diff --git a/api.go b/api.go
index 691e076ff..3f3e8bd50 100644
--- a/api.go
+++ b/api.go
@@ -90,14 +90,14 @@ func (api *API) validate(f apiMethod) error {
 // Query parses a PQL query out of the request and executes it.
 func (api *API) Query(ctx context.Context, req *QueryRequest) (QueryResponse, error) {
 	if err := api.validate(apiQuery); err != nil {
-		return QueryResponse{}, errors.Wrap(err, "validate api method")
+		return QueryResponse{}, errors.Wrap(err, "validating api method")
 	}
 
 	resp := QueryResponse{}
 
 	q, err := pql.NewParser(strings.NewReader(req.Query)).Parse()
 	if err != nil {
-		return resp, err
+		return resp, errors.Wrap(err, "parsing")
 	}
 	execOpts := &ExecOptions{
 		Remote:       req.Remote,
@@ -106,7 +106,7 @@ func (api *API) Query(ctx context.Context, req *QueryRequest) (QueryResponse, er
 	}
 	results, err := api.Executor.Execute(ctx, req.Index, q, req.Slices, execOpts)
 	if err != nil {
-		return resp, err
+		return resp, errors.Wrap(err, "executing")
 	}
 	resp.Results = results
 
@@ -125,7 +125,7 @@ func (api *API) Query(ctx context.Context, req *QueryRequest) (QueryResponse, er
 		// Retrieve column attributes across all calls.
 		columnAttrSets, err := api.readColumnAttrSets(api.Holder.Index(req.Index), columnIDs)
 		if err != nil {
-			return resp, err
+			return resp, errors.Wrap(err, "reading column attrs")
 		}
 		resp.ColumnAttrSets = columnAttrSets
 	}
@@ -143,7 +143,7 @@ func (api *API) readColumnAttrSets(index *Index, ids []uint64) ([]*ColumnAttrSet
 		// Read attributes for column. Skip column if empty.
 		attrs, err := index.ColumnAttrStore().Attrs(id)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "getting attrs")
 		} else if len(attrs) == 0 {
 			continue
 		}
@@ -158,13 +158,13 @@ func (api *API) readColumnAttrSets(index *Index, ids []uint64) ([]*ColumnAttrSet
 // CreateIndex makes a new Pilosa index.
 func (api *API) CreateIndex(ctx context.Context, indexName string, options IndexOptions) (*Index, error) {
 	if err := api.validate(apiCreateIndex); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Create index.
 	index, err := api.Holder.CreateIndex(indexName, options)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "creating index")
 	}
 	// Send the create index message to all nodes.
 	err = api.Broadcaster.SendSync(
@@ -174,7 +174,7 @@ func (api *API) CreateIndex(ctx context.Context, indexName string, options Index
 		})
 	if err != nil {
 		api.Logger.Printf("problem sending CreateIndex message: %s", err)
-		return nil, err
+		return nil, errors.Wrap(err, "sending CreateIndex message")
 	}
 	api.Holder.Stats.Count("createIndex", 1, 1.0)
 	return index, nil
@@ -183,7 +183,7 @@ func (api *API) CreateIndex(ctx context.Context, indexName string, options Index
 // Index retrieves the named index.
 func (api *API) Index(ctx context.Context, indexName string) (*Index, error) {
 	if err := api.validate(apiIndex); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	index := api.Holder.Index(indexName)
@@ -197,13 +197,13 @@ func (api *API) Index(ctx context.Context, indexName string) (*Index, error) {
 // nothing and returns no error.
 func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 	if err := api.validate(apiDeleteIndex); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Delete index from the holder.
 	err := api.Holder.DeleteIndex(indexName)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "deleting index")
 	}
 	// Send the delete index message to all nodes.
 	err = api.Broadcaster.SendSync(
@@ -212,7 +212,7 @@ func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 		})
 	if err != nil {
 		api.Logger.Printf("problem sending DeleteIndex message: %s", err)
-		return err
+		return errors.Wrap(err, "sending DeleteIndex message")
 	}
 	api.Holder.Stats.Count("deleteIndex", 1, 1.0)
 	return nil
@@ -221,7 +221,7 @@ func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 // 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) {
 	if err := api.validate(apiCreateFrame); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Find index.
@@ -233,7 +233,7 @@ func (api *API) CreateFrame(ctx context.Context, indexName string, frameName str
 	// Create frame.
 	frame, err := index.CreateFrame(frameName, options)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "creating frame")
 	}
 
 	// Send the create frame message to all nodes.
@@ -245,7 +245,7 @@ func (api *API) CreateFrame(ctx context.Context, indexName string, frameName str
 		})
 	if err != nil {
 		api.Logger.Printf("problem sending CreateFrame message: %s", err)
-		return nil, err
+		return nil, errors.Wrap(err, "sending CreateFrame message")
 	}
 	api.Holder.Stats.CountWithCustomTags("createFrame", 1, 1.0, []string{fmt.Sprintf("index:%s", indexName)})
 	return frame, nil
@@ -256,7 +256,7 @@ func (api *API) CreateFrame(ctx context.Context, indexName string, frameName str
 // action is taken.
 func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName string) error {
 	if err := api.validate(apiDeleteFrame); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Find index.
@@ -267,7 +267,7 @@ func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName str
 
