feat(platform): harden telemetry pipeline and unify Semi UI workspaces

2026-07-18 00:26:36 +08:00
parent 65b4e4f055
commit 159c80b0ae
136 changed files with 21616 additions and 1785 deletions
--- a/go/vehicle-gateway/cmd/feichi-bridge/main.go
+++ b/go/vehicle-gateway/cmd/feichi-bridge/main.go
@@ -0,0 +1,211 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"os/signal"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/feichibridge"
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/health"
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/metrics"
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/observability"
+)
+
+type authSecret struct {
+	Username string `json:"username"`
+	Password string `json:"password"`
+}
+
+type targetSecret struct {
+	PlatformID string `json:"platformId"`
+	Username   string `json:"username"`
+	Password   string `json:"password"`
+}
+
+type config struct {
+	BaseURL         string
+	AuthSecretFile  string
+	TargetSecret    string
+	TargetAddress   string
+	StateFile       string
+	HealthAddress   string
+	HTTPTimeout     time.Duration
+	TargetTimeout   time.Duration
+	OCRImage        string
+	OCRTimeout      time.Duration
+	LoginAttempts   int
+	LoginRetryDelay time.Duration
+	Service         feichibridge.ServiceConfig
+}
+
+func main() {
+	logger := observability.NewLogger("feichi-bridge")
+	cfg, err := loadConfig()
+	if err != nil {
+		logger.Error("load configuration failed", "error", err)
+		os.Exit(1)
+	}
+	auth, err := readJSONSecret[authSecret](cfg.AuthSecretFile)
+	if err != nil {
+		logger.Error("read Feichi API secret failed", "error", err)
+		os.Exit(1)
+	}
+	credentials, err := readJSONSecret[targetSecret](cfg.TargetSecret)
+	if err != nil {
+		logger.Error("read GB/T 32960 target secret failed", "error", err)
+		os.Exit(1)
+	}
+	source, err := feichibridge.NewAuthenticatedAPIClient(
+		cfg.BaseURL,
+		feichibridge.LoginCredentials{
+			Username: auth.Username, Password: auth.Password,
+			MaxAttempts: cfg.LoginAttempts, RetryDelay: cfg.LoginRetryDelay,
+		},
+		feichibridge.DockerCaptchaSolver{Image: cfg.OCRImage, Timeout: cfg.OCRTimeout},
+		cfg.HTTPTimeout,
+	)
+	if err != nil {
+		logger.Error("build Feichi API client failed", "error", err)
+		os.Exit(1)
+	}
+	state, err := feichibridge.OpenStateStore(cfg.StateFile)
+	if err != nil {
+		logger.Error("open bridge state failed", "error", err)
+		os.Exit(1)
+	}
+	target, err := feichibridge.NewTarget(feichibridge.TargetConfig{
+		Address: cfg.TargetAddress, PlatformID: credentials.PlatformID,
+		Username: credentials.Username, Password: credentials.Password,
+		Timeout: cfg.TargetTimeout,
+	}, state)
+	if err != nil {
+		logger.Error("build GB/T 32960 target failed", "error", err)
+		os.Exit(1)
+	}
+	registry := metrics.NewRegistry()
+	service, err := feichibridge.NewService(cfg.Service, source, target, state, logger, registry)
+	if err != nil {
+		logger.Error("build bridge service failed", "error", err)
+		os.Exit(1)
+	}
+
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+	health.Start(ctx, logger, health.NewServer(cfg.HealthAddress, "feichi-bridge", []health.Check{
+		{Name: "bridge", Check: service.Ready},
+	}, registry))
+	logger.Info("Feichi bridge starting",
+		"base_url", cfg.BaseURL,
+		"target_address", cfg.TargetAddress,
+		"poll_interval", cfg.Service.PollInterval,
+		"backfill_enabled", cfg.Service.BackfillEnabled,
+	)
+	if strings.HasPrefix(strings.ToLower(cfg.BaseURL), "http://") {
+		logger.Warn("Feichi source uses clear-text HTTP; deploy only through a controlled egress path")
+	}
+	if err := service.Run(ctx); err != nil && !errors.Is(err, context.Canceled) {
+		logger.Error("Feichi bridge stopped unexpectedly", "error", err)
+		os.Exit(1)
+	}
+	logger.Info("Feichi bridge stopped")
+}
+
+func loadConfig() (config, error) {
+	cfg := config{
+		BaseURL:         strings.TrimSpace(os.Getenv("FEICHI_BASE_URL")),
+		AuthSecretFile:  env("FEICHI_AUTH_SECRET_FILE", strings.TrimSpace(os.Getenv("FEICHI_AUTH_HEADERS_FILE"))),
+		TargetSecret:    strings.TrimSpace(os.Getenv("FEICHI_TARGET_SECRET_FILE")),
+		TargetAddress:   env("FEICHI_TARGET_ADDR", "127.0.0.1:32960"),
+		StateFile:       env("FEICHI_STATE_FILE", "/var/lib/lingniu-feichi-bridge/state.json"),
+		HealthAddress:   env("HEALTH_ADDR", "127.0.0.1:20219"),
+		HTTPTimeout:     seconds("FEICHI_HTTP_TIMEOUT_SECONDS", 15),
+		TargetTimeout:   seconds("FEICHI_TARGET_TIMEOUT_SECONDS", 10),
+		OCRImage:        env("FEICHI_OCR_IMAGE", "lingniu/feichi-captcha-ocr:1.0.0"),
+		OCRTimeout:      seconds("FEICHI_OCR_TIMEOUT_SECONDS", 20),
+		LoginAttempts:   envInt("FEICHI_LOGIN_MAX_ATTEMPTS", 20),
+		LoginRetryDelay: seconds("FEICHI_LOGIN_RETRY_SECONDS", 1),
+		Service: feichibridge.ServiceConfig{
+			PollInterval:        seconds("FEICHI_POLL_INTERVAL_SECONDS", 10),
+			DiscoveryInterval:   seconds("FEICHI_DISCOVERY_INTERVAL_SECONDS", 300),
+			BackfillInterval:    seconds("FEICHI_BACKFILL_INTERVAL_SECONDS", 3600),
+			BackfillLookback:    seconds("FEICHI_BACKFILL_LOOKBACK_SECONDS", 3600),
+			BackfillWindow:      seconds("FEICHI_BACKFILL_WINDOW_SECONDS", 1200),
+			BackfillSafetyLag:   seconds("FEICHI_BACKFILL_SAFETY_SECONDS", 30),
+			SourceStaleAfter:    seconds("FEICHI_SOURCE_STALE_SECONDS", 120),
+			FetchConcurrency:    envInt("FEICHI_FETCH_CONCURRENCY", 4),
+			BackfillEnabled:     envBool("FEICHI_BACKFILL_ENABLED", true),
+			StaleReissueEnabled: envBool("FEICHI_STALE_REISSUE_ENABLED", true),
+		},
+	}
+	var missing []string
+	if cfg.BaseURL == "" {
+		missing = append(missing, "FEICHI_BASE_URL")
+	}
+	if cfg.AuthSecretFile == "" {
+		missing = append(missing, "FEICHI_AUTH_SECRET_FILE")
+	}
+	if cfg.TargetSecret == "" {
+		missing = append(missing, "FEICHI_TARGET_SECRET_FILE")
+	}
+	if len(missing) > 0 {
+		return config{}, fmt.Errorf("required configuration missing: %s", strings.Join(missing, ", "))
+	}
+	if cfg.Service.BackfillWindow > 24*time.Hour {
+		return config{}, errors.New("FEICHI_BACKFILL_WINDOW_SECONDS must not exceed 86400")
+	}
+	return cfg, nil
+}
+
+func readJSONSecret[T any](path string) (T, error) {
+	var value T
+	encoded, err := os.ReadFile(path)
+	if err != nil {
+		return value, err
+	}
+	if err := json.Unmarshal(encoded, &value); err != nil {
+		return value, fmt.Errorf("decode %s: %w", path, err)
+	}
+	return value, nil
+}
+
+func env(name, fallback string) string {
+	if value := strings.TrimSpace(os.Getenv(name)); value != "" {
+		return value
+	}
+	return fallback
+}
+
+func envInt(name string, fallback int) int {
+	value := strings.TrimSpace(os.Getenv(name))
+	if value == "" {
+		return fallback
+	}
+	parsed, err := strconv.Atoi(value)
+	if err != nil || parsed <= 0 {
+		return fallback
+	}
+	return parsed
+}
+
+func envBool(name string, fallback bool) bool {
+	value := strings.TrimSpace(os.Getenv(name))
+	if value == "" {
+		return fallback
+	}
+	parsed, err := strconv.ParseBool(value)
+	if err != nil {
+		return fallback
+	}
+	return parsed
+}
+
+func seconds(name string, fallback int) time.Duration {
+	return time.Duration(envInt(name, fallback)) * time.Second
+}
--- a/go/vehicle-gateway/cmd/stat-writer/main.go
+++ b/go/vehicle-gateway/cmd/stat-writer/main.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"sort"
 	"strconv"
 	"strings"
@@ -54,6 +55,7 @@ func main() {
 	registry.SetGauge("vehicle_stat_cache_retention_seconds", nil, cfg.CacheRetention.Seconds())
 	registry.SetGauge("vehicle_stat_cache_cleanup_interval_seconds", nil, cfg.CacheCleanupInterval.Seconds())
 	registry.SetGauge("vehicle_stat_baseline_miss_ttl_seconds", nil, cfg.BaselineMissTTL.Seconds())
+	registry.SetGauge("vehicle_stat_baseline_hit_ttl_seconds", nil, cfg.BaselineHitTTL.Seconds())
 	registry.SetGauge("vehicle_stat_config", metrics.Labels{"setting": "workers"}, float64(cfg.Workers))
 	health.Start(ctx, logger, health.NewServer(env("HEALTH_ADDR", ""), "vehicle-stat-writer", []health.Check{
 		{Name: "mysql", Check: db.PingContext},
@@ -65,6 +67,7 @@ func main() {
 	writer.SetCacheRetention(cfg.CacheRetention)
 	writer.SetCacheCleanupInterval(cfg.CacheCleanupInterval)
 	writer.SetBaselineMissTTL(cfg.BaselineMissTTL)
+	writer.SetBaselineHitTTL(cfg.BaselineHitTTL)
 	writer.SetMaxCacheEntries(cfg.CacheMaxEntries)
 	if cfg.EnsureSchema {
 		if err := writer.EnsureSchema(ctx); err != nil {
@@ -89,14 +92,15 @@ func main() {
 		delay:    cfg.RetryDelay,
 		registry: registry,
 	}
+	quarantiner := fileStatMessageQuarantiner{dir: cfg.QuarantineDir}

