CS194-3/CS16x Introduction to Systems Lecture 27 Course Wrap-up and Various Topics December 5, 2007...

CS194-3/CS16xIntroduction to Systems

Lecture 27

Course Wrap-up and Various Topics

December 5, 2007

Prof. Anthony D. Joseph

http://www.cs.berkeley.edu/~adj/cs16x

Lec 27.212/5/07 Joseph CS194-3/16x ©UCB Fall 2007

Goals for Today

• Course wrap-up

• Various topics

Note: Some slides and/or pictures in the following areadapted from slides ©2005 Silberschatz, Galvin, and Gagne. Slides courtesy of Kubiatowicz, AJ Shankar, George Necula, Alex Aiken, Eric Brewer, Ras Bodik, Ion Stoica, Doug Tygar, and David Wagner.


• You’ve gained a basic knowledge of systems, networking, databases, security, and software engineering problems, challenges, and solutions– And, you’ve worked with a large-scale codebase and

built two real-world applications– But, there’s a lot more!– Take CS 162, CS 186, CS 169, EE 122, CS 161

• Some common themes:– Complexity, modularity, abstractions, layering, SW

flaws– Dealing with large systems and groups is very hard!

• Methods:– Programming and documentation style, E2E arguments– Project team organization, IDEs, testing, and other tools

Course Summary


• Database relational model, SQL– ACID model, query operators– Information Retrieval: Boolean search

• Programming parallel and distributed systems– Processes and threads: “Building a Thread System”– Concurrency control in languages, systems, and DBMSs:

» Mutual exclusion, semaphores, condition variables, monitors

– Serializability, conflict serializability, 2PL and strict 2PL, 2PC, logging, recovery, deadlock

– “Programming with MapReduce”

• Operating Systems– Kernel and address spaces– Address translation, caching, TLBs, and demand paging– Memory management policies in DBMSs and OSs

Course Summary


• I/O Systems– Disk management, file systems, naming, directories– File system organization and DBMS indexing (B+ trees)

• Networking– Architectures, layering, protocols (UDP and TCP), flow

control, congestion control– “Building a Peer-to-Peer Application”

• Computer and network security– Cryptosystems, viruses, worms, firewalls, VPNs

• Post-graduation? Consider continuing education, extension, …

Course Summary


Some Topics People Requested

• User Interface design• Computing for

developing nations• Sensor networks• Web programming• Dragons

– No, not really…– But, here is a Chinese

dragon from Wikipedia

• And the topic is…

• Datacenter is the Computer


• Google program == Web search, Gmail,…• Google computer ==

– Thousands of computers, networking, storage• Warehouse-sized facilities and workloads may

be unusual today but are likely to be more common in the next few years

Datacenter is the Computer

(From Luiz Barroso’s talk at Berkeley)



• Orders of magnitude more devices (CPU’s/rack, Number of racks/managed facility)

• 1980’s: Bank of America datacenter ≈20 IBM 370 mainframes ≈100 CPU’s, ≈100 disks

• 1995: Network of Workstations-1 ≈100 CPUs, 200 disks; NOW-2 ≈1000 CPUs, 2000 disks

• 2000: Inktomi ≈ 10,000 nodes in 4 DCs• 2005: Google ≈ 450,000 Nodes in ≥ 25 DC*

• Computer Architecture == Architecture!

• What should be the basic “building” block?*John Markoff, “Google's not-so-very-secret weapon,” NY Times, 6/13/06


9


• A datacenter composed of 20 ft. containers– Power/cooling for 200 KW of racked HW– External taps for electricity, network, water

• 250 Servers, 7 TB DRAM, or 1.5 PB disk– Up to 2,000 cores, providing 8,000

simultaneous processing threads

Project Blackbox10/17/06


Sun’s Project BlackBox


10G Ethernet

PDAs Cell PhonesFuture Devices

WirelessInfrastructure

DesktopPCs

Edge Servers

Datacenter




• Re-inventing Client/Server Computing (and the web)

• The Datacenter is the (Server) Computer

• The Handheld is the (Client) Computer– Dell ships more laptops than desktops in 2008?

