fix(edgestacks): add a status update coordinator to increase performance BE-11572 (#337)

api/http/handler/edgestacks/edgestack_status_update.go

@@ -8,7 +8,6 @@ import (
 	"time"
 
 	portainer "github.com/portainer/portainer/api"
-	"github.com/portainer/portainer/api/dataservices"
 	httperror "github.com/portainer/portainer/pkg/libhttp/error"
 	"github.com/portainer/portainer/pkg/libhttp/request"
 	"github.com/portainer/portainer/pkg/libhttp/response"
@@ -69,15 +68,17 @@ func (handler *Handler) edgeStackStatusUpdate(w http.ResponseWriter, r *http.Req
 		return httperror.BadRequest("Invalid request payload", fmt.Errorf("edge polling error: %w. Environment ID: %d", err, payload.EndpointID))
 	}
 
-	var stack *portainer.EdgeStack
-	if err := handler.DataStore.UpdateTx(func(tx dataservices.DataStoreTx) error {
-		if err := r.Context().Err(); err != nil {
-			return err
-		}
+	endpoint, err := handler.DataStore.Endpoint().Endpoint(payload.EndpointID)
+	if err != nil {
+		return handlerDBErr(fmt.Errorf("unable to find the environment from the database: %w. Environment ID: %d", err, payload.EndpointID), "unable to find the environment")
+	}
 
-		stack, err = handler.updateEdgeStackStatus(tx, r, portainer.EdgeStackID(stackID), payload)
-		return err
-	}); err != nil {
+	if err := handler.requestBouncer.AuthorizedEdgeEndpointOperation(r, endpoint); err != nil {
+		return httperror.Forbidden("Permission denied to access environment", fmt.Errorf("unauthorized edge endpoint operation: %w. Environment name: %s", err, endpoint.Name))
+	}
+
+	stack, err := handler.stackCoordinator.UpdateStatus(r, endpoint, portainer.EdgeStackID(stackID), payload)
+	if err != nil {
 		var httpErr *httperror.HandlerError
 		if errors.As(err, &httpErr) {
 			return httpErr
@@ -93,36 +94,11 @@ func (handler *Handler) edgeStackStatusUpdate(w http.ResponseWriter, r *http.Req
 	return response.JSON(w, stack)
 }
 
-func (handler *Handler) updateEdgeStackStatus(tx dataservices.DataStoreTx, r *http.Request, stackID portainer.EdgeStackID, payload updateStatusPayload) (*portainer.EdgeStack, error) {
-	stack, err := tx.EdgeStack().EdgeStack(stackID)
-	if err != nil {
-		if dataservices.IsErrObjectNotFound(err) {
-			// Skip error because agent tries to report on deleted stack
-			log.Debug().
-				Err(err).
-				Int("stackID", int(stackID)).
-				Int("status", int(*payload.Status)).
-				Msg("Unable to find a stack inside the database, skipping error")
-
-			return nil, nil
-		}
-
-		return nil, fmt.Errorf("unable to retrieve Edge stack from the database: %w. Environment ID: %d", err, payload.EndpointID)
-	}
-
+func (handler *Handler) updateEdgeStackStatus(stack *portainer.EdgeStack, endpoint *portainer.Endpoint, r *http.Request, stackID portainer.EdgeStackID, payload updateStatusPayload) (*portainer.EdgeStack, error) {
 	if payload.Version > 0 && payload.Version < stack.Version {
 		return stack, nil
 	}
 
-	endpoint, err := tx.Endpoint().Endpoint(payload.EndpointID)
-	if err != nil {
-		return nil, handlerDBErr(fmt.Errorf("unable to find the environment from the database: %w. Environment ID: %d", err, payload.EndpointID), "unable to find the environment")
-	}
-
-	if err := handler.requestBouncer.AuthorizedEdgeEndpointOperation(r, endpoint); err != nil {
-		return nil, httperror.Forbidden("Permission denied to access environment", fmt.Errorf("unauthorized edge endpoint operation: %w. Environment name: %s", err, endpoint.Name))
-	}
-
 	status := *payload.Status
 
 	log.Debug().
@@ -138,10 +114,6 @@ func (handler *Handler) updateEdgeStackStatus(tx dataservices.DataStoreTx, r *ht
 
 	updateEnvStatus(payload.EndpointID, stack, deploymentStatus)
 
-	if err := tx.EdgeStack().UpdateEdgeStack(stackID, stack); err != nil {
-		return nil, handlerDBErr(fmt.Errorf("unable to update Edge stack to the database: %w. Environment name: %s", err, endpoint.Name), "unable to update Edge stack")
-	}
-
 	return stack, nil
 }
 

