Add data file compaction to iceberg maintenance (Phase 2) (#8503)

* Add iceberg_maintenance plugin worker handler (Phase 1) Implement automated Iceberg table maintenance as a new plugin worker job type. The handler scans S3 table buckets for tables needing maintenance and executes operations in the correct Iceberg order: expire snapshots, remove orphan files, and rewrite manifests. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com> * Add data file compaction to iceberg maintenance handler (Phase 2) Implement bin-packing compaction for small Parquet data files: - Enumerate data files from manifests, group by partition - Merge small files using parquet-go (read rows, write merged output) - Create new manifest with ADDED/DELETED/EXISTING entries - Commit new snapshot with compaction metadata Add 'compact' operation to maintenance order (runs before expire_snapshots), configurable via target_file_size_bytes and min_input_files thresholds. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com> * Fix memory exhaustion in mergeParquetFiles by processing files sequentially Previously all source Parquet files were loaded into memory simultaneously, risking OOM when a compaction bin contained many small files. Now each file is loaded, its rows are streamed into the output writer, and its data is released before the next file is loaded — keeping peak memory proportional to one input file plus the output buffer. * Validate bucket/namespace/table names against path traversal Reject names containing '..', '/', or '\' in Execute to prevent directory traversal via crafted job parameters. * Add filer address failover in iceberg maintenance handler Try each filer address from cluster context in order instead of only using the first one. This improves resilience when the primary filer is temporarily unreachable. * Add separate MinManifestsToRewrite config for manifest rewrite threshold The rewrite_manifests operation was reusing MinInputFiles (meant for compaction bin file counts) as its manifest count threshold. Add a dedicated MinManifestsToRewrite field with its own config UI section and default value (5) so the two thresholds can be tuned independently. * Fix risky mtime fallback in orphan removal that could delete new files When entry.Attributes is nil, mtime defaulted to Unix epoch (1970), which would always be older than the safety threshold, causing the file to be treated as eligible for deletion. Skip entries with nil Attributes instead, matching the safer logic in operations.go. * Fix undefined function references in iceberg_maintenance_handler.go Use the exported function names (ShouldSkipDetectionByInterval, BuildDetectorActivity, BuildExecutorActivity) matching their definitions in vacuum_handler.go. * Remove duplicated iceberg maintenance handler in favor of iceberg/ subpackage The IcebergMaintenanceHandler and its compaction code in the parent pluginworker package duplicated the logic already present in the iceberg/ subpackage (which self-registers via init()). The old code lacked stale-plan guards, proper path normalization, CAS-based xattr updates, and error-returning parseOperations. Since the registry pattern (default "all") makes the old handler unreachable, remove it entirely. All functionality is provided by iceberg.Handler with the reviewed improvements. * Fix MinManifestsToRewrite clamping to match UI minimum of 2 The clamp reset values below 2 to the default of 5, contradicting the UI's advertised MinValue of 2. Clamp to 2 instead. * Sort entries by size descending in splitOversizedBin for better packing Entries were processed in insertion order which is non-deterministic from map iteration. Sorting largest-first before the splitting loop improves bin packing efficiency by filling bins more evenly. * Add context cancellation check to drainReader loop The row-streaming loop in drainReader did not check ctx between iterations, making long compaction merges uncancellable. Check ctx.Done() at the top of each iteration. * Fix splitOversizedBin to always respect targetSize limit The minFiles check in the split condition allowed bins to grow past targetSize when they had fewer than minFiles entries, defeating the OOM protection. Now bins always split at targetSize, and a trailing runt with fewer than minFiles entries is merged into the previous bin. * Add integration tests for iceberg table maintenance plugin worker Tests start a real weed mini cluster, create S3 buckets and Iceberg table metadata via filer gRPC, then exercise the iceberg.Handler operations (ExpireSnapshots, RemoveOrphans, RewriteManifests) against the live filer. A full maintenance cycle test runs all operations in sequence and verifies metadata consistency. Also adds exported method wrappers (testing_api.go) so the integration test package can call the unexported handler methods. * Fix splitOversizedBin dropping files and add source path to drainReader errors The runt-merge step could leave leading bins with fewer than minFiles entries (e.g. [80,80,10,10] with targetSize=100, minFiles=2 would drop the first 80-byte file). Replace the filter-based approach with an iterative merge that folds any sub-minFiles bin into its smallest neighbor, preserving all eligible files. Also add the source file path to drainReader error messages so callers can identify which Parquet file caused a read/write failure. * Harden integration test error handling - s3put: fail immediately on HTTP 4xx/5xx instead of logging and continuing - lookupEntry: distinguish NotFound (return nil) from unexpected RPC errors (fail the test) - writeOrphan and orphan creation in FullMaintenanceCycle: check CreateEntryResponse.Error in addition to the RPC error * go fmt --------- Co-authored-by: Copilot <copilot@github.com> Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-15 11:27:42 -07:00
parent 47799a5b4f
commit 8cde3d4486
30 changed files with 970 additions and 162 deletions
--- a/test/s3/normal/get_object_attributes_test.go
+++ b/test/s3/normal/get_object_attributes_test.go
@@ -10,14 +10,14 @@ import (
 	"testing"
 	"time"

