Intermediate

Retry with Backoff

Reliability & Latency

Exponential backoff with jitter for resilient retries of transient failures

Core Idea

Retries should be bounded, exponential, and jittered to avoid coordinated retry storms. Only retry idempotent operations and respect server guidance.

When to Use

When encountering transient network errors, 5xx responses, or timeouts on idempotent requests.

Recognition Cues

Indicators that this pattern might be the right solution

Burst of 5xx/timeouts under load
Thundering herd after dependency failure
Client storms synchronized by fixed delays

Pattern Variants & Approaches

Overview

Client performs bounded exponential backoff with jitter on transient failures, respecting idempotency and server hints.

Overview Architecture

When to Use This Variant

Transient 5xx/timeouts
Retry-After headers
Idempotent operations

Use Case

HTTP/gRPC clients, SDKs, and background jobs communicating over unreliable networks.

Advantages

Avoids retry storms
Improves success under flakes
Simple client-side policy

Implementation Example

# Exponential backoff with jitter (pseudocode)
for attempt in range(max_attempts):
  try:
    return call()
  except TransientError:
    sleep(rand(0, base * 2**attempt))

Tradeoffs

Pros

Improves resiliency to transient faults
Reduces load during outages
Simple to implement with libraries

Cons

Increases latency on failure paths
Can amplify load if mis-tuned
Complexity with layered retry policies

Common Pitfalls

Retrying non-idempotent operations
Unbounded attempts or total retry time
Coordinated retries without jitter
Layered retries across gateway, mesh, and client
Ignoring Retry-After headers

Design Considerations

Exponential backoff with full/decorrelated jitter
Cap attempts and total budget per request
Idempotency keys for writes where possible
Status/exception-based retry policies
Outlier detection and hedging for tail latency (sparingly)

Real-World Examples

AWS SDKs

Built-in exponential backoff with jitter

Millions of clients

Google

SRE guidance on jittered retries

Planet-scale services

Stripe

Idempotency keys + retries for payments

Global API traffic

Complexity Analysis

Scalability

Client-side - Applies per call

Implementation Complexity

Low to Medium - Policy tuning

Cost

Low - Library-level feature

Circuit Breaker Rate Limiting Bulkhead Isolation Idempotency Keys