-	logger.Info("stat writer started", "group", cfg.KafkaGroup, "topics", strings.Join(cfg.KafkaTopics, ","), "workers", cfg.Workers, "project_interval_seconds", cfg.ProjectInterval.Seconds(), "source_touch_interval_seconds", cfg.SourceTouchInterval.Seconds(), "cache_retention_seconds", cfg.CacheRetention.Seconds(), "cache_cleanup_interval_seconds", cfg.CacheCleanupInterval.Seconds(), "baseline_miss_ttl_seconds", cfg.BaselineMissTTL.Seconds(), "cache_max_entries", cfg.CacheMaxEntries, "batch_size", cfg.BatchSize, "batch_wait_ms", cfg.BatchWait, "retry_attempts", cfg.RetryAttempts, "retry_delay_ms", cfg.RetryDelay.Milliseconds())
+	logger.Info("stat writer started", "group", cfg.KafkaGroup, "topics", strings.Join(cfg.KafkaTopics, ","), "workers", cfg.Workers, "project_interval_seconds", cfg.ProjectInterval.Seconds(), "source_touch_interval_seconds", cfg.SourceTouchInterval.Seconds(), "cache_retention_seconds", cfg.CacheRetention.Seconds(), "cache_cleanup_interval_seconds", cfg.CacheCleanupInterval.Seconds(), "baseline_miss_ttl_seconds", cfg.BaselineMissTTL.Seconds(), "baseline_hit_ttl_seconds", cfg.BaselineHitTTL.Seconds(), "cache_max_entries", cfg.CacheMaxEntries, "batch_size", cfg.BatchSize, "batch_wait_ms", cfg.BatchWait, "retry_attempts", cfg.RetryAttempts, "retry_delay_ms", cfg.RetryDelay.Milliseconds(), "quarantine_dir", cfg.QuarantineDir)
 	var workers sync.WaitGroup
 	for workerID := 1; workerID <= cfg.Workers; workerID++ {
 		workers.Add(1)
 		go func(id int) {
 			defer workers.Done()
-			runStatConsumer(ctx, logger, registry, appender, cfg, id)
+			runStatConsumer(ctx, logger, registry, appender, quarantiner, cfg, id)
 		}(workerID)
 	}
 	workers.Wait()
@@ -105,7 +109,7 @@ func main() {
 func runStatConsumer(ctx context.Context, logger interface {
 	Error(string, ...any)
 	Warn(string, ...any)
-}, registry *metrics.Registry, appender statAppender, cfg config, workerID int) {
+}, registry *metrics.Registry, appender statAppender, quarantiner statMessageQuarantiner, cfg config, workerID int) {
 	reader := kafka.NewReader(kafka.ReaderConfig{
 		Brokers:     cfg.KafkaBrokers,
 		GroupID:     cfg.KafkaGroup,
@@ -129,7 +133,7 @@ func runStatConsumer(ctx context.Context, logger interface {
 			continue
 		}
 		batch := collectStatBatch(ctx, reader, message, cfg.BatchSize, time.Duration(cfg.BatchWait)*time.Millisecond)
-		processStatBatchReliablyForWorker(ctx, logger, registry, appender, reader, batch, cfg.RetryDelay, workerLabels)
+		processStatBatchReliablyForWorker(ctx, logger, registry, appender, reader, quarantiner, batch, cfg.RetryDelay, workerLabels)
 	}
 }

@@ -155,6 +159,10 @@ type kafkaMessageFetcher interface {
 	FetchMessage(context.Context) (kafka.Message, error)
 }

+type statMessageQuarantiner interface {
+	Quarantine(context.Context, kafka.Message, error) error
+}
+
 type statBatchItem struct {
 	message   kafka.Message
 	processed bool
@@ -163,6 +171,8 @@ type statBatchItem struct {
 type statBatchOutcome struct {
 	commitMessages []kafka.Message
 	retryMessages  []kafka.Message
+	failedMessage  *kafka.Message
+	writeErr       error
 }

 var statWriteDurationBucketsMS = []float64{1, 5, 10, 25, 50, 100, 250, 500, 1000, 5000}
@@ -251,7 +261,12 @@ func processStatBatchForWorker(ctx context.Context, logger interface {
 			addStatMetric(registry, "vehicle_stat_writes_total", message, "error")
 			logger.Error("mysql append failed", "topic", message.Topic, "partition", message.Partition, "offset", message.Offset, "event_id", env.StableEventID(), "error", err)
 			committed, commitErr := commitStatProcessedPrefixAfterFailure(messageCtx, logger, registry, committer, items)
-			outcome := statBatchOutcome{retryMessages: eventbus.MessagesAfterCommittedPrefixes(messages, committed)}
+			failedMessage := message
+			outcome := statBatchOutcome{
+				retryMessages: eventbus.MessagesAfterCommittedPrefixes(messages, committed),
+				failedMessage: &failedMessage,
+				writeErr:      err,
+			}
 			if commitErr != nil {
 				outcome.commitMessages = committed
 			}
@@ -279,13 +294,13 @@ func processStatBatchReliably(ctx context.Context, logger interface {
 	Error(string, ...any)
 	Warn(string, ...any)
 }, registry *metrics.Registry, appender statAppender, committer kafkaMessageCommitter, messages []kafka.Message, retryDelay time.Duration) {
-	processStatBatchReliablyForWorker(ctx, logger, registry, appender, committer, messages, retryDelay, nil)
+	processStatBatchReliablyForWorker(ctx, logger, registry, appender, committer, nil, messages, retryDelay, nil)
 }