 	// Delete frame from the index.
 	if err := index.DeleteFrame(frameName); err != nil {
-		return err
+		return errors.Wrap(err, "deleting frame")
 	}
 
 	// Send the delete frame message to all nodes.
@@ -278,7 +278,7 @@ func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName str
 		})
 	if err != nil {
 		api.Logger.Printf("problem sending DeleteFrame message: %s", err)
-		return err
+		return errors.Wrap(err, "sending DeleteFrame message")
 	}
 	api.Holder.Stats.CountWithCustomTags("deleteFrame", 1, 1.0, []string{fmt.Sprintf("index:%s", indexName)})
 	return nil
@@ -288,7 +288,7 @@ func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName str
 // 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 {
 	if err := api.validate(apiExportCSV); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Validate that this handler owns the slice.
@@ -313,7 +313,7 @@ func (api *API) ExportCSV(ctx context.Context, indexName string, frameName strin
 			strconv.FormatUint(columnID, 10),
 		})
 	}); err != nil {
-		return err
+		return errors.Wrap(err, "writing CSV")
 	}
 
 	// Ensure data is flushed.
@@ -325,7 +325,7 @@ func (api *API) ExportCSV(ctx context.Context, indexName string, frameName strin
 // 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, error) {
 	if err := api.validate(apiSliceNodes); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	return api.Cluster.SliceNodes(indexName, slice), nil
@@ -336,7 +336,7 @@ func (api *API) SliceNodes(ctx context.Context, indexName string, slice uint64)
 // the UnmarshalFragment API call.
 func (api *API) MarshalFragment(ctx context.Context, indexName string, frameName string, viewName string, slice uint64) (io.WriterTo, error) {
 	if err := api.validate(apiMarshalFragment); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve fragment from holder.
@@ -352,7 +352,7 @@ func (api *API) MarshalFragment(ctx context.Context, indexName string, frameName
 // fragment's data.
 func (api *API) UnmarshalFragment(ctx context.Context, indexName string, frameName string, viewName string, slice uint64, reader io.ReadCloser) error {
 	if err := api.validate(apiUnmarshalFragment); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve frame.
@@ -364,18 +364,18 @@ func (api *API) UnmarshalFragment(ctx context.Context, indexName string, frameNa
 	// Retrieve view.
 	view, err := f.CreateViewIfNotExists(viewName)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "creating view")
 	}
 
 	// Retrieve fragment from frame.
 	frag, err := view.CreateFragmentIfNotExists(slice)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "creating fragment")
 	}
 
 	// Read fragment in from request body.
 	if _, err := frag.ReadFrom(reader); err != nil {
-		return err
+		return errors.Wrap(err, "reading fragment")
 	}
 	return nil
 }
@@ -385,7 +385,7 @@ func (api *API) UnmarshalFragment(ctx context.Context, indexName string, frameNa
 // ids from a "block" which is a subdivision of a fragment.
 func (api *API) FragmentBlockData(ctx context.Context, body io.Reader) ([]byte, error) {
 	if err := api.validate(apiFragmentBlockData); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	reqBytes, err := ioutil.ReadAll(body)
@@ -418,7 +418,7 @@ func (api *API) FragmentBlockData(ctx context.Context, body io.Reader) ([]byte,
 // 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) {
 	if err := api.validate(apiFragmentBlocks); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve fragment from holder.
@@ -436,7 +436,7 @@ func (api *API) FragmentBlocks(ctx context.Context, indexName string, frameName
 // 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 {
 	if err := api.validate(apiRestoreFrame); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Create a client for the remote cluster.
@@ -445,7 +445,7 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 	// Determine the maximum number of slices.
 	maxSlices, err := client.MaxSliceByIndex(ctx)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "getting max slice")
 	}
 
 	// Retrieve frame.
@@ -457,7 +457,7 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 	// Retrieve list of all views.
 	views, err := client.FrameViews(ctx, indexName, frameName)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "getting views")
 	}
 
 	// Loop over each slice and import it if this node owns it.
@@ -472,19 +472,19 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 			// Create view.
 			v, err := f.CreateViewIfNotExists(view)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "creating view")
 			}
 
 			// Otherwise retrieve the local fragment.
 			frag, err := v.CreateFragmentIfNotExists(slice)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "creating fragment")
 			}
 
