module GRPC::Core::StatusCodes
StatusCodes
defines the canonical error codes used by gRPC for the RPC API.
Constants
- ABORTED
Aborted
indicates the operation was aborted, typically due to a concurrency issue like sequencer check failures, transaction aborts, etc.See litmus test above for deciding between
FailedPrecondition
,Aborted
, andUnavailable
.- ALREADY_EXISTS
AlreadyExists
means an attempt to create an entity failed because one already exists.- CANCELLED
Canceled indicates the operation was canceled (typically by the caller).
- DATA_LOSS
DataLoss
indicates unrecoverable data loss or corruption.- DEADLINE_EXCEEDED
DeadlineExceeded
means operation expired before completion. For operations that change the state of the system, this error may be returned even if the operation has completed successfully. For example, a successful response from a server could have been delayed long enough for the deadline to expire.- FAILED_PRECONDITION
FailedPrecondition
indicates operation was rejected because the system is not in a state required for the operation's execution. For example, directory to be deleted may be non-empty, an rmdir operation is applied to a non-directory, etc.A litmus test that may help a service implementor in deciding between
FailedPrecondition
,Aborted
, and Unavailable:(a) Use Unavailable if the client can retry just the failing call. (b) Use Aborted if the client should retry at a higher-level (e.g., restarting a read-modify-write sequence). (c) Use FailedPrecondition if the client should not retry until the system state has been explicitly fixed. E.g., if an "rmdir" fails because the directory is non-empty, FailedPrecondition should be returned since the client should not retry unless they have first fixed up the directory by deleting files from it. (d) Use FailedPrecondition if the client performs conditional REST Get/Update/Delete on a resource and the resource on the server does not match the condition. E.g., conflicting read-modify-write on the same resource.
- INTERNAL
Internal
errors. Means some invariants expected by underlying system has been broken. If you see one of these errors, something is very broken.- INVALID_ARGUMENT
InvalidArgument
indicates client specified an invalid argument. Note that this differs fromFailedPrecondition
. It indicates arguments that are problematic regardless of the state of the system (e.g., a malformed file name).- NOT_FOUND
NotFound
means some requested entity (e.g., file or directory) was not found.- OK
OK
is returned on success.- OUT_OF_RANGE
OutOfRange
means operation was attempted past the valid range. E.g., seeking or reading past end of file.Unlike
InvalidArgument
, this error indicates a problem that may be fixed if the system state changes. For example, a 32-bit file system will generateInvalidArgument
if asked to read at an offset that is not in the range [0,2^32-1], but it will generateOutOfRange
if asked to read from an offset past the current file size.There is a fair bit of overlap between
FailedPrecondition
andOutOfRange
. We recommend usingOutOfRange
(the more specific error) when it applies so that callers who are iterating through a space can easily look for anOutOfRange
error to detect when they are done.- PERMISSION_DENIED
PermissionDenied
indicates the caller does not have permission to execute the specified operation. It must not be used for rejections caused by exhausting some resource (useResourceExhausted
instead for those errors). It must not be used if the caller cannot be identified (useUnauthenticated
instead for those errors).- RESOURCE_EXHAUSTED
ResourceExhausted
indicates some resource has been exhausted, perhaps a per-user quota, or perhaps the entire file system is out of space.- UNAUTHENTICATED
Unauthenticated
indicates the request does not have valid authentication credentials for the operation.- UNAVAILABLE
Unavailable
indicates the service is currently unavailable. This is a most likely a transient condition and may be corrected by retrying with a backoff. Note that it is not always safe to retry non-idempotent operations.See litmus test above for deciding between
FailedPrecondition
,Aborted
, andUnavailable
.- UNIMPLEMENTED
Unimplemented
indicates operation is not implemented or not supported/enabled in this service.- UNKNOWN
Unknown
error. An example of where this error may be returned is if a Status value received from another address space belongs to an error-space that is not known in this address space. Also errors raised by APIs that do not return enough error information may be converted to this error.