fix: env

.gitignore

@@ -1 +1,3 @@
 .env
+bin/
+examples/

README.md

@@ -7,7 +7,7 @@ A robust MySQL/MariaDB binlog streaming replication service with automatic initi
 ### Quick Install (Go)
 
 ```bash
-go install git.ma-al.com/goc_marek/replica/cmd/replica@latest
+go install git.ma-al.com/goc_marek/replica@latest
 ```
 
 ### Build from Source
@@ -18,18 +18,15 @@ git clone https://git.ma-al.com/goc_marek/replica.git
 cd replica
 
 # Build the service
-go build -o replica ./cmd/replica
+go build -o bin/replica ./main.go
 
-# Or install globally
+# Run the service
-go install ./cmd/replica
+./bin/replica
 ```
 
-### Docker
+### Docker Compose
 
 ```bash
-# Build the image
-docker build -t replica .
-
 # Run with docker-compose
 docker-compose up -d
 ```
@@ -76,14 +73,14 @@ nano .env
 
 | File | Purpose |
 |------|---------|
-| [`cmd/replica/main.go`](cmd/replica/main.go) | Application entry point and configuration |
+| [`main.go`](main.go) | Application entry point and configuration |
-| [`pkg/replica/service.go`](pkg/replica/service.go) | BinlogSyncService - core replication orchestration |
+| [`replica/service.go`](replica/service.go) | BinlogSyncService - core replication orchestration |
-| [`pkg/replica/handlers.go`](pkg/replica/handlers.go) | EventHandlers - binlog event processing with resilience |
+| [`replica/handlers.go`](replica/handlers.go) | EventHandlers - binlog event processing with resilience |
-| [`pkg/replica/initial_transfer.go`](pkg/replica/initial_transfer.go) | InitialTransfer - bulk data transfer management |
+| [`replica/initial_transfer.go`](replica/initial_transfer.go) | InitialTransfer - bulk data transfer management |
-| [`pkg/replica/position.go`](pkg/replica/position.go) | PositionManager - binlog position persistence |
+| [`replica/position.go`](replica/position.go) | PositionManager - binlog position persistence |
-| [`pkg/replica/sqlbuilder.go`](pkg/replica/sqlbuilder.go) | SQLBuilder - SQL statement generation |
+| [`replica/sqlbuilder.go`](replica/sqlbuilder.go) | SQLBuilder - SQL statement generation |
-| [`pkg/replica/config.go`](pkg/replica/config.go) | Configuration types |
+| [`replica/config.go`](replica/config.go) | Configuration types |
-| [`pkg/replica/logging.go`](pkg/replica/logging.go) | Structured logging with Graylog support |
+| [`replica/logging.go`](replica/logging.go) | Structured logging with Graylog support |
 
 ### Data Flow
 
@@ -116,10 +113,10 @@ BinlogSyncService.processEvent()
 
 ```bash
 # Build the service
-go build -o replica
+go build -o bin/replica ./main.go
 
 # Run the service
-./replica
+./bin/replica
 ```
 
 ### Configuration
@@ -213,7 +210,8 @@ GRAYLOG_SOURCE=binlog-sync-prod
 
 | Variable | Description | Default |
 |----------|-------------|---------|
-| `TRANSFER_BATCH_SIZE` | Rows per transfer chunk | `1000` |
+| `TRANSFER_BATCH_SIZE` | Rows per transfer chunk | `10000` |
+| `TRANSFER_WORKER_COUNT` | Number of parallel transfer workers | `4` |
 | `LOCAL_PROJECT_NAME` | Project name for logging | `naluconcept` |
 
 ## Resilience Features
@@ -359,7 +357,7 @@ When resync is needed (empty replica or no saved position), the service performs
    - Get table schema (column definitions)
    - Check row count
    - Transfer in chunks using primary key or LIMIT/OFFSET
-5. **Progress Checkpointing**: Save progress to JSON file every 1000 rows
+5. **Progress Checkpointing**: Save progress to JSON file every 10000 rows
 6. **Position Reset**: Clear saved binlog position after successful transfer
 7. **Binlog Streaming**: Start streaming from current position
 
@@ -375,7 +373,7 @@ SELECT * FROM table WHERE pk >= 1000 AND pk < 2000 ORDER BY pk
 SELECT * FROM table LIMIT 1000 OFFSET 1000
 ```
 
-**Batch Size:** Configurable (default: 1000 rows per chunk)
+**Batch Size:** Configurable (default: 10000 rows per chunk)
 
