---
title: "Retry Policy"
url: "https://nsta1.github.io/Orleans.Lattice/samples/RetryPolicy/README.html"
source: "https://github.com/NSTA1/Orleans.Lattice/blob/release/9.9/samples/RetryPolicy/README.md"
documents: "Orleans.Lattice 9.9.0 (release line 9.9)"
built: "2026-10-04"
all-pages: "https://nsta1.github.io/Orleans.Lattice/llms.txt"
---
# Retry Policy

Part of [Samples](../index.md).

## What it shows

Storage faults are sometimes transient (a throttle, a brief network blip). This
sample wraps a write in `BoundedExponentialRetryPolicy` and pairs it with a
`LatticeIdempotencyContext` scope, so the operation is retried under a stable
**idempotency key**. A simulated transient fault fails the first two attempts
before the write is issued, and the third succeeds. Every attempt carries the
same idempotency key, so had a failed attempt already landed its write, the
retry would collapse to a single logical mutation rather than apply twice.

## Run it

```
dotnet run --project samples/RetryPolicy
```

## Expected output

```
Silo starting... ready.

== Retrying a write that fails twice under a simulated transient fault ==
  attempt #1...
  attempt #2...
  attempt #3...
  attempt succeeded - write committed.

  tree['orders/42'] = shipped  (after 3 attempts)

Done. The operation survived transient faults and the retried write
collapsed to a single mutation under one idempotency key.
```

## When to use

- Wrapping writes that can hit transient backend faults (throttling, timeouts)
  where a bounded, backing-off retry turns a blip into a success.
- Any retried single-key mutation or range delete that must stay exactly-once:
  supply a caller-owned idempotency key so a replay does not double-apply. The
  batch, atomic, and bulk-load entry points (`SetManyAsync`,
  `SetManyAtomicAsync`, `BulkLoadAsync`, ...) do not take the ambient key.

## When not to use

- Deterministic, non-transient failures (bad input, auth). Retrying just delays
  the inevitable error - let it surface. Classify which exceptions are retryable
  via the policy's classifier.

## Feature docs

[docs/lattice/retry-policy.md](../../docs/lattice/retry-policy.md)