 func processStatBatchReliablyForWorker(ctx context.Context, logger interface {
 	Error(string, ...any)
 	Warn(string, ...any)
-}, registry *metrics.Registry, appender statAppender, committer kafkaMessageCommitter, messages []kafka.Message, retryDelay time.Duration, workerLabels metrics.Labels) {
+}, registry *metrics.Registry, appender statAppender, committer kafkaMessageCommitter, quarantiner statMessageQuarantiner, messages []kafka.Message, retryDelay time.Duration, workerLabels metrics.Labels) {
 	defer registry.SetGauge("vehicle_stat_retry_pending_messages", workerLabels, 0)
 	pending := messages
 	for len(pending) > 0 {
@@ -297,6 +312,19 @@ func processStatBatchReliablyForWorker(ctx context.Context, logger interface {
 			}
 		}
 		pending = outcome.retryMessages
+		if outcome.writeErr != nil && outcome.failedMessage != nil && isQuarantinableStatError(outcome.writeErr) && quarantiner != nil {
+			failed := *outcome.failedMessage
+			if err := quarantiner.Quarantine(ctx, failed, outcome.writeErr); err != nil {
+				logger.Error("stat message quarantine failed", "topic", failed.Topic, "partition", failed.Partition, "offset", failed.Offset, "error", err)
+				registry.IncCounter("vehicle_stat_quarantine_total", metrics.Labels{"status": "error", "topic": failed.Topic})
+			} else {
+				registry.IncCounter("vehicle_stat_quarantine_total", metrics.Labels{"status": "ok", "topic": failed.Topic})
+				logger.Warn("quarantined permanent stat write failure", "topic", failed.Topic, "partition", failed.Partition, "offset", failed.Offset, "error", outcome.writeErr)
+				if retryStatCommit(ctx, logger, registry, committer, []kafka.Message{failed}, retryDelay) {
+					pending = messagesExceptStatMessage(pending, failed)
+				}
+			}
+		}
 		registry.SetGauge("vehicle_stat_retry_pending_messages", workerLabels, float64(len(pending)))
 		if len(pending) == 0 {
 			return
@@ -308,6 +336,105 @@ func processStatBatchReliablyForWorker(ctx context.Context, logger interface {
 	}
 }

+type quarantinedStatMessage struct {
+	QuarantinedAt string `json:"quarantined_at"`
+	Topic         string `json:"topic"`
+	Partition     int    `json:"partition"`
+	Offset        int64  `json:"offset"`
+	Key           []byte `json:"key,omitempty"`
+	Value         []byte `json:"value"`
+	Error         string `json:"error"`
+}
+
+type fileStatMessageQuarantiner struct {
+	dir string
+}
+
+func (q fileStatMessageQuarantiner) Quarantine(ctx context.Context, message kafka.Message, cause error) error {
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+	dir := strings.TrimSpace(q.dir)
+	if dir == "" {
+		return errors.New("stat quarantine directory is empty")
+	}
+	if err := os.MkdirAll(dir, 0o750); err != nil {
+		return fmt.Errorf("create quarantine directory: %w", err)
+	}
+	record := quarantinedStatMessage{
+		QuarantinedAt: time.Now().UTC().Format(time.RFC3339Nano),
+		Topic:         message.Topic,
+		Partition:     message.Partition,
+		Offset:        message.Offset,
+		Key:           message.Key,
+		Value:         message.Value,
+		Error:         cause.Error(),
+	}
+	payload, err := json.Marshal(record)
+	if err != nil {
+		return fmt.Errorf("marshal quarantine record: %w", err)
+	}
+	name := fmt.Sprintf("%s-%d-%d.json", sanitizeStatQuarantineName(message.Topic), message.Partition, message.Offset)
+	temporary, err := os.CreateTemp(dir, "."+name+"-*")
+	if err != nil {
+		return fmt.Errorf("create quarantine record: %w", err)
+	}
+	temporaryName := temporary.Name()
+	removeTemporary := true
+	defer func() {
+		_ = temporary.Close()
+		if removeTemporary {
+			_ = os.Remove(temporaryName)
+		}
+	}()
+	if err := temporary.Chmod(0o600); err != nil {
+		return fmt.Errorf("secure quarantine record: %w", err)
+	}
+	if _, err := temporary.Write(payload); err != nil {
+		return fmt.Errorf("write quarantine record: %w", err)
+	}
+	if err := temporary.Sync(); err != nil {
+		return fmt.Errorf("sync quarantine record: %w", err)
+	}
+	if err := temporary.Close(); err != nil {
+		return fmt.Errorf("close quarantine record: %w", err)
+	}
+	if err := os.Rename(temporaryName, filepath.Join(dir, name)); err != nil {
+		return fmt.Errorf("publish quarantine record: %w", err)
+	}
+	removeTemporary = false
+	return nil
+}
+
+func sanitizeStatQuarantineName(value string) string {
+	value = strings.TrimSpace(value)
+	if value == "" {
+		return "unknown-topic"
+	}
+	var out strings.Builder
+	for _, r := range value {
+		if r >= 'a' && r <= 'z' || r >= 'A' && r <= 'Z' || r >= '0' && r <= '9' || r == '-' || r == '_' || r == '.' {
+			out.WriteRune(r)
+		} else {
+			out.WriteByte('_')
+		}
+	}
+	return out.String()
+}
+
+func messagesExceptStatMessage(messages []kafka.Message, excluded kafka.Message) []kafka.Message {
+	out := make([]kafka.Message, 0, len(messages))
+	removed := false
+	for _, message := range messages {
+		if !removed && message.Topic == excluded.Topic && message.Partition == excluded.Partition && message.Offset == excluded.Offset {
+			removed = true
+			continue
+		}
+		out = append(out, message)
+	}
+	return out
+}
+
 func retryStatCommit(ctx context.Context, logger interface {
 	Error(string, ...any)
 	Warn(string, ...any)
@@ -447,7 +574,7 @@ func (a retryStatAppender) AppendWithResult(ctx context.Context, env envelope.Fr
 	var err error
 	for attempt := 1; attempt <= attempts; attempt++ {
 		result, err = appendStatEnvelope(ctx, a.delegate, env)
-		if err == nil || !isTransientMySQLStatError(err) {
+		if err == nil || (!isTransientMySQLStatError(err) && !isQuarantinableStatError(err)) {
 			return result, err
 		}
 		if attempt == attempts {
@@ -512,6 +639,32 @@ func isTransientMySQLStatError(err error) bool {
 		strings.Contains(text, "no route to host")
 }

