gRPC 4 DEADLINE_EXCEEDED vs 9 FAILED_PRECONDITION
Both gRPC 4 (DEADLINE_EXCEEDED) and 9 (FAILED_PRECONDITION) belong to the gRPC Status Codes category. 4 indicates that the deadline expired before the operation could complete. For operations that change the state of the system, this error may be returned even if the operation has completed successfully. 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.
Descrição
The deadline expired before the operation could complete. For operations that change the state of the system, this error may be returned even if the operation has completed successfully.
Quando você o vê
The RPC took longer than the configured deadline allows. Common in slow network conditions, overloaded servers, or when the deadline is set too aggressively.
Como corrigir
Increase the client deadline, optimize the server-side processing, or add server-side caching. If the operation might have succeeded, check idempotency before retrying.
Descrição
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.
Quando você o vê
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.
Como corrigir
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.
Diferenças principais
gRPC 4: The deadline expired before the operation could complete. For operations that change the state of the system, this error may be returned even if the operation has completed successfully.
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 4 when the RPC took longer than the configured deadline allows. Common in slow network conditions, overloaded servers, or when the deadline is set too aggressively.
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.
Quando usar qual
For 4 (DEADLINE_EXCEEDED): Increase the client deadline, optimize the server-side processing, or add server-side caching. If the operation might have succeeded, check idempotency before retrying. 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.