Saturday Night Disco on Monday Morning

Service discovery must be hard, from ye olde SRV records and UDDI to hip new etcd and serf, we keep inventing new ways to help robots talk to each other. But instead of trying to pick a winner, let's review the space so you can figure out how let applications work with whatever's clever.

Transcript

1. https://www.flickr.com/photos/-staci-/3197185673
   Saturday Night Disco
   on Monday Morning
   

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2. Hi, I’m
   

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5. adjustable capacity
   
   !
   highly available
   
   !
   low latency
   

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6. adjustable capacity
   
   !
   highly available
   
   !
   low latency
   change capacity
   
   !
   fail over
   
   !
   switch data center
   

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9. Name ➝ Connection Info
   

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10. What kind of
    clusters?
    

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11. LB
    

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12. VIP
    s
    s
    M
    s
    

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14. LB
    

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15. Shared Nothing
    
    Master-Slave
    
    JBOS
    
    Auto-balancing
    

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16. Service Facades
    
    Cluster Member Lists
    

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17. Service Facade
    
    Proxy
    
    DNS Record Set
    
    Virtual IP
    

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18. Cluster Member List
    
    Order
    
    Port
    
    Metadata
    

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19. { "myface-facade": [!
    { "hostname": "myface-lb.example.net" } ],!
    "myface": [!
    { "hostname": “myface-docker-001.example.net",!
    "port": 49160 },!
    { "hostname": “myface-docker-002.example.net",!
    "port": 49086 } ],!
    !
    !
    "myface-db-master": [!
    { "hostname": "myface-db-master.example.net" } ],!
    "myface-db-slave": [!
    { "hostname": "myface-db-002.example.net" },!
    { "hostname": "myface-db-003.example.net" } ],!
    !
    !
    "statsd": [!
    { "hostname": "10.0.0.216" } ] }
    

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21. Name ➝ Connection Info
    

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22. Name ➝ Connection Info
    Across Time
    

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23. Now you’ve got
    
    two problems
    

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24. Consistency
    
    Propagation
    

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25. Consistency
    
    Eventual
    
    Read-after-Writes
    
    Linearizable
    !
    chef, serf
    
    dns, s3
    
    zk, consul
    

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26. Propagation
    
    PubSub
    
    Poll
    !
    zk, etcd, serf
    
    dns, chef, consul
    

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27. eventual ryw linearizable
    poll chef dns consul
    pubsub serf zk
    

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29. but my app doesn’t
    like config from
    
    zk, dns, http!
    

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30. Config management
    
    Agent
    
    Remote Exec
    
    confd
    !
    cfengine
    
    ansible
    
    

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31. Facade v Member Set
    
    Ordered Record Sets
    
    Locator + Metadata
    
    !
    Consistency
    
    Propagation
    

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33. Wait, what happened
    to the MySQL master?
    

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34. M
    VIP
    s
    

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