 ### Progress Checkpointing
 
@@ -400,7 +398,7 @@ If the transfer is interrupted, it resumes from the last checkpoint.
 Transfers can be paused and resumed programmatically:
 
 ```go
-transfer := NewInitialTransfer(dsn, dsn, 1000, 1)
+transfer := NewInitialTransfer(dsn, dsn, 10000, 4)
 
 // Pause during transfer
 transfer.Pause()
@@ -445,8 +443,8 @@ type EventHandlers struct {
 type InitialTransfer struct {
     primaryDB      *sql.DB
     secondaryDB    *sql.DB
-    batchSize      int               // Default: 1000
+    batchSize      int               // Default: 10000
-    workerCount    int               // Default: 1
+    workerCount    int               // Default: 4
     excludedDBs    map[string]bool
     checkpointFile string
     progress       TransferProgress
@@ -575,15 +573,15 @@ SELECT COUNT(*) FROM your_table;
 
 ## Performance Considerations
 
-1. **Batch Size**: Start with 1000, adjust based on table size and memory
+1. **Batch Size**: Start with 10000, adjust based on table size and memory
 2. **Connection Pooling**: `SetMaxOpenConns(25)` for moderate load
-3. **Worker Count**: Currently single-threaded (multi-worker planned)
+3. **Worker Count**: Default: 4 workers for parallel processing
 4. **Schema Caching**: Table schemas cached in memory (auto-updated on drift)
 5. **Index Usage**: Chunked transfers require indexed primary key
 
 ## Limitations
 
-- **Single-threaded**: One worker processes events sequentially
+- **Multi-threaded**: Multiple workers process events in parallel (configurable via TRANSFER_WORKER_COUNT)
 - **Position-based**: No GTID support yet (position-based only)
 - **Integer PKs**: Chunking requires integer primary key for efficiency
 - **No Conflict Resolution**: Concurrent writes not handled
@@ -618,11 +616,8 @@ SELECT COUNT(*) FROM your_table;
 
 ```
 replica/
-├── cmd/
+├── main.go                            # Entry point
-│   └── replica/
+├── replica/
-│       └── main.go                    # Entry point
-├── pkg/
-│   └── replica/
 │   ├── service.go                     # Replication orchestration
 │   ├── handlers.go                    # Event processing
 │   ├── initial_transfer.go            # Bulk data transfer
@@ -630,6 +625,11 @@ replica/
 │   ├── sqlbuilder.go                  # SQL generation
 │   ├── config.go                      # Configuration types
 │   └── logging.go                     # Structured logging
+├── examples/
+│   └── binlog-listener/
+│       └── main.go                    # Example binlog listener
+├── bin/
+│   └── replica                        # Compiled binary
 ├── example.env                        # Environment template
 ├── .env                               # Environment (gitignored)
 ├── docker-compose.yml                 # Local development

docker-compose.yml

@@ -12,6 +12,7 @@ services:
       - --log_bin=log_bin
       - --binlog_format=ROW
       - --server-id=${MARIA_SERVER_ID}
+      - --log_bin_trust_function_creators=1
     ports:
       - "${MARIA_PRIMARY_PORT}:3306"
     networks:
@@ -21,8 +22,8 @@ services:
     environment:
       MARIADB_USER: ${MARIA_USER}
       MARIADB_PASSWORD: ${MARIA_PASS}
-      MYSQL_DATABASE: ${MARIA_NAME}
+      MARIADB_DATABASE: ${MARIA_NAME}
-      MYSQL_ROOT_PASSWORD: ${MARIA_PASS}
+      MARIADB_ROOT_PASSWORD: ${MARIA_PASS}
     restart: always
 
   mariadb-secondary:
@@ -46,27 +47,12 @@ services:
     environment:
       MARIADB_USER: ${MARIA_USER}
       MARIADB_PASSWORD: ${MARIA_PASS}
-      MYSQL_DATABASE: ${MARIA_NAME}
+      MARIADB_DATABASE: ${MARIA_NAME}
-      MYSQL_ROOT_PASSWORD: ${MARIA_PASS}
+      MARIADB_ROOT_PASSWORD: ${MARIA_PASS}
     restart: always
     depends_on:
       - mariadb-primary
 
-  # postgresql:
-  #   container_name: ${POSTGRES_HOST}
-  #   restart: always
-  #   image: postgres:18
-  #   networks:
-  #     repl:
-  #   ports:
-  #     - 5432:5432
-  #   volumes:
-  #     - postgres-data:/var/lib/postgresql:Z
-  #   command: postgres -c shared_buffers=512MB -c work_mem=16MB  -c maintenance_work_mem=256MB -c effective_cache_size=4GB -c max_connections=20
-  #   environment:
-  #     POSTGRES_USER: ${POSTGRES_USER}
-  #     POSTGRES_PASSWORD: ${POSTGRES_PASS}
-  #     POSTGRES_DB: ${POSTGRES_NAME}       
 
 
 networks:

example.env

@@ -1,21 +1,22 @@
 # Primary MariaDB Configuration
-MARIA_USER=replica
+MARIA_USER=root
 MARIA_PASS=replica
+MARIA_NAME=replica
 MARIA_SERVER_ID=100
-MARIA_PRIMARY_HOST=mariadb-primary
+MARIA_PRIMARY_HOST=localhost
 MARIA_PRIMARY_PORT=3306
 MARIA_PRIMARY_NAME=mariadb-primary
 
