Exemple #1
0
// GetTopic performs a thread safe operation
// to return a pointer to a Topic object (potentially new)
func (n *NSQD) GetTopic(topicName string) *Topic {
	n.Lock()

	t, ok := n.topicMap[topicName]
	if ok {
		n.Unlock()
		return t
	}
	deleteCallback := func(t *Topic) {
		n.DeleteExistingTopic(t.name)
	}
	t = NewTopic(topicName, &context{n}, deleteCallback)
	n.topicMap[topicName] = t

	n.logf("TOPIC(%s): created", t.name)

	// release our global nsqd lock, and switch to a more granular topic lock while we init our
	// channels from lookupd. This blocks concurrent PutMessages to this topic.
	t.Lock()
	n.Unlock()

	// if using lookupd, make a blocking call to get the topics, and immediately create them.
	// this makes sure that any message received is buffered to the right channels
	lookupdHTTPAddrs := n.lookupdHTTPAddrs()
	if len(lookupdHTTPAddrs) > 0 {
		channelNames, _ := lookupd.GetLookupdTopicChannels(t.name, lookupdHTTPAddrs)
		for _, channelName := range channelNames {
			if strings.HasSuffix(channelName, "#ephemeral") {
				// we don't want to pre-create ephemeral channels
				// because there isn't a client connected
				continue
			}
			t.getOrCreateChannel(channelName)
		}
	}

	t.Unlock()

	// NOTE: I would prefer for this to only happen in topic.GetChannel() but we're special
	// casing the code above so that we can control the locks such that it is impossible
	// for a message to be written to a (new) topic while we're looking up channels
	// from lookupd...
	//
	// update messagePump state
	select {
	case t.channelUpdateChan <- 1:
	case <-t.exitChan:
	}
	return t
}
Exemple #2
0
func (s *httpServer) lookupHandler(w http.ResponseWriter, req *http.Request) {
	reqParams, err := http_api.NewReqParams(req)
	if err != nil {
		s.ctx.nsqadmin.logf("ERROR: failed to parse request params - %s", err)
		http.Error(w, "INVALID_REQUEST", 500)
		return
	}

	channels := make(map[string][]string)
	allTopics, _ := lookupd.GetLookupdTopics(s.ctx.nsqadmin.opts.NSQLookupdHTTPAddresses)
	for _, topicName := range allTopics {
		var producers []string
		producers, _ = lookupd.GetLookupdTopicProducers(topicName, s.ctx.nsqadmin.opts.NSQLookupdHTTPAddresses)
		if len(producers) == 0 {
			topicChannels, _ := lookupd.GetLookupdTopicChannels(topicName, s.ctx.nsqadmin.opts.NSQLookupdHTTPAddresses)
			channels[topicName] = topicChannels
		}
	}

	p := struct {
		Title        string
		GraphOptions *GraphOptions
		TopicMap     map[string][]string
		Lookupd      []string
		Version      string
	}{
		Title:        "NSQ Lookup",
		GraphOptions: NewGraphOptions(w, req, reqParams, s.ctx),
		TopicMap:     channels,
		Lookupd:      s.ctx.nsqadmin.opts.NSQLookupdHTTPAddresses,
		Version:      version.Binary,
	}
	err = templates.T.ExecuteTemplate(w, "lookup.html", p)
	if err != nil {
		s.ctx.nsqadmin.logf("Template Error %s", err)
		http.Error(w, "Template Error", 500)
	}
}