From 7801b81b10c2b3ef0fbc2c308c1f7fa9ab1e758e Mon Sep 17 00:00:00 2001
From: Matt Jaffee <matthew.jaffee@gmail.com>
Date: Mon, 2 Jul 2018 07:56:51 -0500
Subject: [PATCH] unexport cluster (gorename)

---
 api.go                   |   2 +-
 cluster.go               | 120 +++++++++++++++++++--------------------
 cluster_internal_test.go |   6 +-
 executor.go              |   2 +-
 fragment.go              |   2 +-
 holder.go                |   4 +-
 server.go                |   2 +-
 utils_internal_test.go   |   8 +--
 8 files changed, 73 insertions(+), 73 deletions(-)

diff --git a/api.go b/api.go
index 0f19ef19d..bc3840ee5 100644
--- a/api.go
+++ b/api.go
@@ -36,7 +36,7 @@ import (
 // wrapped by a handler which provides an external interface (e.g. HTTP).
 type API struct {
 	Holder  *Holder
-	Cluster *Cluster
+	Cluster *cluster
 	server  *Server
 }
 
diff --git a/cluster.go b/cluster.go
index ce0214537..920c06d8d 100644
--- a/cluster.go
+++ b/cluster.go
@@ -210,8 +210,8 @@ type nodeAction struct {
 	action string
 }
 
-// Cluster represents a collection of nodes.
-type Cluster struct {
+// cluster represents a collection of nodes.
+type cluster struct {
 	id    string
 	Node  *Node
 	Nodes []*Node // TODO phase this out?
@@ -263,8 +263,8 @@ type Cluster struct {
 }
 
 // NewCluster returns a new instance of Cluster with defaults.
-func NewCluster() *Cluster {
-	return &Cluster{
+func NewCluster() *cluster {
+	return &cluster{
 		Hasher:     &jmphasher{},
 		partitionN: DefaultPartitionN,
 		ReplicaN:   1,
@@ -281,18 +281,18 @@ func NewCluster() *Cluster {
 }
 
 // coordinatorNode returns the coordinator node.
-func (c *Cluster) coordinatorNode() *Node {
+func (c *cluster) coordinatorNode() *Node {
 	return c.unprotectedNodeByID(c.Coordinator)
 }
 
 // isCoordinator is true if this node is the coordinator.
-func (c *Cluster) isCoordinator() bool {
+func (c *cluster) isCoordinator() bool {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 	return c.unprotectedIsCoordinator()
 }
 
-func (c *Cluster) unprotectedIsCoordinator() bool {
+func (c *cluster) unprotectedIsCoordinator() bool {
 	return c.Coordinator == c.Node.ID
 }
 
@@ -300,7 +300,7 @@ func (c *Cluster) unprotectedIsCoordinator() bool {
 // Coordinator. In response to this, the current node
 // will consider itself coordinator and update the other
 // nodes with its version of Cluster.Status.
-func (c *Cluster) setCoordinator(n *Node) error {
+func (c *cluster) setCoordinator(n *Node) error {
 	c.mu.Lock()
 	// Verify that the new Coordinator value matches
 	// this node.
@@ -329,13 +329,13 @@ func (c *Cluster) setCoordinator(n *Node) error {
 // changing the corresponding node's IsCoordinator value
 // to true, and sets all other nodes to false. Returns true if the value
 // changed.
-func (c *Cluster) updateCoordinator(n *Node) bool {
+func (c *cluster) updateCoordinator(n *Node) bool {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	return c.unprotectedUpdateCoordinator(n)
 }
 
-func (c *Cluster) unprotectedUpdateCoordinator(n *Node) bool {
+func (c *cluster) unprotectedUpdateCoordinator(n *Node) bool {
 	var changed bool
 	if c.Coordinator != n.ID {
 		c.Coordinator = n.ID
@@ -353,7 +353,7 @@ func (c *Cluster) unprotectedUpdateCoordinator(n *Node) bool {
 