 # Secondary MariaDB Configuration (comma-separated for multiple)
 # Format: host1:port1,host2:port2,host3:port3
 # Or just hostnames and use MARIA_SECONDARY_PORTS for ports
-MARIA_SECONDARY_HOSTS=mariadb-secondary-1,mariadb-secondary-2,mariadb-secondary-3
+MARIA_SECONDARY_HOSTS=localhost
-MARIA_SECONDARY_PORTS=3307,3308,3309
+MARIA_SECONDARY_PORTS=3307
-MARIA_SECONDARY_NAMES=secondary-1,secondary-2,secondary-3
+MARIA_SECONDARY_NAMES=mariadb-secondary
 
 # Optional: Override per-secondary credentials (must match number of secondaries or use defaults)
-# MARIA_SECONDARY_USERS=replica1,replica2,replica3
+MARIA_SECONDARY_USERS=root
-# MARIA_SECONDARY_PASSWORDS=pass1,pass2,pass3
+MARIA_SECONDARY_PASSWORDS=replica
 
 # Legacy single secondary (for backward compatibility)
 # MARIA_SECONDARY_HOST=mariadb-secondary

go.mod

@@ -11,6 +11,7 @@ require (
 	filippo.io/edwards25519 v1.1.0 // indirect
 	github.com/goccy/go-json v0.10.2 // indirect
 	github.com/google/uuid v1.3.0 // indirect
+	github.com/joho/godotenv v1.5.1 // indirect
 	github.com/klauspost/compress v1.17.8 // indirect
 	github.com/pingcap/errors v0.11.5-0.20250318082626-8f80e5cb09ec // indirect
 	github.com/pingcap/log v1.1.1-0.20241212030209-7e3ff8601a2a // indirect

go.sum

@@ -12,6 +12,8 @@ github.com/goccy/go-json v0.10.2 h1:CrxCmQqYDkv1z7lO7Wbh2HN93uovUHgrECaO5ZrCXAU=
 github.com/goccy/go-json v0.10.2/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
 github.com/klauspost/compress v1.17.8 h1:YcnTYrq7MikUT7k0Yb5eceMmALQPYBW/Xltxn0NAMnU=
 github.com/klauspost/compress v1.17.8/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=

main.go

@@ -7,7 +7,7 @@ import (
 	"strconv"
 	"syscall"
 
-	"git.ma-al.com/goc_marek/replica/pkg/replica"
+	"git.ma-al.com/goc_marek/replica/replica"
 	_ "github.com/go-sql-driver/mysql"
 )
 
@@ -88,7 +88,9 @@ func main() {
 
 	// Start all services
 	replica.Info("Starting binlog replication...")
-	multiService.StartAll()
+	if err := multiService.StartAll(cfg.BatchSize, cfg.WorkerCount, cfg.ExcludeSchemas); err != nil {
+		replica.Fatalf("Failed to start all services: %v", err)
+	}
 
 	// Wait for shutdown signal
 	sig := <-sigChan

replica/config.go

@@ -5,6 +5,8 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/joho/godotenv"
 )
 
 // BinlogConfig holds the configuration for connecting to MySQL/MariaDB binlog
@@ -47,6 +49,7 @@ type AppConfig struct {
 
 	// Transfer settings
 	BatchSize      int
+	WorkerCount    int
 	ExcludeSchemas []string
 
 	// Graylog configuration
@@ -55,8 +58,15 @@ type AppConfig struct {
 
 // LoadEnvConfig loads configuration from environment variables
 func LoadEnvConfig() (*AppConfig, error) {
+	// Load .env file
+	if err := godotenv.Load(); err != nil {
+		// It's not an error if the .env file doesn't exist
+		// We just use the system environment variables
+	}
+
 	cfg := &AppConfig{
-		BatchSize:      1000,
+		BatchSize:      10000, // Increase default batch size from 1000 to 10000 for better performance
+		WorkerCount:    4,     // Default to 4 workers for parallel processing
 		ExcludeSchemas: []string{"information_schema", "performance_schema", "mysql", "sys"},
 	}
 
@@ -135,6 +145,11 @@ func LoadEnvConfig() (*AppConfig, error) {
 		cfg.BatchSize = batchSize
 	}
 
