Kinesis Data Streams Capacity Modes (Provisioned & On-Demand) | Overview.

Kinesis Data Streams Capacity Modes (Provisioned & On-Demand) - Overview.

Scope:

• Intro,
• Comparison of  Provisioned Mode Vs On-Demand Mode,
• Provisioned Mode in detail,
• On-Demand Mode in detail,
• Cost Comparison Example (approximate),
• Switching Between Modes.
• Final Recommendation.

Intro:

• Amazon Kinesis Data Streams (KDS) offers two capacity modes to manage throughput and cost depending on twtech application needs:
• Provisioned Mode 
• On-Demand Mode.

Comparison of  Provisioned Mode Vs On-Demand Mode

Feature	Provisioned Mode	On-Demand Mode
Scaling Type	Manual or Auto-Scaling (shard-based)	Automatic
Best For	Predictable or steady traffic	Unpredictable or spiky traffic
Billing Basis	Per shard (ingestion + retrieval + storage)	Pay per GB ingested + read
Setup Complexity	Medium – requires planning shards	Very Low – no shard config
Throughput Limits	Based on number of shards	Starts at ~200 MB/s write / 400 MB/s read, scales automatically
Cost Efficiency	More efficient for consistent, high-volume workloads	Cheaper for low or unpredictable usage
Shard Management	Required (or use Auto-Scaling)	None required
Switching	Must recreate the stream to change mode	Same

 1. Provisioned Mode in detail

• twtech defines the number of shards in its stream.
• Each shard provides:
• 1 MB/sec or 1,000 records/sec write
• 2 MB/sec read
• twtech can manually or automatically scale shard count.
• Suitable for fine-grained cost control and high throughput needs.

twtech uses this when:

• twtech data rate is predictable or consistently high.
• twtech needs cost predictability at scale.

 2. On-Demand Mode in detail

• No need to provision or manage shards.
• Kinesis automatically scales in response to your traffic.
• Starts with:
• 200 MB/sec write (with up to 1000 records/sec/shard equivalent)
• 400 MB/sec read
• Charges are based on GBs written and read, not shard count.

 twtech uses this when:

• twtech workload is spiky or unpredictable.
• twtech wants a simple and maintenance-free setup.

 Cost Comparison Example (approximate)

Usage Pattern	Best Mode
24/7 steady 20 MB/sec	Provisioned (lower cost per throughput)
Occasional 5-minute spikes	On-Demand (only pay when used)
Early-stage app with variable traffic	On-Demand (simplicity + flexibility)

 Switching Between Modes

• twtech cannot switch modes on an existing stream.
• Changes twtech needs To make:
1. Create a new stream in the desired mode.
2. Update producers/consumers to use the new stream.
3. Migrate and delete the old stream.

 twtech Final Recommendation

Scenario	Mode
Startup, dev/test, irregular workloads	✅ On-Demand
Production app with predictable traffic	✅ Provisioned
Cost optimization at scale	✅ Provisioned (with auto-scaling)