allow clock error in the cluster (#397)

config/config.go

@@ -228,15 +228,17 @@ func (config *RecommendConfig) validate() {
 
 // ServerConfig is the configuration for the server.
 type ServerConfig struct {
-	APIKey   string `mapstructure:"api_key"`   // default number of returned items
-	DefaultN int    `mapstructure:"default_n"` // secret key for RESTful APIs (SSL required)
+	APIKey      string `mapstructure:"api_key"`      // default number of returned items
+	DefaultN    int    `mapstructure:"default_n"`    // secret key for RESTful APIs (SSL required)
+	EpsilonTime int    `mapstructure:"epsilon_time"` // clock error in the cluster in seconds
 }
 
 // LoadDefaultIfNil loads default settings if config is nil.
 func (config *ServerConfig) LoadDefaultIfNil() *ServerConfig {
 	if config == nil {
 		return &ServerConfig{
-			DefaultN: 10,
+			DefaultN:    10,
+			EpsilonTime: 5,
 		}
 	}
 	return config
@@ -265,6 +267,7 @@ func init() {
 	defaultServerConfig := *(*ServerConfig)(nil).LoadDefaultIfNil()
 	viper.SetDefault("server.api_key", defaultServerConfig.APIKey)
 	viper.SetDefault("server.default_n", defaultServerConfig.DefaultN)
+	viper.SetDefault("server.epsilon_time", defaultServerConfig.EpsilonTime)
 	// Default recommend config
 	defaultRecommendConfig := *(*RecommendConfig)(nil).LoadDefaultIfNil()
 	viper.SetDefault("recommend.popular_window", defaultRecommendConfig.PopularWindow)

config/config.toml.template

@@ -49,6 +49,7 @@ dashboard_password = "password" # dashboard password
 [server]
 default_n = 10                  # default number of returned items
 api_key = ""                    # secret key for RESTful APIs (SSL required)
+epsilon_time = 5                # clock error in the cluster in seconds
 
 # This section declares settings for recommendation.
 [recommend]

config/config_test.go

@@ -49,6 +49,7 @@ func TestLoadConfig(t *testing.T) {
 	// server configuration
 	assert.Equal(t, 10, config.Server.DefaultN)
 	assert.Equal(t, "", config.Server.APIKey)
+	assert.Equal(t, 5, config.Server.EpsilonTime)
 
 	// recommend configuration
 	assert.Equal(t, 30, config.Recommend.PopularWindow)

docker/config.toml

@@ -47,6 +47,7 @@ meta_timeout = 10               # cluster meta timeout (second)
 [server]
 default_n = 10                  # default number of returned items
 api_key = ""                    # secret key for RESTful APIs (SSL required)
+epsilon_time = 5                # clock error in the cluster in seconds
 
 # This section declares settings for recommendation.
 [recommend]

server/rest.go

@@ -635,7 +635,8 @@ type recommendContext struct {
 
 func (s *RestServer) createRecommendContext(userId, category string, n int) (*recommendContext, error) {
 	// pull ignored items
-	ignoreItems, err := s.CacheClient.GetSortedByScore(cache.Key(cache.IgnoreItems, userId), math.Inf(-1), float64(time.Now().Unix()))
+	ignoreItems, err := s.CacheClient.GetSortedByScore(cache.Key(cache.IgnoreItems, userId),
+		math.Inf(-1), float64(time.Now().Add(time.Duration(s.GorseConfig.Server.EpsilonTime)*time.Second).Unix()))
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
@@ -956,7 +957,7 @@ func (s *RestServer) getRecommend(request *restful.Request, response *restful.Re
 					ItemId:       itemId,
 					FeedbackType: writeBackFeedback,
 				},
-				Timestamp: time.Now().Add(time.Minute * time.Duration(writeBackDelay)),
+				Timestamp: startTime.Add(time.Minute * time.Duration(writeBackDelay)),
 			}
 			err = s.DataClient.BatchInsertFeedback([]data.Feedback{feedback}, false, false, false)
 			if err != nil {

worker/worker.go

@@ -917,13 +917,13 @@ func (w *Worker) refreshCache(userId string) error {
 	} else {
 		return errors.Trace(err)
 	}
-	// clear cache
-	err = w.cacheClient.SetSorted(cache.IgnoreItems, nil)
-	if err != nil {
-		return errors.Trace(err)
-	}
-	// load cache
-	if !w.cfg.Recommend.EnableReplacement {
+	// reload cache
+	if w.cfg.Recommend.EnableReplacement {
+		err = w.cacheClient.SetSorted(cache.IgnoreItems, nil)
+		if err != nil {
+			return errors.Trace(err)
+		}
+	} else {
 		feedback, err := w.dataClient.GetUserFeedback(userId, true)
 		if err != nil {
 			return errors.Trace(err)