+	// Worker count override
+	if workerCount := getEnvInt("TRANSFER_WORKER_COUNT", 0); workerCount > 0 {
+		cfg.WorkerCount = workerCount
+	}
+
 	// Graylog configuration
 	cfg.Graylog.Enabled = getEnvBool("GRAYLOG_ENABLED", false)
 	cfg.Graylog.Endpoint = getEnv("GRAYLOG_ENDPOINT", "localhost:12201")

replica/handlers.go

@@ -3,6 +3,7 @@ package replica
 import (
 	"database/sql"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -90,11 +91,23 @@ func (h *EventHandlers) HandleQuery(e *replication.QueryEvent) error {
 
 	query := string(e.Query)
 	if h.secondaryDB != nil {
+		// Skip CREATE TABLE statements to avoid ER_TABLE_EXISTS_ERROR
+		trimmedQuery := strings.ToUpper(strings.TrimSpace(query))
+		if strings.HasPrefix(trimmedQuery, "CREATE TABLE") {
+			Info("[%s][INFO] Skipping CREATE TABLE query: %s", h.secondaryName, query)
+			return nil
+		}
+
 		_, err := h.secondaryDB.Exec(query)
 		if err != nil {
+			// Skip ER_TABLE_EXISTS_ERROR specifically
+			if strings.Contains(strings.ToUpper(err.Error()), "ER_TABLE_EXISTS_ERROR") {
+				Info("[%s][INFO] Table already exists, skipping query: %s", h.secondaryName, query)
+			} else {
 				Errorf("[%s][ERROR] Query failed: %v", h.secondaryName, err)
 			}
 		}
+	}
 	return nil
 }
 
@@ -292,7 +305,7 @@ func (h *EventHandlers) executeWithRetry(query string) error {
 		if err == nil {
 			if result != nil {
 				rowsAffected, _ := result.RowsAffected()
-				Info("[%s][SUCCESS] %d row(s) affected", h.secondaryName, rowsAffected)
+				Infof("[%s][SUCCESS] %d row(s) affected", h.secondaryName, rowsAffected)
 			}
 			return nil
 		}

replica/initial_transfer.go

@@ -42,7 +42,9 @@ type InitialTransfer struct {
 	progress       TransferProgress
 	pauseChan      chan struct{}
 	resumeChan     chan struct{}
+	stopChan       chan struct{} // New channel for stop signal
 	isPaused       bool
+	isStopped      bool
 }
 
 // NewInitialTransfer creates a new initial transfer handler
@@ -51,16 +53,18 @@ func NewInitialTransfer(primaryDSN, secondaryDSN string, batchSize, workerCount
 	if err != nil {
 		return nil, fmt.Errorf("failed to connect to primary: %v", err)
 	}
-	primaryDB.SetMaxOpenConns(batchSize)
+	// Optimize connection pool settings - use worker count for max open connections
-	primaryDB.SetMaxIdleConns(2)
+	primaryDB.SetMaxOpenConns(workerCount * 2) // 2 connections per worker
+	primaryDB.SetMaxIdleConns(workerCount)
 
 	secondaryDB, err := sql.Open("mysql", secondaryDSN)
 	if err != nil {
 		primaryDB.Close()
 		return nil, fmt.Errorf("failed to connect to secondary: %v", err)
 	}
-	secondaryDB.SetMaxOpenConns(batchSize)
+	// Optimize connection pool settings - use worker count for max open connections
-	secondaryDB.SetMaxIdleConns(2)
+	secondaryDB.SetMaxOpenConns(workerCount * 2) // 2 connections per worker
+	secondaryDB.SetMaxIdleConns(workerCount)
 
 	if err := primaryDB.Ping(); err != nil {
 		primaryDB.Close()
@@ -91,6 +95,7 @@ func NewInitialTransfer(primaryDSN, secondaryDSN string, batchSize, workerCount
 		},
 		pauseChan:  make(chan struct{}),
 		resumeChan: make(chan struct{}),
+		stopChan:   make(chan struct{}), // Initialize stop channel
 	}, nil
 }
 
@@ -122,6 +127,15 @@ func (t *InitialTransfer) Transfer(excludeSchemas []string) error {
 	}
 
 	for i, dbName := range databases {
+		// Check for stop signal
+		select {
+		case <-t.stopChan:
+			Info("[TRANSFER] Transfer stopped, saving progress...")
+			t.saveProgress()
+			return nil
+		default:
+		}
+
 		// Check for pause signal
 		t.checkPause()
 
