Updated with master

2026-10-09 12:27:52 +00:00 · 2018-04-13 03:50:26 +03:00 · 2018-04-13 03:50:26 +03:00 · 3695a8e889
commit 3695a8e889
parent cde6082869 e6dbdcb836
11 changed files with 243 additions and 197 deletions
--- a/api.go
+++ b/api.go
@ -19,6 +19,7 @@ import (
 	"encoding/csv"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net/http"
 	"reflect"
 	"strconv"
@ -31,6 +32,8 @@ import (
 	"github.com/pkg/errors"
 )

+// API provides the top level programmatic interface to Pilosa. It is usually
+// wrapped by a handler which provides an external interface (e.g. HTTP).
 type API struct {
 	Holder *Holder
 	// The execution engine for running queries.
@ -46,6 +49,7 @@ type API struct {
 	Logger           Logger
 }

+// NewAPI returns a new API instance.
 func NewAPI() *API {
 	return &API{
 		Broadcaster: NopBroadcaster,
@ -55,7 +59,8 @@ func NewAPI() *API {
 	}
 }

-func (a *API) ExecuteQuery(ctx context.Context, req *QueryRequest) (QueryResponse, error) {
+// Query parses a PQL query out of the request and executes it.
+func (api *API) Query(ctx context.Context, req *QueryRequest) (QueryResponse, error) {
 	resp := QueryResponse{}

 	q, err := pql.NewParser(strings.NewReader(req.Query)).Parse()
@ -67,7 +72,7 @@ func (a *API) ExecuteQuery(ctx context.Context, req *QueryRequest) (QueryRespons
 		ExcludeAttrs: req.ExcludeAttrs,
 		ExcludeBits:  req.ExcludeBits,
 	}
-	results, err := a.Executor.Execute(ctx, req.Index, q, req.Slices, execOpts)
+	results, err := api.Executor.Execute(ctx, req.Index, q, req.Slices, execOpts)
 	if err != nil {
 		return resp, err
 	}
@ -86,7 +91,7 @@ func (a *API) ExecuteQuery(ctx context.Context, req *QueryRequest) (QueryRespons
 		}

 		// Retrieve column attributes across all calls.
-		columnAttrSets, err := a.readColumnAttrSets(a.Holder.Index(req.Index), columnIDs)
+		columnAttrSets, err := api.readColumnAttrSets(api.Holder.Index(req.Index), columnIDs)
 		if err != nil {
 			return resp, err
 		}
@ -118,6 +123,7 @@ func (api *API) readColumnAttrSets(index *Index, ids []uint64) ([]*ColumnAttrSet
 	return ax, nil
 }

+// CreateIndex makes a new Pilosa index.
 func (api *API) CreateIndex(ctx context.Context, indexName string, options IndexOptions) (*Index, error) {
 	// Create index.
 	index, err := api.Holder.CreateIndex(indexName, options)
@ -138,7 +144,8 @@ func (api *API) CreateIndex(ctx context.Context, indexName string, options Index
 	return index, nil
 }

-func (api *API) ReadIndex(ctx context.Context, indexName string) (*Index, error) {
+// Index retrieves the named index.
+func (api *API) Index(ctx context.Context, indexName string) (*Index, error) {
 	index := api.Holder.Index(indexName)
 	if index == nil {
 		return nil, ErrIndexNotFound
@ -146,6 +153,8 @@ func (api *API) ReadIndex(ctx context.Context, indexName string) (*Index, error)
 	return index, nil
 }

+// DeleteIndex removes the named index. If the index is not found it does
+// nothing and returns no error.
 func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 	// Delete index from the holder.
 	err := api.Holder.DeleteIndex(indexName)
@ -165,6 +174,7 @@ func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 	return nil
 }

+// CreateFrame makes the named frame in the named index with the given options.
 func (api *API) CreateFrame(ctx context.Context, indexName string, frameName string, options FrameOptions) (*Frame, error) {
 	// Find index.
 	index := api.Holder.Index(indexName)
@ -193,6 +203,9 @@ func (api *API) CreateFrame(ctx context.Context, indexName string, frameName str
 	return frame, nil
 }

+// DeleteFrame removes the named frame from the named index. If the index is not
+// found, an error is returned. If the frame is not found, it is ignored and no
+// action is taken.
 func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName string) error {
 	// Find index.
 	index := api.Holder.Index(indexName)
@ -219,9 +232,11 @@ func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName str
 	return nil
 }

+// ExportCSV encodes the fragment designated by the index,frame,view,slice as
+// CSV of the form <row>,<col>
 func (api *API) ExportCSV(ctx context.Context, indexName string, frameName string, viewName string, slice uint64, w io.Writer) error {
 	// Validate that this handler owns the slice.
-	if !api.Cluster.OwnsFragment(api.LocalID(), indexName, slice) {
+	if !api.Cluster.OwnsSlice(api.LocalID(), indexName, slice) {
 		api.Logger.Printf("host does not own slice %s-%s slice:%d", api.URI, indexName, slice)
 		return ErrClusterDoesNotOwnSlice
 	}
@ -251,11 +266,20 @@ func (api *API) ExportCSV(ctx context.Context, indexName string, frameName strin
 	return nil
 }

-func (api *API) FragmentNodes(ctx context.Context, indexName string, slice uint64) []*Node {
-	return api.Cluster.FragmentNodes(indexName, slice)
+// SliceNodes returns the node and all replicas which should contain a slice's data.
+func (api *API) SliceNodes(ctx context.Context, indexName string, slice uint64) []*Node {
+	return api.Cluster.SliceNodes(indexName, slice)
 }

-func (api *API) FragmentData(ctx context.Context, indexName string, frameName string, viewName string, slice uint64) (*Fragment, error) {
+// WriterTo is an interface for any Object which knows how to serialize itself to an io.Writer
+type WriterTo interface {
+	WriteTo(w io.Writer) (n int64, err error)
+}
+
+// MarshalFragment returns an object which can write the specified fragment's data
+// to an io.Writer. The serialized data can be read back into a fragment with
+// the UnmarshalFragment API call.
+func (api *API) MarshalFragment(ctx context.Context, indexName string, frameName string, viewName string, slice uint64) (WriterTo, error) {
 	// Retrieve fragment from holder.
 	f := api.Holder.Fragment(indexName, frameName, viewName, slice)
 	if f == nil {
@ -264,7 +288,10 @@ func (api *API) FragmentData(ctx context.Context, indexName string, frameName st
 	return f, nil
 }

-func (api *API) WriteFragmentData(ctx context.Context, indexName string, frameName string, viewName string, slice uint64, reader io.ReadCloser) error {
+// UnmarshalFragment creates a new fragment (if necessary) and reads data from a
+// Reader which was previously written by MarshalFragment to populate the
+// fragment's data.
+func (api *API) UnmarshalFragment(ctx context.Context, indexName string, frameName string, viewName string, slice uint64, reader io.ReadCloser) error {
 	// Retrieve frame.
 	f := api.Holder.Frame(indexName, frameName)
 	if f == nil {
@ -290,19 +317,38 @@ func (api *API) WriteFragmentData(ctx context.Context, indexName string, frameNa
 	return nil
 }