 // addNode adds a node to the Cluster and updates and saves the
 // new topology.
-func (c *Cluster) addNode(node *Node) error {
+func (c *cluster) addNode(node *Node) error {
 	c.logger.Printf("add node %s to cluster on %s", node, c.Node)
 
 	// If the node being added is the coordinator, set it for this node.
@@ -380,7 +380,7 @@ func (c *Cluster) addNode(node *Node) error {
 
 // removeNode removes a node from the Cluster and updates and saves the
 // new topology.
-func (c *Cluster) removeNode(node *Node) error {
+func (c *cluster) removeNode(node *Node) error {
 	// remove from cluster
 	if !c.removeNodeBasicSorted(node) {
 		return nil
@@ -399,11 +399,11 @@ func (c *Cluster) removeNode(node *Node) error {
 }
 
 // nodeIDs returns the list of IDs in the cluster.
-func (c *Cluster) nodeIDs() []string {
+func (c *cluster) nodeIDs() []string {
 	return Nodes(c.Nodes).IDs()
 }
 
-func (c *Cluster) setID(id string) {
+func (c *cluster) setID(id string) {
 	// Don't overwrite ClusterID.
 	if c.id != "" {
 		return
@@ -414,19 +414,19 @@ func (c *Cluster) setID(id string) {
 	c.Topology.ClusterID = c.id
 }
 
-func (c *Cluster) State() string {
+func (c *cluster) State() string {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 	return c.state
 }
 
-func (c *Cluster) SetState(state string) {
+func (c *cluster) SetState(state string) {
 	c.mu.Lock()
 	c.setState(state)
 	c.mu.Unlock()
 }
 
-func (c *Cluster) setState(state string) {
+func (c *cluster) setState(state string) {
 	// Ignore cases where the state hasn't changed.
 	if state == c.state {
 		return
@@ -463,7 +463,7 @@ func (c *Cluster) setState(state string) {
 	}
 }
 
-func (c *Cluster) setNodeState(state string) error {
+func (c *cluster) setNodeState(state string) error {
 	if c.isCoordinator() {
 		return c.receiveNodeState(c.Node.ID, state)
 	}
@@ -485,7 +485,7 @@ func (c *Cluster) setNodeState(state string) error {
 // receiveNodeState sets node state in Topology in order for the
 // Coordinator to keep track of, during startup, which nodes have
 // finished opening their Holder.
-func (c *Cluster) receiveNodeState(nodeID string, state string) error {
+func (c *cluster) receiveNodeState(nodeID string, state string) error {
 	if !c.isCoordinator() {
 		return nil
 	}
@@ -507,7 +507,7 @@ func (c *Cluster) receiveNodeState(nodeID string, state string) error {
 }
 
 // Status returns the internal ClusterStatus representation.
-func (c *Cluster) Status() *internal.ClusterStatus {
+func (c *cluster) Status() *internal.ClusterStatus {
 	return &internal.ClusterStatus{
 		ClusterID: c.id,
 		State:     c.state,
@@ -515,14 +515,14 @@ func (c *Cluster) Status() *internal.ClusterStatus {
 	}
 }
 
-func (c *Cluster) nodeByID(id string) *Node {
+func (c *cluster) nodeByID(id string) *Node {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 	return c.unprotectedNodeByID(id)
 }
 
 // unprotectedNodeByID returns a node reference by ID.
-func (c *Cluster) unprotectedNodeByID(id string) *Node {
+func (c *cluster) unprotectedNodeByID(id string) *Node {
 	for _, n := range c.Nodes {
 		if n.ID == id {
 			return n
@@ -532,7 +532,7 @@ func (c *Cluster) unprotectedNodeByID(id string) *Node {
 }
 
 // nodePositionByID returns the position of the node in slice c.Nodes.
-func (c *Cluster) nodePositionByID(nodeID string) int {
+func (c *cluster) nodePositionByID(nodeID string) int {
 	for i, n := range c.Nodes {
 		if n.ID == nodeID {
 			return i
@@ -543,7 +543,7 @@ func (c *Cluster) nodePositionByID(nodeID string) int {
 
