640 likes | 886 Views
DISTRIBUTED APPLICATIONS. Session 5 14:00 - 15:00 Dr Deepak B Phatak, IIT Bombay. SESSION OVERVIEW. Indian Banking Scenario Distributed Paradigms How to Construct the Distributed Infrastructure. BANKING BUSINESS. Primarily Based On Interest Spread Fee Based Services
E N D
DISTRIBUTED APPLICATIONS Session 5 14:00 - 15:00 Dr Deepak B Phatak, IIT Bombay
SESSION OVERVIEW • Indian Banking Scenario • Distributed Paradigms • How to Construct the Distributed Infrastructure Distributed Applications
BANKING BUSINESS • Primarily Based On • Interest Spread • Fee Based Services • Multi Location Operations • Hierarchical Branch Network Distributed Applications
BANKING BUSINESS • Requires Emphasis on • Fast Movement of Funds • Purposeful Expansion and Retention of Customer Base • Non Repudiation of Valid Transactions. (TXNs) Distributed Applications
CONVENTIONAL RETAIL BANKING • Low Value High Volume TXNs • Attractive Deposit Products • Speedy Customer Service • Local TXNs, Within a Branch, • Remote TXNs, Within A City, • Anywhere Globally Distributed Applications
COMEERCIAL BANKING • Term Loans • Speedy Application Processing • Avoiding NPAs • Fee Based Services • Fast Turn Around of TXN • Special Services Needed Distributed Applications
HOUSE KEEPING • Management Reporting • Consolidation Reports • Control Reports • Performance Reports • Statutory Reports • Audit Reports Distributed Applications
INDIAN BANKING SCENARIO • Traditionally Branch Centric • GL is Accounting Backbone • S..S..Slow Fund Movement • Rudimentary Central Control • Focus On Customer Service ??? Distributed Applications
INDIAN BANKING SCENARIO • Use Of Modern IT • Started with Back Office • TBM: Better Local Operations • Useless Networks • More Useless MIS, DSS Distributed Applications
INDIAN BANKING SCENARIO • Coexistence of Computerised, Semi-Automated and Manual Branch Operations • Stronger Networks Emerging • Any Banking Paradigm Must • Work in Existing Situation • Quickly Exploit Changes Distributed Applications
DISTRIBUTED PARADIGM • Emerged Primarily • To Provide Autonomous Operations at Multiple Sites • To Exploit Cheaper MIPS on Smaller Machines • All Real Life End to End Computerisation is Distributed Distributed Applications
DISTRIBUTED PARADIGMS • Hierarchies of Servers/Clients • Use of Message Queues and/Or TP Monitors • Multiple Delivery Mechanisms Distributed Applications
METHODOLOGIES • Software Engineering • Distributed Functionality Design • Network Design • Configuring an Application for Growth • Change Management Distributed Applications
DELIVERY MECHANISMS • Post, Telegrams, Fax • Machine Readable Data On Media • Data Transfer Through Networks Distributed Applications
EARLY NETWORKS • Arcnet and Novell • Ethernet and Token ring • TCP/IP gets embedded into BSD Unix Distributed Applications
MODERN NETWORKS • Ethernet • 10 Mbps, 75% Market, Over 40 Million nodes • Token Ring • 4/16 Mbps, 16% • Fast Ethernet • 100 Mbps, 1%, growing fast Distributed Applications
MODERN NETWORKS • FDDI • 100 Mbps, < 1%, Dying • ATM • 25 Mbps to 2.4 Gbps, Nascent Distributed Applications
MODERN NETWORKS (WAN BACKBONE) • North American • T1 or DS1 : 1.54 Mbps • T3 or DS3 : 44.73 Mbps • European (and Indian) • E1 : 2.04 Mbps (CCITT standard) • E2 : 8.44 Mbps • E3 : 34.36Mbps Distributed Applications
MODERN NETWORKS (WAN BACKBONE) • Sonet fibre Standards (ANSI, Synchronous optical Network) • OC1 to OC3 • (51.84, 103.68, 155.52 Mbps) • OC12 (622.08 Mbps) • OC24 and OC48 • (1.244 Gbps, 2.488 Gbps) Distributed Applications
MODERN NETWORKS • LAN-WAN-LAN Interconnect • Various LAN Protocols • TCP/IP, IPX/SPX, SNA, NETBEUI • Remote access PC • SLIP, PPP. Distributed Applications
MODERN NETWORKS • LAN to LAN • Bridge, Gateway • IP Switching. • LAN to WAN • Multi Protocol Routers. • X.25 Switches, Gateway Distributed Applications
MODERN NETWORKS • WAN Backbone • IP Over Leased Circuits / Dial up Lines (Internet Is IP) • X.25, Frame Relay, ATM (IP Can Run Over These) • VSATS ( Delays, 400 ms Per Hop) Distributed Applications
TRANSACTIONS • ACID Properties Revisited • Atomicity: All or None • Consistency : Stable & Correct End State • Isolation : Unaffected by Other Happenings • Durability : Persistent Effect Distributed Applications
TRANSACTIONS • A Single User Example • Is It Simple to Handle? • What Happens in a Crash? • Simple If Things Work Correctly • Difficult If Things Go Wrong. Distributed Applications
TRANSACTIONS • Concurrent Distributed Transactions, More Problems • Consistency and Isolation • Roll Back Is Difficult • Lock Step Synchronization Through Two Phase Commit Distributed Applications
