open-consul/agent/structs/errors.go
James Phillips d1ad538345 Makes RPC handling more robust when rolling servers. (#3561)
* Adds client-side retry for no leader errors.

This paves over the case where the client was connected to the leader
when it loses leadership.

* Adds a configurable server RPC drain time and a fail-fast path for RPCs.

When a server leaves it gets removed from the Raft configuration, so it will
never know who the new leader server ends up being. Without this we'd be
doomed to wait out the RPC hold timeout and then fail. This makes things fail
a little quicker while a sever is draining, and since we added a client retry
AND since the server doing this has already shut down and left the Serf LAN,
clients should retry against some other server.

* Makes the RPC hold timeout configurable.

* Reorders struct members.

* Sets the RPC hold timeout default for test servers.

* Bumps the leave drain time up to 5 seconds.

* Robustifies retries with a simpler client-side RPC hold.

* Reverts untended delete.
2017-10-10 15:19:50 -07:00

33 lines
1 KiB
Go

package structs
import (
"errors"
"strings"
)
const (
errNoLeader = "No cluster leader"
errNoDCPath = "No path to datacenter"
errNoServers = "No known Consul servers"
errNotReadyForConsistentReads = "Not ready to serve consistent reads"
errSegmentsNotSupported = "Network segments are not supported in this version of Consul"
errRPCRateExceeded = "RPC rate limit exceeded"
)
var (
ErrNoLeader = errors.New(errNoLeader)
ErrNoDCPath = errors.New(errNoDCPath)
ErrNoServers = errors.New(errNoServers)
ErrNotReadyForConsistentReads = errors.New(errNotReadyForConsistentReads)
ErrSegmentsNotSupported = errors.New(errSegmentsNotSupported)
ErrRPCRateExceeded = errors.New(errRPCRateExceeded)
)
func IsErrNoLeader(err error) bool {
return err != nil && strings.Contains(err.Error(), errNoLeader)
}
func IsErrRPCRateExceeded(err error) bool {
return err != nil && strings.Contains(err.Error(), errRPCRateExceeded)
}