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Fixing Durable Object storage operation timeouts

Cloudflare Durable Objectsrevision 1

Diagnostic tree

  1. In progressDurable Object storage operation exceeded timeoutA `ctx.storage` write inside a Durable Object fails and the object resets — any in-memory state is lost, and in-flight requests that were touching storage are cut off.
View the whole map (7 more steps)
  • Check the size of the value being written
  • Shard the large value, or move it out of Durable Object storage
  • Check for blockConcurrencyWhile() wrapping slow work
  • Stop using blockConcurrencyWhile() outside initialization
  • Not a size or blockConcurrencyWhile issue — escalate
  • Repeat the action that triggered the timeout
  • Resolved

What to test

Durable Object storage operation exceeded timeout

A `ctx.storage` write inside a Durable Object fails and the object resets — any in-memory state is lost, and in-flight requests that were touching storage are cut off.

What happened?