## CS 591 K1: Data Stream Processing and Analytics Spring 2020 ## 4 /09: Flow control and load shedding Vasiliki (Vasia) Kalavri vkalavri@bu.edu ## Keeping up with the producers • Producers can generate queue: what if the queue grows larger than available memory? • block the producer (back-pressure, flow control) ## Load management approaches ![Image](/uploads/documents/1/8/5/2/1852496083fa00bab53cdd69c80bfbf6/p7_1 applications with strict latency constraints that can tolerate approximate results. Slow down the flow of data: - The system buffers excess data for later processing, once input rates stabilize. •

## CurveBS I/O processing flow Before introducing IO processing flow, we first describe the overall architecture, data organization and topology structure of CURVE.  The flow of user’s read and write request to curve:

# Optimization for number of goroutines using feedback control Yusuke MIYAKE / Pepabo R&D Institute, GMO Pepabo, Inc. 2019.07.25 GopherCon 2019 ![Image](/uploads/documents/4/2/d/f/42dfd7f07b1ef4 ## I ssues to solve for the realization 1. Selection of performance metrics 2. Finding how to control rapidly and continuously ## Performance metrics ## Performance metrics • Independent resource type based on the metrics • Continuously • Rapidly • Accurately • Feedback control meets these conditions. ## Feedback control • Tracking a given set-point using errors from the set-point. • Applying

Configuration 1.31 Flow Control 1.32 Guarantees of sends and commits 1.33 Message Redelivery and Undelivered Messages 1.34 Message Expiry 1.35 Large Messages 1.36 Paging 1.37 Scheduled Messages instructions outlined here. #### 2.25. 0 Full release notes Highlights: • Improvement on Paging Flow Control • Many other bug fixes and improvements #### 2.24. 0 Full release notes Highlights: - Diverts now support multiple addresses - Runtime configuration reloading now supports bridges. • Paging can now be configured by message count. ## Upgrading from older versions 1. Due to XML schema changes

16.16 Dot Syntax for Vectorizing Functions ..... 94 16.17 Further Reading ..... 96 17 Control Flow ..... 97 17.1 Compound Expressions ..... 97 17.2 Conditional Evaluation ..... 98 17.3 Short-Circuit Missing Values 257 28.2 Equality and Comparison Operators 257 28.3 Logical operators 258 28.4 Control Flow and Short-Circuiting Operators 260 28.5 Arrays With Missing Values 260 28.6 Skipping Missing Julia from the command line: | | | | | | To exit the interactive session, type CTRL-D (press the Control/^ key together with the d key), or type exit (). When run in interactive mode, julia displays a banner

15.16 Dot Syntax for Vectorizing Functions ..... 92 15.17 Further Reading ..... 94 16 Control Flow ..... 95 16.1 Compound Expressions ..... 95 16.2 Conditional Evaluation ..... 96 16.3 Short-Circuit Missing Values 255 27.2 Equality and Comparison Operators 255 27.3 Logical operators 256 27.4 Control Flow and Short-Circuiting Operators 258 27.5 Arrays With Missing Values 258 27.6 Skipping Missing | | | | | | | | | | | | | | | | | | | | To exit the interactive session, type CTRL-D (press the Control/^ key together with the d key), or type exit (). When run in interactive mode, julia displays a banner

The var statement 3 5 The assignment statement 3 6 Constants 4 7 The let statement 4 8 Control flow statements 4 8.1 If statement 4 8.2 Case statement 5 8.3 While statement 5 8.4 For statement readLine(stdin) # Error: constant expression expected let input = readLine(stdin) # works ## 8 Control flow statements The greetings program consists of 3 statements that are executed sequentially. Only branching and looping are needed too. ### 8.1 If statement The if statement is one way to branch the control flow: let name = readLine(stdin) if name == "": echo "Poor soul, you lost your name

and piping 95 17.16 Dot Syntax for Vectorizing Functions 96 17.17 Further Reading 98 18 Control Flow 99 18.1 Compound Expressions 99 18.2 Conditional Evaluation 100 18.3 Short-Circuit Evaluation 259 29.2 Equality and Comparison Operators ..... 259 29.3 Logical operators ..... 260 29.4 Control Flow and Short-Circuiting Operators ..... 262 29.5 Arrays With Missing Values ..... 262 29.6 Skipping Julia from the command line: | | | | | | To exit the interactive session, type CTRL-D (press the Control/^ key together with the d key), or type exit (). When run in interactive mode, Julia displays a banner

Deciphering C++ Coroutines Mastering Asynchronous Control Flow ## ANDREAS WEIS ## Deciphering Coroutines - Part 2 Mastering Asynchronous Control Flow Andreas Weis CppCon 2024 ## About me - Andreas Weis synchronization needed. ■ Green Threads cooperatively decide when to suspend and resume Intuition about control-flow is still very similar to threads ☐ Stackless We can only suspend one function at a time If we std::vector<> my_children ## Conclusion Coroutines allow for extremely powerful manipulation of control flow between functions ☑ To achieve best results, there should be some amount of uniformity between

Pomodoro is a technique for increasing productivity and focus by getting yourself into a state of flow. Basic requirements ① A kitchen timer  Flow: The Psychology of Optimal Experience by Mihaly Csikszentmihalyi $ ^{[3]} $ ### From Amazon.com revealed that what makes an experience genuinely satisfying is a state of consciousness called flow. During flow, people typically experience deep enjoyment, creativity, and a total involvement with life.