Advanced OS Topics Mobile OS and Distributed Systems Android OS BitCoin, Hadoop, P2P, Web2.0 & WebOS, and Emerging Internet Apps.

The insider’s view of a Centralized OS (Roughly patterned after XINU [Comer 1984]) user programs file system 1 device manager and device drivers real-time clock manager 2 process coordinator process manager 3 memory manager hardware 1 remote files 2 + remote device access 3 + remote process management

Natural Extensions Two Trends Emerging Distributed Apps System Virtualization Allow multiple instances of (possibly different) OSes on a single machine Distributed OS Large scale networked systems/machines Emerging Distributed Apps BitCoin P2P file sharing, Hadoop Data outsourcing: Google Docs, Data centers, Yahoo Photo Album, etc. IPTV/VoIP Web2.0 & WebOS: Myspace, Wikipedia, etc.

Before Virtualization After Virtualization Idea: Decouple [OS, service] pair from hardware Multiplex lightly-used services on common host hardware Migrate services from host to host as needed Introduce new [OS, service] pairs as needed

Distributed Systems and Applications

Bitcoin – Open source P2P Money http://bitcoin.org/en/

Hadoop http://hadoop.apache.org/

Google Office Google Docs & Spreadsheets mimic functions of Microsoft Office tools on the Web Free storage, linked with Gmail Work and collaborate as long as you have access to a Web browser Uniform look and feel on all OS platforms Ajax and other software techniques make it as responsive as local applications – network latencies are hidden The future of computing? Web browser + open source, or Google + Linux? No need to buy computers and software Who will pay for Windows and Office in the future?

Multicast The key application was streaming audio/video Webinar Stock Information On-line TV/Video Group-based Apps (game, …)

Electronic Health Care Systems Monitoring a person in a pervasive electronic health care system, using (a) a local hub or (b) a continuous wireless connection

Peer-to-Peer Systems A killer application: Naptser Free music over the Internet Key idea: share the content, storage and bandwidth of individual (home) users Exemplar P2Ps: Naptser, Gnutella, Freenet, CAN, Chord, BitTorrent Internet

Web 2.0: Wikipedia Wikipedia is a multilingual, Web-based, free content encyclopedia project. It is written collaboratively by volunteers, allowing most of its articles to be edited by almost anyone with access to the Web site. The largest collaborative authoring (group editing) project in the world

Security SSL Handshake Protocol Cipher suite: a list of cryptographic algorithm supported by the client Phase 1: Establish security capabilities Phase 2: Sever authentication and key exchange Phase 3: Client authentication and key exchange Phase 4: Finish The client sends a change Cipher Spec message and copies the pending CipherSpec into the current CipherSpec.

The ANDROID™ OS History Google acquires mobile software startup Android™ in 2005 Open Handset Alliance officially starts on November 5th, 2007 Android™ 1.0 source and SDK released in Fall 2008 (http://www.android.com/timeline.html) Phones & Tablets Toshiba Android SmartBook Sony Ericsson Cisco Android Tablet Samsung Galaxy

The ANDROID™ OS System Architecture Linux Version 2.6 or 3.0.1 Davlik Virtual Machine (VM) Application Framework

The ANDROID™ OS Applications Applications are written in Java or Python Applications are run on the Davlik Virtual Machine Development done in the Android™ SDK Development is open to all User driven Android™ Market

ANDROID™ Security Android Security Relies on security of it’s foundations; Linux, Davlik, and Java. Security Goal: “A central design point of the Android security architecture is that no application, by default, has permission to perform any operations that would adversely impact other applications, the operating system, or the user.”

ANDROID™ Security Enforcement strategy Application Sandboxes Application signing and certification. Linux user name base access restriction Permissions Application Sandboxes All Applications run as their own Linux user. Several Inter-Process Communication methods: Activities Services BroadcastReceiver ContentProvider Intent

ANDROID™ Security Android™ Permissions Permissions are static on install Users have open view of permissions http://developer.android.com/reference/android/Manifest.permission.html http://www.simplehelp.net/images/quick_gps/img06.png

ANDROID™ Security Security Concerns for developers Protect your application, use least privilege principle. If you expose, mediate IPCs Provide maximum availability Minimize memory footprint Minimize battery usage Security Concerns for users Do your research Read reviews. Analyze permissions before installing. Use Common sense.

CprE 450/550: Distributed Systems and Middleware You are welcome to join me.