 			// Stream backup from remote node.
 			rd, err := client.BackupSlice(ctx, indexName, frameName, view, slice)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "getting backup")
 			} else if rd == nil {
 				continue // slice doesn't exist
 			}
@@ -493,7 +493,7 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 			if err := func() error {
 				defer rd.Close()
 				if _, err := frag.ReadFrom(rd); err != nil {
-					return err
+					return errors.Wrap(err, "reading fragment")
 				}
 				return nil
 			}(); err != nil {
@@ -514,7 +514,7 @@ func (api *API) Hosts(ctx context.Context) []*Node {
 // 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 {
 	if err := api.validate(apiCreateInputDefinition); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	api.Logger.Printf(`CreateInputDefinition is deprecated and will be removed.
@@ -552,7 +552,7 @@ Please open an issue if you need to continue using it.`)
 // InputDefinition is deprecated and will be removed.
 func (api *API) InputDefinition(ctx context.Context, indexName string, inputDefName string) (*InputDefinition, error) {
 	if err := api.validate(apiInputDefinition); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	api.Logger.Printf(`InputDefinition is deprecated and will be removed.`)
@@ -572,7 +572,7 @@ func (api *API) InputDefinition(ctx context.Context, indexName string, inputDefN
 // DeleteInputDefinition is deprecated and will be removed.
 func (api *API) DeleteInputDefinition(ctx context.Context, indexName string, inputDefName string) error {
 	if err := api.validate(apiDeleteInputDefinition); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	api.Logger.Printf("DeleteInputDefinition is deprecated and will be removed.")
@@ -601,7 +601,7 @@ func (api *API) DeleteInputDefinition(ctx context.Context, indexName string, inp
 // WriteInput is deprecated and will be removed.
 func (api *API) WriteInput(ctx context.Context, indexName string, inputDefName string, reqs []interface{}) error {
 	if err := api.validate(apiWriteInput); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	api.Logger.Printf("WriteInput is deprecated and will be removed.")
@@ -629,7 +629,7 @@ func (api *API) WriteInput(ctx context.Context, indexName string, inputDefName s
 // RecalculateCaches forces all TopN caches to be updated. Used mainly for integration tests.
 func (api *API) RecalculateCaches(ctx context.Context) error {
 	if err := api.validate(apiRecalculateCaches); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	err := api.Broadcaster.SendSync(&internal.RecalculateCaches{})
@@ -644,7 +644,7 @@ func (api *API) RecalculateCaches(ctx context.Context) error {
 // the body and forwards it to the BroadcastHandler.
 func (api *API) ClusterMessage(ctx context.Context, reqBody io.Reader) error {
 	if err := api.validate(apiClusterMessage); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Read entire body.
@@ -680,7 +680,7 @@ func (api *API) Schema(ctx context.Context) []*IndexInfo {
 // 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 {
 	if err := api.validate(apiCreateField); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve frame by name.
@@ -691,7 +691,7 @@ func (api *API) CreateField(ctx context.Context, indexName string, frameName str
 
 	// Create new field.
 	if err := f.CreateField(field); err != nil {
-		return err
+		return errors.Wrap(err, "creating field")
 	}
 
 	// Send the create field message to all nodes.
@@ -704,13 +704,13 @@ func (api *API) CreateField(ctx context.Context, indexName string, frameName str
 	if err != nil {
 		api.Logger.Printf("problem sending CreateField message: %s", err)
 	}
-	return err
+	return errors.Wrap(err, "sending CreateField message")
 }
 
 // DeleteField deletes the given field.
 func (api *API) DeleteField(ctx context.Context, indexName string, frameName string, fieldName string) error {
 	if err := api.validate(apiDeleteField); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve frame by name.
@@ -721,7 +721,7 @@ func (api *API) DeleteField(ctx context.Context, indexName string, frameName str
 
 	// Delete field.
 	if err := f.DeleteField(fieldName); err != nil {
-		return err
+		return errors.Wrap(err, "deleting field")
 	}
 
 	// Send the delete field message to all nodes.
@@ -734,13 +734,13 @@ func (api *API) DeleteField(ctx context.Context, indexName string, frameName str
 	if err != nil {
 		api.Logger.Printf("problem sending DeleteField message: %s", err)
 	}
-	return err
+	return errors.Wrap(err, "sending DeleteField message")
 }
 
 // Fields returns the fields in the given frame.
 func (api *API) Fields(ctx context.Context, indexName string, frameName string) ([]*Field, error) {
 	if err := api.validate(apiFields); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	index := api.Holder.index(indexName)
@@ -759,7 +759,7 @@ func (api *API) Fields(ctx context.Context, indexName string, frameName string)
 // Views returns the views in the given frame.
 func (api *API) Views(ctx context.Context, indexName string, frameName string) ([]*View, error) {
 	if err := api.validate(apiViews); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve views.
@@ -776,7 +776,7 @@ func (api *API) Views(ctx context.Context, indexName string, frameName string) (
 // DeleteView removes the given view.
 func (api *API) DeleteView(ctx context.Context, indexName string, frameName string, viewName string) error {
 	if err := api.validate(apiDeleteView); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve frame.
@@ -789,7 +789,7 @@ func (api *API) DeleteView(ctx context.Context, indexName string, frameName stri
 	if err := f.DeleteView(viewName); err != nil {
 		// Ignore this error because views do not exist on all nodes due to slice distribution.
 		if err != ErrInvalidView {
-			return err
+			return errors.Wrap(err, "deleting view")
 		}
 	}
 
@@ -804,13 +804,13 @@ func (api *API) DeleteView(ctx context.Context, indexName string, frameName stri
 		api.Logger.Printf("problem sending DeleteView message: %s", err)
 	}
 
-	return err
+	return errors.Wrap(err, "sending DeleteView message")
 }
 
 // IndexAttrDiff
 func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []AttrBlock) (map[uint64]map[string]interface{}, error) {
 	if err := api.validate(apiIndexAttrDiff); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve index from holder.
@@ -822,7 +822,7 @@ func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []At
 	// Retrieve local blocks.
 	localBlocks, err := index.ColumnAttrStore().Blocks()
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "getting blocks")
 	}
 