 // addNodeBasicSorted adds a node to the cluster, sorted by id.
 // Returns a pointer to the node and true if the node was added.
-func (c *Cluster) addNodeBasicSorted(node *Node) bool {
+func (c *cluster) addNodeBasicSorted(node *Node) bool {
 	n := c.unprotectedNodeByID(node.ID)
 	if n != nil {
 		return false
@@ -559,7 +559,7 @@ func (c *Cluster) addNodeBasicSorted(node *Node) bool {
 
 // removeNodeBasicSorted removes a node from the cluster, maintaining
 // the sort order. Returns true if the node was removed.
-func (c *Cluster) removeNodeBasicSorted(node *Node) bool {
+func (c *cluster) removeNodeBasicSorted(node *Node) bool {
 	i := c.nodePositionByID(node.ID)
 	if i < 0 {
 		return false
@@ -613,7 +613,7 @@ func (a viewsByField) addView(field, view string) {
 	a[field] = append(a[field], view)
 }
 
-func (c *Cluster) fragsByHost(idx *Index) fragsByHost {
+func (c *cluster) fragsByHost(idx *Index) fragsByHost {
 	// fieldViews is a map of field to slice of views.
 	fieldViews := make(viewsByField)
 
@@ -628,7 +628,7 @@ func (c *Cluster) fragsByHost(idx *Index) fragsByHost {
 
 // fragCombos returns a map (by uri) of lists of fragments for a given index
 // by creating every combination of field/view specified in `fieldViews` up to maxShard.
-func (c *Cluster) fragCombos(idx string, maxShard uint64, fieldViews viewsByField) fragsByHost {
+func (c *cluster) fragCombos(idx string, maxShard uint64, fieldViews viewsByField) fragsByHost {
 	t := make(fragsByHost)
 	for i := uint64(0); i <= maxShard; i++ {
 		nodes := c.shardNodes(idx, i)
@@ -647,7 +647,7 @@ func (c *Cluster) fragCombos(idx string, maxShard uint64, fieldViews viewsByFiel
 // diff compares c with another cluster and determines if a node is being
 // added or removed. An error is returned for any case other than where
 // exactly one node is added or removed.
-func (c *Cluster) diff(other *Cluster) (action string, nodeID string, err error) {
+func (c *cluster) diff(other *cluster) (action string, nodeID string, err error) {
 	lenFrom := len(c.Nodes)
 	lenTo := len(other.Nodes)
 	// Determine if a node is being added or removed.
@@ -686,7 +686,7 @@ func (c *Cluster) diff(other *Cluster) (action string, nodeID string, err error)
 
 // fragSources returns a list of ResizeSources - for each node in the `to` cluster -
 // required to move from cluster `c` to cluster `to`.
-func (c *Cluster) fragSources(to *Cluster, idx *Index) (map[string][]*internal.ResizeSource, error) {
+func (c *cluster) fragSources(to *cluster, idx *Index) (map[string][]*internal.ResizeSource, error) {
 	m := make(map[string][]*internal.ResizeSource)
 
 	// Determine if a node is being added or removed.
@@ -773,7 +773,7 @@ func (c *Cluster) fragSources(to *Cluster, idx *Index) (map[string][]*internal.R
 }
 
 // partition returns the partition that a shard belongs to.
-func (c *Cluster) partition(index string, shard uint64) int {
+func (c *cluster) partition(index string, shard uint64) int {
 	var buf [8]byte
 	binary.BigEndian.PutUint64(buf[:], shard)
 
@@ -785,17 +785,17 @@ func (c *Cluster) partition(index string, shard uint64) int {
 }
 
 // shardNodes returns a list of nodes that own a fragment.
-func (c *Cluster) shardNodes(index string, shard uint64) []*Node {
+func (c *cluster) shardNodes(index string, shard uint64) []*Node {
 	return c.partitionNodes(c.partition(index, shard))
 }
 
