Post on 25-Jun-2015
transcript
Firebase introduction
Kewang
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Agenda
● Variety of sync mechanisms● Firebase
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Variety of sync mechanisms
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Variety of sync mechanisms
● Polling● Comet● Long Polling● WebSocket● Engine.IO (Socket.IO)● Polling & Push
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Pollingsend scheduling request
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Polling
client server
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Polling
client server
T0T1
T2
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Polling
client server
T0T1
T2
T4T5
T6
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Polling
client server
T0T1
T2
T4T5
T6
T8T9
T10
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Polling
● Pros– Easy to implement
● Cons– No efficiency
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Cometa never died HTTP request
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Comet
client server
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Comet
client server
T0T1
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Comet
client server
T0T1
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Comet
client server
T0T1
T3T2
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Comet
client server
T0T1
T3
T6
T2
T5
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Comet
client server
T0T1
T3
T6T8
T2
T5T7
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Comet
client server
T0T1
T3
T6T8
T12
T2
T5T7
T11
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Comet
● Pros– Save more network traffic
● Cons– Blocking IO issue– Always get server response, can't send another request
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Long Pollingsend a long time request repeatedly
when response received
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Long Polling
client server
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Long Polling
client server
T0T1
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Long Polling
client server
T0T1
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Long Polling
client server
T0T1
T4
T3
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Long Polling
client server
T0T1
T4
T3
T5
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Long Polling
client server
T0T1
T4
T3
T5
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Long Polling
client server
T0T1
T4
T3
T5
T21T20
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Long Polling
● Pros– Save a little network traffic– Can send another request
● Cons– I don't know
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WebSocketFDX communications channels over a single TCP connection
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WebSocket
client server
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WebSocket
client server
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WebSocket
client server
T0T1
T2
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WebSocket
client server
T0T1
T2
T3T4
T5
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WebSocket
client server
T0T1
T2
T3T4
T5T9
T10T11
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WebSocket
client server
T0T1
T2
T3T4
T5
T17T18
T19
T9T10
T11
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WebSocket
● Pros– Bidirectional communication– Save more network traffic
● Cons– Proxy & Firewall issue
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Engine.IOcommunication layer for Socket.IO
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Engine.IO - Socket.IO history0.1~0.6.2 0.6.3~0.6.17 0.7.0~0.9.17 1.0.0~now
websocket ✓ ✓ ✓ ✓server-events ✓flashsocket ✓ ✓ ✓
htmlfile ✓ ✓xhr-multipart ✓ ✓xhr-polling ✓ ✓ ✓
jsonp-polling ✓polling ✓
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Engine.IO - Overview
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Engine.IO - Overview
● Ensure the most reliable realtime communication
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Engine.IO - Overview
● Ensure the most reliable realtime communication● Always establishes a long-polling connection first
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Engine.IO - Overview
● Ensure the most reliable realtime communication● Always establishes a long-polling connection first
– then tries to upgrade to better transports that are "tested" on the side
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Engine.IO - Upgrade transport seamlessly
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Engine.IO - Upgrade transport seamlessly
● Switches from polling to another transport in between polling cycles
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Engine.IO - Upgrade transport seamlessly
● Switches from polling to another transport in between polling cycles
● To ensure no messages are lost, the upgrade packet will only be sent once all the buffers of the existing transport are flushed and the transport is considered paused
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Engine.IO
client server
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Engine.IO
client server
T0T1
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Engine.IO
client server
T0T1
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Engine.IO
client server
T0T1
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Engine.IO
client server
T0T1T6
T5
T7
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Engine.IO
client server
T0T1
T11
T6T5
T7T10
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Engine.IO
client server
T0T1
T11
T6T5
T7T10
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Engine.IO
client server
T0T1
T11
T6
T12T13
T14
T5
T7T10
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Engine.IO
● Pros– Auto-switch different network scenario
● Cons– Use particular protocol at server & client
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Polling & Pushsimple sync mechanism
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Polling & Push - Push off
client server
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Polling & Push - Push off
client server
T0T1
T2
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Polling & Push - Push off
client server
T0T1
T2
T4T5
T6
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Polling & Push - Push off
client server
T0T1
T2
T4T5
T6
T8T9
T10
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Polling & Push - Push on
client server SNS
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Polling & Push - Push on
client server
T0T1
T2
SNS
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Polling & Push - Push on
client server
T0T1
T2
T22T23
T24
SNS
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Polling & Push - Push on
client server
T0T1
T2
T22T23
T24
SNS
T30
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Polling & Push - Push on
client server
T0T1
T2
T22T23
T24
T31T32
T33
SNS
T30
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Polling & Push
● Pros– Easy to implement
● Cons– No (official statement)
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Firebase
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Firebase
● Save data in the cloud● Realtime Data● Easy authentication● Bulletproof Security● Instant Scalability
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Pattern 1 - Client Only
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Pattern 1 - Client Only
● Developing a brand new application● Needs minimal integration with legacy systems or
other third party services● App doesn’t have heavy data processing needs or
complex user authentication requirements
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Pattern 2 - Client & Server
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Pattern 2 - Client & Server
● To integrate with third party APIs● Advanced authentication requirements● Can’t run computationally intensive code on a
client, or requires code to run on a trusted server
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Pattern 3 - Existing App
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Pattern 3 - Existing App
● An existing full-featured app, and aren’t planning a rewrite
● Codebase is large and cannot change● Add realtime features without touching the rest of
app
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Live DEMO2
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FAQ
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FAQ
● Enterprise solution
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FAQ
● Enterprise solution– Custom SLA– 24*7 support– Dedicated clusters– Training
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FAQ
● Enterprise solution– Custom SLA– 24*7 support– Dedicated clusters– Training
● Concurrent connection
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FAQ
● Enterprise solution– Custom SLA– 24*7 support– Dedicated clusters– Training
● Concurrent connection– Free plan has 50 max connections, otherwise is
unlimited
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FAQ
● Enterprise solution– Custom SLA– 24*7 support– Dedicated clusters– Training
● Concurrent connection– Free plan has 50 max connections, otherwise is
unlimited● Lock-in
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FAQ
● Enterprise solution– Custom SLA– 24*7 support– Dedicated clusters– Training
● Concurrent connection– Free plan has 50 max connections, otherwise is unlimited
● Lock-in– Export data to JSON
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References
● Browser 與 Server 持續同步的作法介紹● Comet (programming)● Engine.IO: the realtime engine● Engine.IO Protocol● How Firebase Works● Firebase Callbacks - what's the underlying trigger?● Firebase under the hood - watching web sockets in
Chrome Developer Tools
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