For more detail, please read [Go vendor design](https://golang.org/s/go15vendor).
## Error Handling
etcd client returns 2 types of errors:
1. context error: canceled or deadline exceeded.
2. gRPC error: see [api/v3rpc/rpctypes](https://godoc.org/github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes).
Here is the example code to handle client errors:
```go
resp, err := cli.Put(ctx, "", "")
if err != nil {
switch err {
case context.Canceled:
log.Fatalf("ctx is canceled by another routine: %v", err)
case context.DeadlineExceeded:
log.Fatalf("ctx is attached with a deadline is exceeded: %v", err)
case rpctypes.ErrEmptyKey:
log.Fatalf("client-side error: %v", err)
default:
log.Fatalf("bad cluster endpoints, which are not etcd servers: %v", err)
}
}
```
## Metrics
The etcd client optionally exposes RPC metrics through [go-grpc-prometheus](https://github.com/grpc-ecosystem/go-grpc-prometheus). See the [examples](https://github.com/coreos/etcd/blob/master/clientv3/example_metrics_test.go).
## Namespacing
The [namespace](https://godoc.org/github.com/coreos/etcd/clientv3/namespace) package provides `clientv3` interface wrappers to transparently isolate client requests to a user-defined prefix.
## Examples
More code examples can be found at [GoDoc](https://godoc.org/github.com/coreos/etcd/clientv3).