 // ownsShard returns true if a host owns a fragment.
-func (c *Cluster) ownsShard(nodeID string, index string, shard uint64) bool {
+func (c *cluster) ownsShard(nodeID string, index string, shard uint64) bool {
 	return Nodes(c.shardNodes(index, shard)).ContainsID(nodeID)
 }
 
 // partitionNodes returns a list of nodes that own a partition.
-func (c *Cluster) partitionNodes(partitionID int) []*Node {
+func (c *cluster) partitionNodes(partitionID int) []*Node {
 	// Default replica count to between one and the number of nodes.
 	// The replica count can be zero if there are no nodes.
 	replicaN := c.ReplicaN
@@ -818,7 +818,7 @@ func (c *Cluster) partitionNodes(partitionID int) []*Node {
 }
 
 // containsShards is like OwnsShards, but it includes replicas.
-func (c *Cluster) containsShards(index string, maxShard uint64, node *Node) []uint64 {
+func (c *cluster) containsShards(index string, maxShard uint64, node *Node) []uint64 {
 	var shards []uint64
 	for i := uint64(0); i <= maxShard; i++ {
 		p := c.partition(index, i)
@@ -856,7 +856,7 @@ func (h *jmphasher) Hash(key uint64, n int) int {
 	return int(b)
 }
 
-func (c *Cluster) setup() error {
+func (c *cluster) setup() error {
 	// Cluster always comes up in state STARTING until cluster membership is determined.
 	c.state = ClusterStateStarting
 
@@ -883,7 +883,7 @@ func (c *Cluster) setup() error {
 	return nil
 }
 
-func (c *Cluster) open() error {
+func (c *cluster) open() error {
 	err := c.setup()
 	if err != nil {
 		return errors.Wrap(err, "setting up cluster")
@@ -891,7 +891,7 @@ func (c *Cluster) open() error {
 	return c.waitForStarted()
 }
 
-func (c *Cluster) waitForStarted() error {
+func (c *cluster) waitForStarted() error {
 	// If not coordinator then wait for ClusterStatus from coordinator.
 	if !c.isCoordinator() {
 		// In the case where a node has been restarted and memberlist has
@@ -918,7 +918,7 @@ func (c *Cluster) waitForStarted() error {
 	return nil
 }
 
-func (c *Cluster) close() error {
+func (c *cluster) close() error {
 	// Notify goroutines of closing and wait for completion.
 	close(c.closing)
 	c.wg.Wait()
@@ -926,7 +926,7 @@ func (c *Cluster) close() error {
 	return nil
 }
 
-func (c *Cluster) markAsJoined() {
+func (c *cluster) markAsJoined() {
 	c.logger.Printf("mark node as joined (received coordinator update)")
 	if !c.joined {
 		c.joined = true
@@ -934,18 +934,18 @@ func (c *Cluster) markAsJoined() {
 	}
 }
 
-func (c *Cluster) needTopologyAgreement() bool {
+func (c *cluster) needTopologyAgreement() bool {
 	return c.State() == ClusterStateStarting && !stringSlicesAreEqual(c.Topology.NodeIDs, c.nodeIDs())
 }
 
-func (c *Cluster) haveTopologyAgreement() bool {
+func (c *cluster) haveTopologyAgreement() bool {
 	if c.Static {
 		return true
 	}
 	return stringSlicesAreEqual(c.Topology.NodeIDs, c.nodeIDs())
 }
 
-func (c *Cluster) allNodesReady() bool {
+func (c *cluster) allNodesReady() bool {
 	if c.Static {
 		return true
 	}
@@ -957,7 +957,7 @@ func (c *Cluster) allNodesReady() bool {
 	return true
 }
 
-func (c *Cluster) handleNodeAction(nodeAction nodeAction) error {
+func (c *cluster) handleNodeAction(nodeAction nodeAction) error {
 	j, err := c.generateResizeJob(nodeAction)
 	if err != nil {
 		c.logger.Printf("generateResizeJob error: err=%s", err)
@@ -1004,7 +1004,7 @@ func (c *Cluster) handleNodeAction(nodeAction nodeAction) error {
 	return nil
 }
 
