diff --git a/server/admin/internal/repository/money_scope_repository.go b/server/admin/internal/repository/money_scope_repository.go
index af7366a5..72c09d3e 100644
--- a/server/admin/internal/repository/money_scope_repository.go
+++ b/server/admin/internal/repository/money_scope_repository.go
@@ -36,7 +36,9 @@ func (access MoneyAccess) Allows(appCode string, regionID int64) bool {
 }
 
 // RegionIDLooseEqual 对齐 legacy 大区 ID 的浮点圆整误差：雪花/合成 ID 超出 JS 安全整数，
-// 前端写回的 scope/筛选值可能是 float64 圆整后的数（相邻 ID 间距远大于圆整粒度，不会误碰）。
+// 浏览器写回的值是 JS Number 的"最短可往返十进制"（如 …690882 → …691000），与
+// int64(float64(x)) 的回转值（…690880）都不相等，唯一可靠的等价层是 float64 本身：
+// 只要两个十进制落在同一个 float64 桶里就视为同一区域（相邻 ID 间距远大于桶宽，不会误碰）。
 func RegionIDLooseEqual(left int64, right int64) bool {
 	if left == right {
 		return true
@@ -44,7 +46,7 @@ func RegionIDLooseEqual(left int64, right int64) bool {
 	if left == 0 || right == 0 {
 		return false
 	}
-	return int64(float64(left)) == right || left == int64(float64(right))
+	return float64(left) == float64(right)
 }
 
 func (access MoneyAccess) AppCodes() []string {
diff --git a/server/admin/internal/repository/money_scope_repository_test.go b/server/admin/internal/repository/money_scope_repository_test.go
index f4702817..6cf4ffce 100644
--- a/server/admin/internal/repository/money_scope_repository_test.go
+++ b/server/admin/internal/repository/money_scope_repository_test.go
@@ -82,6 +82,15 @@ func TestRegionIDLooseEqual(t *testing.T) {
 	if !RegionIDLooseEqual(exact, rounded) || !RegionIDLooseEqual(rounded, exact) {
 		t.Fatalf("expected rounded/exact pair to match")
 	}
+	// 浏览器实际写回的是 JS Number 的最短十进制表示（…691000），与 float64 回转值（…690880）不同，
+	// 必须在 float64 层等价（线上「区域 2049039732077691000」事故的回归测试）。
+	jsShortest := int64(2049039732077691000)
+	if jsShortest == rounded {
+		t.Fatalf("fixture should differ from cast value")
+	}
+	if !RegionIDLooseEqual(exact, jsShortest) || !RegionIDLooseEqual(jsShortest, exact) {
+		t.Fatalf("expected js shortest-repr id to match exact id")
+	}
 	if !RegionIDLooseEqual(7, 7) {
 		t.Fatalf("expected exact small ids to match")
 	}
diff --git a/services/activity-service/internal/storage/mysql/repository.go b/services/activity-service/internal/storage/mysql/repository.go
index 694ccc71..73e3098d 100644
--- a/services/activity-service/internal/storage/mysql/repository.go
+++ b/services/activity-service/internal/storage/mysql/repository.go
@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"strings"
+	"time"
 
 	_ "github.com/go-sql-driver/mysql"
 	"hyapp/pkg/appcode"
@@ -29,6 +30,11 @@ func Open(ctx context.Context, dsn string) (*Repository, error) {
 		return nil, err
 	}
 
