diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/grpclb_util.go')
-rw-r--r-- | vendor/google.golang.org/grpc/grpclb_util.go | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/grpclb_util.go b/vendor/google.golang.org/grpc/grpclb_util.go new file mode 100644 index 00000000..93ab2db3 --- /dev/null +++ b/vendor/google.golang.org/grpc/grpclb_util.go @@ -0,0 +1,90 @@ +/* + * + * Copyright 2016 gRPC authors. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + */ + +package grpc + +import ( + "google.golang.org/grpc/balancer" + "google.golang.org/grpc/resolver" +) + +// The parent ClientConn should re-resolve when grpclb loses connection to the +// remote balancer. When the ClientConn inside grpclb gets a TransientFailure, +// it calls lbManualResolver.ResolveNow(), which calls parent ClientConn's +// ResolveNow, and eventually results in re-resolve happening in parent +// ClientConn's resolver (DNS for example). +// +// parent +// ClientConn +// +-----------------------------------------------------------------+ +// | parent +---------------------------------+ | +// | DNS ClientConn | grpclb | | +// | resolver balancerWrapper | | | +// | + + | grpclb grpclb | | +// | | | | ManualResolver ClientConn | | +// | | | | + + | | +// | | | | | | Transient | | +// | | | | | | Failure | | +// | | | | | <--------- | | | +// | | | <--------------- | ResolveNow | | | +// | | <--------- | ResolveNow | | | | | +// | | ResolveNow | | | | | | +// | | | | | | | | +// | + + | + + | | +// | +---------------------------------+ | +// +-----------------------------------------------------------------+ + +// lbManualResolver is used by the ClientConn inside grpclb. It's a manual +// resolver with a special ResolveNow() function. +// +// When ResolveNow() is called, it calls ResolveNow() on the parent ClientConn, +// so when grpclb client lose contact with remote balancers, the parent +// ClientConn's resolver will re-resolve. +type lbManualResolver struct { + scheme string + ccr resolver.ClientConn + + ccb balancer.ClientConn +} + +func (r *lbManualResolver) Build(_ resolver.Target, cc resolver.ClientConn, _ resolver.BuildOption) (resolver.Resolver, error) { + r.ccr = cc + return r, nil +} + +func (r *lbManualResolver) Scheme() string { + return r.scheme +} + +// ResolveNow calls resolveNow on the parent ClientConn. +func (r *lbManualResolver) ResolveNow(o resolver.ResolveNowOption) { + r.ccb.ResolveNow(o) +} + +// Close is a noop for Resolver. +func (*lbManualResolver) Close() {} + +// NewAddress calls cc.NewAddress. +func (r *lbManualResolver) NewAddress(addrs []resolver.Address) { + r.ccr.NewAddress(addrs) +} + +// NewServiceConfig calls cc.NewServiceConfig. +func (r *lbManualResolver) NewServiceConfig(sc string) { + r.ccr.NewServiceConfig(sc) +} |