-	"github.com/aws/aws-sdk-go/aws"
-	v1credentials "github.com/aws/aws-sdk-go/aws/credentials"
-	v1signer "github.com/aws/aws-sdk-go/aws/signer/v4"
-	v1s3 "github.com/aws/aws-sdk-go/service/s3"
 	v2aws "github.com/aws/aws-sdk-go-v2/aws"
 	"github.com/aws/aws-sdk-go-v2/credentials"
 	v2s3 "github.com/aws/aws-sdk-go-v2/service/s3"
 	"github.com/aws/aws-sdk-go-v2/service/s3/types"
+	"github.com/aws/aws-sdk-go/aws"
+	v1credentials "github.com/aws/aws-sdk-go/aws/credentials"
+	v1signer "github.com/aws/aws-sdk-go/aws/signer/v4"
+	v1s3 "github.com/aws/aws-sdk-go/service/s3"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
--- a/test/s3tables/maintenance/maintenance_integration_test.go
+++ b/test/s3tables/maintenance/maintenance_integration_test.go
@@ -0,0 +1,681 @@
+// Package maintenance contains integration tests for the iceberg table
+// maintenance plugin worker. Tests start a real weed mini cluster, create
+// tables via the S3 Tables API, populate Iceberg metadata via the filer
+// gRPC API, and then exercise the iceberg.Handler operations against the
+// live filer.
+package maintenance
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"strconv"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/apache/iceberg-go"
+	"github.com/apache/iceberg-go/table"
+	"github.com/aws/aws-sdk-go-v2/aws"
+	v4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+
+	"github.com/seaweedfs/seaweedfs/weed/command"
+	"github.com/seaweedfs/seaweedfs/weed/glog"
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	icebergHandler "github.com/seaweedfs/seaweedfs/weed/plugin/worker/iceberg"
+	"github.com/seaweedfs/seaweedfs/weed/s3api/s3tables"
+)
+
+// ---------------------------------------------------------------------------
+// Cluster lifecycle (mirrors test/s3tables/table-buckets pattern)
+// ---------------------------------------------------------------------------
+
+type testCluster struct {
+	dataDir       string
+	ctx           context.Context
+	cancel        context.CancelFunc
+	wg            sync.WaitGroup
+	filerGrpcPort int
+	s3Port        int
+	s3Endpoint    string
+	isRunning     bool
+}
+
+var shared *testCluster
+
+func TestMain(m *testing.M) {
+	flag.Parse()
+	if testing.Short() {
+		os.Exit(m.Run())
+	}
+
+	testDir, err := os.MkdirTemp("", "seaweed-iceberg-maint-*")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "SKIP: failed to create temp dir: %v\n", err)
+		os.Exit(0)
+	}
+
+	cluster, err := startCluster(testDir, nil)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "SKIP: failed to start cluster: %v\n", err)
+		os.RemoveAll(testDir)
+		os.Exit(0)
+	}
+	shared = cluster
+
+	code := m.Run()
+	shared.stop()
+	os.RemoveAll(testDir)
+	os.Exit(code)
+}
+
+func startCluster(testDir string, extraArgs []string) (*testCluster, error) {
+	ports, err := findPorts(10)
+	if err != nil {
+		return nil, err
+	}
+	masterPort, masterGrpc := ports[0], ports[1]
+	volumePort, volumeGrpc := ports[2], ports[3]
+	filerPort, filerGrpc := ports[4], ports[5]
+	s3Port, s3Grpc := ports[6], ports[7]
+	adminPort, adminGrpc := ports[8], ports[9]
+
+	_ = os.Remove(filepath.Join(testDir, "mini.options"))
+
+	// Empty security.toml disables JWT auth.
+	if err := os.WriteFile(filepath.Join(testDir, "security.toml"), []byte("# test\n"), 0644); err != nil {
+		return nil, err
+	}
+	if os.Getenv("AWS_ACCESS_KEY_ID") == "" {
+		os.Setenv("AWS_ACCESS_KEY_ID", "admin")
+	}
+	if os.Getenv("AWS_SECRET_ACCESS_KEY") == "" {
+		os.Setenv("AWS_SECRET_ACCESS_KEY", "admin")
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	c := &testCluster{
+		dataDir:       testDir,
+		ctx:           ctx,
+		cancel:        cancel,
+		filerGrpcPort: filerGrpc,
+		s3Port:        s3Port,
+		s3Endpoint:    fmt.Sprintf("http://127.0.0.1:%d", s3Port),
+	}
+
+	c.wg.Add(1)
+	go func() {
+		defer c.wg.Done()
+		oldDir, _ := os.Getwd()
+		oldArgs := os.Args
+		defer func() { os.Chdir(oldDir); os.Args = oldArgs }()
+		os.Chdir(testDir)
+
+		args := []string{
+			"-dir=" + testDir,
+			"-master.dir=" + testDir,
+			"-master.port=" + strconv.Itoa(masterPort),
+			"-master.port.grpc=" + strconv.Itoa(masterGrpc),
+			"-volume.port=" + strconv.Itoa(volumePort),
+			"-volume.port.grpc=" + strconv.Itoa(volumeGrpc),
+			"-volume.port.public=" + strconv.Itoa(volumePort),
+			"-volume.publicUrl=127.0.0.1:" + strconv.Itoa(volumePort),
+			"-filer.port=" + strconv.Itoa(filerPort),
+			"-filer.port.grpc=" + strconv.Itoa(filerGrpc),
+			"-s3.port=" + strconv.Itoa(s3Port),
+			"-s3.port.grpc=" + strconv.Itoa(s3Grpc),
+			"-admin.port=" + strconv.Itoa(adminPort),
+			"-admin.port.grpc=" + strconv.Itoa(adminGrpc),
+			"-webdav.port=0",
+			"-admin.ui=false",
+			"-master.volumeSizeLimitMB=32",
+			"-ip=127.0.0.1",
+			"-master.peers=none",
+			"-s3.iam.readOnly=false",
+		}
+		args = append(args, extraArgs...)
+		os.Args = append([]string{"weed"}, args...)
+		glog.MaxSize = 1024 * 1024
+		for _, cmd := range command.Commands {
+			if cmd.Name() == "mini" && cmd.Run != nil {
+				cmd.Flag.Parse(os.Args[1:])
+				command.MiniClusterCtx = ctx
+				cmd.Run(cmd, cmd.Flag.Args())
+				command.MiniClusterCtx = nil
+				return
+			}
+		}
+	}()
+
+	if err := waitReady(c.s3Endpoint, 30*time.Second); err != nil {
+		cancel()
+		return nil, err
+	}
+	c.isRunning = true
+	return c, nil
+}
+
+func (c *testCluster) stop() {
+	if c.cancel != nil {
+		c.cancel()
+	}
+	if c.isRunning {
+		time.Sleep(500 * time.Millisecond)
+	}
+	done := make(chan struct{})
+	go func() { c.wg.Wait(); close(done) }()
+	select {
+	case <-done:
+	case <-time.After(2 * time.Second):
+	}
+}
+
+func (c *testCluster) filerConn(t *testing.T) (*grpc.ClientConn, filer_pb.SeaweedFilerClient) {
+	t.Helper()
+	addr := fmt.Sprintf("127.0.0.1:%d", c.filerGrpcPort)
+	conn, err := grpc.NewClient(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	require.NoError(t, err)
+	t.Cleanup(func() { conn.Close() })
+	return conn, filer_pb.NewSeaweedFilerClient(conn)
+}
+
+func findPorts(n int) ([]int, error) {
+	ls := make([]*net.TCPListener, n)
+	ps := make([]int, n)
+	for i := 0; i < n; i++ {
+		l, err := net.Listen("tcp", "127.0.0.1:0")
+		if err != nil {
+			for j := 0; j < i; j++ {
+				ls[j].Close()
+			}
+			return nil, err
+		}
+		ls[i] = l.(*net.TCPListener)
+		ps[i] = ls[i].Addr().(*net.TCPAddr).Port
+	}
+	for _, l := range ls {
+		l.Close()
+	}
+	return ps, nil
+}
+
+func waitReady(endpoint string, timeout time.Duration) error {
+	client := &http.Client{Timeout: 1 * time.Second}
+	deadline := time.Now().Add(timeout)
+	for time.Now().Before(deadline) {
+		resp, err := client.Get(endpoint)
+		if err == nil {
+			resp.Body.Close()
+			time.Sleep(500 * time.Millisecond)
+			return nil
+		}
+		time.Sleep(200 * time.Millisecond)
+	}
+	return fmt.Errorf("timeout waiting for %s", endpoint)
+}
+
+func randomSuffix() string {
+	b := make([]byte, 4)
+	rand.Read(b)
+	return fmt.Sprintf("%x", b)
+}
+
+// ---------------------------------------------------------------------------
+// Helpers for populating Iceberg table state via filer gRPC
+// ---------------------------------------------------------------------------
+
+func newTestSchema() *iceberg.Schema {
+	return iceberg.NewSchema(0,
+		iceberg.NestedField{ID: 1, Type: iceberg.PrimitiveTypes.Int64, Name: "id", Required: true},
+		iceberg.NestedField{ID: 2, Type: iceberg.PrimitiveTypes.String, Name: "name", Required: false},
+	)
+}
+
+func buildMetadata(t *testing.T, snapshots []table.Snapshot) table.Metadata {
+	t.Helper()
+	schema := newTestSchema()
+	meta, err := table.NewMetadata(schema, iceberg.UnpartitionedSpec, table.UnsortedSortOrder, "s3://test/table", nil)
+	require.NoError(t, err)
+	if len(snapshots) == 0 {
+		return meta
+	}
+
+	// Iceberg validates that snapshot timestamps >= metadata lastUpdatedMs.
+	// Offset all timestamps so they're safely after the metadata was created.
+	baseMs := time.Now().UnixMilli() + 100
+	for i := range snapshots {
+		snapshots[i].TimestampMs = baseMs + int64(i)
+	}
+
+	builder, err := table.MetadataBuilderFromBase(meta, "s3://test/table")
+	require.NoError(t, err)
+	var lastID int64
+	for i := range snapshots {
+		s := snapshots[i]
+		require.NoError(t, builder.AddSnapshot(&s))
+		lastID = s.SnapshotID
+	}
+	require.NoError(t, builder.SetSnapshotRef(table.MainBranch, lastID, table.BranchRef))
+	result, err := builder.Build()
+	require.NoError(t, err)
+	return result
+}
+
+// s3put performs an S3-signed PUT request. When key is empty it creates a
+// bucket; otherwise it uploads an object.
+func s3put(t *testing.T, s3Endpoint, bucket, key string, body []byte) {
+	t.Helper()
+	urlPath := "/" + bucket
+	if key != "" {
+		urlPath += "/" + key
+	}
+	var reader *bytes.Reader
+	if body != nil {
+		reader = bytes.NewReader(body)
+	} else {
+		reader = bytes.NewReader(nil)
+	}
+	req, err := http.NewRequest(http.MethodPut, s3Endpoint+urlPath, reader)
+	require.NoError(t, err)
+	req.Header.Set("Host", req.URL.Host)
+	hash := sha256.Sum256(body)
+	err = v4.NewSigner().SignHTTP(context.Background(),
+		aws.Credentials{AccessKeyID: "admin", SecretAccessKey: "admin"},
+		req, hex.EncodeToString(hash[:]), "s3", "us-east-1", time.Now())
+	require.NoError(t, err)
+	resp, err := (&http.Client{Timeout: 10 * time.Second}).Do(req)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+	if resp.StatusCode >= 400 {
+		b, _ := io.ReadAll(resp.Body)
+		require.FailNowf(t, "s3put failed", "s3put(%s/%s) → %d: %s", bucket, key, resp.StatusCode, string(b))
+	}
+}
+
+// createBucketViaS3 creates a regular S3 bucket via the S3 PUT Bucket API.
+// populateTableViaFiler creates the Iceberg directory structure, metadata xattr,
+// manifests, and data files for a table directly in the filer.
+// The table bucket, namespace, and table must already exist (created via S3
+// Tables API).
+func populateTableViaFiler(
+	t *testing.T,
+	client filer_pb.SeaweedFilerClient,
+	s3Endpoint, bucketName, namespace, tableName string,
+	snapshots []table.Snapshot,
+) table.Metadata {
+	t.Helper()
+	ctx := context.Background()
+	meta := buildMetadata(t, snapshots)
+	fullJSON, err := json.Marshal(meta)
+	require.NoError(t, err)
+
+	tablePath := path.Join(namespace, tableName)
+	bucketsPath := s3tables.TablesPath
+	tableFilerPath := path.Join(bucketsPath, bucketName, tablePath)
+	metaDir := path.Join(tableFilerPath, "metadata")
+	dataDir := path.Join(tableFilerPath, "data")
+
+	// Build the table metadata xattr
+	internalMeta := map[string]interface{}{
+		"metadataVersion":  1,
+		"metadataLocation": "metadata/v1.metadata.json",
+		"metadata": map[string]interface{}{
+			"fullMetadata": json.RawMessage(fullJSON),
+		},
+	}
+	xattr, err := json.Marshal(internalMeta)
+	require.NoError(t, err)
+
+	// Create the S3 bucket via PUT, then create the directory tree via S3 PUT
+	// object with zero-byte content (the filer creates intermediate dirs).
+	s3put(t, s3Endpoint, bucketName, "", nil)                              // create bucket
+	s3put(t, s3Endpoint, bucketName, namespace+"/.dir", []byte{})          // create ns dir
+	s3put(t, s3Endpoint, bucketName, tablePath+"/.dir", []byte{})          // create table dir
+	s3put(t, s3Endpoint, bucketName, tablePath+"/metadata/.dir", []byte{}) // create metadata dir
+	s3put(t, s3Endpoint, bucketName, tablePath+"/data/.dir", []byte{})     // create data dir
+
+	// Now set the table bucket and table xattrs via filer gRPC.
+	// Mark bucket as table bucket.
+	bucketEntry := lookupEntry(t, client, bucketsPath, bucketName)
+	require.NotNil(t, bucketEntry, "bucket should exist after S3 PUT")
+	if bucketEntry.Extended == nil {
