feat: bring new HDD related performance enhancements (#18239)

Optionally allows customers to enable 

- Enable an external cache to catch GET/HEAD responses 
- Enable skipping disks that are slow to respond in GET/HEAD 
  when we have already achieved a quorum

cmd/config-current.go

@@ -27,6 +27,7 @@ import (
 	"github.com/minio/madmin-go/v3"
 	"github.com/minio/minio/internal/config"
 	"github.com/minio/minio/internal/config/api"
+	"github.com/minio/minio/internal/config/cache"
 	"github.com/minio/minio/internal/config/callhome"
 	"github.com/minio/minio/internal/config/compress"
 	"github.com/minio/minio/internal/config/dns"
@@ -68,6 +69,7 @@ func initHelp() {
 		config.ScannerSubSys:        scanner.DefaultKVS,
 		config.SubnetSubSys:         subnet.DefaultKVS,
 		config.CallhomeSubSys:       callhome.DefaultKVS,
+		config.CacheSubSys:          cache.DefaultKVS,
 	}
 	for k, v := range notify.DefaultNotificationKVS {
 		kvs[k] = v
@@ -206,6 +208,12 @@ func initHelp() {
 			Key:         config.EtcdSubSys,
 			Description: "persist IAM assets externally to etcd",
 		},
+		config.HelpKV{
+			Key:         config.CacheSubSys,
+			Type:        "string",
+			Description: "enable various cache optimizations on MinIO for reads",
+			Optional:    true,
+		},
 	}
 
 	if globalIsErasure {
@@ -250,6 +258,7 @@ func initHelp() {
 		config.LambdaWebhookSubSys:  lambda.HelpWebhook,
 		config.SubnetSubSys:         subnet.HelpSubnet,
 		config.CallhomeSubSys:       callhome.HelpCallhome,
+		config.CacheSubSys:          cache.Help,
 	}
 
 	config.RegisterHelpSubSys(helpMap)
@@ -357,6 +366,10 @@ func validateSubSysConfig(ctx context.Context, s config.Config, subSys string, o
 		if cfg.Enabled() && !globalSubnetConfig.Registered() {
 			return errors.New("Deployment is not registered with SUBNET. Please register the deployment via 'mc license register ALIAS'")
 		}
+	case config.CacheSubSys:
+		if _, err := cache.LookupConfig(s[config.CacheSubSys][config.Default], globalRemoteTargetTransport); err != nil {
+			return err
+		}
 	case config.PolicyOPASubSys:
 		// In case legacy OPA config is being set, we treat it as if the
 		// AuthZPlugin is being set.
@@ -632,6 +645,13 @@ func applyDynamicConfigForSubSys(ctx context.Context, objAPI ObjectLayer, s conf
 				initCallhome(ctx, objAPI)
 			}
 		}
+	case config.CacheSubSys:
+		cacheCfg, err := cache.LookupConfig(s[config.CacheSubSys][config.Default], globalRemoteTargetTransport)
+		if err != nil {
+			logger.LogIf(ctx, fmt.Errorf("Unable to load cache config: %w", err))
+		} else {
+			globalCacheConfig.Update(cacheCfg)
+		}
 	}
 	globalServerConfigMu.Lock()
 	defer globalServerConfigMu.Unlock()