```
commit faf013ec84051b92ae0f420a658b8d35bb7bb000
Author: Klaus Post <******@****.***>
Date:   Thu Nov 18 12:15:22 2021 -0800

    Improve performance on multiple versions (#13573)
```

- A fix must be a valid fix that was reproduced and seen in a customer environment, for example.

```
commit 886262e58af77ebc7c836ef587c08544e9a0c271
Author: Harshavardhana <******@****.***>
Date:   Wed Nov 17 15:49:12 2021 -0800

	globalAuthPluginMutex.Lock()
	defer globalAuthPluginMutex.Unlock()
	return globalAuthZPlugin
}

func setGlobalAuthNPlugin(authn *idplugin.AuthNPlugin) {
	globalAuthPluginMutex.Lock()
	globalAuthNPlugin = authn
	globalAuthPluginMutex.Unlock()
}

func setGlobalAuthZPlugin(authz *polplugin.AuthZPlugin) {
	globalAuthPluginMutex.Lock()
	globalAuthZPlugin = authz

					Help:      "When plugin authentication is configured, returns average round-trip-time of successful requests in the last full minute",
					Type:      gaugeMetric,
				},
				Value: pluginAuthNMetrics.AvgSuccRTTMs,
			},
			{
				Description: MetricDescription{
					Namespace: nodeMetricNamespace,
					Subsystem: iamSubsystem,

	// From OpenID
	if riMap := sys.OpenIDConfig.GetRoleInfo(); riMap != nil {
		sys.validateAndAddRolePolicyMappings(ctx, riMap)
	}

	// From AuthN plugin if enabled.
	if authn := newGlobalAuthNPluginFn(); authn != nil {
		riMap := authn.GetRoleInfo()
		sys.validateAndAddRolePolicyMappings(ctx, riMap)
	}

	sys.printIAMRoles()

	bootstrapTraceMsg("finishing IAM loading")
}

			return
		}
		if debugPrint {
			fmt.Printf("handler: Got Connect Req %+v\n", cReq)
		}
		writeErr(remote.handleIncoming(ctx, conn, cReq))
	}
}

// AuthFn should provide an authentication string for the given aud.
type AuthFn func(aud string) string

// Connection will return the connection for the specified host.
// If the host does not exist nil will be returned.

type metricsV3Server struct {
	registry *prometheus.Registry
	opts     promhttp.HandlerOpts
	authFn   func(http.Handler) http.Handler

	metricsData *metricsV3Collection
}

func newMetricsV3Server(authType prometheusAuthType) *metricsV3Server {
	registry := prometheus.NewRegistry()
	authFn := AuthMiddleware
	if authType == prometheusPublic {
		authFn = NoAuthMiddleware
	}

	metricGroups := newMetricGroups(registry)

| `minio_cluster_iam_plugin_authn_service_failed_requests_minute` | `counter` | When plugin authentication is configured, returns failed requests count in the last full minute                          |        |

    a) Disclaiming warranty or limiting liability differently from the
    terms of sections 15 and 16 of this License; or

    b) Requiring preservation of specified reasonable legal notices or
    author attributions in that material or in the Appropriate Legal
    Notices displayed by works containing it; or

    c) Prohibiting misrepresentation of the origin of that material, or

//
// When **no** flags are passed, the behavior is to trace both headers and body,
// gzip the response and throttle the handler via `maxClients`. Each of these
// can be disabled via the corresponding `s3HFlag`.
//
// CAUTION: for requests involving large req/resp bodies ensure to pass the
// `traceHdrsS3HFlag`, otherwise both headers and body will be traced, causing
// high memory usage!

	// Holding the lock allows safe reads of State, and guarantees that changes will be detected.
	connChange *sync.Cond
	handlers   *handlers

	remote             *RemoteClient
	auth               AuthFn
	clientPingInterval time.Duration
	connPingInterval   time.Duration
	tlsConfig          *tls.Config
	blockConnect       chan struct{}

	incomingBytes func(n int64) // Record incoming bytes.