-func (api *API) FragmentBlockData(ctx context.Context, req internal.BlockDataRequest) (internal.BlockDataResponse, error) {
+// FragmentBlockData is an endpoint for internal usage. It is not guaranteed to
+// return anything useful. Currently it returns protobuf encoded row and column
+// ids from a "block" which is a subdivision of a fragment.
+func (api *API) FragmentBlockData(ctx context.Context, body io.Reader) ([]byte, error) {
+	reqBytes, err := ioutil.ReadAll(body)
+	if err != nil {
+		return nil, BadRequestError{errors.Wrap(err, "read body error")}
+	}
+	var req internal.BlockDataRequest
+	if err := proto.Unmarshal(reqBytes, &req); err != nil {
+		return nil, BadRequestError{errors.Wrap(err, "unmarshal body error")}
+	}
+
 	// Retrieve fragment from holder.
 	f := api.Holder.Fragment(req.Index, req.Frame, req.View, req.Slice)
 	if f == nil {
-		return internal.BlockDataResponse{}, ErrFragmentNotFound
+		return nil, ErrFragmentNotFound
 	}

-	// Read data
-	var resp internal.BlockDataResponse
+	var resp = internal.BlockDataResponse{}
 	resp.RowIDs, resp.ColumnIDs = f.BlockData(int(req.Block))
-	return resp, nil
+
+	// Encode response.
+	buf, err := proto.Marshal(&resp)
+	if err != nil {
+		return nil, errors.Wrap(err, "merge block response encoding error: %s")
+	}
+
+	return buf, nil
 }

+// FragmentBlocks returns the checksums and block ids for all blocks in the specified fragment.
 func (api *API) FragmentBlocks(ctx context.Context, indexName string, frameName string, viewName string, slice uint64) ([]FragmentBlock, error) {
 	// Retrieve fragment from holder.
 	f := api.Holder.Fragment(indexName, frameName, viewName, slice)
@ -315,6 +361,8 @@ func (api *API) FragmentBlocks(ctx context.Context, indexName string, frameName
 	return blocks, nil
 }

+// RestoreFrame reads all the data that this host should have for a given frame
+// from replicas in the cluster and restores that data to it.
 func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName string, host *URI) error {
 	// Create a client for the remote cluster.
 	client := NewInternalHTTPClientFromURI(host, api.RemoteClient)
@ -340,7 +388,7 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 	// Loop over each slice and import it if this node owns it.
 	for slice := uint64(0); slice <= maxSlices[indexName]; slice++ {
 		// Ignore this slice if we don't own it.
-		if !api.Cluster.OwnsFragment(api.LocalID(), indexName, slice) {
+		if !api.Cluster.OwnsSlice(api.LocalID(), indexName, slice) {
 			continue
 		}

@ -382,11 +430,16 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 	return nil
 }

-func (api *API) ClusterHosts(ctx context.Context) []*Node {
+// Hosts returns a list of the hosts in the cluster including their ID,
+// URL, and which is the coordinator.
+func (api *API) Hosts(ctx context.Context) []*Node {
 	return api.Cluster.Nodes
 }

+// CreateInputDefinition is deprecated and will be removed. Do not use it.
 func (api *API) CreateInputDefinition(ctx context.Context, indexName string, inputDefName string, inputDef InputDefinitionInfo) error {
+	api.Logger.Printf(`CreateInputDefinition is deprecated and will be removed.
+Please open an issue if you need to continue using it.`)
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
@ -417,7 +470,9 @@ func (api *API) CreateInputDefinition(ctx context.Context, indexName string, inp
 	return nil
 }

+// InputDefinition is deprecated and will be removed.
 func (api *API) InputDefinition(ctx context.Context, indexName string, inputDefName string) (*InputDefinition, error) {
+	api.Logger.Printf(`InputDefinition is deprecated and will be removed.`)
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
@ -431,7 +486,9 @@ func (api *API) InputDefinition(ctx context.Context, indexName string, inputDefN
 	return inputDef, nil
 }

+// DeleteInputDefinition is deprecated and will be removed.
 func (api *API) DeleteInputDefinition(ctx context.Context, indexName string, inputDefName string) error {
+	api.Logger.Printf("DeleteInputDefinition is deprecated and will be removed.")
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
@ -454,7 +511,9 @@ func (api *API) DeleteInputDefinition(ctx context.Context, indexName string, inp
 	return nil
 }

+// WriteInput is deprecated and will be removed.
 func (api *API) WriteInput(ctx context.Context, indexName string, inputDefName string, reqs []interface{}) error {
+	api.Logger.Printf("WriteInput is deprecated and will be removed.")
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
@ -476,6 +535,7 @@ func (api *API) WriteInput(ctx context.Context, indexName string, inputDefName s
 	return nil
 }

+// RecalculateCaches forces all TopN caches to be updated. Used mainly for integration tests.
 func (api *API) RecalculateCaches(ctx context.Context) error {
 	err := api.Broadcaster.SendSync(&internal.RecalculateCaches{})
 	if err != nil {
@ -485,27 +545,41 @@ func (api *API) RecalculateCaches(ctx context.Context) error {
 	return nil
 }

-func (api *API) PostClusterMessage(ctx context.Context, pb proto.Message) error {
+// PostClusterMessage is for internal use. It decodes a protobuf message out of
+// the body and forwards it to the BroadcastHandler.
+func (api *API) PostClusterMessage(ctx context.Context, reqBody io.Reader) error {
+	// Read entire body.
+	body, err := ioutil.ReadAll(reqBody)
+	if err != nil {
+		return errors.Wrap(err, "reading body")
+	}
+
+	// Marshal into request object.
+	pb, err := UnmarshalMessage(body)
+	if err != nil {
+		return errors.Wrap(err, "unmarshaling message")
+	}
+
 	// Forward the error message.
 	if err := api.BroadcastHandler.ReceiveMessage(pb); err != nil {
-		return err
+		return errors.Wrap(err, "receiving message")
 	}
 	return nil
 }

+// LocalID returns the current node's ID.
 func (api *API) LocalID() string {
 	return api.Cluster.Node.ID
 }

+// Schema returns information about each index in Pilosa including which frames
+// and views they contain.
 func (api *API) Schema(ctx context.Context) []*IndexInfo {
 	return api.Holder.Schema()
 }

-func (api *API) Status(ctx context.Context) (proto.Message, error) {
-	return api.StatusHandler.ClusterStatus()
-}
-
-func (api *API) CreateFrameField(ctx context.Context, indexName string, frameName string, field *Field) error {
+// CreateField creates a new BSI field in the given index and frame.
+func (api *API) CreateField(ctx context.Context, indexName string, frameName string, field *Field) error {
 	// Retrieve frame by name.
 	f := api.Holder.Frame(indexName, frameName)
 	if f == nil {
@ -530,7 +604,8 @@ func (api *API) CreateFrameField(ctx context.Context, indexName string, frameNam
 	return err
 }

-func (api *API) DeleteFrameField(ctx context.Context, indexName string, frameName string, fieldName string) error {
+// DeleteField deletes the given field.
+func (api *API) DeleteField(ctx context.Context, indexName string, frameName string, fieldName string) error {
 	// Retrieve frame by name.
 	f := api.Holder.Frame(indexName, frameName)
 	if f == nil {
@ -555,7 +630,8 @@ func (api *API) DeleteFrameField(ctx context.Context, indexName string, frameNam
 	return err
 }

-func (api *API) FrameFields(ctx context.Context, indexName string, frameName string) ([]*Field, error) {
+// Fields returns the fields in the given frame.
+func (api *API) Fields(ctx context.Context, indexName string, frameName string) ([]*Field, error) {
 	index := api.Holder.index(indexName)
 	if index == nil {
 		return nil, ErrIndexNotFound
@ -569,7 +645,8 @@ func (api *API) FrameFields(ctx context.Context, indexName string, frameName str
 	return frame.GetFields()
 }