+	// 标准库默认不限制连接数，高并发下会打爆 MySQL max_connections，必须显式设上限。
+	db.SetMaxOpenConns(20)
+	db.SetMaxIdleConns(10)
+	db.SetConnMaxLifetime(30 * time.Minute)
+
 	if err := db.PingContext(ctx); err != nil {
 		_ = db.Close()
 		return nil, err
diff --git a/services/cron-service/internal/storage/mysql/repository.go b/services/cron-service/internal/storage/mysql/repository.go
index 7a7939ab..29c026ea 100644
--- a/services/cron-service/internal/storage/mysql/repository.go
+++ b/services/cron-service/internal/storage/mysql/repository.go
@@ -42,6 +42,11 @@ func Open(ctx context.Context, dsn string) (*Repository, error) {
 	if err != nil {
 		return nil, err
 	}
+	// database/sql defaults to unlimited connections; cap the pool so bursts
+	// cannot exhaust MySQL max_connections.
+	db.SetMaxOpenConns(20)
+	db.SetMaxIdleConns(10)
+	db.SetConnMaxLifetime(30 * time.Minute)
 	if err := db.PingContext(ctx); err != nil {
 		_ = db.Close()
 		return nil, err
diff --git a/services/game-service/internal/storage/mysql/repository.go b/services/game-service/internal/storage/mysql/repository.go
index ec7c391a..7fa55b19 100644
--- a/services/game-service/internal/storage/mysql/repository.go
+++ b/services/game-service/internal/storage/mysql/repository.go
@@ -31,6 +31,10 @@ func Open(ctx context.Context, dsn string) (*Repository, error) {
 	if err != nil {
 		return nil, err
 	}
+	// 标准库默认不限制连接数，高并发下会打爆 MySQL max_connections，必须显式设上限。
+	db.SetMaxOpenConns(20)
+	db.SetMaxIdleConns(10)
+	db.SetConnMaxLifetime(30 * time.Minute)
 	if err := db.PingContext(ctx); err != nil {
 		_ = db.Close()
 		return nil, err
diff --git a/services/statistics-service/internal/storage/mysql/repository.go b/services/statistics-service/internal/storage/mysql/repository.go
index 576635db..ce5474a5 100644
--- a/services/statistics-service/internal/storage/mysql/repository.go
+++ b/services/statistics-service/internal/storage/mysql/repository.go
@@ -43,6 +43,11 @@ func Open(ctx context.Context, dsn string, activityDSNs ...string) (*Repository,
 	if err != nil {
 		return nil, err
 	}
+	// database/sql defaults to unlimited connections; cap the pool so bursts
+	// cannot exhaust MySQL max_connections.
+	db.SetMaxOpenConns(20)
+	db.SetMaxIdleConns(10)
+	db.SetConnMaxLifetime(30 * time.Minute)
 	if err := db.PingContext(ctx); err != nil {
 		_ = db.Close()
 		return nil, err
@@ -54,6 +59,11 @@ func Open(ctx context.Context, dsn string, activityDSNs ...string) (*Repository,
 			_ = db.Close()
 			return nil, err
 		}
+		// The activity connection only serves low-volume snapshot reads, so it
+		// gets a smaller cap than the primary pool.
+		activityDB.SetMaxOpenConns(8)
+		activityDB.SetMaxIdleConns(4)
+		activityDB.SetConnMaxLifetime(30 * time.Minute)
 		if err := activityDB.PingContext(ctx); err != nil {
 			_ = activityDB.Close()
 			_ = db.Close()
diff --git a/services/user-service/internal/storage/mysql/db.go b/services/user-service/internal/storage/mysql/db.go
index 60b6508b..49c9a247 100644
--- a/services/user-service/internal/storage/mysql/db.go
+++ b/services/user-service/internal/storage/mysql/db.go
@@ -5,6 +5,7 @@ import (
 	"context"
 	"database/sql"
 	"strings"
+	"time"
 
 	"hyapp/pkg/xerr"
 )
@@ -29,6 +30,12 @@ func Open(ctx context.Context, dsn string) (*Repository, error) {
 		return nil, err
 	}
 
+	// 标准库默认不限制连接数，高并发下会打爆 MySQL max_connections，必须显式设上限。
+	db.SetMaxOpenConns(20)
+	db.SetMaxIdleConns(10)
+	// 长连接定期轮换，避免云数据库或网络层回收导致长期坏连接驻留。
+	db.SetConnMaxLifetime(30 * time.Minute)
+
 	if err := db.PingContext(ctx); err != nil {
 		// 启动探测失败时关闭连接池，避免返回半初始化 repository。
 		_ = db.Close()
diff --git a/services/wallet-service/internal/storage/mysql/repository.go b/services/wallet-service/internal/storage/mysql/repository.go
index 3ed0a045..6e6c7c4f 100644
--- a/services/wallet-service/internal/storage/mysql/repository.go
+++ b/services/wallet-service/internal/storage/mysql/repository.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"strings"
+	"time"
 
 	"hyapp/pkg/xerr"
 )
@@ -25,6 +26,11 @@ func Open(ctx context.Context, dsn string) (*Repository, error) {
 		return nil, err
 	}
 
+	// 标准库默认不限制连接数，高并发下会打爆 MySQL max_connections，必须显式设上限。
+	db.SetMaxOpenConns(20)
+	db.SetMaxIdleConns(10)
+	db.SetConnMaxLifetime(30 * time.Minute)
+
 	if err := db.PingContext(ctx); err != nil {
 		_ = db.Close()
 		return nil, err