TRANSACTIONS • Flat Transactions • Activities Are at Same Level • SQL Implements Two Phase Commit Protocol • Backbone of Most (Leaf-level) Applications Distributed Applications
FLAT TRANSACTIONS • Limitations • Complex Sub-activities With Partial Roll Back? • Human in the Loop Locks Resources • Temporally Long Transactions • Bulk Update Transaction Distributed Applications
PAYMENT SETTLEMENT A Complex Transaction • Jena of Jharsuguda gives a cheque to Kantheeswaran at Kandivali • Kanthee Banks with Bank A at Kandiwali: A(K) • Jena With Bank B(J) Distributed Applications
PAYMENT SETTLEMENT • Kanthee Presents Cheque to A(K) and demands money • A(J) credits Kanthee’s account AFTER collecting from B(J) Distributed Applications
DISTRIBUTED PROCESSING SOLUTION NCC Bank A Distributed Transaction Bank B Kandiwali Jharsuguda Local Data Base Local Data Base Jena Kantheeswaran Distributed Applications
PAYMENT SETTLEMENT • A presents the instrument to NCC • NCC records information • Sorts all Instruments for Bank B • Asks B to pay A • B sends Cheque to Jharsuguda (J) Distributed Applications
PAYMENT SETTLEMENT • B(J) debits Jena • Informs NCC and A(K) • A(K) credits Kanthee • Multiple Service Branches Are Actually Involved Distributed Applications
PAYMENT SETTLEMENT • Transaction becomes funny if • Jena has no funds • Cheque is lost in transit • B Debits Jena But Sits Tight • A Receives Info, But Does Not Credit Kanthee Distributed Applications
PAYMENT SETTLEMENT • More fun • NCC Asks B to Pay A • Later, B says give back my money • Jena debited but Kanthee not credited (Someone Using Float) • Kanthee sues A for delay Distributed Applications
DISTRIBUTED PROCESSING SOLUTION NCC Inter Bank Transaction Switch B Switch A Switch Bank A Distributed Transaction Bank B Kandiwali Jharsuguda Local Data Base Local Data Base Jena Kantheeswaran Distributed Applications
TRANSACTIONS • Emerging Transaction requirements • Distributed Transaction • Multiple Processing Nodes • Not All Nodes Computerised • Not All Links Electronic Distributed Applications
TRANSACTIONS • ACID properties difficult to maintain for a Complex Transaction • Human in the Loop is a MUST • Carry Physical Instruments • Multiple Data Capture • Verify Signatures at B(J) Distributed Applications
TRANSACTIONS • A Possible Solution is To Reduce Humans in the Loop • Cheque Is a Message and Not a Physical Instrument • NCC Is a Swithing System and Not a Physical Clearing House • Electronic Transfer Distributed Applications
TRANSACTIONS • Multiple Ways of Handling • MICR processing • Electronic Fund Transfer • Debit and Credit Clearing • Completely Automated Switch Distributed Applications
TRANSACTIONS • Emerging Requirements • Multi Location Transactions • Incorporation of Work Flow • Internet Transactions Distributed Applications
MIDDLEWARE • A Vague Term • All Distributed Software Components That Support Interactions Between Application Software Executing On Clients and Servers Distributed Applications
MIDDLEWARE • General • Communication stacks • Distributed Directories • Authentication Service • Remote Procedure calls • Queuing Services • Message Oriented Middleware (MOM) Distributed Applications
MIDDLEWARE • Service Specific • Database related : ODBC, DRDA, CLI • OLTP Specific : ATMI ( Tuxedo) • Groupware Specific : MAPI, LN calls • Object Specific : CORBA, OLE • Internet Specific : HTTP, SSL • Management Specific : SNMP, ORBs Distributed Applications
PEER TO PEER COMMUNICATION • Connection Oriented • Synchronous • Connection Less • Asynchronous, Store and Forward Distributed Applications
EXAMPLES OF DISTRIBUTED PARADIGM • Bank Master and Branch Power • Bancs 2000 • Micro Banker and Finware Distributed Applications
EXAMPLES OF DISTRIBUTED PARADIGM • Provide Branch Functionality When Network Non Functional • Provide Complete Customer Account and TXN Info • Attempt to Provide Retail and Commercial Functionality Distributed Applications
EXAMPLES OF DISTRIBUTED PARADIGM • SBI • IDBI Bank • ICICI Bank • HDFC Bank • A Malysian Bank Uses Four Servers For Many Branches Distributed Applications
DISTRIBUTED INFRASTRUCTURE • Needs Indian Messaging Standards • Needs Proper Application Software Development • Needs Work Flow Changes Distributed Applications
BUILDING BLOCKS • OS Services • Task Preemption, Task Priority • Semaphores, Inter process communications • Threads • Netware, NT, OS2 Warp, UNIX Distributed Applications
BUILDING BLOCKS • OS Services • Multi user high performance File System • Efficient Memory Management • Dynamically linked run time extensions Distributed Applications