+		bucketEntry.Extended = make(map[string][]byte)
+	}
+	bucketEntry.Extended[s3tables.ExtendedKeyTableBucket] = []byte("true")
+	_, err = client.UpdateEntry(ctx, &filer_pb.UpdateEntryRequest{
+		Directory: bucketsPath, Entry: bucketEntry,
+	})
+	require.NoError(t, err)
+
+	// Set table metadata xattr.
+	nsDir := path.Join(bucketsPath, bucketName, namespace)
+	tableEntry := lookupEntry(t, client, nsDir, tableName)
+	require.NotNil(t, tableEntry, "table dir should exist after S3 PUT")
+	if tableEntry.Extended == nil {
+		tableEntry.Extended = make(map[string][]byte)
+	}
+	tableEntry.Extended[s3tables.ExtendedKeyMetadata] = xattr
+	_, err = client.UpdateEntry(ctx, &filer_pb.UpdateEntryRequest{
+		Directory: nsDir, Entry: tableEntry,
+	})
+	require.NoError(t, err)
+
+	// Write manifest + manifest list + data file for each snapshot
+	schema := meta.CurrentSchema()
+	spec := meta.PartitionSpec()
+	version := meta.Version()
+
+	for _, snap := range snapshots {
+		if snap.ManifestList == "" {
+			continue
+		}
+		snapID := snap.SnapshotID
+		dataFileName := fmt.Sprintf("snap-%d-data.parquet", snapID)
+		dfBuilder, err := iceberg.NewDataFileBuilder(
+			spec, iceberg.EntryContentData,
+			path.Join("data", dataFileName), iceberg.ParquetFile,
+			map[int]any{}, nil, nil, 10, 4096,
+		)
+		require.NoError(t, err)
+
+		entry := iceberg.NewManifestEntry(
+			iceberg.EntryStatusADDED, &snapID, nil, nil, dfBuilder.Build(),
+		)
+
+		// Manifest
+		manifestName := fmt.Sprintf("manifest-%d.avro", snapID)
+		var manifestBuf bytes.Buffer
+		mf, err := iceberg.WriteManifest(
+			path.Join("metadata", manifestName), &manifestBuf,
+			version, spec, schema, snapID, []iceberg.ManifestEntry{entry},
+		)
+		require.NoError(t, err)
+		writeFile(t, ctx, client, metaDir, manifestName, manifestBuf.Bytes())
+
+		// Manifest list
+		mlName := path.Base(snap.ManifestList)
+		var mlBuf bytes.Buffer
+		parent := snap.ParentSnapshotID
+		seqNum := snap.SequenceNumber
+		require.NoError(t, iceberg.WriteManifestList(
+			version, &mlBuf, snapID, parent, &seqNum, 0,
+			[]iceberg.ManifestFile{mf},
+		))
+		writeFile(t, ctx, client, metaDir, mlName, mlBuf.Bytes())
+
+		// Data file (dummy content)
+		writeFile(t, ctx, client, dataDir, dataFileName, []byte("fake-parquet"))
+	}
+
+	// Wait for snapshot timestamps (set slightly in the future by
+	// buildMetadata) to move into the past so expiration checks work.
+	time.Sleep(200 * time.Millisecond)
+
+	return meta
+}
+
+func writeFile(t *testing.T, ctx context.Context, client filer_pb.SeaweedFilerClient, dir, name string, content []byte) {
+	t.Helper()
+	resp, err := client.CreateEntry(ctx, &filer_pb.CreateEntryRequest{
+		Directory: dir,
+		Entry: &filer_pb.Entry{
+			Name: name,
+			Attributes: &filer_pb.FuseAttributes{
+				Mtime: time.Now().Unix(), Crtime: time.Now().Unix(),
+				FileMode: uint32(0644), FileSize: uint64(len(content)),
+			},
+			Content: content,
+		},
+	})
+	require.NoError(t, err, "writeFile(%s, %s): rpc error", dir, name)
+	require.Empty(t, resp.Error, "writeFile(%s, %s): resp error", dir, name)
+}
+
+func lookupEntry(t *testing.T, client filer_pb.SeaweedFilerClient, dir, name string) *filer_pb.Entry {
+	t.Helper()
+	resp, err := filer_pb.LookupEntry(context.Background(), client, &filer_pb.LookupDirectoryEntryRequest{
+		Directory: dir, Name: name,
+	})
+	if err != nil {
+		if errors.Is(err, filer_pb.ErrNotFound) {
+			return nil
+		}
+		require.NoError(t, err, "lookupEntry(%s, %s): unexpected error", dir, name)
+	}
+	return resp.Entry
+}
+
+// ---------------------------------------------------------------------------
+// Integration tests
+// ---------------------------------------------------------------------------
+
+func TestIcebergMaintenanceIntegration(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test in short mode")
+	}
+
+	t.Run("ExpireSnapshots", testExpireSnapshots)
+	t.Run("RemoveOrphans", testRemoveOrphans)
+	t.Run("RewriteManifests", testRewriteManifests)
+	t.Run("FullMaintenanceCycle", testFullMaintenanceCycle)
+}
+
+func testExpireSnapshots(t *testing.T) {
+	_, client := shared.filerConn(t)
+	suffix := randomSuffix()
+	bucket := "maint-expire-" + suffix
+	ns := "ns"
+	tbl := "tbl"
+
+	now := time.Now().UnixMilli()
+	snapshots := []table.Snapshot{
+		{SnapshotID: 1, TimestampMs: now, ManifestList: "metadata/snap-1.avro"},
+		{SnapshotID: 2, TimestampMs: now + 1, ManifestList: "metadata/snap-2.avro"},
+		{SnapshotID: 3, TimestampMs: now + 2, ManifestList: "metadata/snap-3.avro"},
+	}
+	populateTableViaFiler(t, client, shared.s3Endpoint, bucket, ns, tbl, snapshots)
+
+	handler := icebergHandler.NewHandler(nil)
+	config := icebergHandler.Config{
+		SnapshotRetentionHours: 0, // instant expiry — everything eligible
+		MaxSnapshotsToKeep:     1, // keep only the current snapshot
+		MaxCommitRetries:       3,
+	}
+
+	result, err := handler.ExpireSnapshots(context.Background(), client, bucket, path.Join(ns, tbl), config)
+	require.NoError(t, err)
+	assert.Contains(t, result, "expired")
+	t.Logf("ExpireSnapshots result: %s", result)
+
+	// Verify metadata was updated
+	entry := lookupEntry(t, client, path.Join(s3tables.TablesPath, bucket, ns), tbl)
+	require.NotNil(t, entry)
+	xattr := entry.Extended[s3tables.ExtendedKeyMetadata]
+	require.NotEmpty(t, xattr)
+
+	// Parse updated metadata to verify snapshot count
+	var internalMeta struct {
+		MetadataVersion int `json:"metadataVersion"`
+	}
+	require.NoError(t, json.Unmarshal(xattr, &internalMeta))
+	assert.Greater(t, internalMeta.MetadataVersion, 1, "metadata version should have been incremented")
+}
+
+func testRemoveOrphans(t *testing.T) {
+	_, client := shared.filerConn(t)
+	suffix := randomSuffix()
+	bucket := "maint-orphan-" + suffix
+	ns := "ns"
+	tbl := "tbl"
+
+	now := time.Now().UnixMilli()
+	snapshots := []table.Snapshot{
+		{SnapshotID: 1, TimestampMs: now, ManifestList: "metadata/snap-1.avro"},
+	}
+	populateTableViaFiler(t, client, shared.s3Endpoint, bucket, ns, tbl, snapshots)
+
+	ctx := context.Background()
+	tablePath := path.Join(ns, tbl)
+	tableFilerPath := path.Join(s3tables.TablesPath, bucket, tablePath)
+	dataDir := path.Join(tableFilerPath, "data")
+	metaDir := path.Join(tableFilerPath, "metadata")
+
+	// Create orphan files (old enough to be removed)
+	oldTime := time.Now().Add(-200 * time.Hour).Unix()
+	writeOrphan := func(dir, name string) {
+		resp, err := client.CreateEntry(ctx, &filer_pb.CreateEntryRequest{
+			Directory: dir,
+			Entry: &filer_pb.Entry{
+				Name: name,
+				Attributes: &filer_pb.FuseAttributes{
+					Mtime: oldTime, Crtime: oldTime,
+					FileMode: uint32(0644), FileSize: 100,
+				},
+				Content: []byte("orphan"),
+			},
+		})
+		require.NoError(t, err, "writeOrphan(%s, %s): rpc error", dir, name)
+		require.Empty(t, resp.Error, "writeOrphan(%s, %s): resp error", dir, name)
+	}
+	writeOrphan(dataDir, "orphan-data.parquet")
+	writeOrphan(metaDir, "orphan-meta.avro")
+
+	// Create a recent orphan (should NOT be removed)
+	writeFile(t, ctx, client, dataDir, "recent-orphan.parquet", []byte("new"))
+
+	handler := icebergHandler.NewHandler(nil)
+	config := icebergHandler.Config{
+		OrphanOlderThanHours: 72,
+		MaxCommitRetries:     3,
+	}
+
+	result, err := handler.RemoveOrphans(ctx, client, bucket, tablePath, config)
+	require.NoError(t, err)
+	assert.Contains(t, result, "removed")
+	t.Logf("RemoveOrphans result: %s", result)
+
+	// Verify orphans were removed
+	assert.Nil(t, lookupEntry(t, client, dataDir, "orphan-data.parquet"), "old orphan data file should be deleted")
+	assert.Nil(t, lookupEntry(t, client, metaDir, "orphan-meta.avro"), "old orphan meta file should be deleted")
+
+	// Verify recent orphan was kept
+	assert.NotNil(t, lookupEntry(t, client, dataDir, "recent-orphan.parquet"), "recent orphan should be kept")
+}
+
+func testRewriteManifests(t *testing.T) {
+	_, client := shared.filerConn(t)
+	suffix := randomSuffix()
+	bucket := "maint-rewrite-" + suffix
+	ns := "ns"
+	tbl := "tbl"
+
+	// Each snapshot gets its own manifest list with one manifest. The current
+	// snapshot (latest) therefore has only 1 manifest — below the rewrite
+	// threshold. This tests the threshold check against a real filer.
+	now := time.Now().UnixMilli()
+	snapshots := []table.Snapshot{
+		{SnapshotID: 1, TimestampMs: now, ManifestList: "metadata/snap-1.avro"},
+	}
+	populateTableViaFiler(t, client, shared.s3Endpoint, bucket, ns, tbl, snapshots)
+
+	handler := icebergHandler.NewHandler(nil)
+	config := icebergHandler.Config{
+		MinManifestsToRewrite: 5, // threshold higher than 1 manifest
+		MaxCommitRetries:      3,
+	}
+
+	tablePath := path.Join(ns, tbl)
+	result, err := handler.RewriteManifests(context.Background(), client, bucket, tablePath, config)
+	require.NoError(t, err)
+	assert.Contains(t, result, "below threshold")
+	t.Logf("RewriteManifests result: %s", result)
+}
+
+func testFullMaintenanceCycle(t *testing.T) {
+	_, client := shared.filerConn(t)
+	suffix := randomSuffix()
+	bucket := "maint-full-" + suffix
+	ns := "ns"
+	tbl := "tbl"
+
+	now := time.Now().UnixMilli()
+	snapshots := []table.Snapshot{
+		{SnapshotID: 1, TimestampMs: now, ManifestList: "metadata/snap-1.avro"},
+		{SnapshotID: 2, TimestampMs: now + 1, ManifestList: "metadata/snap-2.avro"},
+		{SnapshotID: 3, TimestampMs: now + 2, ManifestList: "metadata/snap-3.avro"},
+	}
+	populateTableViaFiler(t, client, shared.s3Endpoint, bucket, ns, tbl, snapshots)
+
+	ctx := context.Background()
+	tablePath := path.Join(ns, tbl)
+
+	// Add an orphan
+	dataDir := path.Join(s3tables.TablesPath, bucket, tablePath, "data")
+	oldTime := time.Now().Add(-200 * time.Hour).Unix()
+	orphanResp, err := client.CreateEntry(ctx, &filer_pb.CreateEntryRequest{
+		Directory: dataDir,
+		Entry: &filer_pb.Entry{
+			Name: "orphan.parquet",
+			Attributes: &filer_pb.FuseAttributes{
+				Mtime: oldTime, Crtime: oldTime,
+				FileMode: uint32(0644), FileSize: 100,
+			},
+			Content: []byte("orphan"),
+		},
+	})
+	require.NoError(t, err)
+	require.Empty(t, orphanResp.Error)
+
+	handler := icebergHandler.NewHandler(nil)
+
+	// Step 1: Expire snapshots
+	expireConfig := icebergHandler.Config{
+		SnapshotRetentionHours: 0, // instant expiry
+		MaxSnapshotsToKeep:     1,
+		MaxCommitRetries:       3,
+	}
+	result, err := handler.ExpireSnapshots(ctx, client, bucket, tablePath, expireConfig)
+	require.NoError(t, err)
+	assert.Contains(t, result, "expired")
+	t.Logf("Step 1 (expire): %s", result)
+
+	// Step 2: Remove orphans
+	orphanConfig := icebergHandler.Config{
+		OrphanOlderThanHours: 72,
+		MaxCommitRetries:     3,
+	}
+	result, err = handler.RemoveOrphans(ctx, client, bucket, tablePath, orphanConfig)
+	require.NoError(t, err)
+	t.Logf("Step 2 (orphans): %s", result)
+	// The orphan and the unreferenced files from expired snapshots should be gone
+	assert.Contains(t, result, "removed")
+
+	// Step 3: Verify metadata is consistent
+	entry := lookupEntry(t, client, path.Join(s3tables.TablesPath, bucket, ns), tbl)
+	require.NotNil(t, entry)
+	xattr := entry.Extended[s3tables.ExtendedKeyMetadata]
+	require.NotEmpty(t, xattr)
+
+	var internalMeta struct {
+		MetadataVersion int `json:"metadataVersion"`
+	}
+	require.NoError(t, json.Unmarshal(xattr, &internalMeta))
+	assert.Greater(t, internalMeta.MetadataVersion, 1, "metadata version should have advanced through the cycle")
+	t.Logf("Final metadata version: %d", internalMeta.MetadataVersion)
+}
--- a/weed/admin/plugin/plugin.go
+++ b/weed/admin/plugin/plugin.go
@@ -392,7 +392,6 @@ func (r *Plugin) SaveJobTypeConfig(config *plugin_pb.PersistedJobTypeConfig) err
 	return nil
 }