 	// Read all attributes from all mismatched blocks.
@@ -831,7 +831,7 @@ func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []At
 		// Retrieve block data.
 		m, err := index.ColumnAttrStore().BlockData(blockID)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "getting block")
 		}
 
 		// Copy to index-wide struct.
@@ -844,7 +844,7 @@ func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []At
 
 func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName string, blocks []AttrBlock) (map[uint64]map[string]interface{}, error) {
 	if err := api.validate(apiFrameAttrDiff); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve index from holder.
@@ -856,7 +856,7 @@ func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName s
 	// Retrieve local blocks.
 	localBlocks, err := f.RowAttrStore().Blocks()
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "getting blocks")
 	}
 
 	// Read all attributes from all mismatched blocks.
@@ -865,7 +865,7 @@ func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName s
 		// Retrieve block data.
 		m, err := f.RowAttrStore().BlockData(blockID)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "getting block")
 		}
 
 		// Copy to index-wide struct.
@@ -879,12 +879,12 @@ func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName s
 // Import bulk imports data into a particular index,frame,slice.
 func (api *API) Import(ctx context.Context, req internal.ImportRequest) error {
 	if err := api.validate(apiImport); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	_, frame, err := api.indexFrame(req.Index, req.Frame, req.Slice)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "getting frame")
 	}
 
 	// Convert timestamps to time.Time.
@@ -902,18 +902,18 @@ func (api *API) Import(ctx context.Context, req internal.ImportRequest) error {
 	if err != nil {
 		api.Logger.Printf("import error: index=%s, frame=%s, slice=%d, bits=%d, err=%s", req.Index, req.Frame, req.Slice, len(req.ColumnIDs), err)
 	}
-	return err
+	return errors.Wrap(err, "importing")
 }
 
 // ImportValue bulk imports values into a particular field.
 func (api *API) ImportValue(ctx context.Context, req internal.ImportValueRequest) error {
 	if err := api.validate(apiImportValue); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	_, frame, err := api.indexFrame(req.Index, req.Frame, req.Slice)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "getting frame")
 	}
 
 	// Import into fragment.
@@ -921,7 +921,7 @@ func (api *API) ImportValue(ctx context.Context, req internal.ImportValueRequest
 	if err != nil {
 		api.Logger.Printf("import error: index=%s, frame=%s, slice=%d, field=%s, bits=%d, err=%s", req.Index, req.Frame, req.Slice, req.Field, len(req.ColumnIDs), err)
 	}
-	return err
+	return errors.Wrap(err, "importing")
 }
 
 // MaxSlices returns the maximum slice number for each index in a map.
@@ -1049,7 +1049,7 @@ func (api *API) inputJSONDataParser(req map[string]interface{}, index *Index, na
 // SetCoordinator makes a new Node the cluster coordinator.
 func (api *API) SetCoordinator(ctx context.Context, id string) (oldNode, newNode *Node, err error) {
 	if err := api.validate(apiSetCoordinator); err != nil {
-		return nil, nil, errors.Wrap(err, "validate api method")
+		return nil, nil, errors.Wrap(err, "validating api method")
 	}
 
 	oldNode = api.Cluster.NodeByID(api.Cluster.Coordinator)
@@ -1079,7 +1079,7 @@ func (api *API) SetCoordinator(ctx context.Context, id string) (oldNode, newNode
 // removing the given node.
 func (api *API) RemoveNode(id string) (*Node, error) {
 	if err := api.validate(apiRemoveNode); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	removeNode := api.Cluster.nodeByID(id)
@@ -1098,7 +1098,7 @@ func (api *API) RemoveNode(id string) (*Node, error) {
 // ResizeAbort stops the current resize job.
 func (api *API) ResizeAbort() error {
 	if err := api.validate(apiResizeAbort); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	err := api.Cluster.CompleteCurrentJob(ResizeJobStateAborted)
diff --git a/fragment.go b/fragment.go
index 7168f4443..6b5021c99 100644
--- a/fragment.go
+++ b/fragment.go
@@ -21,7 +21,6 @@ import (
 	"container/heap"
 	"context"
 	"encoding/binary"
-	"errors"
 	"fmt"
 	"hash"
 	"io"
@@ -42,6 +41,7 @@ import (
 	"github.com/pilosa/pilosa/internal"
 	"github.com/pilosa/pilosa/pql"
 	"github.com/pilosa/pilosa/roaring"
+	"github.com/pkg/errors"
 )
 
 const (
@@ -160,12 +160,12 @@ func (f *Fragment) Open() error {
 	if err := func() error {
 		// Initialize storage in a function so we can close if anything goes wrong.
 		if err := f.openStorage(); err != nil {
-			return err
+			return errors.Wrap(err, "opening storage")
 		}
 
 		// Fill cache with rows persisted to disk.
 		if err := f.openCache(); err != nil {
-			return err
+			return errors.Wrap(err, "opening cache")
 		}
 