+func isQuarantinableStatError(err error) bool {
+	if err == nil || errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+		return false
+	}
+	text := strings.ToLower(strings.TrimSpace(err.Error()))
+	// Only deterministic row-data failures may advance past a Kafka message
+	// after the configured finite retries. Schema, permission and unknown
+	// application errors remain failure-closed so a systemic outage cannot
+	// silently quarantine an entire stream.
+	return strings.Contains(text, "error 1048") ||
+		strings.Contains(text, "cannot be null") ||
+		strings.Contains(text, "error 1264") ||
+		strings.Contains(text, "out of range value") ||
+		strings.Contains(text, "error 1265") ||
+		strings.Contains(text, "data truncated") ||
+		strings.Contains(text, "error 1292") ||
+		strings.Contains(text, "incorrect datetime value") ||
+		strings.Contains(text, "error 1366") ||
+		strings.Contains(text, "incorrect decimal value") ||
+		strings.Contains(text, "incorrect integer value") ||
+		strings.Contains(text, "error 1406") ||
+		strings.Contains(text, "data too long for column") ||
+		strings.Contains(text, "error 3819") ||
+		strings.Contains(text, "check constraint")
+}
+
 func addStatMetric(registry *metrics.Registry, name string, message kafka.Message, status string) {
 	if registry == nil {
 		return
@@ -686,6 +839,7 @@ type config struct {
 	CacheRetention                  time.Duration
 	CacheCleanupInterval            time.Duration
 	BaselineMissTTL                 time.Duration
+	BaselineHitTTL                  time.Duration
 	CacheMaxEntries                 int
 	Workers                         int
 	BatchSize                       int
@@ -694,6 +848,7 @@ type config struct {
 	RetryDelay                      time.Duration
 	NormalizePlatformSourcesOnStart bool
 	NormalizePlatformSourcesTimeout time.Duration
+	QuarantineDir                   string
 }

 func (c config) Validate() error {
@@ -728,6 +883,7 @@ func loadConfig() config {
 		CacheRetention:                  time.Duration(envInt("STATS_CACHE_RETENTION_HOURS", 72)) * time.Hour,
 		CacheCleanupInterval:            time.Duration(envInt("STATS_CACHE_CLEANUP_INTERVAL_SECONDS", 600)) * time.Second,
 		BaselineMissTTL:                 time.Duration(envInt("STATS_BASELINE_MISS_TTL_SECONDS", 60)) * time.Second,
+		BaselineHitTTL:                  time.Duration(envInt("STATS_BASELINE_HIT_TTL_SECONDS", 300)) * time.Second,
 		CacheMaxEntries:                 envInt("STATS_CACHE_MAX_ENTRIES", 1000000),
 		Workers:                         envInt("STATS_WORKERS", 3),
 		BatchSize:                       envInt("STATS_BATCH_SIZE", 200),
@@ -736,6 +892,7 @@ func loadConfig() config {
 		RetryDelay:                      time.Duration(envInt("STATS_RETRY_DELAY_MS", 20)) * time.Millisecond,
 		NormalizePlatformSourcesOnStart: env("STATS_NORMALIZE_PLATFORM_SOURCES_ON_START", "true") != "false",
 		NormalizePlatformSourcesTimeout: time.Duration(envInt("STATS_NORMALIZE_PLATFORM_SOURCES_TIMEOUT_SECONDS", 30)) * time.Second,
+		QuarantineDir:                   env("STATS_QUARANTINE_DIR", "/var/lib/lingniu-go-native/stat-writer-quarantine"),
 	}
 }

--- a/go/vehicle-gateway/cmd/stat-writer/main_test.go
+++ b/go/vehicle-gateway/cmd/stat-writer/main_test.go
@@ -4,6 +4,8 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 	"time"
@@ -664,6 +666,72 @@ func TestProcessStatBatchReliablyRetriesFailedSuffix(t *testing.T) {
 	}
 }

+func TestProcessStatBatchReliablyQuarantinesPermanentFailureAndContinues(t *testing.T) {
+	env := envelope.FrameEnvelope{Protocol: envelope.ProtocolJT808, Phone: "13307795425", MessageID: "0x0200"}
+	payload := marshalStatTestFieldsEnvelope(t, env)
+	appender := &contextCheckingStatAppender{failOnCount: 1, err: errors.New("Error 1048 (23000): Column 'daily_mileage_km' cannot be null")}
+	committer := &contextCheckingStatCommitter{}
+	quarantiner := &recordingStatQuarantiner{}
+	registry := metrics.NewRegistry()
+	messages := []kafka.Message{
+		{Topic: "vehicle.fields.go.jt808.v1", Partition: 1, Offset: 10, Value: payload},
+		{Topic: "vehicle.fields.go.jt808.v1", Partition: 1, Offset: 11, Value: payload},
+	}
+
+	processStatBatchReliablyForWorker(
+		context.Background(),
+		discardStatLogger{},
+		registry,
+		appender,
+		committer,
+		quarantiner,
+		messages,
+		time.Nanosecond,
+		nil,
+	)
+
+	if appender.count != 2 {
+		t.Fatalf("append attempts = %d, want failed message once and following message once", appender.count)
+	}
+	if quarantiner.count != 1 || quarantiner.message.Offset != 10 {
+		t.Fatalf("quarantine = %d/%d, want one message at offset 10", quarantiner.count, quarantiner.message.Offset)
+	}
+	if got := committedOffsets(committer.messages); len(got) != 2 || got[0] != 10 || got[1] != 11 {
+		t.Fatalf("committed offsets = %#v, want [10 11]", got)
+	}
+	text := registry.Render()
+	if !strings.Contains(text, `vehicle_stat_quarantine_total{status="ok",topic="vehicle.fields.go.jt808.v1"} 1`) {
+		t.Fatalf("quarantine success metric missing:\n%s", text)
+	}
+}
+
+func TestFileStatMessageQuarantinerPersistsOriginalKafkaMessage(t *testing.T) {
+	dir := t.TempDir()
+	message := kafka.Message{
+		Topic:     "vehicle.fields.go.jt808.v1",
+		Partition: 2,
+		Offset:    5094052,
+		Key:       []byte("vehicle-key"),
+		Value:     []byte(`{"event_id":"poison:fields"}`),
+	}
+	wantErr := errors.New("permanent mysql error")
+
+	if err := (fileStatMessageQuarantiner{dir: dir}).Quarantine(context.Background(), message, wantErr); err != nil {
+		t.Fatalf("Quarantine() error = %v", err)
+	}
+	payload, err := os.ReadFile(filepath.Join(dir, "vehicle.fields.go.jt808.v1-2-5094052.json"))
+	if err != nil {
+		t.Fatalf("read quarantine record: %v", err)
+	}
+	var record quarantinedStatMessage
+	if err := json.Unmarshal(payload, &record); err != nil {
+		t.Fatalf("unmarshal quarantine record: %v", err)
+	}
+	if record.Topic != message.Topic || record.Partition != message.Partition || record.Offset != message.Offset || string(record.Key) != string(message.Key) || string(record.Value) != string(message.Value) || record.Error != wantErr.Error() {
+		t.Fatalf("quarantine record = %#v, want original message and error", record)
+	}
+}
+
 func TestProcessStatBatchReliablyRetriesCommitWithoutReappending(t *testing.T) {
 	env := envelope.FrameEnvelope{Protocol: envelope.ProtocolJT808, Phone: "13307795425", MessageID: "0x0200"}
 	payload := marshalStatTestFieldsEnvelope(t, env)
@@ -826,6 +894,30 @@ func TestRetryStatAppenderRecordsExhaustedTransientError(t *testing.T) {
 	}
 }

+func TestRetryStatAppenderRetriesQuarantinableDataErrorBeforeIsolation(t *testing.T) {
+	registry := metrics.NewRegistry()
+	delegate := &contextCheckingStatAppender{err: errors.New("Error 1048 (23000): Column 'daily_mileage_km' cannot be null")}
+	appender := retryStatAppender{delegate: delegate, attempts: 3, registry: registry}
+
+	_, err := appender.AppendWithResult(context.Background(), envelope.FrameEnvelope{Protocol: envelope.ProtocolJT808})
+
+	if err == nil {
+		t.Fatal("AppendWithResult() error = nil, want exhausted data error")
+	}
+	if delegate.count != 3 {
+		t.Fatalf("append attempts = %d, want configured finite retries", delegate.count)
+	}
+	text := registry.Render()
+	for _, want := range []string{
+		`vehicle_stat_write_retries_total{operation="single",status="retry"} 2`,
+		`vehicle_stat_write_retries_total{operation="single",status="exhausted"} 1`,
+	} {
+		if !strings.Contains(text, want) {
+			t.Fatalf("retry metric missing %s:\n%s", want, text)
+		}
+	}
+}
+
 func TestRetryStatAppenderDoesNotRetryNonTransientError(t *testing.T) {
 	wantErr := errors.New("validation failed")
 	delegate := &contextCheckingStatAppender{err: wantErr}
@@ -841,6 +933,34 @@ func TestRetryStatAppenderDoesNotRetryNonTransientError(t *testing.T) {
 	}
 }