-func (c *Cluster) setStateAndBroadcast(state string) error {
+func (c *cluster) setStateAndBroadcast(state string) error {
 	c.SetState(state)
 	if c.Static {
 		return nil
@@ -1014,7 +1014,7 @@ func (c *Cluster) setStateAndBroadcast(state string) error {
 	return c.broadcaster.SendSync(c.Status())
 }
 
-func (c *Cluster) sendTo(node *Node, msg proto.Message) error {
+func (c *cluster) sendTo(node *Node, msg proto.Message) error {
 	if err := c.broadcaster.SendTo(node, msg); err != nil {
 		return errors.Wrap(err, "sending")
 	}
@@ -1022,7 +1022,7 @@ func (c *Cluster) sendTo(node *Node, msg proto.Message) error {
 }
 
 // listenForJoins handles cluster-resize events.
-func (c *Cluster) listenForJoins() {
+func (c *cluster) listenForJoins() {
 	c.wg.Add(1)
 	go func() {
 		defer c.wg.Done()
@@ -1077,7 +1077,7 @@ func (c *Cluster) listenForJoins() {
 // generateResizeJob creates a new resizeJob based on the new node being
 // added/removed. It also saves a reference to the resizeJob in the `jobs` map
 // for future lookup by JobID.
-func (c *Cluster) generateResizeJob(nodeAction nodeAction) (*resizeJob, error) {
+func (c *cluster) generateResizeJob(nodeAction nodeAction) (*resizeJob, error) {
 	c.logger.Printf("generateResizeJob: %v", nodeAction)
 	c.mu.Lock()
 	defer c.mu.Unlock()
@@ -1104,7 +1104,7 @@ func (c *Cluster) generateResizeJob(nodeAction nodeAction) (*resizeJob, error) {
 // the difference between Cluster and a new Cluster with/without uri.
 // Broadcaster is associated to the resizeJob here for use in broadcasting
 // the resize instructions to other nodes in the cluster.
-func (c *Cluster) generateResizeJobByAction(nodeAction nodeAction) (*resizeJob, error) {
+func (c *cluster) generateResizeJobByAction(nodeAction nodeAction) (*resizeJob, error) {
 	j := newResizeJob(c.Nodes, nodeAction.node, nodeAction.action)
 	j.Broadcaster = c.broadcaster
 
@@ -1161,7 +1161,7 @@ func (c *Cluster) generateResizeJobByAction(nodeAction nodeAction) (*resizeJob,
 
 // completeCurrentJob sets the state of the current resizeJob
 // then removes the pointer to currentJob.
-func (c *Cluster) completeCurrentJob(state string) error {
+func (c *cluster) completeCurrentJob(state string) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	if !c.unprotectedIsCoordinator() {
@@ -1176,7 +1176,7 @@ func (c *Cluster) completeCurrentJob(state string) error {
 }
 
 // followResizeInstruction is run by any node that receives a ResizeInstruction.
-func (c *Cluster) followResizeInstruction(instr *internal.ResizeInstruction) error {
+func (c *cluster) followResizeInstruction(instr *internal.ResizeInstruction) error {
 	c.logger.Printf("follow resize instruction on %s", c.Node.ID)
 	// Make sure the cluster status on this node agrees with the Coordinator
 	// before attempting a resize.
@@ -1272,7 +1272,7 @@ func (c *Cluster) followResizeInstruction(instr *internal.ResizeInstruction) err
 	return nil
 }
 
-func (c *Cluster) markResizeInstructionComplete(complete *internal.ResizeInstructionComplete) error {
+func (c *cluster) markResizeInstructionComplete(complete *internal.ResizeInstructionComplete) error {
 
 	j := c.job(complete.JobID)
 
@@ -1300,7 +1300,7 @@ func (c *Cluster) markResizeInstructionComplete(complete *internal.ResizeInstruc
 }
 