@@ -140,6 +154,12 @@ func (t *InitialTransfer) Transfer(excludeSchemas []string) error {
 		t.saveProgress()
 
 		if err := t.transferDatabase(dbName); err != nil {
+			// Check if the error is due to transfer being stopped
+			if t.isStopped {
+				Info("[TRANSFER] Transfer stopped, saving progress...")
+				t.saveProgress()
+				return nil
+			}
 			return fmt.Errorf("failed to transfer database %s: %v", dbName, err)
 		}
 
@@ -162,12 +182,24 @@ func (t *InitialTransfer) Transfer(excludeSchemas []string) error {
 	return nil
 }
 
-// checkPause checks if transfer should be paused
+// checkPause checks if transfer should be paused or stopped
 func (t *InitialTransfer) checkPause() {
+	select {
+	case <-t.stopChan:
+		Info("[TRANSFER] Transfer stopped")
+		return
+	default:
+	}
+
 	if t.isPaused {
 		Info("[TRANSFER] Transfer paused, waiting for resume...")
-		<-t.resumeChan
+		select {
+		case <-t.resumeChan:
 			Info("[TRANSFER] Transfer resumed")
+		case <-t.stopChan:
+			Info("[TRANSFER] Transfer stopped while paused")
+			t.isPaused = false
+		}
 	}
 }
 
@@ -189,6 +221,15 @@ func (t *InitialTransfer) Resume() {
 	}
 }
 
+// Stop stops the transfer
+func (t *InitialTransfer) Stop() {
+	if !t.isStopped {
+		t.isStopped = true
+		close(t.stopChan)
+		Info("[TRANSFER] Transfer stop requested")
+	}
+}
+
 // saveProgress saves the current progress to a checkpoint file
 func (t *InitialTransfer) saveProgress() {
 	t.progress.LastCheckpoint = time.Now()
@@ -268,23 +309,64 @@ func (t *InitialTransfer) transferDatabase(dbName string) error {
 
 	Infof("[TRANSFER] Found %d tables in %s", len(tables), dbName)
 
+	// All tables need to be processed - we'll resume from where we left off within each table
+	var unprocessedTables []string
 	for _, table := range tables {
+		unprocessedTables = append(unprocessedTables, table)
+	}
+
+	// Create worker pool
+	jobs := make(chan string, len(unprocessedTables))
+	results := make(chan error, len(unprocessedTables))
+
+	for w := 0; w < t.workerCount; w++ {
+		go func(workerID int) {
+			for table := range jobs {
+				// Check for stop signal
+				select {
+				case <-t.stopChan:
+					results <- nil // Signal stop
+					return
+				default:
+				}
+
 				// Check for pause signal
 				t.checkPause()
 
-		// Skip already processed tables
-		tableKey := dbName + "." + table
-		if t.progress.TablesProcessed[tableKey] > 0 {
-			Infof("[TRANSFER] Skipping already processed table: %s", tableKey)
-			continue
-		}
-
 				if err := t.transferTable(dbName, table); err != nil {
-			Errorf("[ERROR] Failed to transfer table %s.%s: %v", dbName, table, err)
+					// Check if the error is due to transfer being stopped
+					if t.isStopped {
+						results <- nil // Signal stop
+						return
+					}
+					Errorf("[ERROR] Worker %d: Failed to transfer table %s.%s: %v", workerID, dbName, table, err)
 					t.mu.Lock()
 					t.stats.Errors = append(t.stats.Errors, fmt.Sprintf("%s.%s: %v", dbName, table, err))
 					t.mu.Unlock()
 				}
+				results <- nil
+			}
+		}(w)
+	}
+
+	// Send jobs to workers
+	for _, table := range unprocessedTables {
+		jobs <- table
+	}
+	close(jobs)
+
+	// Wait for all workers to complete
+	for range unprocessedTables {
+		select {
+		case <-t.stopChan:
+			Info("[TRANSFER] Transfer stopped, saving progress...")
+			t.saveProgress()
+			return nil
+		case err := <-results:
+			if err != nil {
+				return err
+			}
+		}
 	}
 
 	return nil
@@ -313,12 +395,26 @@ func (t *InitialTransfer) getTables(dbName string) ([]string, error) {
 
 // transferTable transfers a single table with chunked reads
 func (t *InitialTransfer) transferTable(dbName, tableName string) error {
+	// Check for stop signal
+	select {
+	case <-t.stopChan:
+		Info("[TRANSFER] Transfer stopped, saving progress...")
+		t.saveProgress()
+		return nil
+	default:
+	}
+
 	// Get table structure
 	schema, err := t.getTableSchema(dbName, tableName)
 	if err != nil {
 		return fmt.Errorf("failed to get table schema: %v", err)
 	}
 