• Intel's Otellini Keynote: “Digital Convergence, Wireless Will Help Buoy Industry” 10/12/2006 – He and others at Intel demonstrated prototype "Universal Communicator“ – combo cell phone, PC, and video device that transfers real-time video, voice and data wirelessly

• But, how to make a limited capability mobile device equal a wired, always-on desktop??


• Key insight: – Enable “weak/limited” end devices to use (wireless)

networking to leverage powerful infrastructure resources

– Examples:» Smartphones: Google web search, Microsoft Live Search,

Apple iPhone web applications» Google Apps versus Microsoft Office» Others?

• Use “Web Services” as library functions for apps– Ruby on Rails, Ajax, XML, SOAP– MapReduce (Hadoop), Chubby distributed lock manager

• Use Web Services for application storage– E.g., Amazon Simple Storage Service (S3) and Elastic

Computing (EC2), Google FS, Bigtable» Smugmug (≈ Flickr) saves $0.5M/yr using Amazon S3



• Limited capabilities– 433 Mhz AMD x86 CPU– 256 MB RAM– 1 GB NAND Flash

» No disk drive

– 802.11b/g WiFi– 7.5” dual-mode TFT

display» Grayscale reflective

1200x900» Color 800x600

– Color video camera

• Ultra low-cost: $200• But, how to network in

the 3rd world?

One Laptop Per Child (OLPC)


OLPC Uses Mesh Networking to Reach Infrastructure


Unmanned Airborne Vehicles (UAV) as Rapidly Deployable Airborne Radio

Networks?• Stratellite statistics:

– 245 ft length, 145 ft width, 87 ft height, 1.3 million ft3

– Solar cells power electric motors

– Payload capacity: 3,000 lbs– Maximum altitude: 70,000 ft– LoS to a 300,000 sq mile area– Wireless reach to 200 mile

radius– Maximum duration: 18

months– But, not yet commercially

available/feasible

Stratellite


Administrivia

• Project 3 code due Thursday 12/6

• Midterm 3 Exam is Monday 12/10• In-class 9-10:45• Course survey followed by exam


Sensor Networking Wireless Vision

A symphony of embedded devices!!

Asset Tracking

Home Automation

Military Scenarios

Security


UCB 1st Generation Sensor ‘Mote’

• 4Mhz, 8bit MCU (ATMEL)512 bytes RAM, 8K ROM

• 900Mhz Radio (RF Monolithics)10-100 ft. range

• Temperature Sensor• Light Sensor• LED outputs• Serial Port

COTS Dust

weC Mote


UCB 2nd Generation Sensor ‘Mote’

• Two Board Sandwich– Main CPU board

with Radio Communication

– Secondary Sensor Board

• Allows for expansion and customization

Current sensors include: Acceleration, Magnetic Field, Temperature, Pressure, Humidity, Light, and RF Signal Strength.

Can control RF transmission strength & Sense Reception Strength


UCB Sensor Mote Design Lineage

• COTS dust prototypes (Kris Pister et al.)

• weC Mote (~30 produced)• Rene Mote (850+ produced)• Dot (1000 produced)• Mica node (1800+ produced)

?


Multi-Hop Routing Demo

• Sensors automatically assemble and determine routing topology– Parallel Breadth First Search– Shortest path to all nodes remembered

• Base station broadcasts out routing information• Individuals listen for and propagate route update

– N messages sent• Generational scheme to prevent cycles in routing table

Base


Cory Energy Monitoring/Mgmt System

• 50 nodes on single floor• 5 level ad hoc net• 30 sec sampling• 250K samples to database over 6 weeks


Structural Performance due to Multi-Directional Ground Motions (Glaser &

CalTech)

Wiring for traditional structural instrumentation+ truckload of equipment

Mote infrastructureMote Layou

t

Comparison of Results


Vehicle Tracking


UAV-based Sensor Network Deployment


• Datacenter is the computer!• Many benefits

– Centralized, robust resources– Amortize costs across tens of millions of

users– Simple, low cost devices can leverage billion

dollar investments

• Many issues– Dependence on network connectivity– One outage affects many users– Insufficient power resources for datacenters– Data privacy

Summary

CS194-3/CS16x Introduction to Systems Lecture 27 Course Wrap-up and Various Topics December 5, 2007...

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