Suppress too many bad error messages when reading from corrupted journal in Journalbeat (#26224) (#26530)

(cherry picked from commit 2f9ae33)

Co-authored-by: Noémi Ványi <[email protected]>

Author: mergify[bot]

journalbeat/input/input.go

@@ -18,12 +18,18 @@
 package input
 
 import (
+	"context"
 	"fmt"
+	"strings"
 	"sync"
+	"syscall"
+	"time"
 
 	"github.com/elastic/beats/v7/libbeat/processors/add_formatted_index"
+	"github.com/elastic/go-concert/timed"
 
 	"github.com/elastic/beats/v7/libbeat/common/acker"
+	"github.com/elastic/beats/v7/libbeat/common/atomic"
 	"github.com/elastic/beats/v7/libbeat/common/fmtstr"
 
 	"github.com/elastic/beats/v7/journalbeat/checkpoint"
@@ -158,6 +164,10 @@ func (i *Input) publishAll() {
 		go func() {
 			defer wg.Done()
 
+			suppressed := atomic.NewBool(false)
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+
 			for {
 				select {
 				case <-i.done:
@@ -168,6 +178,10 @@ func (i *Input) publishAll() {
 				event, err := r.Next()
 				if event == nil {
 					if err != nil {
+						if i.isErrSuppressed(ctx, err, suppressed) {
+							i.logger.Debugf("Error message suppressed: EBADMSG")
+							continue
+						}
 						i.logger.Errorf("Error while reading event: %v", err)
 					}
 					continue
@@ -191,6 +205,26 @@ func (i *Input) publishAll() {
 	}
 }
 
+// isErrSuppressed checks if the error is due to a corrupt journal. If yes, only the first error message
+// is displayed and then it is suppressed for 5 seconds.
+func (i *Input) isErrSuppressed(ctx context.Context, err error, suppressed *atomic.Bool) bool {
+	if strings.Contains(err.Error(), syscall.EBADMSG.Error()) {
+		if suppressed.Load() {
+			return true
+		}
+
+		suppressed.Store(true)
+		go func(ctx context.Context, suppressed *atomic.Bool) {
+			if err := timed.Wait(ctx, 5*time.Second); err == nil {
+				suppressed.Store(false)
+			}
+
+		}(ctx, suppressed)
+	}
+
+	return false
+}
+
 // Stop stops all readers of the input.
 func (i *Input) Stop() {
 	for _, r := range i.readers {