-
 func (r *Plugin) LoadDescriptor(jobType string) (*plugin_pb.JobTypeDescriptor, error) {
 	return r.store.LoadDescriptor(jobType)
 }
--- a/weed/iamapi/iamapi_group_handlers.go
+++ b/weed/iamapi/iamapi_group_handlers.go
@@ -326,4 +326,3 @@ func buildUserGroupsIndex(s3cfg *iam_pb.S3ApiConfiguration) map[string][]string
 	}
 	return index
 }
-
--- a/weed/plugin/worker/erasure_coding_handler.go
+++ b/weed/plugin/worker/erasure_coding_handler.go
@@ -11,8 +11,8 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb/plugin_pb"
 	"github.com/seaweedfs/seaweedfs/weed/pb/worker_pb"
-	"github.com/seaweedfs/seaweedfs/weed/util"
 	ecstorage "github.com/seaweedfs/seaweedfs/weed/storage/erasure_coding"
+	"github.com/seaweedfs/seaweedfs/weed/util"
 	"github.com/seaweedfs/seaweedfs/weed/util/wildcard"
 	erasurecodingtask "github.com/seaweedfs/seaweedfs/weed/worker/tasks/erasure_coding"
 	workertypes "github.com/seaweedfs/seaweedfs/weed/worker/types"
--- a/weed/plugin/worker/iceberg/compact.go
+++ b/weed/plugin/worker/iceberg/compact.go
@@ -364,14 +364,23 @@ func buildCompactionBins(entries []iceberg.ManifestEntry, targetSize int64, minF

