gRPC 5 NOT_FOUND vs 9 FAILED_PRECONDITION
Both gRPC 5 (NOT_FOUND) and 9 (FAILED_PRECONDITION) belong to the gRPC Status Codes category. 5 indicates that some requested entity was not found. For example, a file or directory that the RPC was supposed to operate on does not exist. Meanwhile, 9 means that the operation was rejected because the system is not in a state required for the operation's execution. For example, deleting a non-empty directory.
Description
Some requested entity was not found. For example, a file or directory that the RPC was supposed to operate on does not exist.
When You See It
The resource referenced in the request doesn't exist — such as looking up a user by ID that has been deleted or never created.
How to Fix
Verify the resource identifier is correct. Ensure the resource was created before accessing it, or handle the not-found case gracefully in your client.
Description
The operation was rejected because the system is not in a state required for the operation's execution. For example, deleting a non-empty directory.
When You See It
The request is valid on its own, but the system's current state doesn't allow it — like trying to delete a non-empty directory or update a resource that has been modified concurrently.
How to Fix
Bring the system into the required state before retrying. For example, empty the directory first, or re-read the resource to get the latest version before updating.
Key Differences
gRPC 5: Some requested entity was not found. For example, a file or directory that the RPC was supposed to operate on does not exist.
gRPC 9: The operation was rejected because the system is not in a state required for the operation's execution. For example, deleting a non-empty directory.
You encounter 5 when the resource referenced in the request doesn't exist — such as looking up a user by ID that has been deleted or never created.
You encounter 9 when the request is valid on its own, but the system's current state doesn't allow it — like trying to delete a non-empty directory or update a resource that has been modified concurrently.
When to Use Which
For 5 (NOT_FOUND): Verify the resource identifier is correct. Ensure the resource was created before accessing it, or handle the not-found case gracefully in your client. For 9 (FAILED_PRECONDITION): Bring the system into the required state before retrying. For example, empty the directory first, or re-read the resource to get the latest version before updating.