 // job returns a resizeJob by id.
-func (c *Cluster) job(id int64) *resizeJob {
+func (c *cluster) job(id int64) *resizeJob {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 	return c.jobs[id]
@@ -1516,7 +1516,7 @@ func (t *Topology) Encode() *internal.Topology {
 }
 
 // loadTopology reads the topology for the node.
-func (c *Cluster) loadTopology() error {
+func (c *cluster) loadTopology() error {
 	buf, err := ioutil.ReadFile(filepath.Join(c.Path, ".topology"))
 	if os.IsNotExist(err) {
 		c.Topology = NewTopology()
@@ -1539,7 +1539,7 @@ func (c *Cluster) loadTopology() error {
 }
 
 // saveTopology writes the current topology to disk.
-func (c *Cluster) saveTopology() error {
+func (c *cluster) saveTopology() error {
 
 	if err := os.MkdirAll(c.Path, 0777); err != nil {
 		return errors.Wrap(err, "creating directory")
@@ -1579,7 +1579,7 @@ func decodeTopology(topology *internal.Topology) (*Topology, error) {
 	return t, nil
 }
 
-func (c *Cluster) considerTopology() error {
+func (c *cluster) considerTopology() error {
 	// Create ClusterID if one does not already exist.
 	if c.id == "" {
 		u := uuid.NewV4()
@@ -1612,7 +1612,7 @@ func (c *Cluster) considerTopology() error {
 }
 
 // ReceiveEvent represents an implementation of EventHandler.
-func (c *Cluster) ReceiveEvent(e *nodeEvent) error {
+func (c *cluster) ReceiveEvent(e *nodeEvent) error {
 	// Ignore events sent from this node.
 	if e.Node.ID == c.Node.ID {
 		return nil
@@ -1635,7 +1635,7 @@ func (c *Cluster) ReceiveEvent(e *nodeEvent) error {
 	return nil
 }
 
-func (c *Cluster) nodeJoin(node *Node) error {
+func (c *cluster) nodeJoin(node *Node) error {
 	if c.needTopologyAgreement() {
 		// A host that is not part of the topology can't be added to the STARTING cluster.
 		if !c.Topology.ContainsID(node.ID) {
@@ -1699,7 +1699,7 @@ func (c *Cluster) nodeJoin(node *Node) error {
 }
 
 // nodeLeave initiates the removal of a node from the cluster.
-func (c *Cluster) nodeLeave(node *Node) error {
+func (c *cluster) nodeLeave(node *Node) error {
 	// Refuse the request if this is not the coordinator.
 	if !c.isCoordinator() {
 		return fmt.Errorf("node removal requests are only valid on the coordinator node: %s", c.coordinatorNode().ID)
@@ -1752,7 +1752,7 @@ func (c *Cluster) nodeLeave(node *Node) error {
 	return nil
 }
 
-func (c *Cluster) mergeClusterStatus(cs *internal.ClusterStatus) error {
+func (c *cluster) mergeClusterStatus(cs *internal.ClusterStatus) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	c.logger.Printf("merge cluster status: %v", cs)
@@ -1801,7 +1801,7 @@ func (c *Cluster) mergeClusterStatus(cs *internal.ClusterStatus) error {
 	return nil
 }
 
-func (c *Cluster) setStatic(hosts []string) error {
+func (c *cluster) setStatic(hosts []string) error {
 	c.Static = true
 	c.Coordinator = c.Node.ID
 	for _, address := range hosts {
diff --git a/cluster_internal_test.go b/cluster_internal_test.go
index 8e4621653..d607cd883 100644
--- a/cluster_internal_test.go
+++ b/cluster_internal_test.go
@@ -172,8 +172,8 @@ func TestFragSources(t *testing.T) {
 	}
 
 	tests := []struct {
-		from     *Cluster
-		to       *Cluster
+		from     *cluster
+		to       *cluster
 		idx      *Index
 		expected map[string][]*internal.ResizeSource
 		err      string
@@ -316,7 +316,7 @@ func TestResizeJob(t *testing.T) {
 