 // splitOversizedBin splits a bin whose total size exceeds targetSize into
 // sub-bins that each stay under targetSize while meeting minFiles.
+// Entries are sorted by size descending before splitting so that large
+// files are placed first, improving bin packing efficiency.
 func splitOversizedBin(bin compactionBin, targetSize int64, minFiles int) []compactionBin {
+	// Sort largest-first for better packing.
+	sorted := make([]iceberg.ManifestEntry, len(bin.Entries))
+	copy(sorted, bin.Entries)
+	sort.Slice(sorted, func(i, j int) bool {
+		return sorted[i].DataFile().FileSizeBytes() > sorted[j].DataFile().FileSizeBytes()
+	})
+
 	var bins []compactionBin
 	current := compactionBin{
 		PartitionKey: bin.PartitionKey,
 		Partition:    bin.Partition,
 	}
-	for _, entry := range bin.Entries {
-		if current.TotalSize > 0 && current.TotalSize+entry.DataFile().FileSizeBytes() > targetSize && len(current.Entries) >= minFiles {
+	for _, entry := range sorted {
+		if current.TotalSize > 0 && current.TotalSize+entry.DataFile().FileSizeBytes() > targetSize {
 			bins = append(bins, current)
 			current = compactionBin{
 				PartitionKey: bin.PartitionKey,
@@ -381,9 +390,44 @@ func splitOversizedBin(bin compactionBin, targetSize int64, minFiles int) []comp
 		current.Entries = append(current.Entries, entry)
 		current.TotalSize += entry.DataFile().FileSizeBytes()
 	}
-	if len(current.Entries) >= minFiles {
+	if len(current.Entries) > 0 {
 		bins = append(bins, current)
 	}
+
+	// Merge any bin with fewer than minFiles entries into its neighbor.
+	// Repeat until no more merges are needed. This handles runts at the
+	// end (from the split) and small leading bins (from largest-first
+	// sorting placing single large files into their own bins).
+	for changed := true; changed && len(bins) > 1; {
+		changed = false
+		for i := 0; i < len(bins); i++ {
+			if len(bins[i].Entries) >= minFiles {
+				continue
+			}
+			// Pick the better neighbor to merge into.
+			var target int
+			if i == 0 {
+				target = 1
+			} else if i == len(bins)-1 {
+				target = i - 1
+			} else if bins[i-1].TotalSize <= bins[i+1].TotalSize {
+				target = i - 1
+			} else {
+				target = i + 1
+			}
+			bins[target].Entries = append(bins[target].Entries, bins[i].Entries...)
+			bins[target].TotalSize += bins[i].TotalSize
+			bins = append(bins[:i], bins[i+1:]...)
+			changed = true
+			break // restart scan after structural change
+		}
+	}
+
+	// Final guard: if a single remaining bin has fewer than minFiles
+	// (entire input too small), return nothing.
+	if len(bins) == 1 && len(bins[0].Entries) < minFiles {
+		return nil
+	}
 	return bins
 }