-func (api *API) FrameViews(ctx context.Context, indexName string, frameName string) ([]*View, error) {
+// Views returns the views in the given frame.
+func (api *API) Views(ctx context.Context, indexName string, frameName string) ([]*View, error) {
 	// Retrieve views.
 	f := api.Holder.Frame(indexName, frameName)
 	if f == nil {
@ -581,6 +658,7 @@ func (api *API) FrameViews(ctx context.Context, indexName string, frameName stri
 	return views, nil
 }

+// DeleteView removes the given view.
 func (api *API) DeleteView(ctx context.Context, indexName string, frameName string, viewName string) error {
 	// Retrieve frame.
 	f := api.Holder.Frame(indexName, frameName)
@ -590,7 +668,7 @@ func (api *API) DeleteView(ctx context.Context, indexName string, frameName stri

 	// Delete the view.
 	if err := f.DeleteView(viewName); err != nil {
-		// Ingore this error becuase views do not exist on all nodes due to slice distribution.
+		// Ignore this error becuase views do not exist on all nodes due to slice distribution.
 		if err != ErrInvalidView {
 			return err
 		}
@ -610,6 +688,7 @@ func (api *API) DeleteView(ctx context.Context, indexName string, frameName stri
 	return err
 }

+// IndexAttrDiff
 func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []AttrBlock) (map[uint64]map[string]interface{}, error) {
 	// Retrieve index from holder.
 	index := api.Holder.Index(indexName)
@ -670,6 +749,7 @@ func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName s
 	return attrs, nil
 }

+// Import bulk imports data into a particular index,frame,slice.
 func (api *API) Import(ctx context.Context, req internal.ImportRequest) error {
 	_, frame, err := api.indexFrame(req.Index, req.Frame, req.Slice)
 	if err != nil {
@ -694,6 +774,7 @@ func (api *API) Import(ctx context.Context, req internal.ImportRequest) error {
 	return err
 }

+// ImportValue bulk imports values into a particular field.
 func (api *API) ImportValue(ctx context.Context, req internal.ImportValueRequest) error {
 	_, frame, err := api.indexFrame(req.Index, req.Frame, req.Slice)
 	if err != nil {
@ -708,6 +789,7 @@ func (api *API) ImportValue(ctx context.Context, req internal.ImportValueRequest
 	return err
 }

+// ModifyIndexTimeQuantum changes the default time quantum on the given index.
 func (api *API) ModifyIndexTimeQuantum(ctx context.Context, indexName string, timeQuantum TimeQuantum) error {
 	// Retrieve index by name.
 	index := api.Holder.Index(indexName)
@ -719,6 +801,8 @@ func (api *API) ModifyIndexTimeQuantum(ctx context.Context, indexName string, ti
 	return index.SetTimeQuantum(timeQuantum)
 }

+// ModifyFrameTimeQuantum changes the time quantum on the given frame. TODO:
+// what happens if there is already data in the frame?
 func (api *API) ModifyFrameTimeQuantum(ctx context.Context, indexName string, frameName string, timeQuantum TimeQuantum) error {
 	// Retrieve index by name.
 	frame := api.Holder.Frame(indexName, frameName)
@ -730,14 +814,19 @@ func (api *API) ModifyFrameTimeQuantum(ctx context.Context, indexName string, fr
 	return frame.SetTimeQuantum(timeQuantum)
 }

+// MaxSlices returns the maximum slice number for each index in a map.
 func (api *API) MaxSlices(ctx context.Context) map[string]uint64 {
 	return api.Holder.MaxSlices()
 }

+// MaxInverseSlices returns the maximum inverse slice number for each index in a
+// map.
 func (api *API) MaxInverseSlices(ctx context.Context) map[string]uint64 {
 	return api.Holder.MaxInverseSlices()
 }

+// StatsWithTags returns an instance of whatever implementation of StatsClient
+// pilosa is using with the given tags.
 func (api *API) StatsWithTags(tags []string) StatsClient {
 	if api.Holder == nil || api.Cluster == nil {
 		return nil
@ -745,7 +834,9 @@ func (api *API) StatsWithTags(tags []string) StatsClient {
 	return api.Holder.Stats.WithTags(tags...)
 }

-func (api *API) ClusterLongQueryTime() time.Duration {
+// LongQueryTime returns the configured threshold for logging/statting
+// long running queries.
+func (api *API) LongQueryTime() time.Duration {
 	if api.Cluster == nil {
 		return 0
 	}
@ -754,7 +845,7 @@ func (api *API) ClusterLongQueryTime() time.Duration {

 func (api *API) indexFrame(indexName string, frameName string, slice uint64) (*Index, *Frame, error) {
 	// Validate that this handler owns the slice.
-	if !api.Cluster.OwnsFragment(api.LocalID(), indexName, slice) {
+	if !api.Cluster.OwnsSlice(api.LocalID(), indexName, slice) {
 		api.Logger.Printf("host does not own slice %s-%s slice:%d", api.URI, indexName, slice)
 		return nil, nil, ErrClusterDoesNotOwnSlice
 	}
@ -776,7 +867,7 @@ func (api *API) indexFrame(indexName string, frameName string, slice uint64) (*I
 	return index, frame, nil
 }

-// inputJSONDataParser validates input json file and executes SetBit.
+// inputJSONDataParser validates input json file and executes SetBit. Deprecated - remove with input definition stuff.
 func (api *API) inputJSONDataParser(req map[string]interface{}, index *Index, name string) (map[string][]*Bit, error) {
 	inputDef, err := index.InputDefinition(name)
 	if err != nil {
@ -845,6 +936,7 @@ func (api *API) inputJSONDataParser(req map[string]interface{}, index *Index, na
 	return setBits, nil
 }

+// SetCoordinator makes a new Node the cluster coordinator.
 func (api *API) SetCoordinator(ctx context.Context, id string) (oldNode, newNode *Node, err error) {
 	oldNode = api.Cluster.nodeByID(api.Cluster.Coordinator)
 	newNode = api.Cluster.nodeByID(id)
@ -869,6 +961,8 @@ func (api *API) SetCoordinator(ctx context.Context, id string) (oldNode, newNode
 	return oldNode, newNode, nil
 }

+// RemoveNode puts the cluster into the "RESIZING" state and begins the job of
+// removing the given node.
 func (api *API) RemoveNode(id string) (*Node, error) {
 	removeNode := api.Cluster.nodeByID(id)
 	if removeNode == nil {
@ -883,6 +977,7 @@ func (api *API) RemoveNode(id string) (*Node, error) {
 	return removeNode, nil
 }

+// ResizeAbort stops the current resize job.
 func (api *API) ResizeAbort() error {
 	if !api.Cluster.IsCoordinator() {
 		return ErrNodeNotCoordinator
@ -891,6 +986,14 @@ func (api *API) ResizeAbort() error {
 	return errors.Wrap(err, "complete current job")
 }

+// State returns the cluster state which is usually "NORMAL", but could be
+// "STARTING", "RESIZING", or potentially others. See cluster.go for more
+// details.
 func (api *API) State() string {
 	return api.Cluster.State()
 }
+
+// Version returns the Pilosa version.
+func (api *API) Version() string {
+	return strings.TrimPrefix(Version, "v")
+}
--- a/cluster.go
+++ b/cluster.go
@ -654,7 +654,7 @@ func (c *Cluster) fragsByHost(idx *Index) fragsByHost {
 func (c *Cluster) fragCombos(idx string, maxSlice uint64, frameViews viewsByFrame) fragsByHost {
 	t := make(fragsByHost)
 	for i := uint64(0); i <= maxSlice; i++ {
-		nodes := c.FragmentNodes(idx, i)
+		nodes := c.SliceNodes(idx, i)
 		for _, n := range nodes {
 			// for each frame/view combination:
 			for frame, views := range frameViews {
@ -807,14 +807,14 @@ func (c *Cluster) Partition(index string, slice uint64) int {
 	return int(h.Sum64() % uint64(c.PartitionN))
 }

