diff --git a/pool/tree/pool_test.go b/pool/tree/pool_test.go
new file mode 100644
index 0000000..8c8a0cf
--- /dev/null
+++ b/pool/tree/pool_test.go
@@ -0,0 +1,294 @@
+package tree
+
+import (
+	"context"
+	"errors"
+	grpcService "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool/tree/service"
+	"testing"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zaptest"
+)
+
+type treeClientMock struct {
+	address string
+	err     bool
+}
+
+func (t *treeClientMock) serviceClient() (grpcService.TreeServiceClient, error) {
+	if t.err {
+		return nil, errors.New("serviceClient() mock error")
+	}
+	return nil, nil
+}
+
+func (t *treeClientMock) endpoint() string {
+	return t.address
+}
+
+func (t *treeClientMock) isHealthy() bool {
+	return true
+}
+
+func (t *treeClientMock) setHealthy(bool) {
+	return
+}
+
+func (t *treeClientMock) dial(context.Context) error {
+	return nil
+}
+
+func (t *treeClientMock) redialIfNecessary(context.Context) (bool, error) {
+	if t.err {
+		return false, errors.New("redialIfNecessary() mock error")
+	}
+	return false, nil
+}
+
+func (t *treeClientMock) close() error {
+	return nil
+}
+
+func TestHandleError(t *testing.T) {
+	defaultError := errors.New("default error")
+	for _, tc := range []struct {
+		err           error
+		expectedError error
+	}{
+		{
+			err:           defaultError,
+			expectedError: defaultError,
+		},
+		{
+			err:           errors.New("something not found"),
+			expectedError: ErrNodeNotFound,
+		},
+		{
+			err:           errors.New("something is denied by some acl rule"),
+			expectedError: ErrNodeAccessDenied,
+		},
+	} {
+		t.Run("", func(t *testing.T) {
+			err := handleError("err message", tc.err)
+			require.True(t, errors.Is(err, tc.expectedError))
+		})
+	}
+}
+
+func TestRetry(t *testing.T) {
+	nodes := [][]string{
+		{"node00", "node01", "node02", "node03"},
+		{"node10", "node11", "node12", "node13"},
+	}
+
+	p := &Pool{
+		logger:     zaptest.NewLogger(t),
+		innerPools: makeInnerPool(nodes),
+	}
+
+	makeFn := func(client grpcService.TreeServiceClient) error {
+		return nil
+	}
+
+	t.Run("first ok", func(t *testing.T) {
+		err := p.requestWithRetry(makeFn)
+		require.NoError(t, err)
+		checkIndicesAndReset(t, p, 0, 0)
+	})
+
+	t.Run("first failed", func(t *testing.T) {
+		setErrors(p, "node00")
+		err := p.requestWithRetry(makeFn)
+		require.NoError(t, err)
+		checkIndicesAndReset(t, p, 0, 1)
+	})
+
+	t.Run("all failed", func(t *testing.T) {
+		setErrors(p, nodes[0]...)
+		setErrors(p, nodes[1]...)
+		err := p.requestWithRetry(makeFn)
+		require.Error(t, err)
+		checkIndicesAndReset(t, p, 0, 0)
+	})
+
+	t.Run("round", func(t *testing.T) {
+		setErrors(p, nodes[0][0], nodes[0][1])
+		setErrors(p, nodes[1]...)
+		err := p.requestWithRetry(makeFn)
+		require.NoError(t, err)
+		checkIndices(t, p, 0, 2)
+		resetClientsErrors(p)
+
+		setErrors(p, nodes[0][2], nodes[0][3])
+		err = p.requestWithRetry(makeFn)
+		require.NoError(t, err)
+		checkIndicesAndReset(t, p, 0, 0)
+	})
+
+	t.Run("group switch", func(t *testing.T) {
+		setErrors(p, nodes[0]...)
+		setErrors(p, nodes[1][0])
+		err := p.requestWithRetry(makeFn)
+		require.NoError(t, err)
+		checkIndicesAndReset(t, p, 1, 1)
+	})
+
+	t.Run("group round", func(t *testing.T) {
+		setErrors(p, nodes[0][1:]...)
+		err := p.requestWithRetry(makeFn)
+		require.NoError(t, err)
+		checkIndicesAndReset(t, p, 0, 0)
+	})
+
+	t.Run("group round switch", func(t *testing.T) {
+		setErrors(p, nodes[0]...)