@@ -413,10 +457,11 @@ func partitionKey(partition map[int]any) string {
 }

 // mergeParquetFiles reads multiple small Parquet files and merges them into
-// a single Parquet file. It reads rows from each source and writes them to
-// the output using the schema from the first file.
-//
-// Files are loaded into memory (appropriate for compacting small files).
+// a single Parquet file. Files are processed one at a time: each source file
+// is loaded, its rows are streamed into the output writer, and then its data
+// is released before the next file is loaded. This keeps peak memory
+// proportional to the size of a single input file plus the output buffer,
+// rather than the sum of all inputs.
 func mergeParquetFiles(
 	ctx context.Context,
 	filerClient filer_pb.SeaweedFilerClient,
@@ -427,72 +472,84 @@ func mergeParquetFiles(
 		return nil, 0, fmt.Errorf("no entries to merge")
 	}

-	// Read all source files and create parquet readers
-	type sourceFile struct {
-		reader *parquet.Reader
-		data   []byte
+	// Load the first file to obtain the schema for the writer.
+	firstData, err := loadFileByIcebergPath(ctx, filerClient, bucketName, tablePath, entries[0].DataFile().FilePath())
+	if err != nil {
+		return nil, 0, fmt.Errorf("read parquet file %s: %w", entries[0].DataFile().FilePath(), err)
 	}
-	var sources []sourceFile
-	defer func() {
-		for _, src := range sources {
-			if src.reader != nil {
-				src.reader.Close()
+	firstReader := parquet.NewReader(bytes.NewReader(firstData))
+	parquetSchema := firstReader.Schema()
+	if parquetSchema == nil {
+		firstReader.Close()
+		return nil, 0, fmt.Errorf("no parquet schema found in %s", entries[0].DataFile().FilePath())
 	}
-		}
-	}()

