The canonical error codes for gRPC APIs.
Sometimes multiple error codes may apply. Services should return
the most specific error code that applies. For example, prefer
OUT_OF_RANGE
over FAILED_PRECONDITION
if both codes apply.
Similarly prefer NOT_FOUND
or ALREADY_EXISTS
over FAILED_PRECONDITION
.
Constants
OK
value: 0
Not an error; returned on success
HTTP Mapping: 200 OK
CANCELLED
value: 1
The operation was cancelled, typically by the caller.
HTTP Mapping: 499 Client Closed Request
UNKNOWN
value: 2
Unknown error. For example, this error may be returned when
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.
HTTP Mapping: 500 Internal Server Error
INVALID_ARGUMENT
value: 3
The client specified an invalid argument. Note that this differs
from FAILED_PRECONDITION
. INVALID_ARGUMENT
indicates arguments
that are problematic regardless of the state of the system
(e.g., a malformed file name).
HTTP Mapping: 400 Bad Request
DEADLINE_EXCEEDED
value: 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. For example, a
successful response from a server could have been delayed long
enough for the deadline to expire.
HTTP Mapping: 504 Gateway Timeout
NOT_FOUND
value: 5
Some requested entity (e.g., file or directory) was not found.
Note to server developers: if a request is denied for an entire class
of users, such as gradual feature rollout or undocumented whitelist,
NOT_FOUND
may be used. If a request is denied for some users within
a class of users, such as user-based access control, PERMISSION_DENIED
must be used.
HTTP Mapping: 404 Not Found
ALREADY_EXISTS
value: 6
The entity that a client attempted to create (e.g., file or directory)
already exists.
HTTP Mapping: 409 Conflict
PERMISSION_DENIED
value: 7
The caller does not have permission to execute the specified
operation. PERMISSION_DENIED
must not be used for rejections
caused by exhausting some resource (use RESOURCE_EXHAUSTED
instead for those errors). PERMISSION_DENIED
must not be
used if the caller can not be identified (use UNAUTHENTICATED
instead for those errors). This error code does not imply the
request is valid or the requested entity exists or satisfies
other pre-conditions.
HTTP Mapping: 403 Forbidden
UNAUTHENTICATED
value: 16
The request does not have valid authentication credentials for the
operation.
HTTP Mapping: 401 Unauthorized
RESOURCE_EXHAUSTED
value: 8
Some resource has been exhausted, perhaps a per-user quota, or
perhaps the entire file system is out of space.
HTTP Mapping: 429 Too Many Requests
FAILED_PRECONDITION
value: 9
The operation was rejected because the system is not in a state
required for the operation's execution. For example, the directory
to be deleted is non-empty, an rmdir operation is applied to
a non-directory, etc.
Service implementors can use the following guidelines to decide
between FAILED_PRECONDITION
, 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., when a client-specified test-and-set fails, indicating the
client should restart a read-modify-write sequence).
(c) Use FAILED_PRECONDITION
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, FAILED_PRECONDITION
should be returned since the client should not retry unless
the files are deleted from the directory.
HTTP Mapping: 400 Bad Request
ABORTED
value: 10
The operation was aborted, typically due to a concurrency issue such as
a sequencer check failure or transaction abort.
See the guidelines above for deciding between FAILED_PRECONDITION
,
ABORTED
, and UNAVAILABLE
.
HTTP Mapping: 409 Conflict
OUT_OF_RANGE
value: 11
The operation was attempted past the valid range. E.g., seeking or
reading past end-of-file.
Unlike INVALID_ARGUMENT
, this error indicates a problem that may
be fixed if the system state changes. For example, a 32-bit file
system will generate INVALID_ARGUMENT
if asked to read at an
offset that is not in the range [0,2^32-1], but it will generate
OUT_OF_RANGE
if asked to read from an offset past the current
file size.
There is a fair bit of overlap between FAILED_PRECONDITION
and
OUT_OF_RANGE
. We recommend using OUT_OF_RANGE
(the more specific
error) when it applies so that callers who are iterating through
a space can easily look for an OUT_OF_RANGE
error to detect when
they are done.
HTTP Mapping: 400 Bad Request
UNIMPLEMENTED
value: 12
The operation is not implemented or is not supported/enabled in this
service.
HTTP Mapping: 501 Not Implemented
INTERNAL
value: 13
Internal errors. This means that some invariants expected by the
underlying system have been broken. This error code is reserved
for serious errors.
HTTP Mapping: 500 Internal Server Error
UNAVAILABLE
value: 14
The service is currently unavailable. This is most likely a
transient condition, which can be corrected by retrying with
a backoff. Note that it is not always safe to retry
non-idempotent operations.
See the guidelines above for deciding between FAILED_PRECONDITION
,
ABORTED
, and UNAVAILABLE
.
HTTP Mapping: 503 Service Unavailable
DATA_LOSS
value: 15
Unrecoverable data loss or corruption.
HTTP Mapping: 500 Internal Server Error