Finagle, linkerd, and Apache Mesos: Twitter-style microservices at scale

Finagle (Twitter's Apache-licensed RPC stack) and Apache Mesos are two core technologies used by Twitter to scale its multi-service architecture to high-volume traffic loads. In this talk, we describe how Twitter used Finagle and Mesos together to address the challenges of scaling its application. We introduce linkerd, an Apache-licensed proxy form of Finagle, which extends Finagle's operational model to non-JVM or polyglot multi-service applications. Finally, we show how linkerd can be used to "wrap" applications running in Apache Mesos to provide higher-level, service-based semantics around scalability, reliability, and fault-tolerance for multi-service or microservice applications---even in the presence of high traffic loads and unreliable hardware.

Transcript

1. Finagle, linkerd, and Mesos
 Twitter-style microservices at scale oliver gould
 cto, buoyant ApacheCon North America, May 2016 from
2. oliver gould • cto @ buoyant
 open-source microservice infrastructure • previously, tech lead @ twitter:
 observability, traffic • core contributor: finagle • creator: linkerd • loves: dogs @olix0r
 ver@buoyant.io
3. overview • 2010: A Failwhale Odyssey • Automating the Datacenter • Microservices: A Silver Bullet • Finagle: The Once and Future Layer 5 • Introducing linkerd • Demo • Q&A
4. 2010 A FAILWHALE ODYSSEY
5. Twitter, 2010 107 users 107 tweets/day 102 engineers 101 services 101 deploys/week 102 hosts 0 datacenters 101 user-facing outages/week https://blog.twitter.com/2010/measuring-tweets
8. The Monorail, 2010 103 of RPS 102 of RPS/host 101 of RPS/process hardware lb the monorail mysql memcache kestrel
9. Problems with the Monorail Ruby performance MySQL scaling Memcache operability Deploys
10. Events https://blog.twitter.com/2013/new-tweets-per-second-record-and-how
11. Asymmetry Photo by Troy Holden
12. Provisioning
13. automating the datacenter
14. mesos.apache.org UC Berkeley, 2010 Twitter, 2011 Apache, 2012 Abstracts compute resources Promise: don’t worry about the hosts
15. aurora.apache.org Twitter, 2011 Apache, 2013 Schedules processes on Mesos Promise: no more puppet, monit, etc
16. timelines Aurora (or Marathon, or …) host Mesos host host host host host users notifications x800 x300 x1000
17. microservices A SILVER BULLET
18. scaling teams growing software
19. flexibility
20. performance correctness monitoring debugging efficiency security resilience
21. not a silver bullet. (sorry.)
22. Resilience is an imperative: our software runs on the truly dismal computers we call datacenters. Besides being heinously
 complex… they are unreliable and prone to
 operator error. Marius Eriksen @marius
 RPC Redux
23. resilience in microservices software you didn’t write hardware you can’t touch network you can’t configure break in new and surprising ways and your customers shouldn’t notice
24. resilient microservices means resilient communication
25. datacenter [1] physical [2] link [3] network [4] transport aurora, marathon, … mesos 
 canal, weave, … aws, azure, digitalocean, gce, … business languages, libraries [7] application rpc [5] session [6] presentation json, protobuf, thrift, … http/2, mux, …
26. layer 5 dispatches requests onto layer 4 connections
27. finagle THE ONCE AND FUTURE LAYER 5
28. github.com/twitter/finagle RPC library (JVM) asynchronous built on Netty scala functional strongly typed first commit: Oct 2010
29. used by…
30. programming finagle val users = Thrift.newIface[UserSvc](“/s/users”)
 val timelines = Thrift.newIface[TimelineSvc](“/s/timeline”) Http.serve(“:8080”, Service.mk[Request, Response] { req => for { user <- users.get(userReq(req)) timeline <- timelines.get(user) } yield renderHTML(user, timeline) })
31. operating finagle transport security service discovery circuit breaking backpressure deadlines retries tracing metrics keep-alive multiplexing load balancing per-request routing service-level objectives Observe Session timeout Retries Request draining Load balancer Monitor Observe Trace Failure accrual Request timeout Pool Fail fast Expiration Dispatcher
32. “It’s slow”
 is the hardest problem you’ll ever debug. Jeff Hodges @jmhodges
 Notes on Distributed Systems for Young Bloods
33. the more components you deploy, the more problems you have
34. the more components you deploy, the more problems you have
35. the more components you deploy, the more problems you have
36. lb algorithms: • round-robin • fewest connections • queue depth • exponentially-weighted moving average (ewma) • aperture load balancing at layer 5
37. timeouts & retries timelines users web db timeout=400ms retries=3 timeout=400ms retries=2 timeout=200ms retries=3 timelines users web db
38. deadlines timelines users web db timeout=400ms deadline=223ms deadline=10ms 177ms elapsed 213ms elapsed
39. retry budget typical: retries=3 worst-case: 300% more load!!! better:
 retryBudget=20% worst-case: 20% more load
40. tracing
41. tracing
42. tracing
43. layer 5 routing
44. layer 5 routing applications refer to logical names
 requests are bound to concrete names
 delegations express routing /s/users /io.l5d.zk/prod/users /s => /io.l5d.zk/prod/http
45. per-request routing: staging GET / HTTP/1.1
 Host: mysite.com
 Dtab-local: /s/B => /s/B2
46. per-request routing: debug proxy GET / HTTP/1.1
 Host: mysite.com
 Dtab-local: /s/E => /s/P/s/E
47. so all i have to do is rewrite my app in scala?
48. linkerd
49. github.com/buoyantio/linkerd microservice rpc proxy layer-5 router aka l5d built on finagle & netty pluggable http, thrift, … etcd, consul, kubernetes, marathon, zookeeper, … …
50. magic resiliency sprinkles transport security service discovery circuit breaking backpressure deadlines retries tracing metrics keep-alive multiplexing load balancing per-request routing service-level objectives Service B instance linkerd Service C instance linkerd Service A instance linkerd
51. namerd released in March centralized routing policy delegates logical names to service discovery pluggable etcd kubernetes zookeeper …
52. namerd
53. demo: gob’s microservice
54. web word gen l5d l5d l5d
55. web word gen gen-v2 l5d l5d l5d l5d
56. web word gen gen-v2 l5d l5d l5d l5d namerd
57. master dc/os marathon zookeeper node node public node node … ELB ELB
58. master dc/os marathon zookeeper node node public node node … linkerd linkerd linkerd linkerd ELB ELB namerd
59. master dc/os marathon zookeeper node node public node node … linkerd linkerd linkerd linkerd ELB ELB namerd web (x1) gen (x3) word (x3) word-growthhack (x3)
60. github.com/buoyantio/linkerd-examples
61. linkerd roadmap • Netty4.1 • HTTP/2+gRPC linkerd#174 • TLS client certs • Richer routing policies • Announcers • More configurable everything
62. more at linkerd.io slack: slack.linkerd.io email: ver@buoyant.io twitter: • @olix0r • @linkerd thanks!