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Router refresh (#1912)

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* checkpoint

* Refresh and prune routes periodically in the registry router

* remove comment
This commit is contained in:
Asim Aslam 2020-08-07 20:53:38 +01:00 committed by GitHub
parent d69a4a30cd
commit 324c4e6886
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 247 additions and 90 deletions
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160
router/registry/registry.go
View File

@ -14,6 +14,10 @@ import (
)
var (
// RefreshInterval is the time at which we completely refresh the table
RefreshInterval = time.Second * 120
// PruneInterval is how often we prune the routing table
PruneInterval = time.Second * 10
// AdvertiseEventsTick is time interval in which the router advertises route updates
AdvertiseEventsTick = 10 * time.Second
// DefaultAdvertTTL is default advertisement TTL
@ -55,7 +59,7 @@ func NewRouter(opts ...router.Option) router.Router {
// create the new table, passing the fetchRoute method in as a fallback if
// the table doesn't contain the result for a query.
r.table = newTable(r.fetchRoutes)
r.table = newTable(r.lookup)
// start the router
r.start()
@ -96,6 +100,20 @@ func (r *rtr) Table() router.Table {
return r.table
}
func getDomain(srv *registry.Service) string {
// check the service metadata for domain
// TODO: domain as Domain field in registry?
if srv.Metadata != nil && len(srv.Metadata["domain"]) > 0 {
return srv.Metadata["domain"]
} else if len(srv.Nodes) > 0 && srv.Nodes[0].Metadata != nil {
return srv.Nodes[0].Metadata["domain"]
}
// otherwise return wildcard
// TODO: return GlobalDomain or PublicDomain
return registry.WildcardDomain
}
// manageRoute applies action on a given route
func (r *rtr) manageRoute(route router.Route, action string) error {
switch action {
@ -118,15 +136,12 @@ func (r *rtr) manageRoute(route router.Route, action string) error {
return nil
}
// manageServiceRoutes applies action to all routes of the service.
// It returns error of the action fails with error.
func (r *rtr) manageRoutes(service *registry.Service, action, network string) error {
// action is the routing table action
action = strings.ToLower(action)
// createRoutes turns a service into a list routes basically converting nodes to routes
func (r *rtr) createRoutes(service *registry.Service, network string) []router.Route {
var routes []router.Route
// take route action on each service node
for _, node := range service.Nodes {
route := router.Route{
routes = append(routes, router.Route{
Service: service.Name,
Address: node.Address,
Gateway: "",
@ -135,8 +150,33 @@ func (r *rtr) manageRoutes(service *registry.Service, action, network string) er
Link: router.DefaultLink,
Metric: router.DefaultLocalMetric,
Metadata: node.Metadata,
}
})
}
return routes
}
// manageServiceRoutes applies action to all routes of the service.
// It returns error of the action fails with error.
func (r *rtr) manageRoutes(service *registry.Service, action, network string) error {
// action is the routing table action
action = strings.ToLower(action)
// create a set of routes from the service
routes := r.createRoutes(service, network)
// if its a delete action and there's no nodes
// it means we need to wipe out all the routes
// for that service
if action == "delete" && len(routes) == 0 {
// delete the service entirely
r.table.deleteService(service.Name, network)
return nil
}
// create the routes in the table
for _, route := range routes {
logger.Tracef("Creating route %v domain: %v", route, network)
if err := r.manageRoute(route, action); err != nil {
return err
}
@ -147,7 +187,7 @@ func (r *rtr) manageRoutes(service *registry.Service, action, network string) er
// manageRegistryRoutes applies action to all routes of each service found in the registry.
// It returns error if either the services failed to be listed or the routing table action fails.
func (r *rtr) manageRegistryRoutes(reg registry.Registry, action string) error {
func (r *rtr) loadRoutes(reg registry.Registry) error {
services, err := reg.ListServices(registry.ListDomain(registry.WildcardDomain))
if err != nil {
return fmt.Errorf("failed listing services: %v", err)
@ -156,20 +196,16 @@ func (r *rtr) manageRegistryRoutes(reg registry.Registry, action string) error {
// add each service node as a separate route
for _, service := range services {
// get the services domain from metadata. Fallback to wildcard.
var domain string
domain := getDomain(service)
if service.Metadata != nil && len(service.Metadata["domain"]) > 0 {
domain = service.Metadata["domain"]
} else {
domain = registry.WildcardDomain
}
// create the routes