 		// Clear checksums.
@@ -206,7 +206,7 @@ func (f *Fragment) openStorage() error {
 	// If the file is empty then initialize it with an empty bitmap.
 	fi, err := f.file.Stat()
 	if err != nil {
-		return err
+		return errors.Wrap(err, "statting file before")
 	} else if fi.Size() == 0 {
 		bi := bufio.NewWriter(f.file)
 		if _, err := f.storage.WriteTo(bi); err != nil {
@@ -215,7 +215,7 @@ func (f *Fragment) openStorage() error {
 		bi.Flush()
 		fi, err = f.file.Stat()
 		if err != nil {
-			return err
+			return errors.Wrap(err, "statting file after")
 		}
 	}
 
@@ -298,13 +298,13 @@ func (f *Fragment) close() error {
 	// Flush cache if closing gracefully.
 	if err := f.flushCache(); err != nil {
 		f.Logger.Printf("fragment: error flushing cache on close: err=%s, path=%s", err, f.path)
-		return err
+		return errors.Wrap(err, "flushing cache")
 	}
 
 	// Close underlying storage.
 	if err := f.closeStorage(); err != nil {
 		f.Logger.Printf("fragment: error closing storage: err=%s, path=%s", err, f.path)
-		return err
+		return errors.Wrap(err, "closing storage")
 	}
 
 	// Remove checksums.
@@ -393,12 +393,12 @@ func (f *Fragment) setBit(rowID, columnID uint64) (changed bool, err error) {
 	// Determine the position of the bit in the storage.
 	pos, err := f.pos(rowID, columnID)
 	if err != nil {
-		return false, err
+		return false, errors.Wrap(err, "getting bit ops")
 	}
 
 	// Write to storage.
 	if changed, err = f.storage.Add(pos); err != nil {
-		return false, err
+		return false, errors.Wrap(err, "writing")
 	}
 
 	// Don't update the cache if nothing changed.
@@ -411,7 +411,7 @@ func (f *Fragment) setBit(rowID, columnID uint64) (changed bool, err error) {
 
 	// Increment number of operations until snapshot is required.
 	if err := f.incrementOpN(); err != nil {
-		return false, err
+		return false, errors.Wrap(err, "incrementing")
 	}
 
 	// Get the row from row cache or fragment.storage.
@@ -445,12 +445,12 @@ func (f *Fragment) clearBit(rowID, columnID uint64) (changed bool, err error) {
 	// Determine the position of the bit in the storage.
 	pos, err := f.pos(rowID, columnID)
 	if err != nil {
-		return false, err
+		return false, errors.Wrap(err, "getting bit pos")
 	}
 
 	// Write to storage.
 	if changed, err = f.storage.Remove(pos); err != nil {
-		return false, err
+		return false, errors.Wrap(err, "writing")
 	}
 
 	// Don't update the cache if nothing changed.
@@ -463,7 +463,7 @@ func (f *Fragment) clearBit(rowID, columnID uint64) (changed bool, err error) {
 
 	// Increment number of operations until snapshot is required.
 	if err := f.incrementOpN(); err != nil {
-		return false, err
+		return false, errors.Wrap(err, "incrementing")
 	}
 
 	// Get the row from cache or fragment.storage.
@@ -493,7 +493,7 @@ func (f *Fragment) FieldValue(columnID uint64, bitDepth uint) (value uint64, exi
 
 	// If existence bit is unset then ignore remaining bits.
 	if v, err := f.bit(uint64(bitDepth), columnID); err != nil {
-		return 0, false, err
+		return 0, false, errors.Wrap(err, "getting existence bit")
 	} else if !v {
 		return 0, false, nil
 	}
@@ -501,7 +501,7 @@ func (f *Fragment) FieldValue(columnID uint64, bitDepth uint) (value uint64, exi
 	// Compute other bits into a value.
 	for i := uint(0); i < bitDepth; i++ {
 		if v, err := f.bit(uint64(i), columnID); err != nil {
-			return 0, false, err
+			return 0, false, errors.Wrapf(err, "getting value bit %d", i)
 		} else if v {
 			value |= (1 << i)
 		}
@@ -533,7 +533,7 @@ func (f *Fragment) SetFieldValue(columnID uint64, bitDepth uint, value uint64) (
 
 	// Mark value as set.
 	if c, err := f.setBit(uint64(bitDepth), columnID); err != nil {
-		return changed, err
+		return changed, errors.Wrap(err, "marking not-null")
 	} else if c {
 		changed = true
 	}
@@ -548,20 +548,20 @@ func (f *Fragment) importSetFieldValue(columnID uint64, bitDepth uint, value uin
 		if value&(1<<i) != 0 {
 			bit, err := f.pos(uint64(i), columnID)
 			if err != nil {
-				return changed, err
+				return changed, errors.Wrap(err, "getting set pos")
 			}
 			if c, err := f.storage.Add(bit); err != nil {
-				return changed, err
+				return changed, errors.Wrap(err, "adding")
 			} else if c {
 				changed = true
 			}
 		} else {
 			bit, err := f.pos(uint64(i), columnID)
 			if err != nil {
-				return changed, err
+				return changed, errors.Wrap(err, "getting clear pos")
 			}
 			if c, err := f.storage.Remove(bit); err != nil {
-				return changed, err
+				return changed, errors.Wrap(err, "removing")
 			} else if c {
 				changed = true
 			}
@@ -571,10 +571,10 @@ func (f *Fragment) importSetFieldValue(columnID uint64, bitDepth uint, value uin
 	// Mark value as set.
 	p, err := f.pos(uint64(bitDepth), columnID)
 	if err != nil {
-		return changed, err
+		return changed, errors.Wrap(err, "marking not-null")
 	}
 	if c, err := f.storage.Add(p); err != nil {
-		return changed, err
+		return changed, errors.Wrap(err, "adding to storage")
 	} else if c {
 		changed = true
 	}
@@ -945,7 +945,7 @@ func (f *Fragment) Top(opt TopOptions) ([]Pair, error) {
 		if filters != nil {
 			attr, err := f.RowAttrStore.Attrs(rowID)
 			if err != nil {
-				return nil, err
+				return nil, errors.Wrap(err, "getting attrs")
 			} else if attr == nil {
 				continue
 			} else if attrValue := attr[opt.FilterField]; attrValue == nil {
@@ -1308,14 +1308,14 @@ func (f *Fragment) MergeBlock(id int, data []PairSet) (sets, clears []PairSet, e
 	// Set local bits.
 	for i := range sets[0].ColumnIDs {
 		if _, err := f.setBit(sets[0].RowIDs[i], (f.Slice()*SliceWidth)+sets[0].ColumnIDs[i]); err != nil {
-			return nil, nil, err
+			return nil, nil, errors.Wrap(err, "setting")
 		}
 	}
 