-// FragmentNodes returns a list of nodes that own a fragment.
-func (c *Cluster) FragmentNodes(index string, slice uint64) []*Node {
+// SliceNodes returns a list of nodes that own a fragment.
+func (c *Cluster) SliceNodes(index string, slice uint64) []*Node {
 	return c.PartitionNodes(c.Partition(index, slice))
 }

-// OwnsFragment returns true if a host owns a fragment.
-func (c *Cluster) OwnsFragment(nodeID string, index string, slice uint64) bool {
-	return Nodes(c.FragmentNodes(index, slice)).ContainsID(nodeID)
+// OwnsSlice returns true if a host owns a fragment.
+func (c *Cluster) OwnsSlice(nodeID string, index string, slice uint64) bool {
+	return Nodes(c.SliceNodes(index, slice)).ContainsID(nodeID)
 }

 // PartitionNodes returns a list of nodes that own a partition.
--- a/docs/getting-started.md
+++ b/docs/getting-started.md
@ -129,7 +129,7 @@ Which repositories did user 14 star:
 ``` request
 curl localhost:10101/index/repository/query \
     -X POST \
-     -d 'Bitmap(frame="stargazer", rowID=14)'
+     -d 'Bitmap(frame="stargazer", row=14)'
 ```
 ``` response
 {
@ -167,8 +167,8 @@ Which repositories were starred by user 14 and 19:
 curl localhost:10101/index/repository/query \
     -X POST \
     -d 'Intersect(
-            Bitmap(frame="stargazer", rowID=14), 
-            Bitmap(frame="stargazer", rowID=19)
+            Bitmap(frame="stargazer", row=14), 
+            Bitmap(frame="stargazer", row=19)
        )'
 ```
 ``` response
@ -187,8 +187,8 @@ Which repositories were starred by user 14 or 19:
 curl localhost:10101/index/repository/query \
     -X POST \
     -d 'Union(
-            Bitmap(frame="stargazer", rowID=14),
-            Bitmap(frame="stargazer", rowID=19)
+            Bitmap(frame="stargazer", row=14),
+            Bitmap(frame="stargazer", row=19)
        )'
 ```
 ``` response
@ -207,9 +207,9 @@ Which repositories were starred by user 14 and 19 and also were written in langu
 curl localhost:10101/index/repository/query \
     -X POST \
     -d 'Intersect(
-            Bitmap(frame="stargazer", rowID=14),
-            Bitmap(frame="stargazer", rowID=19),
-            Bitmap(frame="language", rowID=1)
+            Bitmap(frame="stargazer", row=14),
+            Bitmap(frame="stargazer", row=19),
+            Bitmap(frame="language", row=1)
        )'
 ```
 ``` response
@ -227,7 +227,7 @@ Set user 99999 as a stargazer for repository 77777:
 ``` request
 curl localhost:10101/index/repository/query \
     -X POST \
-     -d 'SetBit(frame="stargazer", columnID=77777, rowID=99999)'
+     -d 'SetBit(frame="stargazer", column=77777, row=99999)'
 ```
 ``` response
 {"results":[true]}
--- a/docs/tutorials.md
+++ b/docs/tutorials.md
@ -70,6 +70,8 @@ We now should have `pilosa.local.gossip32` in the current directory with 32 rand

 Pilosa supports passing configuration items using the command line, environment variables or a configuration file. We will use the last option in this tutorial and create three configuration files for our three nodes.

+One of the nodes in the cluster must be chosen as the *coordinator*. We choose the first node as the coordinator in this tutorial. The coordinator is only important during cluster resizing operations, and otherwise acts like any other node in the cluster. In the future, the coordinator will be chosen transparently by distributed consensus, and this option will be deprecated.
+
 Create `node1.config.toml` in the project directory and paste the following in it:

 ```toml
@ -79,7 +81,7 @@ data-dir = "node1_data"
 bind = "https://01.pilosa.local:10501"

 [cluster]
-hosts = ["https://01.pilosa.local:10501", "https://02.pilosa.local:10502", "https://03.pilosa.local:10503"]
+coordinator = true

 [tls]
 certificate = "pilosa.local.crt"
@ -87,7 +89,7 @@ key = "pilosa.local.key"
 skip-verify = true

 [gossip]
-seed = "01.pilosa.local:15000"
+seeds = ["01.pilosa.local:15000"]
 port = 15000
 key = "pilosa.local.gossip32"
 ```
@ -100,16 +102,13 @@ Create `node2.config.toml` in the project directory and paste the following in i
 data-dir = "node2_data"
 bind = "https://02.pilosa.local:10502"

-[cluster]
-hosts = ["https://01.pilosa.local:10501", "https://02.pilosa.local:10502", "https://03.pilosa.local:10503"]
-
 [tls]
 certificate = "pilosa.local.crt"
 key = "pilosa.local.key"
 skip-verify = true

 [gossip]
-seed = "01.pilosa.local:15000"
+seeds = ["01.pilosa.local:15000"]
 port = 16000
 key = "pilosa.local.gossip32"
 ```
@ -122,16 +121,13 @@ Create `node3.config.toml` in the project directory and paste the following in i
 data-dir = "node3_data"
 bind = "https://03.pilosa.local:10503"

-[cluster]
-hosts = ["https://01.pilosa.local:10501", "https://02.pilosa.local:10502", "https://03.pilosa.local:10503"]
-
 [tls]
 certificate = "pilosa.local.crt"
 key = "pilosa.local.key"
 skip-verify = true

 [gossip]
-seed = "01.pilosa.local:15000"
+seeds = ["01.pilosa.local:15000"]
 port = 17000
 key = "pilosa.local.gossip32"
 ```
@ -140,9 +136,9 @@ Here is some explanation of the configuration items:

 * `data-dir` points to the directory where the Pilosa server writes its data. If it doesn't exist, the server will create it.
 * `bind` is the address to which the server listens for incoming requests. The address is composed of three parts: scheme, host, and port. The default scheme is `http` so we explicitly specify `https` to use the HTTPS protocol for communication between nodes.
-* `[cluster]` section contains the settings for a cluster. `hosts` field is the most important, which contains the list of addresses of other nodes. See [Cluster Configuration](../configuration/#cluster-hosts) for other settings.
+* `[cluster]` section contains the settings for a cluster. We set `coordinator = true` for only the first node to choose that as the coordinator node. See [Cluster Configuration](../configuration/#cluster-coordinator) for other settings.
 * `[tls]` section contains the TLS settings, including the path to the SSL certificate and the corresponding key. Set `skip-verify` to `true` in order to disable host name verification and other security measures. Do not set `skip-verify` to `true` on production servers.
-* `[gossip]` section contains settings for the Gossip protocol. `seed` is the host and port for the main gossip node which coordinates other nodes. The `port` setting is the gossip listen address for the node. It should be different for each node, if the cluster is running on the same computer, otherwise you can set it to the same value. Finally, the `key` points to the gossip encryption key we created before.
+* `[gossip]` section contains settings for the Gossip protocol. `seeds` contain the seed nodes which other nodes gather cluster topology. There must be at least one gossip seed. The `port` setting is the gossip listen address for the node. It should be different for each node, if the cluster is running on the same computer, otherwise you can set it to the same value. Finally, the `key` points to the gossip encryption key we created before.