-	var parquetSchema *parquet.Schema
-	for _, entry := range entries {
+	var outputBuf bytes.Buffer
+	writer := parquet.NewWriter(&outputBuf, parquetSchema)
+
+	// drainReader streams all rows from reader into writer, then closes reader.
+	// source identifies the input file for error messages.
+	var totalRows int64
+	rows := make([]parquet.Row, 256)
+	drainReader := func(reader *parquet.Reader, source string) error {
+		defer reader.Close()
+		for {
 			select {
 			case <-ctx.Done():
+				return ctx.Err()
+			default:
+			}
+			n, readErr := reader.ReadRows(rows)
+			if n > 0 {
+				if _, writeErr := writer.WriteRows(rows[:n]); writeErr != nil {
+					return fmt.Errorf("write rows from %s: %w", source, writeErr)
+				}
+				totalRows += int64(n)
+			}
+			if readErr != nil {
+				if readErr == io.EOF {
+					return nil
+				}
+				return fmt.Errorf("read rows from %s: %w", source, readErr)
+			}
+		}
+	}
+
+	// Drain the first file.
+	firstSource := entries[0].DataFile().FilePath()
+	if err := drainReader(firstReader, firstSource); err != nil {
+		writer.Close()
+		return nil, 0, err
+	}
+	firstData = nil // allow GC
+
+	// Process remaining files one at a time.
+	for _, entry := range entries[1:] {
+		select {
+		case <-ctx.Done():
+			writer.Close()
 			return nil, 0, ctx.Err()
 		default:
 		}

 		data, err := loadFileByIcebergPath(ctx, filerClient, bucketName, tablePath, entry.DataFile().FilePath())
 		if err != nil {
+			writer.Close()
 			return nil, 0, fmt.Errorf("read parquet file %s: %w", entry.DataFile().FilePath(), err)
 		}

 		reader := parquet.NewReader(bytes.NewReader(data))
-		readerSchema := reader.Schema()
-		if parquetSchema == nil {
-			parquetSchema = readerSchema
-		} else if !schemasEqual(parquetSchema, readerSchema) {
+		if !schemasEqual(parquetSchema, reader.Schema()) {
+			reader.Close()
+			writer.Close()
 			return nil, 0, fmt.Errorf("schema mismatch in %s: cannot merge files with different schemas", entry.DataFile().FilePath())
 		}
-		sources = append(sources, sourceFile{reader: reader, data: data})
-	}

-	if parquetSchema == nil {
-		return nil, 0, fmt.Errorf("no parquet schema found")
-	}
-
-	// Write merged output
-	var outputBuf bytes.Buffer
-	writer := parquet.NewWriter(&outputBuf, parquetSchema)
-
-	var totalRows int64
-	rows := make([]parquet.Row, 256)
-
-	for _, src := range sources {
-		for {
-			n, err := src.reader.ReadRows(rows)
-			if n > 0 {
-				if _, writeErr := writer.WriteRows(rows[:n]); writeErr != nil {
+		if err := drainReader(reader, entry.DataFile().FilePath()); err != nil {
 			writer.Close()
-					return nil, 0, fmt.Errorf("write rows: %w", writeErr)
-				}
-				totalRows += int64(n)
-			}
-			if err != nil {
-				if err == io.EOF {
-					break
-				}
-				writer.Close()
-				return nil, 0, fmt.Errorf("read rows: %w", err)
-			}
+			return nil, 0, err
 		}
+		// data goes out of scope here, eligible for GC before next iteration.
 	}

 	if err := writer.Close(); err != nil {
--- a/weed/plugin/worker/iceberg/config.go
+++ b/weed/plugin/worker/iceberg/config.go
@@ -18,6 +18,7 @@ const (
 	defaultMaxCommitRetries       = 5
 	defaultTargetFileSizeBytes    = 256 * 1024 * 1024
 	defaultMinInputFiles          = 5
+	defaultMinManifestsToRewrite  = 5
 	defaultOperations             = "all"
 )

@@ -29,6 +30,7 @@ type Config struct {
 	MaxCommitRetries       int64
 	TargetFileSizeBytes    int64
 	MinInputFiles          int64
+	MinManifestsToRewrite  int64
 	Operations             string
 }

@@ -42,6 +44,7 @@ func ParseConfig(values map[string]*plugin_pb.ConfigValue) Config {
 		MaxCommitRetries:       readInt64Config(values, "max_commit_retries", defaultMaxCommitRetries),
 		TargetFileSizeBytes:    readInt64Config(values, "target_file_size_bytes", defaultTargetFileSizeBytes),
 		MinInputFiles:          readInt64Config(values, "min_input_files", defaultMinInputFiles),
+		MinManifestsToRewrite:  readInt64Config(values, "min_manifests_to_rewrite", defaultMinManifestsToRewrite),
 		Operations:             readStringConfig(values, "operations", defaultOperations),
 	}

@@ -64,6 +67,9 @@ func ParseConfig(values map[string]*plugin_pb.ConfigValue) Config {
 	if cfg.MinInputFiles < 2 {
 		cfg.MinInputFiles = defaultMinInputFiles
 	}
+	if cfg.MinManifestsToRewrite < 2 {
+		cfg.MinManifestsToRewrite = 2
+	}

 	return cfg
 }
--- a/weed/plugin/worker/iceberg/exec_test.go
+++ b/weed/plugin/worker/iceberg/exec_test.go
@@ -649,7 +649,8 @@ func TestRewriteManifestsBelowThreshold(t *testing.T) {

 	handler := NewHandler(nil)
 	config := Config{
-		MinInputFiles:    10, // threshold higher than actual count (1)
+		MinInputFiles:         10,
+		MinManifestsToRewrite: 10, // threshold higher than actual manifest count (1)
 		MaxCommitRetries:      3,
 	}