api/http/handler/edgestacks/edgestack_status_update_coordinator.go

@@ -0,0 +1,166 @@
+package edgestacks
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+
+	portainer "github.com/portainer/portainer/api"
+	"github.com/portainer/portainer/api/dataservices"
+
+	"github.com/rs/zerolog/log"
+)
+
+type statusRequest struct {
+	r        *http.Request
+	respCh   chan statusResponse
+	endpoint *portainer.Endpoint
+	stackID  portainer.EdgeStackID
+	payload  updateStatusPayload
+}
+
+type statusResponse struct {
+	Stack *portainer.EdgeStack
+	Error error
+}
+
+type statusUpdateFn func(stack *portainer.EdgeStack, endpoint *portainer.Endpoint, r *http.Request, stackID portainer.EdgeStackID, payload updateStatusPayload) (*portainer.EdgeStack, error)
+
+type EdgeStackStatusUpdateCoordinator struct {
+	updateCh       chan statusRequest
+	dataStore      dataservices.DataStore
+	statusUpdateFn statusUpdateFn
+}
+
+var errAnotherStackUpdateInProgress = errors.New("another stack update is in progress")
+
+func NewEdgeStackStatusUpdateCoordinator(
+	dataStore dataservices.DataStore,
+	statusUpdateFn statusUpdateFn,
+) *EdgeStackStatusUpdateCoordinator {
+	return &EdgeStackStatusUpdateCoordinator{
+		updateCh:       make(chan statusRequest),
+		dataStore:      dataStore,
+		statusUpdateFn: statusUpdateFn,
+	}
+}
+
+func (c *EdgeStackStatusUpdateCoordinator) Start() {
+	for {
+		c.loop()
+	}
+}
+
+func (c *EdgeStackStatusUpdateCoordinator) loop() {
+	u := <-c.updateCh
+
+	respChs := []chan statusResponse{u.respCh}
+
+	var stack *portainer.EdgeStack
+
+	err := c.dataStore.UpdateTx(func(tx dataservices.DataStoreTx) error {
+		// 1. Load the edge stack
+		var err error
+
+		stack, err = loadEdgeStack(tx, u.stackID)
+		if err != nil {
+			return err
+		}
+
+		// 2. Mutate the edge stack opportunistically until there are no more pending updates
+		for {
+			stack, err = c.statusUpdateFn(stack, u.endpoint, u.r, stack.ID, u.payload)
+			if err != nil {
+				return err
+			}
+
+			if m, ok := c.getNextUpdate(stack.ID); ok {
+				u = m
+			} else {
+				break
+			}
+
+			respChs = append(respChs, u.respCh)
+		}
+
+		// 3. Save the changes back to the database
+		if err := tx.EdgeStack().UpdateEdgeStack(stack.ID, stack); err != nil {
+			return handlerDBErr(fmt.Errorf("unable to update Edge stack: %w.", err), "Unable to persist the stack changes inside the database")
+		}
+
+		return nil
+	})
+
+	// 4. Send back the responses
+	for _, ch := range respChs {
+		ch <- statusResponse{Stack: stack, Error: err}
+	}
+}
+
+func loadEdgeStack(tx dataservices.DataStoreTx, stackID portainer.EdgeStackID) (*portainer.EdgeStack, error) {
+	stack, err := tx.EdgeStack().EdgeStack(stackID)
+	if err != nil {
+		if dataservices.IsErrObjectNotFound(err) {
+			// Skip the error when the agent tries to update the status on a deleted stack
+			log.Debug().
+				Err(err).
+				Int("stackID", int(stackID)).
+				Msg("Unable to find a stack inside the database, skipping error")
+
+			return nil, nil
+		}
+
+		return nil, fmt.Errorf("unable to retrieve Edge stack from the database: %w.", err)
+	}
+
+	return stack, nil
+}
+
+func (c *EdgeStackStatusUpdateCoordinator) getNextUpdate(stackID portainer.EdgeStackID) (statusRequest, bool) {
+	for {
+		select {
+		case u := <-c.updateCh:
+			// Discard the update and let the agent retry
+			if u.stackID != stackID {
+				u.respCh <- statusResponse{Error: errAnotherStackUpdateInProgress}
+
+				continue
+			}
+
+			return u, true
+
+		default:
+			return statusRequest{}, false
+		}
+	}
+}
+
+func (c *EdgeStackStatusUpdateCoordinator) UpdateStatus(
+	r *http.Request,
+	endpoint *portainer.Endpoint,
+	stackID portainer.EdgeStackID,
+	payload updateStatusPayload) (
+	*portainer.EdgeStack,
+	error,
+) {
+	respCh := make(chan statusResponse)
+	defer close(respCh)
+
+	msg := statusRequest{
+		respCh:   respCh,
+		r:        r,
+		endpoint: endpoint,
+		stackID:  stackID,
+		payload:  payload,
+	}
+
+	select {
+	case c.updateCh <- msg:
+		r := <-respCh
+
+		return r.Stack, r.Error
+
+	case <-r.Context().Done():
+		return nil, r.Context().Err()
+	}
+}

api/http/handler/edgestacks/handler.go

@@ -22,6 +22,7 @@ type Handler struct {
 	GitService         portainer.GitService
 	edgeStacksService  *edgestackservice.Service
 	KubernetesDeployer portainer.KubernetesDeployer
+	stackCoordinator   *EdgeStackStatusUpdateCoordinator
 }
 
 // NewHandler creates a handler to manage environment(endpoint) group operations.
@@ -33,6 +34,10 @@ func NewHandler(bouncer security.BouncerService, dataStore dataservices.DataStor
 		edgeStacksService: edgeStacksService,
 	}
 
+	h.stackCoordinator = NewEdgeStackStatusUpdateCoordinator(dataStore, h.updateEdgeStackStatus)
+
+	go h.stackCoordinator.Start()
+
 	h.Handle("/edge_stacks/create/{method}",
 		bouncer.AdminAccess(bouncer.EdgeComputeOperation(httperror.LoggerHandler(h.edgeStackCreate)))).Methods(http.MethodPost)
 	h.Handle("/edge_stacks",