Merge pull request #1530 from ydb-platform/use_common_balancer_in_shared_drivers

allow to use common balancer in child drivers

Author: asmyasnikov

CHANGELOG.md

@@ -1,3 +1,5 @@
+* Added option `ydb.WithSharedBalancer(*Driver)` for child drivers
+
 ## v3.89.0
 * Fixed send optional arguments to the server with `ydb.ParamsBuilder`
 

driver.go

@@ -415,10 +415,11 @@ func (d *Driver) connect(ctx context.Context) (err error) {
 	if d.pool == nil {
 		d.pool = conn.NewPool(ctx, d.config)
 	}
-
-	d.balancer, err = balancer.New(ctx, d.config, d.pool, d.discoveryOptions...)
-	if err != nil {
-		return xerrors.WithStackTrace(err)
+	if d.balancer == nil {
+		d.balancer, err = balancer.New(ctx, d.config, d.pool, d.discoveryOptions...)
+		if err != nil {
+			return xerrors.WithStackTrace(err)
+		}
 	}
 
 	d.table = xsync.OnceValue(func() (*internalTable.Client, error) {

options.go

@@ -599,6 +599,15 @@ func WithPanicCallback(panicCallback func(e interface{})) Option {
 	}
 }
 
+// WithSharedBalancer sets balancer from parent driver to child driver
+func WithSharedBalancer(parent *Driver) Option {
+	return func(ctx context.Context, c *Driver) error {
+		c.balancer = parent.balancer
+
+		return nil
+	}
+}
+
 // WithTraceTable appends trace.Table into table traces
 func WithTraceTable(t trace.Table, opts ...trace.TableComposeOption) Option { //nolint:gocritic
 	return func(ctx context.Context, c *Driver) error {