+func TestIsQuarantinableStatErrorOnlyAcceptsDeterministicRowDataFailures(t *testing.T) {
+	for _, err := range []error{
+		errors.New("Error 1048 (23000): Column 'daily_mileage_km' cannot be null"),
+		errors.New("Error 1264: Out of range value for column 'daily_mileage_km'"),
+		errors.New("Error 1265: Data truncated for column 'daily_mileage_km'"),
+		errors.New("Error 1292: Incorrect datetime value"),
+		errors.New("Error 1366: Incorrect decimal value"),
+		errors.New("Error 1406: Data too long for column"),
+		errors.New("Error 3819: Check constraint is violated"),
+	} {
+		if !isQuarantinableStatError(err) {
+			t.Fatalf("isQuarantinableStatError(%q) = false, want true", err.Error())
+		}
+	}
+	for _, err := range []error{
+		errors.New("Error 1054: Unknown column 'daily_mileage_km'"),
+		errors.New("Error 1142: INSERT command denied"),
+		errors.New("validation failed"),
+		context.Canceled,
+		context.DeadlineExceeded,
+		nil,
+	} {
+		if isQuarantinableStatError(err) {
+			t.Fatalf("isQuarantinableStatError(%v) = true, want false", err)
+		}
+	}
+}
+
 func TestIsTransientMySQLStatError(t *testing.T) {
 	for _, err := range []error{
 		errors.New("dial tcp 127.0.0.1:3306: connection refused"),
@@ -903,6 +1023,9 @@ func TestLoadConfigDefaultsToGoFieldsTopics(t *testing.T) {
 	if cfg.BaselineMissTTL != time.Minute {
 		t.Fatalf("BaselineMissTTL = %s, want 1m", cfg.BaselineMissTTL)
 	}
+	if cfg.BaselineHitTTL != 5*time.Minute {
+		t.Fatalf("BaselineHitTTL = %s, want 5m", cfg.BaselineHitTTL)
+	}
 	if cfg.RetryAttempts != 3 {
 		t.Fatalf("RetryAttempts = %d, want 3", cfg.RetryAttempts)
 	}
@@ -965,6 +1088,7 @@ func TestLoadConfigSetsStatWriteIntervals(t *testing.T) {
 	t.Setenv("STATS_CACHE_RETENTION_HOURS", "48")
 	t.Setenv("STATS_CACHE_CLEANUP_INTERVAL_SECONDS", "300")
 	t.Setenv("STATS_BASELINE_MISS_TTL_SECONDS", "45")
+	t.Setenv("STATS_BASELINE_HIT_TTL_SECONDS", "180")
 	t.Setenv("STATS_CACHE_MAX_ENTRIES", "12345")

 	cfg := loadConfig()
@@ -984,6 +1108,9 @@ func TestLoadConfigSetsStatWriteIntervals(t *testing.T) {
 	if cfg.BaselineMissTTL != 45*time.Second {
 		t.Fatalf("BaselineMissTTL = %s, want 45s", cfg.BaselineMissTTL)
 	}
+	if cfg.BaselineHitTTL != 3*time.Minute {
+		t.Fatalf("BaselineHitTTL = %s, want 3m", cfg.BaselineHitTTL)
+	}
 	if cfg.CacheMaxEntries != 12345 {
 		t.Fatalf("CacheMaxEntries = %d, want 12345", cfg.CacheMaxEntries)
 	}
@@ -997,6 +1124,7 @@ func TestLoadConfigReadsStatBatchSettings(t *testing.T) {
 	t.Setenv("STATS_RETRY_DELAY_MS", "33")
 	t.Setenv("STATS_NORMALIZE_PLATFORM_SOURCES_ON_START", "false")
 	t.Setenv("STATS_NORMALIZE_PLATFORM_SOURCES_TIMEOUT_SECONDS", "17")
+	t.Setenv("STATS_QUARANTINE_DIR", "/tmp/stat-writer-quarantine-test")

 	cfg := loadConfig()

@@ -1021,6 +1149,9 @@ func TestLoadConfigReadsStatBatchSettings(t *testing.T) {
 	if cfg.NormalizePlatformSourcesTimeout != 17*time.Second {
 		t.Fatalf("NormalizePlatformSourcesTimeout = %s, want 17s", cfg.NormalizePlatformSourcesTimeout)
 	}
+	if cfg.QuarantineDir != "/tmp/stat-writer-quarantine-test" {
+		t.Fatalf("QuarantineDir = %q, want env override", cfg.QuarantineDir)
+	}
 }

 type contextCheckingStatAppender struct {
@@ -1070,6 +1201,18 @@ type contextCheckingStatCommitter struct {
 	failOnCount  int
 }

+type recordingStatQuarantiner struct {
+	count   int
+	message kafka.Message
+	err     error
+}
+
+func (q *recordingStatQuarantiner) Quarantine(_ context.Context, message kafka.Message, _ error) error {
+	q.count++
+	q.message = message
+	return q.err
+}
+
 func (c *contextCheckingStatCommitter) CommitMessages(ctx context.Context, messages ...kafka.Message) error {
 	c.ctxErr = ctx.Err()
 	c.count++
--- a/go/vehicle-gateway/cmd/stats-backfill/main.go
+++ b/go/vehicle-gateway/cmd/stats-backfill/main.go
@@ -36,6 +36,7 @@ type config struct {
 	Debug             bool
 	EventTimeFullScan bool
 	ProgressEvery     int64
+	BaselineLookback  int
 	Location          *time.Location
 }

@@ -50,6 +51,7 @@ type rawFrameRow struct {
 	EventTimeMS    int64
 	ReceivedAtMS   int64
 	ParsedJSON     string
+	RawText        string
 }

 type metricAgg struct {
@@ -188,6 +190,9 @@ func main() {
 			}
 		}
 		fields := fieldsForStats(row.Protocol, row.VIN, text)
+		if len(fields) == 0 && row.Protocol == envelope.ProtocolYutongMQTT {
+			fields = fieldsForStats(row.Protocol, row.VIN, row.RawText)
+		}
 		if cfg.Debug && scanned <= 5 {
 			slog.Info("debug raw frame",
 				"protocol", row.Protocol,
@@ -427,7 +432,7 @@ func buildLastDiffAggregates(ctx context.Context, mysqlDB *sql.DB, tdDB *sql.DB,
 	return aggregates, nil
 }