routes := r.createRoutes(service, domain)
// we already have nodes
if len(service.Nodes) > 0 {
logger.Tracef("Creating route %v domain: %v", service, domain)
if err := r.manageRoutes(service, action, domain); err != nil {
logger.Tracef("Failed to manage route for %v domain: %v", service, domain)
}
// if the routes exist save them
if len(routes) > 0 {
logger.Tracef("Creating routes for service %v domain: %v", service, domain)
// save the routes without pumping out events
r.table.saveRoutes(service.Name, routes)
continue
}
@ -184,10 +220,11 @@ func (r *rtr) manageRegistryRoutes(reg registry.Registry, action string) error {
// manage the routes for all returned services
for _, srv := range srvs {
logger.Tracef("Creating route %v domain: %v", srv, domain)
if err := r.manageRoutes(srv, action, domain); err != nil {
logger.Tracef("Failed to manage route for %v domain: %v", srv, domain)
continue
routes := r.createRoutes(srv, domain)
if len(routes) > 0 {
logger.Tracef("Creating routes for service %v domain: %v", srv, domain)
r.table.saveRoutes(srv.Name, routes)
}
}
}
@ -195,40 +232,29 @@ func (r *rtr) manageRegistryRoutes(reg registry.Registry, action string) error {
return nil
}
// fetchRoutes retrieves all the routes for a given service and creates them in the routing table
func (r *rtr) fetchRoutes(service string) error {
// lookup retrieves all the routes for a given service and creates them in the routing table
func (r *rtr) lookup(service string) ([]router.Route, error) {
logger.Tracef("Fetching route for %s domain: %v", service, registry.WildcardDomain)
services, err := r.options.Registry.GetService(service, registry.GetDomain(registry.WildcardDomain))
if err == registry.ErrNotFound {
logger.Tracef("Failed to find route for %s", service)
return nil
return nil, router.ErrRouteNotFound
} else if err != nil {
logger.Tracef("Failed to find route for %s: %v", service, err)
return fmt.Errorf("failed getting services: %v", err)
return nil, fmt.Errorf("failed getting services: %v", err)
}
var routes []router.Route
for _, srv := range services {
var domain string
// since a wildcard query was performed, the service could belong
// to one of many namespaces, to get this information we check
// the node metadata. TODO: Add Domain to registry.Service
if srv.Metadata != nil && len(srv.Metadata["domain"]) > 0 {
domain = srv.Metadata["domain"]
} else if len(srv.Nodes) > 0 && srv.Nodes[0].Metadata != nil {
domain = srv.Nodes[0].Metadata["domain"]
} else {
domain = registry.WildcardDomain
}
logger.Tracef("Creating route %v domain: %v", srv, domain)
if err := r.manageRoutes(srv, "create", domain); err != nil {
logger.Tracef("Failed to create route for %v domain %v: %v", err)
continue
}
domain := getDomain(srv)
// TODO: should we continue to send the event indicating we created a route?
// lookup is only called in the query path so probably not
routes = append(routes, r.createRoutes(srv, domain)...)
}
return nil
return routes, nil
}
// watchRegistry watches registry and updates routing table based on the received events.
@ -252,6 +278,7 @@ func (r *rtr) watchRegistry(w registry.Watcher) error {
}()
for {
// get the next service
res, err := w.Next()
if err != nil {
if err != registry.ErrWatcherStopped {
@ -260,18 +287,15 @@ func (r *rtr) watchRegistry(w registry.Watcher) error {
break
}
// don't process nil entries
if res.Service == nil {
continue
}
// get the services domain from metadata. Fallback to wildcard.
var domain string
if res.Service.Metadata != nil && len(res.Service.Metadata["domain"]) > 0 {
domain = res.Service.Metadata["domain"]
} else {
domain = registry.WildcardDomain
}
domain := getDomain(res.Service)
// create/update or delete the route
if err := r.manageRoutes(res.Service, res.Action, domain); err != nil {
return err
}
@ -496,8 +520,8 @@ func (r *rtr) start() error {
if r.options.Precache {
// add all local service routes into the routing table
if err := r.manageRegistryRoutes(r.options.Registry, "create"); err != nil {
return fmt.Errorf("failed adding registry routes: %s", err)
if err := r.loadRoutes(r.options.Registry); err != nil {
return fmt.Errorf("failed loading registry routes: %s", err)
}
}
@ -521,6 +545,28 @@ func (r *rtr) start() error {
// create error and exit channels
r.exit = make(chan bool)
// periodically refresh all the routes
go func() {
t1 := time.NewTicker(RefreshInterval)
defer t1.Stop()
t2 := time.NewTicker(PruneInterval)
defer t2.Stop()
for {
select {
case <-r.exit:
return
case <-t2.C:
r.table.pruneRoutes(RefreshInterval)
case <-t1.C:
if err := r.loadRoutes(r.options.Registry); err != nil {
logger.Errorf("failed refreshing registry routes: %s", err)
}
}
}
}()
go func() {
var err error
var w registry.Watcher