 #### Final Touches Before Running the Cluster

@ -189,9 +185,9 @@ curl -k --ipv4 https://01.pilosa.local:10501/status

 The `-k` flag is used to tell curl that it shouldn't bother with checking the certificate the server provides and `--ipv4` workarounds an issue on MacOS where the curl requests take a long time if the address resolves to `127.0.0.1`. You can leave it out on Linux and WSL.

-All nodes should be in the `UP` state:
+All nodes should be in the `NORMAL` state:
 ``` response
-{"status":{"Nodes":[{"Host":"01.pilosa.local:10501","State":"UP"},{"Host":"02.pilosa.local:10502","State":"UP"},{"Host":"03.pilosa.local:10503","State":"UP"}]}}
+{"state":"NORMAL","nodes":[{"id":"98ebd177-c082-4c54-8d48-7e7c75857b52","uri":{"scheme":"https","host":"02.pilosa.local","port":10502},"isCoordinator":false},{"id":"a33dc0d6-c35f-4559-984a-e582bf032a21","uri":{"scheme":"https","host":"03.pilosa.local","port":10503},"isCoordinator":false},{"id":"e24ac014-ee2f-4cb0-b565-74df6c551f0a","uri":{"scheme":"https","host":"01.pilosa.local","port":10501},"isCoordinator":true}]}
 ```

 #### Running Queries
@ -216,7 +212,7 @@ We just created frame `sample-frame` with default options.

 Let's run a `SetBit` query:
 ``` request
-curl -k --ipv4 https://01.pilosa.local:10501/index/sample-index/query -d 'SetBit(frame="sample-frame", rowID=1, columnID=100)'
+curl -k --ipv4 https://01.pilosa.local:10501/index/sample-index/query -d 'SetBit(frame="sample-frame", row=1, col=100)'
 ```
 ``` response
 {"results":[true]}
@ -224,7 +220,7 @@ curl -k --ipv4 https://01.pilosa.local:10501/index/sample-index/query -d 'SetBit

 Confirm that the bit was indeed set:
 ``` request
-curl -k --ipv4 https://01.pilosa.local:10501/index/sample-index/query -d 'Bitmap(frame="sample-frame", rowID=1)'
+curl -k --ipv4 https://01.pilosa.local:10501/index/sample-index/query -d 'Bitmap(frame="sample-frame", row=1)'
 ```
 ``` response
 {"results":[{"attrs":{},"bits":[100]}]}
@ -232,7 +228,7 @@ curl -k --ipv4 https://01.pilosa.local:10501/index/sample-index/query -d 'Bitmap

