1 / 22

TPlite is Back!

Explore the evolution of database systems to three-tier computing, discussing history, workflow management, application objects, server technology, and the shift to web services. Delve into the complexity, challenges, and integration possibilities in the modern landscape.

robertdiaz
Download Presentation

TPlite is Back!

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. TPlite is Back! Jim Gray Microsoft Research http://research.microsoft.com/~gray/talks/ High Performance Transaction Processing Workshop, Asilomar, CA., 27 September 2005,

  2. Summary Statement • Database system’s have changed • Is a web service (listens to port 80, does wsdl+soap,…) • Hosts a programming environment(J2EE VM or .NET CLR or… ) • So, Client-Server (a.k.a. tplite) • is possible • Has always been easier than 3-tier.

  3. Outline • History: Everyone Went to 3-tier (and why) • New news (DB + Languages + WS-*): • Extensible DBs have arrived. • Full blown programming environment inside • Fewer technologies: • DB integrated with language. • Web service integrated with class/method. • Fears • DMZ and attack surface.

  4. Fat Thin Fat Thin Work Distribution Spectrum • Presentation and plug-ins • Workflow manages session & invokes objects • Application Objects • Database Presentation workflows App Objects Database

  5. Server green screen 3270 Active Transaction Processing Evolution to 3 Tier Mainframe • Mainframe Batch processing (centralized) • Dumb terminals & Remote Job Entry • Intelligent terminals database backends • Workflow SystemsObject Request BrokersApplication Generators cards TP Monitor ORB

  6. PC Evolution to Three Tier • Stand-alone PC (centralized) • PC + File & print servermessage per I/O • PC + Database server message per SQL statement • PC + App server message per transaction • ActiveX Client, ORB ActiveX server, Xscript IO request reply disk I/O SQL Statement Transaction

  7. Mosaic DHTML AJAX Web Evolution to Three Tier Web Server WAIS • Character-mode clients, smart servers • GUI Browsers - Web file servers • GUI Plugins - Web dispatchers - CGI • Smart clients - Web dispatcher (ORB)pools of app servers (ISAPI, Viper)workflow scripts at client & server archie ghopher green screen

  8. The Pattern: Three Tier Computing • Clients do presentation, gather input • Clients do some workflow (Xscript) • Clients send high-level requests to ORB • ORB dispatches workflows • Server-side workflow scripts orchestrate distributed App objects • State stored in DB Presentation workflow App Objects Database

  9. Why Did Everyone Go To Three-Tier? • Manageability • App rules must be with data • Middleware operations tools • Performance (scalability) • Server resources are precious • ORB dispatches requests to server pools • DBMS was DREADFUL at connections • Connection pools • Technology & Physics • Put UI processing near user • Put shared data processing near shared data Presentation workflow App Objects Database

  10. Multiplexing ORB DB • DB client connection: • Mega-instruction set up • Mega-byte state • TP mon or Web Server or ORB • Lightweight connection setup • Multiplex many clients to few DB connections (connection pool) • Act as ORB (manage & dispatch server pools). • Act as object container.

  11. Complexity: Dark Side of 3-Tier • 3 programming environments • Lots of configuration choices • Lots of interface problems • SQL, PL/SQL, T-SQL, … in DB • It isn’t simple!!

  12. Outline • History: Everyone Went to 3-tier (and why) • New news (DB + Languages + WS-*): • Extensible DBs have arrived. • Full blown programming environment inside • Fewer technologies: • DB integrated with language. • Web service integrated with class/method. • Fears • DMZ and attack surface.

  13. DB Systems Get VMs A Server • DB has language VM execution environment • Language guys are “embracing” DB • Class is a web service:Generate WSDL • VERY simple • programming • debugging • Fewer languages & Tools to learn • See SQLJ or LINQ or… EJB Network Receiver Queue Management Connections Security Context Configuration Thread Pool Service logic Shared Data

  14. The New World – Programs + Data • It finally happened • Languages have sets (lists, dictionaries, …) • Table inherits from iEnumerable • List <employee> E = new Employee(); • for each e in E {} • Rows are objects • Query answers are collections • Supports transactions • Push a button and you have a web service.

  15. Old Data Access in API’s SqlConnection c = new SqlConnection(…); c.Open(); SqlCommand cmd = new SqlCommand( @“SELECT c.Name, c.Phone FROM Customers c WHERE c.City = @p0” ); cmd.Parameters[“@po”] = “London”; DataReader dr = c.Execute(cmd); while (dr.Read()) { string name = r.GetString(0); string phone = r.GetString(1); DateTime date = r.GetDateTime(2); } r.Close(); Queries in quotes Arguments loosely bound Results loosely typed Compiler cannot help catch mistakes

  16. Integrated Data Access Classes describe data public class Customer { public int Id; public string Name; public string Phone; … } Table<Customer> customers = …; foreach(c in customers.Where(City == “London”)) { Console.WriteLine(“Name: {0} Phone: {1}”, c.Name, c.Phone); } Tables are real objects Query is natural part of the language Results are strongly typed

  17. Web Services • Now trivial to publish your data. • Just say: “Make this method a web service.” • Everything else is automatic • Performance is easy to understand • Simplest configuration • Simplest management • Minimal data movement • Fewest round trips.

  18. Foreigners Client DB Other Data Sources us DBs are FederatingSo Now Do Connection Management • DB needs to • talk to peers scaleout • Talk to foreigners data integration • So, it is a client for multiplexing & connection pooling • So, now they get it, (they finally had to write an app) and they are doing it. • So, DB now does multiplexing

  19. Outline • History: Everyone Went to 3-tier (and why) • New news (DB + Languages + WS-*): • Extensible DBs have arrived. • Full blown programming environment inside • Fewer technologies: • DB integrated with language. • Web service integrated with class/method. • Fears • DMZ and attack surface.

  20. Fears • DB has large attack surface • Web servers act as DMZ to Internet. • Premise: • We can lock-down the DBMS interfaces • Only show “public” web services to outside.

  21. Summary Statement • Database system’s have changed • Is a web service (listens to port 80, does wsdl+soap,…) • Hosts a programming environment(J2EE VM or .NET CLR or… ) • So, Client-Server (a.k.a. TPlite) • is possible • Has always been easier than 3-tier. • Integration of DB and Language makes it VERY natural

  22. threads shared memory Distributed ExecutionThreads and Messages • Thread is Execution unit(software analog of cpu+memory) • Threads execute at a node • Threads communicate via • Shared memory (local) • Messages (local and remote) messages

More Related