166
router/registry/table.go
View File

@ -12,20 +12,98 @@ import (
// table is an in-memory routing table
type table struct {
sync.RWMutex
// fetchRoutes for a service
fetchRoutes func(string) error
// lookup for a service
lookup func(string) ([]router.Route, error)
// routes stores service routes
routes map[string]map[uint64]router.Route
routes map[string]map[uint64]*route
// watchers stores table watchers
watchers map[string]*tableWatcher
}
type route struct {
route router.Route
updated time.Time
}
// newtable creates a new routing table and returns it
func newTable(fetchRoutes func(string) error, opts ...router.Option) *table {
func newTable(lookup func(string) ([]router.Route, error), opts ...router.Option) *table {
return &table{
fetchRoutes: fetchRoutes,
routes: make(map[string]map[uint64]router.Route),
watchers: make(map[string]*tableWatcher),
lookup: lookup,
routes: make(map[string]map[uint64]*route),
watchers: make(map[string]*tableWatcher),
}
}
// pruneRoutes will prune routes older than the time specified
func (t *table) pruneRoutes(olderThan time.Duration) {
var routes []router.Route
t.Lock()
// search for all the routes
for _, routeList := range t.routes {
for _, r := range routeList {
// if any route is older than
if time.Since(r.updated).Seconds() > olderThan.Seconds() {
routes = append(routes, r.route)
}
}
}
t.Unlock()
// delete the routes we've found
for _, route := range routes {
t.Delete(route)
}
}
// deleteService removes the entire service
func (t *table) deleteService(service, network string) {
t.Lock()
routes, ok := t.routes[service]
if !ok {
return
}
// delete the routes for the service
for hash, rt := range routes {
// TODO: check if this causes a problem
// with * in the network if that is a thing
// or blank strings
if rt.route.Network != network {
continue
}
delete(routes, hash)
}
// delete the map for the service if its empty
if len(routes) == 0 {
delete(t.routes, service)
return
}
// save the routes
t.routes[service] = routes
t.Unlock()
}
// saveRoutes completely replaces the routes for a service
func (t *table) saveRoutes(service string, routes []router.Route) {
t.Lock()
defer t.Unlock()
// delete old routes
delete(t.routes, service)
// make new map
t.routes[service] = make(map[uint64]*route)
// iterate through new routes and save
for _, rt := range routes {
// save the new route
t.routes[service][rt.Hash()] = &route{rt, time.Now()}
}
}
@ -58,20 +136,25 @@ func (t *table) Create(r router.Route) error {
// check if there are any routes in the table for the route destination
if _, ok := t.routes[service]; !ok {
t.routes[service] = make(map[uint64]router.Route)
t.routes[service] = make(map[uint64]*route)
}
// add new route to the table for the route destination
if _, ok := t.routes[service][sum]; !ok {
t.routes[service][sum] = r
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Router emitting %s for route: %s", router.Create, r.Address)
}
go t.sendEvent(&router.Event{Type: router.Create, Timestamp: time.Now(), Route: r})
return nil
if _, ok := t.routes[service][sum]; ok {
return router.ErrDuplicateRoute
}
return router.ErrDuplicateRoute
// create the route
t.routes[service][sum] = &route{r, time.Now()}
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Router emitting %s for route: %s", router.Create, r.Address)
}
// send a route created event
go t.sendEvent(&router.Event{Type: router.Create, Timestamp: time.Now(), Route: r})
return nil
}
// Delete deletes the route from the routing table
@ -90,10 +173,14 @@ func (t *table) Delete(r router.Route) error {
return router.ErrRouteNotFound
}
// delete the route from the service
delete(t.routes[service], sum)
// delete the whole map if there are no routes left
if len(t.routes[service]) == 0 {
delete(t.routes, service)
}
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Router emitting %s for route: %s", router.Delete, r.Address)
}
@ -112,11 +199,13 @@ func (t *table) Update(r router.Route) error {
// check if the route destination has any routes in the table