 // Ensure the cluster can fairly distribute partitions across the nodes.
 func TestCluster_Owners(t *testing.T) {
-	c := Cluster{
+	c := cluster{
 		Nodes: []*Node{
 			{URI: NewTestURIFromHostPort("serverA", 1000)},
 			{URI: NewTestURIFromHostPort("serverB", 1000)},
diff --git a/executor.go b/executor.go
index c3e9ec77c..1977665cb 100644
--- a/executor.go
+++ b/executor.go
@@ -43,7 +43,7 @@ type Executor struct {
 
 	// Local hostname & cluster configuration.
 	Node    *Node
-	Cluster *Cluster
+	Cluster *cluster
 
 	// Client used for remote requests.
 	client InternalQueryClient
diff --git a/fragment.go b/fragment.go
index a5a40d68f..30fb67fca 100644
--- a/fragment.go
+++ b/fragment.go
@@ -1717,7 +1717,7 @@ type FragmentSyncer struct {
 	Fragment *Fragment
 
 	Node    *Node
-	Cluster *Cluster
+	Cluster *cluster
 
 	Closing <-chan struct{}
 }
diff --git a/holder.go b/holder.go
index eb6eacd57..0141d365e 100644
--- a/holder.go
+++ b/holder.go
@@ -569,7 +569,7 @@ type HolderSyncer struct {
 	Holder *Holder
 
 	Node    *Node
-	Cluster *Cluster
+	Cluster *cluster
 
 	// Stats
 	Stats StatsClient
@@ -778,7 +778,7 @@ type HolderCleaner struct {
 	Node *Node
 
 	Holder  *Holder
-	Cluster *Cluster
+	Cluster *cluster
 
 	// Signals that the sync should stop.
 	Closing <-chan struct{}
diff --git a/server.go b/server.go
index d64b9efa7..47a97bd24 100644
--- a/server.go
+++ b/server.go
@@ -51,7 +51,7 @@ type Server struct {
 
 	// Internal
 	holder          *Holder
-	cluster         *Cluster
+	cluster         *cluster
 	translateFile   *TranslateFile
 	diagnostics     *DiagnosticsCollector
 	executor        *Executor
diff --git a/utils_internal_test.go b/utils_internal_test.go
index 6a84d168d..171955b4e 100644
--- a/utils_internal_test.go
+++ b/utils_internal_test.go
@@ -28,7 +28,7 @@ import (
 )
 
 // NewTestCluster returns a cluster with n nodes and uses a mod-based hasher.
-func NewTestCluster(n int) *Cluster {
+func NewTestCluster(n int) *cluster {
 	path, err := ioutil.TempDir("", "pilosa-cluster-")
 	if err != nil {
 		panic(err)
@@ -82,7 +82,7 @@ func (*TestModHasher) Hash(key uint64, n int) int { return int(key) % n }
 // has a Cluster.
 // ClusterCluster implements Broadcaster interface.
 type ClusterCluster struct {
-	Clusters []*Cluster
+	Clusters []*cluster
 
 	common *commonClusterSettings
 
@@ -141,7 +141,7 @@ func (t *ClusterCluster) SetBit(index, field string, rowID, colID uint64, x *tim
 	return nil
 }
 
-func (t *ClusterCluster) clusterByID(id string) *Cluster {
+func (t *ClusterCluster) clusterByID(id string) *cluster {
 	for _, c := range t.Clusters {
 		if c.Node.ID == id {
 			return c
@@ -194,7 +194,7 @@ func (t *ClusterCluster) WriteTopology(path string, top *Topology) error {
 	return nil
 }
 
-func (t *ClusterCluster) addCluster(i int, saveTopology bool) (*Cluster, error) {
+func (t *ClusterCluster) addCluster(i int, saveTopology bool) (*cluster, error) {
 
 	id := fmt.Sprintf("node%d", i)
 	uri := NewTestURI("http", fmt.Sprintf("host%d", i), uint16(0))