--- a/weed/plugin/worker/iceberg/handler.go
+++ b/weed/plugin/worker/iceberg/handler.go
@@ -165,6 +165,21 @@ func (h *Handler) Descriptor() *plugin_pb.JobTypeDescriptor {
 						},
 					},
 				},
+				{
+					SectionId:   "manifests",
+					Title:       "Manifest Rewriting",
+					Description: "Controls for merging small manifests.",
+					Fields: []*plugin_pb.ConfigField{
+						{
+							Name:        "min_manifests_to_rewrite",
+							Label:       "Min Manifests",
+							Description: "Minimum number of manifests before rewriting is triggered.",
+							FieldType:   plugin_pb.ConfigFieldType_CONFIG_FIELD_TYPE_INT64,
+							Widget:      plugin_pb.ConfigWidget_CONFIG_WIDGET_NUMBER,
+							MinValue:    &plugin_pb.ConfigValue{Kind: &plugin_pb.ConfigValue_Int64Value{Int64Value: 2}},
+						},
+					},
+				},
 				{
 					SectionId:   "general",
 					Title:       "General",
@@ -192,6 +207,7 @@ func (h *Handler) Descriptor() *plugin_pb.JobTypeDescriptor {
 			DefaultValues: map[string]*plugin_pb.ConfigValue{
 				"target_file_size_bytes":   {Kind: &plugin_pb.ConfigValue_Int64Value{Int64Value: defaultTargetFileSizeBytes}},
 				"min_input_files":          {Kind: &plugin_pb.ConfigValue_Int64Value{Int64Value: defaultMinInputFiles}},
+				"min_manifests_to_rewrite": {Kind: &plugin_pb.ConfigValue_Int64Value{Int64Value: defaultMinManifestsToRewrite}},
 				"snapshot_retention_hours": {Kind: &plugin_pb.ConfigValue_Int64Value{Int64Value: defaultSnapshotRetentionHours}},
 				"max_snapshots_to_keep":    {Kind: &plugin_pb.ConfigValue_Int64Value{Int64Value: defaultMaxSnapshotsToKeep}},
 				"orphan_older_than_hours":  {Kind: &plugin_pb.ConfigValue_Int64Value{Int64Value: defaultOrphanOlderThanHours}},
@@ -255,11 +271,10 @@ func (h *Handler) Detect(ctx context.Context, request *plugin_pb.RunDetectionReq
 	namespaceFilter := strings.TrimSpace(readStringConfig(request.GetAdminConfigValues(), "namespace_filter", ""))
 	tableFilter := strings.TrimSpace(readStringConfig(request.GetAdminConfigValues(), "table_filter", ""))

-	// Connect to filer to scan table buckets
-	filerAddress := filerAddresses[0]
-	conn, err := grpc.NewClient(filerAddress, h.grpcDialOption)
+	// Connect to filer — try each address until one succeeds.
+	filerAddress, conn, err := h.connectToFiler(filerAddresses)
 	if err != nil {
-		return fmt.Errorf("connect to filer %s: %w", filerAddress, err)
+		return fmt.Errorf("connect to filer: %w", err)
 	}
 	defer conn.Close()
 	filerClient := filer_pb.NewSeaweedFilerClient(conn)
@@ -329,6 +344,12 @@ func (h *Handler) Execute(ctx context.Context, request *plugin_pb.ExecuteJobRequ
 	if bucketName == "" || namespace == "" || tableName == "" || filerAddress == "" {
 		return fmt.Errorf("missing required parameters: bucket_name=%q, namespace=%q, table_name=%q, filer_address=%q", bucketName, namespace, tableName, filerAddress)
 	}
+	// Reject path traversal in bucket/namespace/table names.
+	for _, name := range []string{bucketName, namespace, tableName} {
+		if strings.Contains(name, "..") || strings.ContainsAny(name, "/\\") {
+			return fmt.Errorf("invalid name %q: must not contain path separators or '..'", name)
+		}
+	}
 	if tablePath == "" {
 		tablePath = path.Join(namespace, tableName)
 	}
@@ -467,5 +488,24 @@ func (h *Handler) sendEmptyDetection(sender pluginworker.DetectionSender) error
 	})
 }

+// connectToFiler tries each filer address in order and returns the first
+// successful gRPC connection. If all addresses fail, it returns a
+// consolidated error.
+func (h *Handler) connectToFiler(addresses []string) (string, *grpc.ClientConn, error) {
+	var lastErr error
+	for _, addr := range addresses {
+		conn, err := grpc.NewClient(addr, h.grpcDialOption)
+		if err != nil {
+			lastErr = fmt.Errorf("filer %s: %w", addr, err)
+			continue
+		}
+		return addr, conn, nil
+	}
+	if lastErr == nil {
+		lastErr = fmt.Errorf("no filer addresses provided")
+	}
+	return "", nil, lastErr
+}
+
 // Ensure Handler implements JobHandler.
 var _ pluginworker.JobHandler = (*Handler)(nil)
--- a/weed/plugin/worker/iceberg/operations.go
+++ b/weed/plugin/worker/iceberg/operations.go
@@ -322,8 +322,8 @@ func (h *Handler) rewriteManifests(
 		return "", fmt.Errorf("parse manifest list: %w", err)
 	}

-	if int64(len(manifests)) < config.MinInputFiles {
-		return fmt.Sprintf("only %d manifests, below threshold of %d", len(manifests), config.MinInputFiles), nil
+	if int64(len(manifests)) < config.MinManifestsToRewrite {
+		return fmt.Sprintf("only %d manifests, below threshold of %d", len(manifests), config.MinManifestsToRewrite), nil
 	}

 	// Collect all entries from data manifests, grouped by partition spec ID
--- a/weed/plugin/worker/iceberg/testing_api.go
+++ b/weed/plugin/worker/iceberg/testing_api.go
@@ -0,0 +1,26 @@
+package iceberg
+
+import (
+	"context"
+
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+)
+
+// The following methods export the internal maintenance operations for use
+// by integration tests. They are intentionally thin wrappers.
+
+func (h *Handler) ExpireSnapshots(ctx context.Context, client filer_pb.SeaweedFilerClient, bucketName, tablePath string, config Config) (string, error) {
+	return h.expireSnapshots(ctx, client, bucketName, tablePath, config)
+}
+
+func (h *Handler) RemoveOrphans(ctx context.Context, client filer_pb.SeaweedFilerClient, bucketName, tablePath string, config Config) (string, error) {
+	return h.removeOrphans(ctx, client, bucketName, tablePath, config)
+}
+
+func (h *Handler) RewriteManifests(ctx context.Context, client filer_pb.SeaweedFilerClient, bucketName, tablePath string, config Config) (string, error) {
+	return h.rewriteManifests(ctx, client, bucketName, tablePath, config)
+}
+
+func (h *Handler) CompactDataFiles(ctx context.Context, client filer_pb.SeaweedFilerClient, bucketName, tablePath string, config Config) (string, error) {
+	return h.compactDataFiles(ctx, client, bucketName, tablePath, config)
+}
--- a/weed/plugin/worker/volume_balance_handler.go
+++ b/weed/plugin/worker/volume_balance_handler.go
@@ -14,8 +14,8 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb/plugin_pb"
 	"github.com/seaweedfs/seaweedfs/weed/pb/worker_pb"
-	balancetask "github.com/seaweedfs/seaweedfs/weed/worker/tasks/balance"
 	"github.com/seaweedfs/seaweedfs/weed/util/wildcard"
+	balancetask "github.com/seaweedfs/seaweedfs/weed/worker/tasks/balance"
 	workertypes "github.com/seaweedfs/seaweedfs/weed/worker/types"
 	"google.golang.org/grpc"
 	"google.golang.org/protobuf/proto"
--- a/weed/worker/tasks/balance/replica_placement.go
+++ b/weed/worker/tasks/balance/replica_placement.go
@@ -143,4 +143,3 @@ func findTopRackKeys(m map[rackKey]int) (topKeys []rackKey, max int) {
 	}
 	return
 }
-