The document discusses service discovery in Mesos clusters, highlighting various tools and patterns for managing how services communicate within a cluster. It covers client-side and server-side discovery patterns, along with specific tools like Zookeeper, Consul, and Mesos-DNS, detailing their features and integration capabilities. The presentation also addresses service discovery antipatterns and concludes with a mention of the marathon-lb tool for managing HAProxy in a Mesos environment.

1. Service discovery in
Mesos Cluster
Miguel Angel Guillen
AeriaGames GmbH

2. Who am I?
● From Elche(Spain)
● Working in Berlin
in AeriaGames
● DevOps,Sysadmin,
SRE, etc…
● Video Games

3. AERIA GAMES
Different partners and
technologies

4. Mesos
● Cluster resources
● Supports docker containers
● Is really cool
● Mesos and Beyond was before this talk!!

5. Service discovery
“Service discovery tools manage how
processes and services in a cluster can find
and talk to one another.”

6. DNS
● More basic service discovery
● But A records are really simple
● SRV records are really useful
● Few services supports SRV

7. Service Discovery tools
● Provides a service registry system
● Integrates with an API
● Provides meta-data of the service
● Use or provides a K/V store
● It provides libraries and tools

8. Service Discovery tools
● Zookeeper
K/V store
libraries
● ETCD
K/V store
libraries
REST API
● Consul
K/V store
libraries
REST API
DNS
● All can be used as K/V store for all kind of usage

9. Mesos

10. Mesos

12. Zookeeper
● Zookeeper
K/V store
libraries
● NO YET REST OR DNS!*
● Only library support**
* REST is WIP
** you can use confd for reading, but set data is still from lib or
zkshell

13. What I should do?
● There is other options
● mesos-dns
● marathon-dns
● marathon-lb
● The problem is if service discovery
pattern fits in your needs

14. Service Discovery Patterns
● Client-Side Discovery Pattern
– The client is responsible for determining the
network locations
– Load balancing is managed by the client
– Usually client supports service discovery
with a library integrated (zookeeper)

15. Service Discovery Patterns
● The Server-Side Discovery Pattern
– The client makes a request to a service via a
load balancer
– Client don’t know the service, only load
balancer
– Load Balancer use service registry via DNS
or other kind of integrations.

16. Service Discovery Antipatterns
in microservices
Server side discovery
– We add an extra hop
– Load balancer as SpoF
● Or scale with the microservice
– Adds complexity to the architecture

17. And Finally…. In Mesos

18. Layers
Marathon
Mesos
Docker RegistratorRegistrator
Mesos-dnsMesos-dns
Marathon-lbMarathon-lb
consul RegistratorRegistrator
Mesos-consul

19. Service Discovery in mesos
Registrator
– Reads the event bus of docker and adds the
service to a service registry
● Application is removed from the registry when
docker container is stopped.
– If the host crash the services are still
registered
● If the host is recovered problems can appear
– There are better solutions for using with mesos

20. Mesos-consul
mesos-consul
● “Mesos-consul automatically registers/deregisters
services run as Mesos tasks.”
● Can be deployed in mesos as task or marthon app
● Depends on consul as service registry
● Use a lot of the features of consul like tags
● Develop for mantl(CiscoCloud)

21. Service Discovery in mesos
Mesos-DNS
“Mesos-DNS enables DNS based service discovery in
Apache Mesos clusters.”
● Supports SRV records
● It has special records for marathon
– Ex: leading master: A record (leader.domain) and SRV
records (_leader._tcp.domain and _leader._udp.domain)
● Supports round robin for multiple tasks with the
same name

22. Service Discovery in mesos

23. Service discovery in
mesos/marathon
Marathon-lb
“Marathon-lb is a tool for managing HAProxy, by
consuming Marathon's app state”
● Server side service discovery
● Deployable in marathon it self
● Depends on marathon
● Is included in DCOS

24. ?

25. Vielen Dank!!