Ninja Meeting 2/15/2000 Sam Madden Messages in Paths Ninja Meeting 2/15/2000 Sam Madden

Telegraph Extensions Message (Tuple) Based Transmission Layer

Telegraph Extensions Message (Tuple) Based Transmission Layer Aggregators/Broadcasters

Telegraph Extensions Message (Tuple) Based Transmission Layer Aggregators/Broadcasters Operator Typing System Interoperability Constraints

Telegraph Extensions Message (Tuple) Based Transmission Layer Aggregators/Broadcasters Operator Typing System Interoperability Constraints Mechanisms for Performance Evaluation

Telegraph Extensions Message (Tuple) Based Transmission Layer Aggregators/Broadcasters Operator Typing System Interoperability Constraints Mechanisms for Performance Evaluation

Messages vs. Streams Streams Messages Partitioned Data Unpartitioned Data

Messages vs. Streams Streams Messages Partitioned Data Push or Pull Data Unpartitioned Data Push out data

Messages vs. Streams Streams Messages Partitioned Data Push or Pull Data Higher Overhead Unpartitioned Data Push out data

Messages vs. Streams Streams Messages Partitioned Data Push or Pull Data Higher Overhead More Complicated Programming Model Unpartitioned Data Push out data

Messages vs. Streams Streams Messages Partitioned Data Push or Pull Data Higher Overhead More Complicated Programming Model Unpartitioned Data Push out data No: Type Checking Admission Control Aggregation End-to-End Guarantees

Benefits of Messages Aggregation Improved End-To-End Guarantees Structural Type Checking (not Semantics) Admission Control Pull-based consumption Natural model for databases, Web

Architecture Messages are tuples: <Idenitifer id, int Length, Byte[] data> Identifier may encapsulate semantic information, sequence number, etc.

Architecture Messages are tuples: <Idenitifer id, int Length, Byte[] data> Identifier may encapsulate semantic information, sequence number, etc. Operators Specify Multiple Inputs {<Identifier id, Class C>, … } Incoming messages are packaged as type C via (de)serialization methods.

Architecture #2 Class C may be unstructured (e.g. String) Low overhead Structured classes allow Data verification Admission Control

Architecture #3 Operators can request tuples from an input or push tuples down an output. Generates events on predceding/following node

Architecture #3 Operators can request tuples from an input or push tuples down an output. Generates events on predceding/following node Events model implies VSpace

Architecture #3 Operators can request tuples from an input or push tuples down an output. Generates events on predceding/following node Events model implies VSpace Maybe?

On Top Of Streams Streams (not RMI) are underlying transmission protocol

On Top Of Streams Streams (not RMI) are underlying transmission protocol Some operators still “stream-based”

On Top Of Streams Streams (not RMI) are underlying transmission protocol Some operators still “stream-based” Streams provide Low-level error detection Control over threads/operator Guaranteed reasonable performance