+	// Create table on secondary if it doesn't exist
+	if err := t.createTableOnSecondary(dbName, tableName); err != nil {
+		return fmt.Errorf("failed to create table on secondary: %v", err)
+	}
+
 	// Check if table has data
 	hasData, err := t.tableHasData(dbName, tableName)
 	if err != nil {
@@ -345,7 +441,87 @@ func (t *InitialTransfer) transferTable(dbName, tableName string) error {
 		return t.transferTableFullScan(dbName, tableName, schema, count)
 	}
 
+	// Check if primary key is numeric before attempting chunked transfer
+	if isPrimaryKeyNumeric(dbName, tableName, pkColumn, t.primaryDB) {
 		return t.transferTableChunked(dbName, tableName, schema, pkColumn, count)
+	} else {
+		Warnf("[WARN] Non-numeric primary key found for %s.%s, using full scan", dbName, tableName)
+		return t.transferTableFullScan(dbName, tableName, schema, count)
+	}
+}
+
+// createTableOnSecondary creates the table on the secondary database if it doesn't exist
+func (t *InitialTransfer) createTableOnSecondary(dbName, tableName string) error {
+	// Get CREATE TABLE statement from primary
+	var createSQL string
+	query := fmt.Sprintf("SHOW CREATE TABLE `%s`.`%s`", dbName, tableName)
+	err := t.primaryDB.QueryRow(query).Scan(&tableName, &createSQL)
+	if err != nil {
+		return fmt.Errorf("failed to get CREATE TABLE statement: %v", err)
+	}
+
+	// Execute CREATE TABLE on secondary (with IF NOT EXISTS and foreign key checks disabled)
+	// This prevents errors due to foreign key constraints when tables are created in random order
+	_, err = t.secondaryDB.Exec("SET FOREIGN_KEY_CHECKS = 0")
+	if err != nil {
+		return fmt.Errorf("failed to disable foreign key checks: %v", err)
+	}
+
+	createSQL = strings.Replace(createSQL, "CREATE TABLE", "CREATE TABLE IF NOT EXISTS", 1)
+	_, err = t.secondaryDB.Exec(createSQL)
+	if err != nil {
+		// Try again without foreign key constraints if we still get an error
+		modifiedSQL := removeForeignKeyConstraints(createSQL)
+		_, err = t.secondaryDB.Exec(modifiedSQL)
+		if err != nil {
+			return fmt.Errorf("failed to create table: %v", err)
+		}
+		Infof("[TRANSFER] Table %s.%s created on secondary without foreign key constraints", dbName, tableName)
+	} else {
+		Infof("[TRANSFER] Table %s.%s created on secondary", dbName, tableName)
+	}
+
+	_, err = t.secondaryDB.Exec("SET FOREIGN_KEY_CHECKS = 1")
+	if err != nil {
+		return fmt.Errorf("failed to enable foreign key checks: %v", err)
+	}
+
+	return nil
+}
+
+// removeForeignKeyConstraints removes foreign key constraints from CREATE TABLE SQL
+func removeForeignKeyConstraints(sql string) string {
+	// This is a simple implementation - more complex cases might require proper SQL parsing
+	// Remove FOREIGN KEY clauses
+	sql = strings.ReplaceAll(sql, "FOREIGN KEY", "/* FOREIGN KEY */")
+	return sql
+}
+
+// isPrimaryKeyNumeric checks if the primary key column is numeric type
+func isPrimaryKeyNumeric(dbName, tableName, pkColumn string, db *sql.DB) bool {
+	query := fmt.Sprintf(
+		"SELECT DATA_TYPE FROM INFORMATION_SCHEMA.COLUMNS "+
+			"WHERE TABLE_SCHEMA = '%s' AND TABLE_NAME = '%s' AND COLUMN_NAME = '%s'",
+		dbName, tableName, pkColumn,
+	)
+
+	var dataType string
+	err := db.QueryRow(query).Scan(&dataType)
+	if err != nil {
+		return false
+	}
+
+	// List of numeric data types (MySQL/MariaDB)
+	numericTypes := []string{"tinyint", "smallint", "mediumint", "int", "bigint",
+		"decimal", "numeric", "float", "double", "real"}
+
+	for _, t := range numericTypes {
+		if strings.Contains(strings.ToLower(dataType), t) {
+			return true
+		}
+	}
+
+	return false
 }
 
 // tableHasData checks if a table has any rows
@@ -442,9 +618,24 @@ func (t *InitialTransfer) transferTableChunked(dbName, tableName string, columns
 		startOffset = minMax.Min
 	}
 
