feat: add worker-count config and launch multiple workers

Author: Shivaprasad

cli/config.go

@@ -27,6 +27,7 @@ type Config struct {
 }
 
 type syncerConf struct {
+	WorkerCount     int           `mapstructure:"worker_count" default:"1"`
 	SyncInterval    time.Duration `mapstructure:"sync_interval" default:"1s"`
 	RefreshInterval time.Duration `mapstructure:"refresh_interval" default:"3s"`
 	ExtendLockBy    time.Duration `mapstructure:"extend_lock_by" default:"5s"`

cli/serve.go

@@ -49,6 +49,9 @@ func cmdServe() *cobra.Command {
 			newrelic.ConfigAppName(cfg.Telemetry.ServiceName),
 			newrelic.ConfigLicense(cfg.Telemetry.NewRelicAPIKey),
 		)
+		if err != nil {
+			return err
+		}
 
 		store := setupStorage(cfg.PGConnStr, cfg.Syncer)
 		moduleService := module.NewService(setupRegistry(), store)
@@ -61,11 +64,11 @@ func cmdServe() *cobra.Command {
 		}
 
 		if spawnWorker {
-			go func() {
-				if runErr := resourceService.RunSyncer(cmd.Context(), cfg.Syncer.SyncInterval); runErr != nil {
-					zap.L().Error("syncer exited with error", zap.Error(err))
-				}
-			}()
+			go resourceService.RunSyncer(
+				cmd.Context(),
+				cfg.Syncer.WorkerCount,
+				cfg.Syncer.SyncInterval,
+			)
 		}
 
 		return entropyserver.Serve(cmd.Context(),

core/sync.go

@@ -2,6 +2,7 @@ package core
 
 import (
 	"context"
+	"sync"
 	"time"
 
 	"go.uber.org/zap"
@@ -12,7 +13,24 @@ import (
 
 // RunSyncer runs the syncer thread that keeps performing resource-sync at
 // regular intervals.
-func (svc *Service) RunSyncer(ctx context.Context, interval time.Duration) error {
+func (svc *Service) RunSyncer(ctx context.Context, workerCount int, interval time.Duration) {
+	wg := &sync.WaitGroup{}
+	for i := 0; i < workerCount; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+
+			if err := svc.runWorker(ctx, id, interval); err != nil {
+				zap.L().Error("worker-%d failed", zap.Error(err))
+			}
+		}(i)
+	}
+	wg.Done()
+
+	zap.L().Info("all syncer workers exited")
+}
+
+func (svc *Service) runWorker(ctx context.Context, _ int, interval time.Duration) error {
 	tick := time.NewTimer(interval)
 	defer tick.Stop()
 
@@ -26,7 +44,7 @@ func (svc *Service) RunSyncer(ctx context.Context, interval time.Duration) error
 
 			err := svc.store.SyncOne(ctx, svc.handleSync)
 			if err != nil {
-				zap.L().Warn("SyncOne() failed", zap.Error(err))
+				return err
 			}
 		}
 	}