if _, ok := t.routes[service]; !ok {
t.routes[service] = make(map[uint64]router.Route)
t.routes[service] = make(map[uint64]*route)
}
if _, ok := t.routes[service][sum]; !ok {
t.routes[service][sum] = r
// update the route
t.routes[service][sum] = &route{r, time.Now()}
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Router emitting %s for route: %s", router.Update, r.Address)
}
@ -125,7 +214,7 @@ func (t *table) Update(r router.Route) error {
}
// just update the route, but dont emit Update event
t.routes[service][sum] = r
t.routes[service][sum] = &route{r, time.Now()}
return nil
}
@ -138,7 +227,7 @@ func (t *table) List() ([]router.Route, error) {
var routes []router.Route
for _, rmap := range t.routes {
for _, route := range rmap {
routes = append(routes, route)
routes = append(routes, route.route)
}
}
@ -187,12 +276,21 @@ func isMatch(route router.Route, address, gateway, network, rtr string, strategy
return true
}
// findRoutes finds all the routes for given network and router and returns them
func findRoutes(routes map[uint64]router.Route, address, gateway, network, rtr string, strategy router.Strategy) []router.Route {
// filterRoutes finds all the routes for given network and router and returns them
func filterRoutes(routes map[uint64]*route, opts router.QueryOptions) []router.Route {
address := opts.Address
gateway := opts.Gateway
network := opts.Network
rtr := opts.Router
strategy := opts.Strategy
// routeMap stores the routes we're going to advertise
routeMap := make(map[string][]router.Route)
for _, route := range routes {
for _, rt := range routes {
// get the actual route
route := rt.route
if isMatch(route, address, gateway, network, rtr, strategy) {
// add matchihg route to the routeMap
routeKey := route.Service + "@" + route.Network
@ -254,7 +352,7 @@ func (t *table) Query(q ...router.QueryOption) ([]router.Route, error) {
return nil, false
}
return findRoutes(routes, q.Address, q.Gateway, q.Network, q.Router, q.Strategy), true
return filterRoutes(routes, q), true
}
if opts.Service != "*" {
@ -263,11 +361,17 @@ func (t *table) Query(q ...router.QueryOption) ([]router.Route, error) {
return routes, nil
}
// load the cache and try again
if err := t.fetchRoutes(opts.Service); err != nil {
// lookup the route and try again
// TODO: move this logic out of the hot path
// being hammered on queries will require multiple lookups
routes, err := t.lookup(opts.Service)
if err != nil {
return nil, err
}
// cache the routes
t.saveRoutes(opts.Service, routes)
// try again
if routes, ok := readAndFilter(opts); ok {
return routes, nil
@ -278,9 +382,17 @@ func (t *table) Query(q ...router.QueryOption) ([]router.Route, error) {
// search through all destinations
t.RLock()
for _, routes := range t.routes {
results = append(results, findRoutes(routes, opts.Address, opts.Gateway, opts.Network, opts.Router, opts.Strategy)...)
// filter the routes
found := filterRoutes(routes, opts)
// ensure we don't append zero length routes
if len(found) == 0 {
continue
}
results = append(results, found...)
}
t.RUnlock()
return results, nil

11
router/registry/table_test.go
View File

@ -9,7 +9,7 @@ import (
func testSetup() (*table, router.Route) {
routr := NewRouter().(*rtr)
table := newTable(routr.fetchRoutes)
table := newTable(routr.lookup)
route := router.Route{
Service: "dest.svc",
@ -304,9 +304,8 @@ func TestFallback(t *testing.T) {
Link: router.DefaultLink,
Metric: router.DefaultLocalMetric,
}
r.table = newTable(func(s string) error {
r.table.Create(route)
return nil
r.table = newTable(func(s string) ([]router.Route, error) {
return []router.Route{route}, nil
})
r.start()
@ -338,8 +337,8 @@ func TestFallbackError(t *testing.T) {
subscribers: make(map[string]chan *router.Advert),
options: router.DefaultOptions(),
}
r.table = newTable(func(s string) error {
return fmt.Errorf("ERROR")
r.table = newTable(func(s string) ([]router.Route, error) {
return nil, fmt.Errorf("ERROR")
})
r.start()
_, err := r.Lookup(router.QueryService("go.micro.service.foo"))