 The same response should be returned when querying other nodes in the cluster:
 ``` request
-curl -k --ipv4 https://02.pilosa.local:10502/index/sample-index/query -d 'Bitmap(frame="sample-frame", rowID=1)'
+curl -k --ipv4 https://02.pilosa.local:10502/index/sample-index/query -d 'Bitmap(frame="sample-frame", row=1)'
 ```
 ``` response
 {"results":[{"attrs":{},"bits":[100]}]}
@ -283,7 +279,7 @@ This query sets the age, weight, and t-cell count for the patient with ID `1` in
 ``` request
 curl localhost:10101/index/patients/query \
     -X POST \
-     -d 'SetFieldValue(columnID=1, frame="measurements", age=34, weight=128, tcells=1145)'
+     -d 'SetFieldValue(col=1, frame="measurements", age=34, weight=128, tcells=1145)'
 ```
 ``` response
 {"results":[null]}
@ -373,11 +369,11 @@ Now, let's add some books to our index.
 ``` request
 curl localhost:10101/index/books/query \
     -X POST \
-     -d 'SetColumnAttrs(columnID=1, name="To Kill a Mockingbird", year=1960)
-         SetColumnAttrs(columnID=2, name="No Name in the Street", year=1972)
-         SetColumnAttrs(columnID=3, name="The Tipping Point", year=2000)
-         SetColumnAttrs(columnID=4, name="Out Stealing Horses", year=2003)
-         SetColumnAttrs(columnID=5, name="The Forever War", year=2008)'
+     -d 'SetColumnAttrs(col=1, name="To Kill a Mockingbird", year=1960)
+         SetColumnAttrs(col=2, name="No Name in the Street", year=1972)
+         SetColumnAttrs(col=3, name="The Tipping Point", year=2000)
+         SetColumnAttrs(col=4, name="Out Stealing Horses", year=2003)
+         SetColumnAttrs(col=5, name="The Forever War", year=2008)'
 ```
 ``` response
 {"results":[null,null,null,null,null]}
@ -387,11 +383,11 @@ And add some members.
 ``` request
 curl localhost:10101/index/books/query \
     -X POST \
-     -d 'SetRowAttrs(frame="members", rowID=10001, fullName="John Smith")
-         SetRowAttrs(frame="members", rowID=10002, fullName="Sue Perkins")
-         SetRowAttrs(frame="members", rowID=10003, fullName="Jennifer Hawks")
-         SetRowAttrs(frame="members", rowID=10004, fullName="Pedro Vazquez")
-         SetRowAttrs(frame="members", rowID=10005, fullName="Pat Washington")'
+     -d 'SetRowAttrs(frame="members", row=10001, fullName="John Smith")
+         SetRowAttrs(frame="members", row=10002, fullName="Sue Perkins")
+         SetRowAttrs(frame="members", row=10003, fullName="Jennifer Hawks")
+         SetRowAttrs(frame="members", row=10004, fullName="Pedro Vazquez")
+         SetRowAttrs(frame="members", row=10005, fullName="Pat Washington")'
 ```
 ``` response
 {"results":[null,null,null,null,null]}
@ -401,7 +397,7 @@ At this point we can query one of the `member` records by querying that row.
 ``` request
 curl localhost:10101/index/books/query \
     -X POST \
-     -d 'Bitmap(frame="members", rowID=10002)'
+     -d 'Bitmap(frame="members", row=10002)'
 ```
 ``` response
 {"results":[{"attrs":{"fullName":"Sue Perkins"},"bits":[]}]}
@ -411,23 +407,19 @@ Now let's add some data to the matrix such that each pair represents a member wh
 ``` request
 curl localhost:10101/index/books/query \
     -X POST \
-     -d 'SetBit(frame="members", rowID=10001, columnID=3)
-         SetBit(frame="members", rowID=10001, columnID=5)
-
-         SetBit(frame="members", rowID=10002, columnID=1)
-         SetBit(frame="members", rowID=10002, columnID=2)
-         SetBit(frame="members", rowID=10002, columnID=4)
-
-         SetBit(frame="members", rowID=10003, columnID=3)
-
-         SetBit(frame="members", rowID=10004, columnID=4)
-         SetBit(frame="members", rowID=10004, columnID=5)
-
-         SetBit(frame="members", rowID=10005, columnID=1)
-         SetBit(frame="members", rowID=10005, columnID=2)
-         SetBit(frame="members", rowID=10005, columnID=3)
-         SetBit(frame="members", rowID=10005, columnID=4)
-         SetBit(frame="members", rowID=10005, columnID=5)'
+     -d 'SetBit(frame="members", row=10001, col=3)
+         SetBit(frame="members", row=10001, col=5)
+         SetBit(frame="members", row=10002, col=1)
+         SetBit(frame="members", row=10002, col=2)
+         SetBit(frame="members", row=10002, col=4)
+         SetBit(frame="members", row=10003, col=3)
+         SetBit(frame="members", row=10004, col=4)
+         SetBit(frame="members", row=10004, col=5)
+         SetBit(frame="members", row=10005, col=1)
+         SetBit(frame="members", row=10005, col=2)
+         SetBit(frame="members", row=10005, col=3)
+         SetBit(frame="members", row=10005, col=4)
+         SetBit(frame="members", row=10005, col=5)'
 ```
 ``` response
 {"results":[true,true,true,true,true,true,true,true,true,true,true,true,true]}
@ -437,7 +429,7 @@ Now pull the record for `Sue Perkins` again.
 ``` request
 curl localhost:10101/index/books/query \
     -X POST \
-     -d 'Bitmap(frame="members", rowID=10002)'
+     -d 'Bitmap(frame="members", row=10002)'
 ```
 ``` response
 {"results":[{"attrs":{"fullName":"Sue Perkins"},"bits":[1,2,4]}]}
@ -448,7 +440,7 @@ In order to retrieve the attribute information that we stored for each book, we
 ``` request
 curl localhost:10101/index/books/query?columnAttrs=true \
     -X POST \
-     -d 'Bitmap(frame="members", rowID=10002)'
+     -d 'Bitmap(frame="members", row=10002)'
 ```
 ``` response
 {
@ -466,7 +458,7 @@ Finally, if we want to find out which books were read by both `Sue` and `Pedro`,
 ``` request
 curl localhost:10101/index/books/query?columnAttrs=true \
     -X POST \
-     -d 'Intersect(Bitmap(frame="members", rowID=10002), Bitmap(frame="members", rowID=10004))'
+     -d 'Intersect(Bitmap(frame="members", row=10002), Bitmap(frame="members", row=10004))'
 ```
 ``` response
 {
--- a/executor.go
+++ b/executor.go
@ -941,7 +941,7 @@ func (e *Executor) executeClearBit(ctx context.Context, index string, c *pql.Cal
 func (e *Executor) executeClearBitView(ctx context.Context, index string, c *pql.Call, f *Frame, view string, colID, rowID uint64, opt *ExecOptions) (bool, error) {
 	slice := colID / SliceWidth
 	ret := false
-	for _, node := range e.Cluster.FragmentNodes(index, slice) {
+	for _, node := range e.Cluster.SliceNodes(index, slice) {
 		// Update locally if host matches.
 		if node.ID == e.Node.ID {
 			val, err := f.ClearBit(view, rowID, colID, nil)
@ -1042,7 +1042,7 @@ func (e *Executor) executeSetBitView(ctx context.Context, index string, c *pql.C
 	slice := colID / SliceWidth
 	ret := false

-	for _, node := range e.Cluster.FragmentNodes(index, slice) {
+	for _, node := range e.Cluster.SliceNodes(index, slice) {
 		// Update locally if host matches.
 		if node.ID == e.Node.ID {
 			val, err := f.SetBit(view, rowID, colID, timestamp)
@ -1385,7 +1385,7 @@ func (e *Executor) slicesByNode(nodes []*Node, index string, slices []uint64) (m

 loop:
 	for _, slice := range slices {
-		for _, node := range e.Cluster.FragmentNodes(index, slice) {
+		for _, node := range e.Cluster.SliceNodes(index, slice) {
 			if Nodes(nodes).Contains(node) {
 				m[node] = append(m[node], slice)
 				continue loop
--- a/fragment.go
+++ b/fragment.go
@ -1702,7 +1702,7 @@ func (s *FragmentSyncer) isClosing() bool {
 // then merges any blocks which have differences.
 func (s *FragmentSyncer) SyncFragment() error {
 	// Determine replica set.
-	nodes := s.Cluster.FragmentNodes(s.Fragment.Index(), s.Fragment.Slice())
+	nodes := s.Cluster.SliceNodes(s.Fragment.Index(), s.Fragment.Slice())
 	if len(nodes) == 1 {
 		return nil
 	}
@ -1784,7 +1784,7 @@ func (s *FragmentSyncer) syncBlock(id int) error {
 	// Read pairs from each remote block.
 	var pairSets []PairSet
 	var clients []InternalClient
-	for _, node := range s.Cluster.FragmentNodes(f.Index(), f.Slice()) {
