Error codes

BlockDB returns a business error code (BizErrorCode) that maps to a standard gRPC status code.

Business error code	Meaning	gRPC status
`BIZ_ERROR_CODE_INVALID_ARGUMENT`	Invalid argument	`InvalidArgument`
`BIZ_ERROR_CODE_NOT_FOUND`	Not found	`NotFound`
`BIZ_ERROR_CODE_QUERY_REJECTED`	Query rejected	`FailedPrecondition`
`BIZ_ERROR_CODE_QUEUE_OVERLOAD`	Write queue overloaded	`ResourceExhausted`
`BIZ_ERROR_CODE_WRITE_CONFLICT`	Write conflict	`Aborted`
`BIZ_ERROR_CODE_INTERNAL`	Internal error	`Internal`

BIZ_ERROR_CODE_UNSPECIFIED (value 0) means no error code was specified and is normally not used on its own.

Handling recommendations

INVALID_ARGUMENT: check whether the request fields are valid (table name, primary key, conditions, and so on).
NOT_FOUND: returned when reading a row that does not exist; treat it as an empty result in your business logic.
QUEUE_OVERLOAD: the write queue is full. Retry later or switch to batch writes.
WRITE_CONFLICT: a conditional update conflicted. Decide on your side whether to retry.