 	// Clear local bits.
 	for i := range clears[0].ColumnIDs {
 		if _, err := f.clearBit(clears[0].RowIDs[i], (f.Slice()*SliceWidth)+clears[0].ColumnIDs[i]); err != nil {
-			return nil, nil, err
+			return nil, nil, errors.Wrap(err, "clearing")
 		}
 	}
 
@@ -1346,13 +1346,13 @@ func (f *Fragment) Import(rowIDs, columnIDs []uint64) error {
 			// Determine the position of the bit in the storage.
 			pos, err := f.pos(rowID, columnID)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "getting bit pos")
 			}
 
 			// Write to storage.
 			_, err = f.storage.Add(pos)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "writing")
 			}
 			// Reduce the StatsD rate for high volume stats
 			f.stats.Count("ImportBit", 1, 0.0001)
@@ -1386,7 +1386,7 @@ func (f *Fragment) Import(rowIDs, columnIDs []uint64) error {
 
 	// Write the storage to disk and reload.
 	if err := f.snapshot(); err != nil {
-		return err
+		return errors.Wrap(err, "snapshotting")
 	}
 
 	return nil
@@ -1410,7 +1410,7 @@ func (f *Fragment) ImportValue(columnIDs, values []uint64, bitDepth uint) error
 
 			_, err := f.importSetFieldValue(columnID, bitDepth, value)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "setting")
 			}
 		}
 		return nil
@@ -1420,7 +1420,7 @@ func (f *Fragment) ImportValue(columnIDs, values []uint64, bitDepth uint) error
 		return err
 	}
 	if err := f.snapshot(); err != nil {
-		return err
+		return errors.Wrap(err, "snapshotting")
 	}
 	return nil
 }
@@ -1525,12 +1525,12 @@ func (f *Fragment) flushCache() error {
 	// Marshal cache data to bytes.
 	buf, err := proto.Marshal(&internal.Cache{IDs: ids})
 	if err != nil {
-		return err
+		return errors.Wrap(err, "marshalling")
 	}
 
 	// Write to disk.
 	if err := ioutil.WriteFile(f.CachePath(), buf, 0666); err != nil {
-		return err
+		return errors.Wrap(err, "writing")
 	}
 
 	return nil
@@ -1540,7 +1540,7 @@ func (f *Fragment) flushCache() error {
 func (f *Fragment) WriteTo(w io.Writer) (n int64, err error) {
 	// Force cache flush.
 	if err := f.FlushCache(); err != nil {
-		return 0, err
+		return 0, errors.Wrap(err, "flushing cache")
 	}
 
 	// Write out data and cache to a tar archive.
@@ -1558,7 +1558,7 @@ func (f *Fragment) writeStorageToArchive(tw *tar.Writer) error {
 	// Open separate file descriptor to read from.
 	file, err := os.Open(f.path)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "opening file")
 	}
 	defer file.Close()
 
@@ -1571,7 +1571,7 @@ func (f *Fragment) writeStorageToArchive(tw *tar.Writer) error {
 
 		fi, err := file.Stat()
 		if err != nil {
-			return err
+			return errors.Wrap(err, "statting")
 		}
 		sz = fi.Size()
 
@@ -1587,13 +1587,13 @@ func (f *Fragment) writeStorageToArchive(tw *tar.Writer) error {
 		Size:    sz,
 		ModTime: time.Now(),
 	}); err != nil {
-		return err
+		return errors.Wrap(err, "writing header")
 	}
 
 	// Copy the file up to the last known size.
 	// This is done outside the lock because the storage format is append-only.
 	if _, err := io.CopyN(tw, file, sz); err != nil {
-		return err
+		return errors.Wrap(err, "copying")
 	}
 	return nil
 }
@@ -1607,7 +1607,7 @@ func (f *Fragment) writeCacheToArchive(tw *tar.Writer) error {
 	if os.IsNotExist(err) {
 		return nil
 	} else if err != nil {
-		return err
+		return errors.Wrap(err, "reading cache")
 	}
 