+	for _, node := range s.Cluster.SliceNodes(f.Index(), f.Slice()) {
 		if s.Node.ID == node.ID {
 			continue
 		}
--- a/handler.go
+++ b/handler.go
@ -108,14 +108,14 @@ func BuildRouters(handler *Handler) {

 func (h *Handler) populateValidators() {
 	h.validators = map[string]*queryValidationSpec{}
-	h.validators["GetFragmentNodes"] = QueryValidationSpecRequired("slice", "index")
-	h.validators["GetSliceMax"] = QueryValidationSpecRequired().Optional("inverse")
-	h.validators["PostQuery"] = QueryValidationSpecRequired().Optional("slices", "columnAttrs", "excludeAttrs", "excludeBits")
-	h.validators["GetExport"] = QueryValidationSpecRequired("index", "frame", "view", "slice")
-	h.validators["GetFragmentData"] = QueryValidationSpecRequired("index", "frame", "view", "slice")
-	h.validators["PostFragmentData"] = QueryValidationSpecRequired("index", "frame", "view", "slice")
-	h.validators["GetFragmentBlocks"] = QueryValidationSpecRequired("index", "frame", "view", "slice")
-	h.validators["PostFrameRestore"] = QueryValidationSpecRequired("host")
+	h.validators["GetFragmentNodes"] = queryValidationSpecRequired("slice", "index")
+	h.validators["GetSliceMax"] = queryValidationSpecRequired().Optional("inverse")
+	h.validators["PostQuery"] = queryValidationSpecRequired().Optional("slices", "columnAttrs", "excludeAttrs", "excludeBits")
+	h.validators["GetExport"] = queryValidationSpecRequired("index", "frame", "view", "slice")
+	h.validators["GetFragmentData"] = queryValidationSpecRequired("index", "frame", "view", "slice")
+	h.validators["PostFragmentData"] = queryValidationSpecRequired("index", "frame", "view", "slice")
+	h.validators["GetFragmentBlocks"] = queryValidationSpecRequired("index", "frame", "view", "slice")
+	h.validators["PostFrameRestore"] = queryValidationSpecRequired("host")
 }

 func (h *Handler) queryArgValidator(next http.Handler) http.Handler {
@ -154,7 +154,7 @@ func loadCommon(router *mux.Router, handler *Handler) {
 	router.HandleFunc("/cluster/message", handler.handlePostClusterMessage).Methods("POST")
 	router.HandleFunc("/cluster/resize/set-coordinator", handler.handlePostClusterResizeSetCoordinator).Methods("POST")
 	router.PathPrefix("/debug/pprof/").Handler(http.DefaultServeMux).Methods("GET")
-	router.HandleFunc("/debug/vars", handler.handleExpvar).Methods("GET")
+	router.Handle("/debug/vars", expvar.Handler()).Methods("GET")
 	router.HandleFunc("/fragment/data", handler.handleGetFragmentData).Methods("GET").Name("GetFragmentData")
 	router.HandleFunc("/hosts", handler.handleGetHosts).Methods("GET")
 	router.HandleFunc("/id", handler.handleGetID).Methods("GET")
@ -174,7 +174,7 @@ func loadRestricted(router *mux.Router, handler *Handler) {
 func loadNormal(router *mux.Router, handler *Handler) {
 	router.HandleFunc("/cluster/resize/remove-node", handler.handlePostClusterResizeRemoveNode).Methods("POST")
 	router.PathPrefix("/debug/pprof/").Handler(http.DefaultServeMux).Methods("GET")
-	router.HandleFunc("/debug/vars", handler.handleExpvar).Methods("GET")
+	router.Handle("/debug/vars", expvar.Handler()).Methods("GET")
 	router.HandleFunc("/export", handler.handleGetExport).Methods("GET").Name("GetExport")
 	router.HandleFunc("/fragment/block/data", handler.handleGetFragmentBlockData).Methods("GET")
 	router.HandleFunc("/fragment/blocks", handler.handleGetFragmentBlocks).Methods("GET").Name("GetFragmentBlocks")
@ -241,7 +241,7 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	// Calculate per request StatsD metrics when the handler is fully configured.
 	statsTags := make([]string, 0, 3)

-	longQueryTime := h.API.ClusterLongQueryTime()
+	longQueryTime := h.API.LongQueryTime()
 	if longQueryTime > 0 && dif > longQueryTime {
 		h.Logger.Printf("%s %s %v", r.Method, r.URL.String(), dif)
 		statsTags = append(statsTags, "slow_query")
@ -270,7 +270,7 @@ func (h *Handler) handleWebUI(w http.ResponseWriter, r *http.Request) {
 	}
 	filesystem, err := h.FileSystem.New()
 	if err != nil {
-		h.writeQueryResponse(w, r, &QueryResponse{Err: err})
+		_ = h.writeQueryResponse(w, r, &QueryResponse{Err: err})
 		h.Logger.Printf("Pilosa WebUI is not available. Please run `make generate-statik` before building Pilosa with `make install`.")
 		return
 	}
@ -289,20 +289,11 @@ func (h *Handler) handleGetSchema(w http.ResponseWriter, r *http.Request) {

 // handleGetStatus handles GET /status requests.
 func (h *Handler) handleGetStatus(w http.ResponseWriter, r *http.Request) {
-	pb, err := h.API.Status(r.Context())
-	if err != nil {
-		h.Logger.Printf("cluster status error: %s", err)
-		return
+	status := getStatusResponse{
+		State: h.API.State(),
+		Nodes: h.API.Hosts(r.Context()),
 	}
-
-	cs, ok := pb.(*internal.ClusterStatus)
-	if !ok {
-		panic("status is not a status")
-	}
-	if err := json.NewEncoder(w).Encode(getStatusResponse{
-		State: cs.State,
-		Nodes: DecodeNodes(cs.Nodes),
-	}); err != nil {
+	if err := json.NewEncoder(w).Encode(status); err != nil {
 		h.Logger.Printf("write status response error: %s", err)
 	}
 }
@ -328,7 +319,7 @@ func (h *Handler) handlePostQuery(w http.ResponseWriter, r *http.Request) {
 	// TODO: Remove
 	req.Index = mux.Vars(r)["index"]

-	resp, err := h.API.ExecuteQuery(r.Context(), req)
+	resp, err := h.API.Query(r.Context(), req)
 	if err != nil {
 		w.WriteHeader(http.StatusBadRequest)
 		h.writeQueryResponse(w, r, &QueryResponse{Err: err})
@ -374,7 +365,7 @@ func (h *Handler) handleGetIndexes(w http.ResponseWriter, r *http.Request) {
 // handleGetIndex handles GET /index/<indexname> requests.
 func (h *Handler) handleGetIndex(w http.ResponseWriter, r *http.Request) {
 	indexName := mux.Vars(r)["index"]
-	index, err := h.API.ReadIndex(r.Context(), indexName)
+	index, err := h.API.Index(r.Context(), indexName)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusNotFound)
 		return
@ -742,7 +733,7 @@ func (h *Handler) handlePostFrameField(w http.ResponseWriter, r *http.Request) {
 		Max:  req.Max,
 	}

-	if err := h.API.CreateFrameField(r.Context(), indexName, frameName, field); err != nil {
+	if err := h.API.CreateField(r.Context(), indexName, frameName, field); err != nil {
 		if err == ErrFrameNotFound {
 			http.Error(w, err.Error(), http.StatusNotFound)
 		} else {
@ -771,7 +762,7 @@ func (h *Handler) handleDeleteFrameField(w http.ResponseWriter, r *http.Request)
 	frameName := mux.Vars(r)["frame"]
 	fieldName := mux.Vars(r)["field"]

-	if err := h.API.DeleteFrameField(r.Context(), indexName, frameName, fieldName); err != nil {
+	if err := h.API.DeleteField(r.Context(), indexName, frameName, fieldName); err != nil {
 		if err == ErrFrameNotFound {
 			http.Error(w, err.Error(), http.StatusNotFound)
 		} else {
@ -790,7 +781,7 @@ func (h *Handler) handleGetFrameFields(w http.ResponseWriter, r *http.Request) {
 	indexName := mux.Vars(r)["index"]
 	frameName := mux.Vars(r)["frame"]

-	fields, err := h.API.FrameFields(r.Context(), indexName, frameName)
+	fields, err := h.API.Fields(r.Context(), indexName, frameName)
 	if err != nil {
 		switch err {
 		case ErrIndexNotFound:
@ -824,7 +815,7 @@ func (h *Handler) handleGetFrameViews(w http.ResponseWriter, r *http.Request) {
 	indexName := mux.Vars(r)["index"]
 	frameName := mux.Vars(r)["frame"]

-	views, err := h.API.FrameViews(r.Context(), indexName, frameName)
+	views, err := h.API.Views(r.Context(), indexName, frameName)
 	if err != nil {
 		if err == ErrFrameNotFound {
 			http.Error(w, err.Error(), http.StatusNotFound)
@ -1178,7 +1169,7 @@ func (h *Handler) handleGetFragmentNodes(w http.ResponseWriter, r *http.Request)
 	}

 	// Retrieve fragment owner nodes.
-	nodes := h.API.FragmentNodes(r.Context(), index, slice)
+	nodes := h.API.SliceNodes(r.Context(), index, slice)

