Burst capacity in DynamoDB - Step-by-Step Execution

Concept Flow - Burst capacity

Start with baseline capacity

↓

Traffic spikes occur?

No→Use baseline capacity

Yes↓

Use burst capacity credits

↓

Credits decrease

↓

Credits exhausted?

No→Continue burst

Yes↓

Throttle requests or wait for credits to replenish

Burst capacity lets your database handle sudden traffic spikes by using saved credits above baseline capacity, until credits run out.

Execution Sample

DynamoDB

BaselineCapacity = 100
Credits = 200
RequestRate = [50, 120, 180, 90, 130]

for rate in RequestRate:
  if rate > BaselineCapacity:
    Use credits
  else:
    Use baseline

This simulates how burst capacity credits are used when request rate exceeds baseline capacity.

Execution Table

Step	Request Rate	Baseline Capacity	Credits Before	Credits Used	Credits After	Capacity Used	Throttle?
1	50	100	200	0	200	50 (baseline)	No
2	120	100	200	20	180	100 (baseline) + 20 (credits)	No
3	180	100	180	80	100	100 (baseline) + 80 (credits)	No
4	90	100	100	0	100	90 (baseline)	No
5	130	100	100	30	70	100 (baseline) + 30 (credits)	No

💡 Credits remain after last request, no throttling needed.

Variable Tracker

Variable	Start	After 1	After 2	After 3	After 4	After 5
Credits	200	200	180	100	100	70

Key Moments - 2 Insights

Why do credits only decrease when request rate exceeds baseline capacity?

Because baseline capacity handles normal traffic without using credits, as shown in execution_table rows 1 and 4 where credits stay the same.

What happens when credits run out?

Requests exceeding baseline capacity cannot be served immediately and may be throttled or delayed, but in this example credits remain positive, so no throttling occurs.

Visual Quiz - 3 Questions

Look at the execution table, how many credits are used at step 3?

A 180

B 80

C 100

D 0

💡 Hint

Check the 'Credits Used' column at step 3 in the execution_table.

At which step does the request rate NOT use any credits?

A Step 4

B Step 2

C Step 5

D Step 3

💡 Hint

Look for rows where 'Credits Used' is 0 in the execution_table.

If the baseline capacity was increased to 150, what would happen at step 2?

A Credits would increase

B Credits would be used as before

C No credits would be used because request rate is below baseline

D Request would be throttled

💡 Hint

Compare request rate and baseline capacity at step 2 in the execution_table and consider the new baseline.

Concept Snapshot

Burst capacity lets DynamoDB handle sudden traffic spikes by using saved credits above baseline capacity.
Credits are consumed only when request rate exceeds baseline.
When credits run out, requests may be throttled.
Credits replenish over time during low traffic.
This helps maintain performance without over-provisioning.

Full Transcript

Burst capacity in DynamoDB allows the database to handle sudden increases in traffic by using saved capacity credits. The baseline capacity is the normal throughput the database can handle without extra cost. When requests exceed this baseline, burst credits are used to serve the extra load. Credits decrease as they are used and replenish when traffic is low. If credits run out, requests may be throttled or delayed until credits are available again. This mechanism helps maintain smooth performance during traffic spikes without needing to permanently increase capacity.