-func addRealtimeLocationFallbackAggregates(ctx context.Context, mysqlDB *sql.DB, tdDB *sql.DB, cfg config, aggregates map[string]*metricAgg) (int, error) {
+func addRealtimeLocationFallbackAggregates(ctx context.Context, mysqlDB *sql.DB, _ *sql.DB, cfg config, aggregates map[string]*metricAgg) (int, error) {
 	if aggregates == nil {
 		return 0, fmt.Errorf("aggregates map is nil")
 	}
@@ -441,11 +446,6 @@ func addRealtimeLocationFallbackAggregates(ctx context.Context, mysqlDB *sql.DB,
 			continue
 		}
 		latestHistory := map[sourceHistoryID]dailySourceLast{}
-		preWindow, err := queryPreviousLastSourceRows(ctx, tdDB, cfg, protocol, targetDates[0])
-		if err != nil {
-			return added, err
-		}
-		rememberLatestSourceRows(latestHistory, preWindow)
 		aggregateRowsByDate := indexAggregateSourceRowsByDate(aggregates, protocol)
 		for _, date := range targetDates {
 			current, err := queryRealtimeLocationLastRows(ctx, mysqlDB, cfg, protocol, date)
@@ -656,7 +656,9 @@ func queryDailyLastSourceRows(ctx context.Context, db *sql.DB, cfg config, proto
 	if predicate := mileageBearingFramePredicate(protocol); predicate != "" {
 		where = append(where, predicate)
 	}
-	sqlText := fmt.Sprintf(`SELECT vin, phone, device_id, source_endpoint, FIRST(event_time), FIRST(parsed_json), LAST(event_time), LAST(parsed_json), COUNT(*)
+	sqlText := fmt.Sprintf(`SELECT vin, phone, device_id, source_endpoint,
+  FIRST(event_time), FIRST(parsed_json), FIRST(raw_text),
+  LAST(event_time), LAST(parsed_json), LAST(raw_text), COUNT(*)
 FROM %s.raw_frames
 WHERE %s
 GROUP BY vin, phone, device_id, source_endpoint`, ident(cfg.TDengineDatabase), strings.Join(where, " AND "))
@@ -668,7 +670,7 @@ func queryPreviousLastSourceRows(ctx context.Context, db *sql.DB, cfg config, pr
 	// LAST aggregates the complete pre-window history once per source so empty
 	// calendar days do not make a backfill fall back to the current day's first
 	// sample.
-	where := backfillBeforePredicates(date)
+	where := backfillBeforePredicates(cfg, date)
 	where = append(where,
 		"parse_status = 'OK'",
 		"vin IS NOT NULL",
@@ -679,17 +681,31 @@ func queryPreviousLastSourceRows(ctx context.Context, db *sql.DB, cfg config, pr
 	if predicate := mileageBearingFramePredicate(protocol); predicate != "" {
 		where = append(where, predicate)
 	}
-	sqlText := fmt.Sprintf(`SELECT vin, phone, device_id, source_endpoint, LAST(event_time), LAST(parsed_json), COUNT(*)
+	sqlText := fmt.Sprintf(`SELECT vin, phone, device_id, source_endpoint,
+  LAST(event_time), LAST(parsed_json), LAST(raw_text), COUNT(*)
 FROM %s.raw_frames
 WHERE %s
 GROUP BY vin, phone, device_id, source_endpoint`, ident(cfg.TDengineDatabase), strings.Join(where, " AND "))
 	return querySourceRows(ctx, db, cfg, protocol, sqlText, false)
 }

-func backfillBeforePredicates(eventDateExclusive string) []string {
-	return []string{
+func backfillBeforePredicates(cfg config, eventDateExclusive string) []string {
+	lookbackDays := cfg.BaselineLookback
+	if lookbackDays <= 0 {
+		lookbackDays = 7
+	}
+	eventDateFrom := shiftDate(eventDateExclusive, -lookbackDays)
+	where := []string{
+		fmt.Sprintf("event_time >= '%s 00:00:00'", quote(eventDateFrom)),
 		fmt.Sprintf("event_time < '%s 00:00:00'", quote(eventDateExclusive)),
 	}
+	if !cfg.EventTimeFullScan {
+		where = append([]string{
+			fmt.Sprintf("ts >= '%s 00:00:00'", quote(previousDate(eventDateFrom))),
+			fmt.Sprintf("ts < '%s 00:00:00'", quote(nextDate(eventDateExclusive))),
+		}, where...)
+	}
+	return where
 }

 func queryRealtimeLocationLastRows(ctx context.Context, db *sql.DB, cfg config, protocol envelope.Protocol, date string) (map[string][]dailySourceLast, error) {
@@ -775,27 +791,30 @@ func querySourceRows(ctx context.Context, db *sql.DB, cfg config, protocol envel
 		var sourceEndpoint string
 		var firstTS time.Time
 		var firstParsedJSON string
+		var firstRawText string
 		var ts time.Time
 		var parsedJSON string
+		var rawText string
 		var rawSampleCount int64
 		if includeFirst {
-			if err := rows.Scan(&vin, &phone, &deviceID, &sourceEndpoint, &firstTS, &firstParsedJSON, &ts, &parsedJSON, &rawSampleCount); err != nil {
+			if err := rows.Scan(&vin, &phone, &deviceID, &sourceEndpoint, &firstTS, &firstParsedJSON, &firstRawText, &ts, &parsedJSON, &rawText, &rawSampleCount); err != nil {
 				return nil, err
 			}
 		} else {
-			if err := rows.Scan(&vin, &phone, &deviceID, &sourceEndpoint, &ts, &parsedJSON, &rawSampleCount); err != nil {
+			if err := rows.Scan(&vin, &phone, &deviceID, &sourceEndpoint, &ts, &parsedJSON, &rawText, &rawSampleCount); err != nil {
 				return nil, err
 			}
 			firstTS = ts
 			firstParsedJSON = parsedJSON
+			firstRawText = rawText
 		}
-		latestTotalKM, ok := mileageFromParsed(protocol, vin, parsedJSON, ts, cfg.Location)
+		latestTotalKM, ok := mileageFromEvidence(protocol, vin, parsedJSON, rawText, ts, cfg.Location)
 		if !ok {
 			continue
 		}
 		firstTotalKM := latestTotalKM
 		if includeFirst {
-			if parsedFirst, ok := mileageFromParsed(protocol, vin, firstParsedJSON, firstTS, cfg.Location); ok {
+			if parsedFirst, ok := mileageFromEvidence(protocol, vin, firstParsedJSON, firstRawText, firstTS, cfg.Location); ok {
 				firstTotalKM = parsedFirst
 			}
 		}
@@ -852,6 +871,16 @@ func mileageFromParsed(protocol envelope.Protocol, vin string, parsedJSON string
 	return samples[0].TotalMileageKM, true
 }

+func mileageFromEvidence(protocol envelope.Protocol, vin string, parsedJSON string, rawText string, eventTime time.Time, loc *time.Location) (float64, bool) {
+	if totalKM, ok := mileageFromParsed(protocol, vin, parsedJSON, eventTime, loc); ok {
+		return totalKM, true
+	}
+	if protocol != envelope.ProtocolYutongMQTT || strings.TrimSpace(rawText) == "" {
+		return 0, false
+	}
+	return mileageFromParsed(protocol, vin, rawText, eventTime, loc)
+}
+
 func normalizedSourceKey(protocol string, phone string, deviceID string, endpoint string) string {
 	return normalizedSourceKeyForSource(protocol, phone, deviceID, endpoint, "", "")
 }
@@ -951,6 +980,7 @@ func loadConfig() (config, error) {
 		Debug:             envBool("BACKFILL_DEBUG", false),
 		EventTimeFullScan: envBool("BACKFILL_EVENT_TIME_FULL_SCAN", false),
 		ProgressEvery:     int64(envInt("BACKFILL_PROGRESS_EVERY", 100000)),
+		BaselineLookback:  envInt("BACKFILL_BASELINE_LOOKBACK_DAYS", 7),
 		Location:          loc,
 	}, nil
 }
@@ -1000,7 +1030,7 @@ func queryRawFrames(ctx context.Context, db *sql.DB, cfg config) (*sql.Rows, err
 		where = append(where, "protocol IN ("+strings.Join(quoted, ",")+")")
 	}
 	where = append(where, realtimeMileageFramePredicate())
-	sqlText := fmt.Sprintf(`SELECT protocol, vin, phone, device_id, source_endpoint, event_id, message_id, event_time, received_at, parsed_json
+	sqlText := fmt.Sprintf(`SELECT protocol, vin, phone, device_id, source_endpoint, event_id, message_id, event_time, received_at, parsed_json, raw_text
 FROM %s.raw_frames
 WHERE %s
 	ORDER BY event_time ASC, ts ASC`, ident(cfg.TDengineDatabase), strings.Join(where, " AND "))
@@ -1044,6 +1074,9 @@ func mileageBearingFramePredicate(protocol envelope.Protocol) string {
 	conditions := make([]string, 0, len(tokens))
 	for _, token := range tokens {
 		conditions = append(conditions, fmt.Sprintf("parsed_json LIKE '%%%s%%'", quote(token)))
+		if protocol == envelope.ProtocolYutongMQTT {
+			conditions = append(conditions, fmt.Sprintf("raw_text LIKE '%%%s%%'", quote(token)))
+		}
 	}
 	return "(" + strings.Join(conditions, " OR ") + ")"
 }
@@ -1071,10 +1104,10 @@ func mileageSearchTokens(protocol envelope.Protocol) []string {
 }

