Exam Numbers Cheat Sheet

💡 Every limit and default worth memorizing, in one place. Numbers marked ⚠ are ones AWS occasionally revises — sanity-check anything surprising against current docs.

Lambda

Number	What it is
15 min	Max execution timeout
10 GB	Max memory (CPU scales with it)
1,000 ⚠	Default account concurrency (soft limit)
6 MB / 256 KB	Max payload: synchronous / asynchronous
2 retries	Async invocation retries before discard (→ destination/DLQ)
250 MB / 10 GB	Unzipped deployment package / container image max
512 MB – 10 GB	/tmp storage

SQS / SNS

Number	What it is
256 KB	Max message size (both) — larger → Extended Client Library + S3
4 days / 14 days	Default / max message retention
30 s / 12 h	Default / max visibility timeout
20 s	Max long-polling wait
300 msg/s / 3,000 msg/s ⚠	FIFO throughput: without / with batching
15 min	Max delivery delay (delay queue)
5 min	Deduplication window (FIFO)

Kinesis

Number	What it is
1 MB/s or 1,000 rec/s	Ingest per shard
2 MB/s	Egress per shard (shared across consumers; per-consumer with Enhanced Fan-Out)
24 h / 365 days	Default / max retention
1 MB	Max record size

Step Functions

Number	What it is
1 year / 5 min	Max duration: Standard / Express
25,000	Execution history events (→ Distributed Map for more)
256 KB	Max state input/output payload

DynamoDB

Number	What it is
400 KB	Max item size
48 h	TTL deletion can lag this long after expiry
24 h	Streams retention

S3

Number	What it is
5 TB / 5 GB	Max object / max single PUT (multipart beyond)
100 MB	Multipart recommended above this
3,500 / 5,500	Writes / reads per second per prefix
7 days	Max presigned URL validity (SigV4)

IAM / STS / KMS

Number	What it is
1 h	Default STS session; hard cap for role chaining
12 h	Max role session duration (if configured)
4 KB	Max data for direct KMS Encrypt (→ envelope encryption)
7–30 days	KMS key deletion waiting period
12 h	CodeArtifact auth token max
1 year	Automatic KMS key rotation interval

CI/CD

Number	What it is
60 min / 8 h	CodeBuild default / max build timeout
5	Max targets per EventBridge rule
24 h	EventBridge retry window before drop/DLQ
1,000	Beanstalk application version limit (→ lifecycle policy)
10 / 1	CodeArtifact: max upstreams / max external connections per repo

ASG / EC2 / ELB

Number	What it is
300 s	Default cooldown; default health check grace period
1 h	Default lifecycle hook heartbeat timeout (extend via heartbeat, up to 48 h total)
5 min / 1 min	EC2 metrics: standard / detailed monitoring interval
2 min	Spot interruption notice
1	HttpPutResponseHopLimit that blocks containers from IMDS

CloudWatch / Logs

Number	What it is
1 s	Highest-resolution custom metric granularity
10 s / 30 s	Fastest alarm evaluation on high-res metrics
100	Metric filters per log group
Never expire	Default log retention (set it explicitly!)
15 months	Metric data retention (rolled up over time)

Databases / DR

Number	What it is
< 1 s / < 1 min	Aurora Global Database typical RPO / RTO
15	Max Aurora read replicas per cluster
35 days	Max automated backup retention (RDS/Aurora)
72 h	Aurora Backtrack max window
5	RDS read replicas (non-Aurora) ⚠ (15 for some engines now)

Route 53 / CloudTrail / Misc

Number	What it is
30 s / 10 s	Health check: standard / fast interval
3	Consecutive failures → unhealthy (default)
8	Max records returned by multivalue answer routing
90 days	CloudTrail Event History retention (fixed)
~7 days	CloudTrail Insights baseline stabilization
15 min	S3 Replication Time Control SLA