 	// Write to response.
 	if err := json.NewEncoder(w).Encode(nodes); err != nil {
@ -1197,7 +1188,7 @@ func (h *Handler) handleGetFragmentData(w http.ResponseWriter, r *http.Request)
 	}

 	// Retrieve fragment from holder.
-	f, err := h.API.FragmentData(r.Context(), q.Get("index"), q.Get("frame"), q.Get("view"), slice)
+	f, err := h.API.MarshalFragment(r.Context(), q.Get("index"), q.Get("frame"), q.Get("view"), slice)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusNotFound)
 		return
@ -1219,7 +1210,7 @@ func (h *Handler) handlePostFragmentData(w http.ResponseWriter, r *http.Request)
 		return
 	}

-	if err = h.API.WriteFragmentData(r.Context(), q.Get("index"), q.Get("frame"), q.Get("view"), slice, r.Body); err != nil {
+	if err = h.API.UnmarshalFragment(r.Context(), q.Get("index"), q.Get("frame"), q.Get("view"), slice, r.Body); err != nil {
 		if err == ErrFrameNotFound {
 			http.Error(w, ErrFrameNotFound.Error(), http.StatusNotFound)
 		} else {
@ -1230,19 +1221,11 @@ func (h *Handler) handlePostFragmentData(w http.ResponseWriter, r *http.Request)

 // handleGetFragmentBlockData handles GET /fragment/block/data requests.
 func (h *Handler) handleGetFragmentBlockData(w http.ResponseWriter, r *http.Request) {
-	// Read request object.
-	var req internal.BlockDataRequest
-	if body, err := ioutil.ReadAll(r.Body); err != nil {
-		http.Error(w, "ready body error", http.StatusBadRequest)
-		return
-	} else if err := proto.Unmarshal(body, &req); err != nil {
-		http.Error(w, "unmarshal body error", http.StatusBadRequest)
-		return
-	}
-
-	resp, err := h.API.FragmentBlockData(r.Context(), req)
+	buf, err := h.API.FragmentBlockData(r.Context(), r.Body)
 	if err != nil {
-		if err == ErrFragmentNotFound {
+		if _, ok := err.(BadRequestError); ok {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+		} else if err == ErrFragmentNotFound {
 			http.Error(w, err.Error(), http.StatusNotFound)
 		} else {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
@ -1250,13 +1233,6 @@ func (h *Handler) handleGetFragmentBlockData(w http.ResponseWriter, r *http.Requ
 		return
 	}

-	// Encode response.
-	buf, err := proto.Marshal(&resp)
-	if err != nil {
-		h.Logger.Printf("merge block response encoding error: %s", err)
-		return
-	}
-
 	// Write response.
 	w.Header().Set("Content-Type", "application/protobuf")
 	w.Header().Set("Content-Length", strconv.Itoa(len(buf)))
@ -1329,7 +1305,7 @@ func (h *Handler) handlePostFrameRestore(w http.ResponseWriter, r *http.Request)

 // handleGetHosts handles /hosts requests.
 func (h *Handler) handleGetHosts(w http.ResponseWriter, r *http.Request) {
-	hosts := h.API.ClusterHosts(r.Context())
+	hosts := h.API.Hosts(r.Context())
 	if err := json.NewEncoder(w).Encode(hosts); err != nil {
 		h.Logger.Printf("write version response error: %s", err)
 	}
@ -1337,36 +1313,16 @@ func (h *Handler) handleGetHosts(w http.ResponseWriter, r *http.Request) {

 // handleGetVersion handles /version requests.
 func (h *Handler) handleGetVersion(w http.ResponseWriter, r *http.Request) {
-	version := Version
-	if strings.HasPrefix(version, "v") {
-		// make the version string semver-compatible
-		version = version[1:]
-	}
-	if err := json.NewEncoder(w).Encode(struct {
+	err := json.NewEncoder(w).Encode(struct {
 		Version string `json:"version"`
 	}{
-		Version: version,
-	}); err != nil {
+		Version: h.API.Version(),
+	})
+	if err != nil {
 		h.Logger.Printf("write version response error: %s", err)
 	}
 }

-// handleExpvar handles /debug/vars requests.
-func (h *Handler) handleExpvar(w http.ResponseWriter, r *http.Request) {
-	// Copied from $GOROOT/src/expvar/expvar.go
-	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	fmt.Fprintf(w, "{\n")
-	first := true
-	expvar.Do(func(kv expvar.KeyValue) {
-		if !first {
-			fmt.Fprintf(w, ",\n")
-		}
-		first = false
-		fmt.Fprintf(w, "%q: %s", kv.Key, kv.Value)
-	})
-	fmt.Fprintf(w, "\n}\n")
-}
-
 // QueryResult types.
 const (
 	QueryResultTypeNil uint32 = iota
@ -1771,23 +1727,10 @@ func (h *Handler) handlePostClusterMessage(w http.ResponseWriter, r *http.Reques
 		return
 	}

-	// Read entire body.
-	body, err := ioutil.ReadAll(r.Body)
+	err := h.API.PostClusterMessage(r.Context(), r.Body)
 	if err != nil {
+		// TODO this was the previous behavior, but perhaps not everything is a bad request
 		http.Error(w, err.Error(), http.StatusBadRequest)
-		return
-	}
-
-	// Marshal into request object.
-	pb, err := UnmarshalMessage(body)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
-		return
-	}
-
-	if err := h.API.PostClusterMessage(r.Context(), pb); err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
-		return
 	}

 	if err := json.NewEncoder(w).Encode(defaultClusterMessageResponse{}); err != nil {
@ -1809,7 +1752,7 @@ type queryValidationSpec struct {
 	args     map[string]struct{}
 }

-func QueryValidationSpecRequired(requiredArgs ...string) *queryValidationSpec {
+func queryValidationSpecRequired(requiredArgs ...string) *queryValidationSpec {
 	args := map[string]struct{}{}
 	for _, arg := range requiredArgs {
 		args[arg] = struct{}{}
--- a/handler_test.go
+++ b/handler_test.go
@ -141,6 +141,7 @@ func TestHandler_Status(t *testing.T) {
 	h := test.NewHandler()
 	h.API.Holder = hldr.Holder
 	h.API.Cluster = test.NewCluster(1)
+	h.API.Cluster.SetState(pilosa.ClusterStateNormal)
 	h.API.StatusHandler = s
 	s.Handler = h

@ -148,7 +149,7 @@ func TestHandler_Status(t *testing.T) {
 	h.ServeHTTP(w, test.MustNewHTTPRequest("GET", "/status", nil))
 	if w.Code != http.StatusOK {
 		t.Fatalf("unexpected status code: %d", w.Code)
-	} else if body := w.Body.String(); body != `{"state":"NORMAL","nodes":[{"id":"test-node","uri":{"scheme":"http","host":"localhost","port":10101},"isCoordinator":false}]}`+"\n" {
+	} else if body := w.Body.String(); body != `{"state":"NORMAL","nodes":[{"id":"node0","uri":{"scheme":"http","host":"host0"},"isCoordinator":false}]}`+"\n" {
 		t.Fatalf("unexpected body: %s", body)
 	}
 }
--- a/holder.go
+++ b/holder.go
@ -614,7 +614,7 @@ func (s *HolderSyncer) SyncHolder() error {

 				for slice := uint64(0); slice <= s.Holder.Index(di.Name).MaxSlice(); slice++ {
 					// Ignore slices that this host doesn't own.
-					if !s.Cluster.OwnsFragment(s.Node.ID, di.Name, slice) {
+					if !s.Cluster.OwnsSlice(s.Node.ID, di.Name, slice) {
 						continue
 					}

--- a/pilosa.go
+++ b/pilosa.go
@ -82,6 +82,13 @@ var (
 	ErrResizeNotRunning   = errors.New("no resize job currently running")
 )

+// BadRequestError wraps an error value to signify that a request could not be
+// read, decoded, or parsed such that in an HTTP scenario, http.StatusBadRequest
+// would be returned.
+type BadRequestError struct {
+	error
+}
+
 // Regular expression to validate index and frame names.
 var nameRegexp = regexp.MustCompile(`^[a-z][a-z0-9_-]{0,63}$`)

--- a/test/cluster.go
+++ b/test/cluster.go
@ -129,7 +129,7 @@ func (t *TestCluster) SetBit(index, frame, view string, rowID, colID uint64, x *
 	// Determine which node should receive the SetBit.
 	c0 := t.Clusters[0] // use the first node's cluster to determine slice location.
 	slice := colID / pilosa.SliceWidth
-	nodes := c0.FragmentNodes(index, slice)
+	nodes := c0.SliceNodes(index, slice)

 	for _, node := range nodes {
 		c := t.clusterByID(node.ID)
@ -153,7 +153,7 @@ func (t *TestCluster) SetFieldValue(index, frame string, columnID uint64, name s
 	// Determine which node should receive the SetFieldValue.
 	c0 := t.Clusters[0] // use the first node's cluster to determine slice location.
 	slice := columnID / pilosa.SliceWidth
-	nodes := c0.FragmentNodes(index, slice)
+	nodes := c0.SliceNodes(index, slice)

 	for _, node := range nodes {
 		c := t.clusterByID(node.ID)