 func scanRawFrame(rows *sql.Rows) (rawFrameRow, error) {
-	var protocol, vin, phone, deviceID, sourceEndpoint, eventID, parsed string
+	var protocol, vin, phone, deviceID, sourceEndpoint, eventID, parsed, rawText string
 	var messageID int64
 	var eventTime, receivedAt time.Time
-	if err := rows.Scan(&protocol, &vin, &phone, &deviceID, &sourceEndpoint, &eventID, &messageID, &eventTime, &receivedAt, &parsed); err != nil {
+	if err := rows.Scan(&protocol, &vin, &phone, &deviceID, &sourceEndpoint, &eventID, &messageID, &eventTime, &receivedAt, &parsed, &rawText); err != nil {
 		return rawFrameRow{}, err
 	}
 	return rawFrameRow{
@@ -1088,6 +1121,7 @@ func scanRawFrame(rows *sql.Rows) (rawFrameRow, error) {
 		EventTimeMS:    eventTime.UnixMilli(),
 		ReceivedAtMS:   receivedAt.UnixMilli(),
 		ParsedJSON:     parsed,
+		RawText:        rawText,
 	}, nil
 }

@@ -1267,6 +1301,14 @@ func previousDate(date string) string {
 	return parsed.AddDate(0, 0, -1).Format("2006-01-02")
 }

+func shiftDate(date string, days int) string {
+	parsed, err := time.Parse("2006-01-02", date)
+	if err != nil {
+		return date
+	}
+	return parsed.AddDate(0, 0, days).Format("2006-01-02")
+}
+
 func dateRangeWithPrevious(from string, to string) ([]string, error) {
 	dates, err := dateRange(from, to)
 	if err != nil {
--- a/go/vehicle-gateway/cmd/stats-backfill/main_test.go
+++ b/go/vehicle-gateway/cmd/stats-backfill/main_test.go
@@ -233,23 +233,23 @@ func TestBuildLastDiffAggregatesCarriesNearestHistoryAcrossEmptyDays(t *testing.
 	dayThreeTS := time.Date(2026, 7, 11, 17, 30, 0, 0, loc)
 	currentRows := func() *sqlmock.Rows {
 		return sqlmock.NewRows([]string{
-			"vin", "phone", "device_id", "source_endpoint", "FIRST(event_time)", "FIRST(parsed_json)", "LAST(event_time)", "LAST(parsed_json)", "COUNT(*)",
+			"vin", "phone", "device_id", "source_endpoint", "FIRST(event_time)", "FIRST(parsed_json)", "FIRST(raw_text)", "LAST(event_time)", "LAST(parsed_json)", "LAST(raw_text)", "COUNT(*)",
 		})
 	}
 	previousRows := func() *sqlmock.Rows {
 		return sqlmock.NewRows([]string{
-			"vin", "phone", "device_id", "source_endpoint", "LAST(event_time)", "LAST(parsed_json)", "COUNT(*)",
+			"vin", "phone", "device_id", "source_endpoint", "LAST(event_time)", "LAST(parsed_json)", "LAST(raw_text)", "COUNT(*)",
 		})
 	}

 	mock.ExpectQuery("(?s)SELECT vin.*LAST\\(event_time\\).*event_time < '2026-07-09 00:00:00'.*protocol = 'YUTONG_MQTT'").
 		WillReturnRows(previousRows())
 	mock.ExpectQuery("(?s)SELECT vin.*FIRST\\(event_time\\).*event_time >= '2026-07-09 00:00:00'.*protocol = 'YUTONG_MQTT'").
-		WillReturnRows(currentRows().AddRow(vin, "", vin, endpoint, dayOneTS, `{"data":{"TOTAL_MILEAGE":100000}}`, dayOneTS, `{"data":{"TOTAL_MILEAGE":100000}}`, int64(4)))
+		WillReturnRows(currentRows().AddRow(vin, "", vin, endpoint, dayOneTS, `{"data":{"TOTAL_MILEAGE":100000}}`, "", dayOneTS, `{"data":{"TOTAL_MILEAGE":100000}}`, "", int64(4)))
 	mock.ExpectQuery("(?s)SELECT vin.*FIRST\\(event_time\\).*event_time >= '2026-07-10 00:00:00'.*protocol = 'YUTONG_MQTT'").
 		WillReturnRows(currentRows())
 	mock.ExpectQuery("(?s)SELECT vin.*FIRST\\(event_time\\).*event_time >= '2026-07-11 00:00:00'.*protocol = 'YUTONG_MQTT'").
-		WillReturnRows(currentRows().AddRow(vin, "", vin, endpoint, dayThreeTS, `{"data":{"TOTAL_MILEAGE":120000}}`, dayThreeTS, `{"data":{"TOTAL_MILEAGE":120000}}`, int64(6)))
+		WillReturnRows(currentRows().AddRow(vin, "", vin, endpoint, dayThreeTS, `{"data":{"TOTAL_MILEAGE":120000}}`, "", dayThreeTS, `{"data":{"TOTAL_MILEAGE":120000}}`, "", int64(6)))

 	aggregates, err := buildLastDiffAggregates(context.Background(), nil, tdDB, config{
 		TDengineDatabase: "lingniu_vehicle_ts",
@@ -342,18 +342,10 @@ func TestAddRealtimeLocationFallbackAggregatesUsesHistoricalBaseline(t *testing.
 		WithArgs("YUTONG_MQTT", "2026-07-12", "2026-07-12").
 		WillReturnRows(sqlmock.NewRows([]string{"vin", "peer", "total_mileage_event_time", "total_mileage_km"}).
 			AddRow("LMRKH9AC0R1004086", "mqtt://yutong/ytforward/shln/4", currentTS, 11578.0))
-	tdMock.ExpectQuery("(?s)FROM lingniu_vehicle_ts\\.raw_frames.*event_time < '2026-07-12 00:00:00'.*protocol = 'YUTONG_MQTT'.*TOTAL_MILEAGE").
-		WillReturnRows(sqlmock.NewRows([]string{
-			"vin", "phone", "device_id", "source_endpoint", "LAST(event_time)", "LAST(parsed_json)", "COUNT(*)",
-		}).AddRow(
-			"LMRKH9AC0R1004086",
-			"",
-			"LMRKH9AC0R1004086",
-			"mqtt://yutong/ytforward/shln/4",
-			previousTS,
-			`{"data":{"TOTAL_MILEAGE":11500000}}`,
-			int64(12),
-		))
+	sourceKey := stats.SourceKeyForSource(envelope.ProtocolYutongMQTT, "", "LMRKH9AC0R1004086", "mqtt", "PLATFORM", "yutong")
+	mysqlMock.ExpectQuery("(?s)SELECT latest_total_mileage_km, latest_event_time.*FROM vehicle_daily_mileage_source").
+		WithArgs("LMRKH9AC0R1004086", "2026-07-12", "YUTONG_MQTT", sourceKey).
+		WillReturnRows(sqlmock.NewRows([]string{"latest_total_mileage_km", "latest_event_time"}).AddRow(11500.0, previousTS))

