Tags": [
                        {"Key": "ttl_days", "Value": "1"},
                    ]
                }
            },
            "Expiration": {"Days": 1}
        },
        {
            "ID": "query-cache-ttl-7-days",
            "Status": "Enabled",
            "Filter": {
                "And": {
                    "Tags": [
                        {"Key": "ttl_days", "Value": "7"},
                    ]
                }
            },
            "Expiration": {"Days": 7}
        }
    ]
}
EOF

aws s3api put-bucket-lifecycle-configuration \
    --bucket your-bucket-name \
    --lifecycle-configuration file://lifecycle-config.json

Terraform Configuration

resource "aws_s3_bucket_lifecycle_configuration" "query_cache" {
  bucket = aws_s3_bucket.query_cache.id

  # Repeat this rule block for each TTL value (1, 2, 7, 14, 30 days)
  rule {
    id     = "query-cache-ttl-1-day"
    status = "Enabled"
    filter {
      and {
        tags = {
          ttl_days   = "1"
        }
      }
    }
    expiration {
      days = 1
    }
  }
}

Warning: Objects with ttl_days values lacking lifecycle rules will never expire.