open-consul/agent/grpc-internal/tracker.go
Dan Upton 15c7c03fa5
grpc: switch servers and retry on error (#15892)
This is the OSS portion of enterprise PR 3822.

Adds a custom gRPC balancer that replicates the router's server cycling
behavior. Also enables automatic retries for RESOURCE_EXHAUSTED errors,
which we now get for free.
2023-01-05 10:21:27 +00:00

47 lines
1.4 KiB
Go

package internal
import (
"fmt"
"net/url"
gresolver "google.golang.org/grpc/resolver"
"github.com/hashicorp/consul/agent/grpc-internal/balancer"
"github.com/hashicorp/consul/agent/grpc-internal/resolver"
"github.com/hashicorp/consul/agent/metadata"
"github.com/hashicorp/consul/types"
)
// NewTracker returns an implementation of the router.ServerTracker interface
// backed by the given ServerResolverBuilder and Balancer.
func NewTracker(rb *resolver.ServerResolverBuilder, bb *balancer.Builder) *Tracker {
return &Tracker{rb, bb}
}
// Tracker satisfies the ServerTracker interface the router manager uses to
// register/deregister servers and trigger rebalances.
type Tracker struct {
rb *resolver.ServerResolverBuilder
bb *balancer.Builder
}
// AddServer adds the given server to the resolver.
func (t *Tracker) AddServer(a types.AreaID, s *metadata.Server) { t.rb.AddServer(a, s) }
// RemoveServer removes the given server from the resolver.
func (t *Tracker) RemoveServer(a types.AreaID, s *metadata.Server) { t.rb.RemoveServer(a, s) }
// NewRebalancer returns a function that can be called to randomize the
// priority order of connections for the given datacenter.
func (t *Tracker) NewRebalancer(dc string) func() {
return func() {
t.bb.Rebalance(gresolver.Target{
URL: url.URL{
Scheme: "consul",
Host: t.rb.Authority(),
Path: fmt.Sprintf("server.%s", dc),
},
})
}
}