// ForgetHandler removes a buddy from the buddy list
func ForgetHandler(dependencies *map[string]time.Time, microservices *map[string]chan Message, msg Message) {
microservice := msg.Intention // message body is buddy name to forget
if (*microservices)[microservice] != nil { // an existing buddy to forget
// forget how to talk to this buddy
(*dependencies)[names.Service(microservice)] = msg.Sent // remember when we were told to forget this service
delete(*microservices, microservice)
}
}
// Delete a single node from the given service
func Delete(noodles *map[string]chan gotocol.Message, service string) {
if service != "" {
for node, ch := range *noodles {
if names.Service(node) == service {
gotocol.Message{gotocol.Goodbye, nil, time.Now(), gotocol.NewRequest(), "chaosmonkey"}.GoSend(ch)
log.Println("chaosmonkey delete: " + node)
return
}
}
}
}
func NameDropHandler(dependencies *map[string]time.Time, microservices *map[string]chan Message, msg Message, name string, listener chan Message, eureka map[string]chan Message, crosszone ...bool) {
if msg.ResponseChan == nil { // dependency by service name, needs to be looked up in eureka
(*dependencies)[msg.Intention] = msg.Sent // remember it for later
for _, ch := range eureka {
//log.Println(name + " looking up " + msg.Intention)
Send(ch, Message{GetRequest, listener, time.Now(), NilContext, msg.Intention})
}
} else { // update dependency with full name and listener channel
microservice := msg.Intention // message body is buddy name
if len(crosszone) > 0 || names.Zone(name) == names.Zone(microservice) {
if microservice != name && (*microservices)[microservice] == nil { // don't talk to myself or record duplicates
// remember how to talk to this buddy
(*microservices)[microservice] = msg.ResponseChan // message channel is buddy's listener
(*dependencies)[names.Service(microservice)] = msg.Sent
for _, ch := range eureka {
// tell one of the service registries I have a new buddy to talk to so it doesn't get logged more than once
Send(ch, Message{Inform, listener, time.Now(), NilContext, name + " " + microservice})
return
}
}
}
}
}
// Start eureka discovery service and set name directly
func Start(listener chan gotocol.Message, name string) {
// use a waitgroup so whoever starts eureka can tell it's ready and when stopping that the logs have been flushed
Wg.Add(1)
defer Wg.Done()
var msg gotocol.Message
var ok bool
hist := collect.NewHist(name)
microservices := make(map[string]chan gotocol.Message, archaius.Conf.Dunbar)
eurekaservices := make(map[string]chan gotocol.Message, 2)
metadata := make(map[string]meta, archaius.Conf.Dunbar)
lastrequest := make(map[callback]time.Time) // remember time of last request for a service from this requestor
log.Println(name + ": starting")
for {
msg, ok = <-listener
collect.Measure(hist, time.Since(msg.Sent))
if !ok {
break // channel was closed
}
if archaius.Conf.Msglog {
log.Printf("%v(backlog %v): %v\n", name, len(listener), msg)
}
switch msg.Imposition {
// used to wire up connections to other eureka nodes only
case gotocol.NameDrop:
if msg.Intention != name { // don't talk to myself
eurekaservices[msg.Intention] = msg.ResponseChan
}
// for new nodes record the data, replicate and maybe pass on to be logged
case gotocol.Put:
if microservices[msg.Intention] == nil { // ignore duplicate requests
microservices[msg.Intention] = msg.ResponseChan
metadata[msg.Intention] = meta{true, msg.Sent}
// replicate request, everyone ends up with the same timestamp for state change of this service
for _, c := range eurekaservices {
gotocol.Message{gotocol.Replicate, msg.ResponseChan, msg.Sent, msg.Intention}.GoSend(c)
}
if edda.Logchan != nil {
edda.Logchan <- msg
}
}
case gotocol.Replicate:
if microservices[msg.Intention] == nil { // ignore multiple requests
microservices[msg.Intention] = msg.ResponseChan
metadata[msg.Intention] = meta{true, msg.Sent}
}
case gotocol.Inform:
// don't store edges in discovery but do log them
if edda.Logchan != nil {
edda.Logchan <- msg
}
case gotocol.GetRequest:
if msg.Intention == "" {
log.Fatal(name + ": empty GetRequest")
}
if microservices[msg.Intention] != nil { // matched a unique full name
gotocol.Message{gotocol.NameDrop, microservices[msg.Intention], time.Now(), msg.Intention}.GoSend(msg.ResponseChan)
break
}
for n, ch := range microservices { // respond with all the online names that match the service component
if names.Service(n) == msg.Intention {
// if there was an update for the looked up service since last check
// log.Printf("%v: matching %v with %v, last: %v metadata: %v\n", name, n, msg.Intention, lastrequest[callback{n, msg.ResponseChan}], metadata[n].registered)
if metadata[n].registered.After(lastrequest[callback{n, msg.ResponseChan}]) {
if metadata[n].online {
gotocol.Message{gotocol.NameDrop, ch, time.Now(), n}.GoSend(msg.ResponseChan)
} else {
log.Printf("%v:Forget %v\n", name, n)
gotocol.Message{gotocol.Forget, ch, time.Now(), n}.GoSend(msg.ResponseChan)
}
}
// remember for next time
lastrequest[callback{n, msg.ResponseChan}] = msg.Sent
}
}
case gotocol.Delete: // remove a node
if microservices[msg.Intention] != nil { // matched a unique full name
metadata[msg.Intention] = meta{false, time.Now()}
// replicate request
for _, c := range eurekaservices {
gotocol.Message{gotocol.Replicate, nil, time.Now(), msg.Intention}.GoSend(c)
}
if edda.Logchan != nil {
edda.Logchan <- msg
}
}
case gotocol.Goodbye:
gotocol.Message{gotocol.Goodbye, nil, time.Now(), name}.GoSend(msg.ResponseChan)
log.Println(name + ": closing")
return
}
}
}