+	// Check if table has already been fully processed
+	if startOffset >= minMax.Max {
+		Infof("[TRANSFER] Table %s.%s already fully processed, skipping", dbName, tableName)
+		return nil
+	}
+
 	// Transfer chunks
 	offset := startOffset
 	for offset < minMax.Max {
+		// Check for stop signal
+		select {
+		case <-t.stopChan:
+			Info("[TRANSFER] Transfer stopped, saving progress...")
+			t.saveProgress()
+			return nil
+		default:
+		}
+
 		// Check for pause signal
 		t.checkPause()
 
@@ -462,6 +653,12 @@ func (t *InitialTransfer) transferTableChunked(dbName, tableName string, columns
 		rows.Close()
 
 		if err != nil {
+			// Check if the error is due to transfer being stopped
+			if t.isStopped {
+				Info("[TRANSFER] Transfer stopped, saving progress...")
+				t.saveProgress()
+				return nil
+			}
 			return fmt.Errorf("failed to insert chunk: %v", err)
 		}
 
@@ -470,14 +667,15 @@ func (t *InitialTransfer) transferTableChunked(dbName, tableName string, columns
 		t.progress.TablesProcessed[tableKey] = offset + int64(t.batchSize)
 		t.mu.Unlock()
 
-		// Save checkpoint every 1000 rows
+		// Save checkpoint every 100 rows (for testing purposes)
-		if rowsInserted%1000 == 0 {
+		if rowsInserted%100 == 0 {
 			t.saveProgress()
 		}
 
 		offset += int64(t.batchSize)
 	}
 
+	Infof("[TRANSFER] Table %s.%s fully processed", dbName, tableName)
 	return nil
 }
 
@@ -510,9 +708,24 @@ func (t *InitialTransfer) transferTableFullScan(dbName, tableName string, column
 	// Get starting offset from progress
 	startOffset := t.progress.TablesProcessed[tableKey]
 
+	// Check if table has already been fully processed
+	if startOffset >= rowCount {
+		Infof("[TRANSFER] Table %s.%s already fully processed, skipping", dbName, tableName)
+		return nil
+	}
+
 	var offset int64 = startOffset
 
 	for offset < rowCount {
+		// Check for stop signal
+		select {
+		case <-t.stopChan:
+			Info("[TRANSFER] Transfer stopped, saving progress...")
+			t.saveProgress()
+			return nil
+		default:
+		}
+
 		// Check for pause signal
 		t.checkPause()
 
@@ -530,6 +743,12 @@ func (t *InitialTransfer) transferTableFullScan(dbName, tableName string, column
 		rows.Close()
 
 		if err != nil {
+			// Check if the error is due to transfer being stopped
+			if t.isStopped {
+				Info("[TRANSFER] Transfer stopped, saving progress...")
+				t.saveProgress()
+				return nil
+			}
 			return fmt.Errorf("failed to insert chunk: %v", err)
 		}
 
@@ -538,19 +757,27 @@ func (t *InitialTransfer) transferTableFullScan(dbName, tableName string, column
 		t.progress.TablesProcessed[tableKey] = offset
 		t.mu.Unlock()
 
-		// Save checkpoint every 1000 rows
+		// Save checkpoint every 100 rows (for testing purposes)
-		if rowsInserted%1000 == 0 {
+		if rowsInserted%100 == 0 {
 			t.saveProgress()
 		}
 
 		offset += int64(t.batchSize)
 	}
 
+	Infof("[TRANSFER] Table %s.%s fully processed", dbName, tableName)
 	return nil
 }
 
 // insertRows inserts rows from a query result into the secondary database
 func (t *InitialTransfer) insertRows(db *sql.DB, dbName, tableName string, columns []ColumnInfo, rows *sql.Rows) (int64, error) {
+	// Disable foreign key checks to avoid errors due to constraint violations
+	_, err := db.Exec("SET FOREIGN_KEY_CHECKS = 0")
+	if err != nil {
+		return 0, fmt.Errorf("failed to disable foreign key checks: %v", err)
+	}
+	defer db.Exec("SET FOREIGN_KEY_CHECKS = 1") // Ensure foreign key checks are re-enabled
+
 	// Build INSERT statement
 	placeholders := make([]string, len(columns))
 	colNames := make([]string, len(columns))
@@ -560,7 +787,7 @@ func (t *InitialTransfer) insertRows(db *sql.DB, dbName, tableName string, colum
 	}
 
 	insertSQL := fmt.Sprintf(
-		"INSERT INTO `%s`.`%s` (%s) VALUES (%s)",
+		"INSERT IGNORE INTO `%s`.`%s` (%s) VALUES (%s)",
 		dbName, tableName, strings.Join(colNames, ", "), strings.Join(placeholders, ", "),
 	)
 
@@ -587,7 +814,9 @@ func (t *InitialTransfer) insertRows(db *sql.DB, dbName, tableName string, colum
 
