feat(mc2mc): Improve multiple query logs

mc2mc/mc2mc.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	e "errors"
 	"fmt"
+	"log/slog"
 	"os"
 	"os/signal"
 	"strings"
@@ -162,35 +163,53 @@ func mc2mc(envs []string) error {
 
 	// only support concurrent execution for REPLACE method
 	if cfg.LoadMethod == "REPLACE" {
-		return executeConcurrently(ctx, c, cfg.Concurrency, queriesToExecute, cfg.AdditionalHints)
+		return executeConcurrently(ctx, l, c, cfg.Concurrency, queriesToExecute, cfg.AdditionalHints)
 	}
 	// otherwise execute sequentially
-	return execute(ctx, c, queriesToExecute, cfg.AdditionalHints)
+	return execute(ctx, l, c, queriesToExecute, cfg.AdditionalHints)
 }
 
-func executeConcurrently(ctx context.Context, c *client.Client, concurrency int, queriesToExecute []string, additionalHints map[string]string) error {
+func executeConcurrently(ctx context.Context, l *slog.Logger, c *client.Client, concurrency int, queriesToExecute []string, additionalHints map[string]string) error {
 	// execute query concurrently
 	sem := make(chan uint8, concurrency)
 	wg := sync.WaitGroup{}
 	wg.Add(len(queriesToExecute))
 	errChan := make(chan error, len(queriesToExecute))
+	ids := sync.Map{} // id to boolean map to track running ids
 
 	for i, queryToExecute := range queriesToExecute {
 		sem <- 0
-		executeFn := c.ExecuteFn(i + 1)
-		go func(queryToExecute string, errChan chan error) {
+		id := i + 1
+		ids.Store(id, false)
+		executeFn := c.ExecuteFn(id)
+		go func(id int, queryToExecute string, errChan chan error) {
+			defer func() {
+				wg.Done()
+				<-sem
+				ids.Delete(id)
+				// logs the remaining running ids
+				remainingIds := []int{}
+				ids.Range(func(key, value any) bool {
+					remainingIds = append(remainingIds, key.(int))
+					return true
+				})
+				if len(remainingIds) > 0 {
+					l.Info(fmt.Sprintf("remaining running ids: %v", remainingIds))
+					l.Info(fmt.Sprintf("waiting for %d other queries to finish...", len(remainingIds)))
+				}
+			}()
 			err := executeFn(ctx, queryToExecute, additionalHints)
 			if err != nil {
 				errChan <- errors.WithStack(err)
 			}
-			wg.Done()
-			<-sem
-		}(queryToExecute, errChan)
+		}(id, queryToExecute, errChan)
 	}
 
 	wg.Wait()
 	close(errChan)
 
+	l.Info("all queries have been processed")
+
 	// check error
 	var errs error
 	for err := range errChan {
@@ -201,14 +220,17 @@ func executeConcurrently(ctx context.Context, c *client.Client, concurrency int,
 	return errs
 }
 
-func execute(ctx context.Context, c *client.Client, queriesToExecute []string, additionalHints map[string]string) error {
+func execute(ctx context.Context, l *slog.Logger, c *client.Client, queriesToExecute []string, additionalHints map[string]string) error {
 	for i, queryToExecute := range queriesToExecute {
+		l.Info(fmt.Sprintf("processing query %d of %d", i+1, len(queriesToExecute)))
 		executeFn := c.ExecuteFn(i + 1)
 		err := executeFn(ctx, queryToExecute, additionalHints)
 		if err != nil {
 			return errors.WithStack(err)
 		}
 	}
+
+	l.Info("all queries have been processed")
 	return nil
 }