 	// Write archive header.
@@ -1617,12 +1617,12 @@ func (f *Fragment) writeCacheToArchive(tw *tar.Writer) error {
 		Size:    int64(len(buf)),
 		ModTime: time.Now(),
 	}); err != nil {
-		return err
+		return errors.Wrap(err, "writing header")
 	}
 
 	// Write data to archive.
 	if _, err := tw.Write(buf); err != nil {
-		return err
+		return errors.Wrap(err, "writing")
 	}
 	return nil
 }
@@ -1639,18 +1639,18 @@ func (f *Fragment) ReadFrom(r io.Reader) (n int64, err error) {
 		if err == io.EOF {
 			break
 		} else if err != nil {
-			return 0, err
+			return 0, errors.Wrap(err, "opening")
 		}
 
 		// Process file based on file name.
 		switch hdr.Name {
 		case "data":
 			if err := f.readStorageFromArchive(tr); err != nil {
-				return 0, err
+				return 0, errors.Wrap(err, "reading storage")
 			}
 		case "cache":
 			if err := f.readCacheFromArchive(tr); err != nil {
-				return 0, err
+				return 0, errors.Wrap(err, "reading cache")
 			}
 		default:
 			return 0, fmt.Errorf("invalid fragment archive file: %s", hdr.Name)
@@ -1665,28 +1665,28 @@ func (f *Fragment) readStorageFromArchive(r io.Reader) error {
 	path := f.path + CopyExt
 	file, err := os.Create(path)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "creating directory")
 	}
 	defer file.Close()
 
 	// Copy reader into temporary path.
 	if _, err = io.Copy(file, r); err != nil {
-		return err
+		return errors.Wrap(err, "copying")
 	}
 
 	// Close current storage.
 	if err := f.closeStorage(); err != nil {
-		return err
+		return errors.Wrap(err, "closing")
 	}
 
 	// Move snapshot to data file location.
 	if err := os.Rename(path, f.path); err != nil {
-		return err
+		return errors.Wrap(err, "renaming")
 	}
 
 	// Reopen storage.
 	if err := f.openStorage(); err != nil {
-		return err
+		return errors.Wrap(err, "opening")
 	}
 
 	return nil
@@ -1696,14 +1696,14 @@ func (f *Fragment) readCacheFromArchive(r io.Reader) error {
 	// Slurp data from reader and write to disk.
 	buf, err := ioutil.ReadAll(r)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "reading")
 	} else if err := ioutil.WriteFile(f.CachePath(), buf, 0666); err != nil {
-		return err
+		return errors.Wrap(err, "writing")
 	}
 
 	// Re-open cache.
 	if err := f.openCache(); err != nil {
-		return err
+		return errors.Wrap(err, "opening")
 	}
 
 	return nil
@@ -1785,7 +1785,7 @@ func (s *FragmentSyncer) SyncFragment() error {
 		client := NewInternalHTTPClientFromURI(&node.URI, s.RemoteClient)
 		blocks, err := client.FragmentBlocks(context.Background(), s.Fragment.Index(), s.Fragment.Frame(), s.Fragment.View(), s.Fragment.Slice())
 		if err != nil && err != ErrFragmentNotFound {
-			return err
+			return errors.Wrap(err, "getting blocks")
 		}
 		blockSets = append(blockSets, blocks)
 
@@ -1864,7 +1864,7 @@ func (s *FragmentSyncer) syncBlock(id int) error {
 		// Only sync the standard block.
 		rowIDs, columnIDs, err := client.BlockData(context.Background(), f.Index(), f.Frame(), ViewStandard, f.Slice(), id)
 		if err != nil {
-			return err
+			return errors.Wrap(err, "getting block")
 		}
 
 		pairSets = append(pairSets, PairSet{
@@ -1881,7 +1881,7 @@ func (s *FragmentSyncer) syncBlock(id int) error {
 	// Merge blocks together.
 	sets, clears, err := f.MergeBlock(id, pairSets)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "merging")
 	}
 