 	aggregates := map[string]*metricAgg{}
 	added, err := addRealtimeLocationFallbackAggregates(context.Background(), mysqlDB, tdDB, config{
@@ -373,7 +365,7 @@ func TestAddRealtimeLocationFallbackAggregatesUsesHistoricalBaseline(t *testing.
 		if agg.FirstKM != 11500 || agg.LatestKM != 11578 {
 			t.Fatalf("km range = %v -> %v", agg.FirstKM, agg.LatestKM)
 		}
-		if agg.SourceKey != stats.SourceKeyForSource(envelope.ProtocolYutongMQTT, "", "LMRKH9AC0R1004086", "mqtt", "PLATFORM", "yutong") {
+		if agg.SourceKey != sourceKey {
 			t.Fatalf("source key = %q", agg.SourceKey)
 		}
 		if agg.SourceCode != "yutong" || agg.PlatformName != "宇通" || agg.SourceKind != "PLATFORM" {
@@ -410,10 +402,6 @@ func TestAddRealtimeLocationFallbackReusesAggregateHistoryAcrossEmptyDays(t *tes
 	dayOneTS := time.Date(2026, 7, 9, 23, 50, 0, 0, loc)
 	dayThreeTS := time.Date(2026, 7, 11, 17, 30, 0, 0, loc)

-	tdMock.ExpectQuery("(?s)SELECT vin.*LAST\\(event_time\\).*event_time < '2026-07-09 00:00:00'.*protocol = 'YUTONG_MQTT'").
-		WillReturnRows(sqlmock.NewRows([]string{
-			"vin", "phone", "device_id", "source_endpoint", "LAST(event_time)", "LAST(parsed_json)", "COUNT(*)",
-		}))
 	for _, date := range []string{"2026-07-09", "2026-07-10"} {
 		mysqlMock.ExpectQuery("(?s)FROM vehicle_realtime_location l.*l.protocol = \\?").
 			WithArgs("YUTONG_MQTT", date, date).
@@ -483,16 +471,18 @@ func TestQueryDailyLastSourceRowsFiltersYutongToMileageFrames(t *testing.T) {
 	lastTS := time.Date(2026, 7, 8, 18, 0, 0, 0, loc)
 	mock.ExpectQuery("(?s)FROM lingniu_vehicle_ts\\.raw_frames.*protocol = 'YUTONG_MQTT'.*parsed_json LIKE '%yutong_mqtt\\.data\\.total_mileage%'.*parsed_json LIKE '%TOTAL_MILEAGE%'").
 		WillReturnRows(sqlmock.NewRows([]string{
-			"vin", "phone", "device_id", "source_endpoint", "FIRST(event_time)", "FIRST(parsed_json)", "LAST(event_time)", "LAST(parsed_json)", "COUNT(*)",
+			"vin", "phone", "device_id", "source_endpoint", "FIRST(event_time)", "FIRST(parsed_json)", "FIRST(raw_text)", "LAST(event_time)", "LAST(parsed_json)", "LAST(raw_text)", "COUNT(*)",
 		}).AddRow(
 			"LMRKH9AC6R1004108",
 			"",
 			"LMRKH9AC6R1004108",
 			"mqtt://yutong/ytforward/shln/3",
 			firstTS,
-			`{"yutong_mqtt.data.total_mileage":"65422000"}`,
+			`{"yutong_mqtt.data.latitude":"30.0"}`,
+			`{"data":{"TOTAL_MILEAGE":65422000}}`,
 			lastTS,
-			`{"yutong_mqtt.data.total_mileage":"65423000"}`,
+			`{"yutong_mqtt.data.latitude":"30.1"}`,
+			`{"data":{"TOTAL_MILEAGE":65423000}}`,
 			int64(42),
 		))

@@ -526,14 +516,15 @@ func TestQueryPreviousLastSourceRowsFiltersYutongToMileageFrames(t *testing.T) {
 	lastTS := time.Date(2026, 7, 7, 23, 58, 0, 0, loc)
 	mock.ExpectQuery("(?s)FROM lingniu_vehicle_ts\\.raw_frames.*event_time < '2026-07-08 00:00:00'.*protocol = 'YUTONG_MQTT'.*parsed_json LIKE '%yutong_mqtt\\.data\\.total_mileage%'.*parsed_json LIKE '%TOTAL_MILEAGE%'").
 		WillReturnRows(sqlmock.NewRows([]string{
-			"vin", "phone", "device_id", "source_endpoint", "LAST(event_time)", "LAST(parsed_json)", "COUNT(*)",
+			"vin", "phone", "device_id", "source_endpoint", "LAST(event_time)", "LAST(parsed_json)", "LAST(raw_text)", "COUNT(*)",
 		}).AddRow(
 			"LMRKH9AC6R1004108",
 			"",
 			"LMRKH9AC6R1004108",
 			"mqtt://yutong/ytforward/shln/3",
 			lastTS,
-			`{"yutong_mqtt.data.total_mileage":"65377000"}`,
+			`{"yutong_mqtt.data.latitude":"30.0"}`,
+			`{"data":{"TOTAL_MILEAGE":65377000}}`,
 			int64(31),
 		))

@@ -556,13 +547,19 @@ func TestQueryPreviousLastSourceRowsFiltersYutongToMileageFrames(t *testing.T) {
 	}
 }

-func TestBackfillBeforePredicatesSearchesAllEarlierHistory(t *testing.T) {
-	where := strings.Join(backfillBeforePredicates("2026-07-08"), " AND ")
+func TestBackfillBeforePredicatesBoundsHistoryScan(t *testing.T) {
+	where := strings.Join(backfillBeforePredicates(config{BaselineLookback: 7}, "2026-07-08"), " AND ")
 	if !strings.Contains(where, "event_time < '2026-07-08 00:00:00'") {
 		t.Fatalf("pre-window predicate missing exclusive upper bound: %s", where)
 	}
-	if strings.Contains(where, "event_time >=") || strings.Contains(where, "ts >=") {
-		t.Fatalf("pre-window predicate must not stop at the previous day: %s", where)
+	for _, predicate := range []string{
+		"event_time >= '2026-07-01 00:00:00'",
+		"ts >= '2026-06-30 00:00:00'",
+		"ts < '2026-07-09 00:00:00'",
+	} {
+		if !strings.Contains(where, predicate) {
+			t.Fatalf("pre-window predicate missing %q: %s", predicate, where)
+		}
 	}
 }

@@ -577,7 +574,7 @@ func TestQueryPreviousLastSourceRowsNormalizesScannedTimestampToBusinessTimezone
 	utcInstant := time.Date(2026, 7, 12, 15, 59, 59, 0, time.UTC)
 	mock.ExpectQuery("(?s)FROM lingniu_vehicle_ts\\.raw_frames.*protocol = 'YUTONG_MQTT'").
 		WillReturnRows(sqlmock.NewRows([]string{
-			"vin", "phone", "device_id", "source_endpoint", "LAST(event_time)", "LAST(parsed_json)", "COUNT(*)",
+			"vin", "phone", "device_id", "source_endpoint", "LAST(event_time)", "LAST(parsed_json)", "LAST(raw_text)", "COUNT(*)",
 		}).AddRow(
 			"LMRKH9AC7R1004098",
 			"",
@@ -585,6 +582,7 @@ func TestQueryPreviousLastSourceRowsNormalizesScannedTimestampToBusinessTimezone
 			"mqtt://yutong/ytforward/shln/4",
 			utcInstant,
 			`{"yutong_mqtt.data.total_mileage":"41249000"}`,
+			"",
 			int64(1),
 		))