+		p.setStartIndices(0, 1)
+		err := p.requestWithRetry(makeFn)
+		require.NoError(t, err)
+		checkIndicesAndReset(t, p, 1, 0)
+	})
+}
+
+func TestRebalance(t *testing.T) {
+	nodes := [][]string{
+		{"node00", "node01"},
+		{"node10", "node11"},
+	}
+
+	p := &Pool{
+		logger:     zaptest.NewLogger(t),
+		innerPools: makeInnerPool(nodes),
+		rebalanceParams: rebalanceParameters{
+			nodesGroup: makeNodesGroup(nodes),
+		},
+	}
+
+	ctx := context.Background()
+	buffers := makeBuffer(p)
+
+	t.Run("check dirty buffers", func(t *testing.T) {
+		p.updateNodesHealth(ctx, buffers)
+		checkIndices(t, p, 0, 0)
+		setErrors(p, nodes[0][0])
+		p.updateNodesHealth(ctx, buffers)
+		checkIndices(t, p, 0, 1)
+		resetClients(p)
+	})
+
+	t.Run("don't change healthy status", func(t *testing.T) {
+		p.updateNodesHealth(ctx, buffers)
+		checkIndices(t, p, 0, 0)
+		resetClients(p)
+	})
+
+	t.Run("switch to second group", func(t *testing.T) {
+		setErrors(p, nodes[0][0], nodes[0][1])
+		p.updateNodesHealth(ctx, buffers)
+		checkIndices(t, p, 1, 0)
+		resetClients(p)
+	})
+
+	t.Run("switch back and forth", func(t *testing.T) {
+		setErrors(p, nodes[0][0], nodes[0][1])
+		p.updateNodesHealth(ctx, buffers)
+		checkIndices(t, p, 1, 0)
+
+		p.updateNodesHealth(ctx, buffers)
+		checkIndices(t, p, 1, 0)
+
+		setNoErrors(p, nodes[0][0])
+		p.updateNodesHealth(ctx, buffers)
+		checkIndices(t, p, 0, 0)
+
+		resetClients(p)
+	})
+}
+
+func makeInnerPool(nodes [][]string) []*innerPool {
+	res := make([]*innerPool, len(nodes))
+
+	for i, group := range nodes {
+		res[i] = &innerPool{clients: make([]client, len(group))}
+		for j, node := range group {
+			res[i].clients[j] = &treeClientMock{address: node}
+		}
+	}
+
+	return res
+}
+
+func makeNodesGroup(nodes [][]string) [][]pool.NodeParam {
+	res := make([][]pool.NodeParam, len(nodes))
+
+	for i, group := range nodes {
+		res[i] = make([]pool.NodeParam, len(group))
+		for j, node := range group {
+			res[i][j] = pool.NewNodeParam(1, node, 1)
+		}
+	}
+
+	return res
+}
+
+func makeBuffer(p *Pool) [][]bool {
+	buffers := make([][]bool, len(p.rebalanceParams.nodesGroup))
+	for i, nodes := range p.rebalanceParams.nodesGroup {
+		buffers[i] = make([]bool, len(nodes))
+	}
+	return buffers
+}
+
+func checkIndicesAndReset(t *testing.T, p *Pool, iExp, jExp int) {
+	checkIndices(t, p, iExp, jExp)
+	resetClients(p)
+}
+
+func checkIndices(t *testing.T, p *Pool, iExp, jExp int) {
+	i, j := p.getStartIndices()
+	require.Equal(t, iExp, i)
+	require.Equal(t, jExp, j)
+}
+
+func resetClients(p *Pool) {
+	resetClientsErrors(p)
+	p.setStartIndices(0, 0)
+}
+
+func resetClientsErrors(p *Pool) {
+	for _, group := range p.innerPools {
+		for _, cl := range group.clients {
+			node := cl.(*treeClientMock)
+			node.err = false
+		}
+	}
+}
+
+func setErrors(p *Pool, nodes ...string) {
+	setErrorsBase(p, true, nodes...)
+}
+
+func setNoErrors(p *Pool, nodes ...string) {
+	setErrorsBase(p, false, nodes...)
+}
+
+func setErrorsBase(p *Pool, err bool, nodes ...string) {
+	for _, group := range p.innerPools {
+		for _, cl := range group.clients {
+			node := cl.(*treeClientMock)
+			if containsStr(nodes, node.address) {
+				node.err = err
+			}
+		}
+	}
+}
+
+func containsStr(list []string, item string) bool {
+	for i := range list {
+		if list[i] == item {
+			return true
+		}
+	}
+
+	return false
+}