 	// Write updates to remote blocks.
@@ -1926,7 +1926,7 @@ func (s *FragmentSyncer) syncBlock(id int) error {
 			}
 			_, err := clients[i].Query(context.Background(), f.Index(), queryRequest)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "executing")
 			}
 		}
 	}
diff --git a/handler_test.go b/handler_test.go
index db198c508..ec1bf8aa3 100644
--- a/handler_test.go
+++ b/handler_test.go
@@ -639,7 +639,7 @@ func TestHandler_Query_Err_JSON(t *testing.T) {
 	h.ServeHTTP(w, test.MustNewHTTPRequest("POST", "/index/i/query", strings.NewReader(`Bitmap(id=100)`)))
 	if w.Code != http.StatusBadRequest {
 		t.Fatalf("unexpected status code: %d", w.Code)
-	} else if body := w.Body.String(); body != `{"error":"marker"}`+"\n" {
+	} else if body := w.Body.String(); body != `{"error":"executing: marker"}`+"\n" {
 		t.Fatalf("unexpected body: %q", body)
 	}
 }
@@ -667,7 +667,7 @@ func TestHandler_Query_Err_Protobuf(t *testing.T) {
 	var resp internal.QueryResponse
 	if err := proto.Unmarshal(w.Body.Bytes(), &resp); err != nil {
 		t.Fatal(err)
-	} else if s := resp.Err; s != `marker` {
+	} else if s := resp.Err; s != `executing: marker` {
 		t.Fatalf("unexpected error: %s", s)
 	}
 }
@@ -699,7 +699,7 @@ func TestHandler_Query_ErrParse(t *testing.T) {
 	h.ServeHTTP(w, test.MustNewHTTPRequest("POST", "/index/idx0/query?slices=0,1", strings.NewReader("bad_fn(")))
 	if w.Code != http.StatusBadRequest {
 		t.Fatalf("unexpected status code: %d", w.Code)
-	} else if body := w.Body.String(); body != `{"error":"expected comma, right paren, or identifier, found \"\" occurred at line 1, char 8"}`+"\n" {
+	} else if body := w.Body.String(); body != `{"error":"parsing: expected comma, right paren, or identifier, found \"\" occurred at line 1, char 8"}`+"\n" {
 		t.Fatalf("unexpected body: %s", body)
 	}
 }
@@ -909,7 +909,7 @@ func TestHandler_Frame_AddField(t *testing.T) {
 		)
 		if err != nil {
 			t.Fatal(err)
-		} else if body := MustReadAll(resp.Body); string(body) != `validating field: invalid field type`+"\n" {
+		} else if body := MustReadAll(resp.Body); string(body) != `creating field: validating field: invalid field range`+"\n" {
 			t.Fatalf("unexpected body: %q", body)
 		} else if err := resp.Body.Close(); err != nil {
 			t.Fatal(err)
@@ -931,7 +931,7 @@ func TestHandler_Frame_AddField(t *testing.T) {
 		)
 		if err != nil {
 			t.Fatal(err)
-		} else if body := MustReadAll(resp.Body); string(body) != `validating field: invalid field range`+"\n" {
+		} else if body := MustReadAll(resp.Body); string(body) != `creating field: validating field: invalid field range`+"\n" {
 			t.Fatalf("unexpected body: %q", body)
 		} else if err := resp.Body.Close(); err != nil {
 			t.Fatal(err)
@@ -955,7 +955,7 @@ func TestHandler_Frame_AddField(t *testing.T) {
 		)
 		if err != nil {
 			t.Fatal(err)
-		} else if body := MustReadAll(resp.Body); string(body) != `field already exists`+"\n" {
+		} else if body := MustReadAll(resp.Body); string(body) != `creating field: field already exists`+"\n" {
 			t.Fatalf("unexpected body: %q", body)
 		} else if err := resp.Body.Close(); err != nil {
 			t.Fatal(err)
@@ -1021,7 +1021,7 @@ func TestHandler_Frame_DeleteField(t *testing.T) {
 			t.Fatal(err)
 		} else if body, err := ioutil.ReadAll(resp.Body); err != nil {
 			t.Fatal(err)
-		} else if strings.TrimSpace(string(body)) != `field not found` {
+		} else if strings.TrimSpace(string(body)) != `deleting field: field not found` {
 			t.Fatalf("unexpected body: %q", body)
 		} else if err := resp.Body.Close(); err != nil {
 			t.Fatal(err)
diff --git a/holder_test.go b/holder_test.go
index 419f69287..c0981d9ad 100644
--- a/holder_test.go
+++ b/holder_test.go
@@ -243,7 +243,7 @@ func TestHolder_Open(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		if err := h.Reopen(); err == nil || !strings.Contains(err.Error(), "open fragment: slice=0, err=unmarshal storage") {
+		if err := h.Reopen(); err == nil || !strings.Contains(err.Error(), "open fragment: slice=0, err=opening storage: unmarshal storage") {
 			t.Fatalf("unexpected error: %s", err)
 		}
 	})
diff --git a/server/server_test.go b/server/server_test.go
index 512ce5c11..b78e8b79f 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -32,7 +32,6 @@ import (
 	"github.com/pilosa/pilosa"
 	"github.com/pilosa/pilosa/server"
 	"github.com/pilosa/pilosa/test"
-	"github.com/pkg/errors"
 )
 
 // Ensure program can process queries and maintain consistency.
@@ -53,10 +52,10 @@ func TestMain_Set_Quick(t *testing.T) {
 
 		// Execute SetBit() commands.
 		for _, cmd := range cmds {
-			if err := client.CreateIndex(context.Background(), "i", pilosa.IndexOptions{}); err != nil && errors.Cause(err) != pilosa.ErrIndexExists {
+			if err := client.CreateIndex(context.Background(), "i", pilosa.IndexOptions{}); err != nil && !strings.Contains(err.Error(), "index already exists") {
 				t.Fatal(err)
 			}
-			if err := client.CreateFrame(context.Background(), "i", cmd.Frame, pilosa.FrameOptions{}); err != nil && err != pilosa.ErrFrameExists {
+			if err := client.CreateFrame(context.Background(), "i", cmd.Frame, pilosa.FrameOptions{}); err != nil && !strings.Contains(err.Error(), "frame already exists") {
 				t.Fatal(err)
 			}
 			if _, err := m.Query("i", "", fmt.Sprintf(`SetBit(row=%d, frame=%q, col=%d)`, cmd.ID, cmd.Frame, cmd.ColumnID)); err != nil {