From 71737d7538ad86e65d0bd968c4ac943b6b900774 Mon Sep 17 00:00:00 2001
From: zhiqiangxu <652732310@qq.com>
Date: Fri, 7 Mar 2025 06:16:15 +0800
Subject: [PATCH] op-node: continue sequencing when `L1TemporaryErrorEvent`
 happens (#14062)

* continue sequencing when L1TemporaryErrorEvent happens

* add TestSequencerL1TemporaryErrorEvent

* address comment

* fix test
---
 op-node/rollup/sequencing/sequencer.go      |  2 +
 op-node/rollup/sequencing/sequencer_test.go | 54 +++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/op-node/rollup/sequencing/sequencer.go b/op-node/rollup/sequencing/sequencer.go
index 9e6a7e96c3726..d66bcbad02248 100644
--- a/op-node/rollup/sequencing/sequencer.go
+++ b/op-node/rollup/sequencing/sequencer.go
@@ -491,6 +491,8 @@ func (d *Sequencer) startBuildingBlock() {
 	// Figure out which L1 origin block we're going to be building on top of.
 	l1Origin, err := d.l1OriginSelector.FindL1Origin(ctx, l2Head)
 	if err != nil {
+		d.nextAction = d.timeNow().Add(time.Second)
+		d.nextActionOK = d.active.Load()
 		d.log.Error("Error finding next L1 Origin", "err", err)
 		d.emitter.Emit(rollup.L1TemporaryErrorEvent{Err: err})
 		return
diff --git a/op-node/rollup/sequencing/sequencer_test.go b/op-node/rollup/sequencing/sequencer_test.go
index 9c4e77ee72532..094ed0b09c013 100644
--- a/op-node/rollup/sequencing/sequencer_test.go
+++ b/op-node/rollup/sequencing/sequencer_test.go
@@ -3,6 +3,7 @@ package sequencing
 import (
 	"context"
 	"encoding/binary"
+	"fmt"
 	"math/rand" // nosemgrep
 	"testing"
 	"time"
@@ -613,6 +614,59 @@ func TestSequencerBuild(t *testing.T) {
 	require.Equal(t, testClock.Now(), nextTime, "start asap on the next block")
 }
 
+func TestSequencerL1TemporaryErrorEvent(t *testing.T) {
+	logger := testlog.Logger(t, log.LevelError)
+	seq, deps := createSequencer(logger)
+	testClock := clock.NewSimpleClock()
+	seq.timeNow = testClock.Now
+	testClock.SetTime(30000)
+	emitter := &testutils.MockEmitter{}
+	seq.AttachEmitter(emitter)
+
+	// Init will request a forkchoice update
+	emitter.ExpectOnce(engine.ForkchoiceRequestEvent{})
+	require.NoError(t, seq.Init(context.Background(), true))
+	emitter.AssertExpectations(t)
+	require.True(t, seq.Active(), "started in active mode")
+
+	// It will request a forkchoice update, it needs the head before being able to build on top of it
+	emitter.ExpectOnce(engine.ForkchoiceRequestEvent{})
+	seq.OnEvent(SequencerActionEvent{})
+	emitter.AssertExpectations(t)
+
+	// Now send the forkchoice data, for the sequencer to learn what to build on top of.
+	head := eth.L2BlockRef{
+		Hash:   common.Hash{0x22},
+		Number: 100,
+		L1Origin: eth.BlockID{
+			Hash:   common.Hash{0x11, 0xa},
+			Number: 1000,
+		},
+		Time: uint64(testClock.Now().Unix()),
+	}
+	seq.OnEvent(engine.ForkchoiceUpdateEvent{UnsafeL2Head: head})
+	emitter.AssertExpectations(t)
+
+	// force FindL1Origin to return an error
+	deps.l1OriginSelector.l1OriginFn = func(l2Head eth.L2BlockRef) (eth.L1BlockRef, error) {
+		return eth.L1BlockRef{}, fmt.Errorf("l1OriginFn error")
+	}
+
+	emitter.ExpectOnceRun(func(ev event.Event) {
+		_, ok := ev.(rollup.L1TemporaryErrorEvent)
+		require.True(t, ok)
+	})
+
+	sealTargetTime1, ok1 := seq.NextAction()
+	seq.OnEvent(SequencerActionEvent{})
+	emitter.AssertExpectations(t)
+
+	// FindL1Origin error will updating d.nextAction
+	sealTargetTime2, ok2 := seq.NextAction()
+
+	require.True(t, ok1 == ok2 && sealTargetTime2.After(sealTargetTime1))
+}
+
 type sequencerTestDeps struct {
 	cfg              *rollup.Config
 	attribBuilder    *FakeAttributesBuilder