func (e *Etcd) watchRing(r torus.Ring) {
ctx, cancel := context.WithCancel(e.getContext())
defer cancel()
wch := e.Client.Watch(ctx, MkKey("meta", "the-one-ring"))
for resp := range wch {
if err := resp.Err(); err != nil {
clog.Errorf("error watching ring: %s", err)
return
}
for _, ev := range resp.Events {
newRing, err := ring.Unmarshal(ev.Kv.Value)
if err != nil {
clog.Debugf("corrupted ring: %#v", ev.Kv.Value)
clog.Errorf("Failed to unmarshal ring: %s", err)
clog.Error("corrupted ring? Continuing with current ring")
continue
}
clog.Infof("got new ring")
if r.Version() == newRing.Version() {
clog.Warningf("Same ring version: %d", r.Version())
}
e.mut.RLock()
for _, x := range e.ringListeners {
x <- newRing
}
r = newRing
e.mut.RUnlock()
}
}
}
func setRing(cfg torus.Config, r torus.Ring) error {
client, err := etcdv3.New(etcdv3.Config{Endpoints: []string{cfg.MetadataAddress}, TLS: cfg.TLS})
if err != nil {
return err
}
defer client.Close()
resp, err := client.Get(context.Background(), MkKey("meta", "the-one-ring"))
if err != nil {
return err
}
if len(resp.Kvs) == 0 {
return torus.ErrNoGlobalMetadata
}
oldr, err := ring.Unmarshal(resp.Kvs[0].Value)
if err != nil {
return err
}
if oldr.Version() != r.Version()-1 {
return torus.ErrNonSequentialRing
}
b, err := r.Marshal()
if err != nil {
return err
}
_, err = client.Put(context.Background(), MkKey("meta", "the-one-ring"), string(b))
return err
}
func (c *etcdCtx) getRing() (torus.Ring, int64, error) {
promOps.WithLabelValues("get-ring").Inc()
resp, err := c.etcd.Client.Get(c.getContext(), MkKey("meta", "the-one-ring"))
if err != nil {
return nil, 0, err
}
if len(resp.Kvs) == 0 {
return nil, 0, torus.ErrNoGlobalMetadata
}
ring, err := ring.Unmarshal(resp.Kvs[0].Value)
if err != nil {
return nil, 0, err
}
return ring, resp.Kvs[0].Version, nil
}