 		_, err := stmt.Exec(values...)
 		if err != nil {
-			return rowCount, fmt.Errorf("failed to insert row: %v", err)
+			// Log the error but continue with other rows
+			Warnf("[TRANSFER] Failed to insert row into %s.%s: %v", dbName, tableName, err)
+			continue
 		}
 		rowCount++
 	}
@@ -598,7 +827,6 @@ func (t *InitialTransfer) insertRows(db *sql.DB, dbName, tableName string, colum
 	t.mu.Unlock()
 
 	Infof("[TRANSFER] Inserted %d rows into %s.%s", rowCount, dbName, tableName)
-
 	return rowCount, rows.Err()
 }
 

replica/service.go

@@ -275,7 +275,7 @@ func (s *BinlogSyncService) checkSecondaryHasData() (bool, error) {
 }
 
 // RunInitialTransfer performs the initial data transfer
-func (s *BinlogSyncService) RunInitialTransfer(batchSize int, excludeSchemas []string) error {
+func (s *BinlogSyncService) RunInitialTransfer(batchSize, workerCount int, excludeSchemas []string) error {
 	Infof("[%s] Starting initial data transfer...", s.secondaryName)
 
 	// Get secondary DB from handlers
@@ -289,7 +289,7 @@ func (s *BinlogSyncService) RunInitialTransfer(batchSize int, excludeSchemas []s
 		primaryDB:   s.primaryDB,
 		secondaryDB: secondaryDB,
 		batchSize:   batchSize,
-		workerCount: 1,
+		workerCount: workerCount,
 		excludedDBs: map[string]bool{
 			"information_schema": true,
 			"performance_schema": true,
@@ -300,11 +300,28 @@ func (s *BinlogSyncService) RunInitialTransfer(batchSize int, excludeSchemas []s
 		progress: TransferProgress{
 			TablesProcessed: make(map[string]int64),
 		},
+		stopChan: make(chan struct{}),
 	}
 
-	if err := transfer.Transfer(excludeSchemas); err != nil {
+	// Start transfer in goroutine
+	errChan := make(chan error)
+	go func() {
+		errChan <- transfer.Transfer(excludeSchemas)
+	}()
+
+	// Wait for transfer completion or stop signal
+	select {
+	case <-s.stopChan:
+		Info("[%s] Initial transfer stopping...", s.secondaryName)
+		transfer.Stop()
+		<-errChan // Wait for transfer to finish stopping
+		Info("[%s] Initial transfer stopped", s.secondaryName)
+		return nil
+	case err := <-errChan:
+		if err != nil {
 			return fmt.Errorf("transfer failed: %v", err)
 		}
+	}
 
 	// Reset position after successful transfer
 	if err := s.positionMgr.Reset(); err != nil {
@@ -316,7 +333,7 @@ func (s *BinlogSyncService) RunInitialTransfer(batchSize int, excludeSchemas []s
 }
 
 // StartWithResync starts binlog streaming with automatic resync if needed
-func (s *BinlogSyncService) StartWithResync(batchSize int, excludeSchemas []string) error {
+func (s *BinlogSyncService) StartWithResync(batchSize, workerCount int, excludeSchemas []string) error {
 	if err := s.positionMgr.InitTable(); err != nil {
 		Warnf("[%s][WARN] Failed to init position table: %v", s.secondaryName, err)
 	}
@@ -328,7 +345,7 @@ func (s *BinlogSyncService) StartWithResync(batchSize int, excludeSchemas []stri
 	}
 
 	if needResync {
-		if err := s.RunInitialTransfer(batchSize, excludeSchemas); err != nil {
+		if err := s.RunInitialTransfer(batchSize, workerCount, excludeSchemas); err != nil {
 			return fmt.Errorf("initial transfer failed: %v", err)
 		}
 	}
@@ -363,13 +380,13 @@ func (m *MultiBinlogSyncService) AddService(service *BinlogSyncService) {
 }
 
 // StartAll starts all services
-func (m *MultiBinlogSyncService) StartAll() error {
+func (m *MultiBinlogSyncService) StartAll(batchSize, workerCount int, excludeSchemas []string) error {
 	for _, service := range m.services {
 		m.wg.Add(1)
 		go func(svc *BinlogSyncService) {
 			defer m.wg.Done()
 			Infof("[%s] Starting binlog sync service", svc.GetSecondaryName())
-			if err := svc.StartWithResync(1000, []string{"information_schema", "performance_schema", "mysql", "sys"}); err != nil {
+			if err := svc.StartWithResync(batchSize, workerCount, excludeSchemas); err != nil {
 				Errorf("[%s] Service error: %v", svc.GetSecondaryName(), err)
 			}
 		}(service)