Toto, Were Not in Kansas Anymore On Transitioning from Research to the Real World Mike Carey FellowS

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Toto, Were Notin Kansas AnymoreOn
Transitioning fromResearch to the Real
WorldMike CareyFellow-Systems
ArchitecturePlatform Divisioncarey_at_propel.com

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Todays Talk

• Background information
• Lessons from the "Road to Propel"
• The UW-Madison years
• The IBM Almaden years
• The Propel (web) years
• Database research in the new millennium
• Maturity brings its own challenges
• Research opportunities in e-commerce
• Some operational recommendations

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Part One

• Background information

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Background Info

• UW-Madison CS Professor (1983-1995)
• Concurrency control algorithms
• Query processing performance
• Main memory databases
• Extensible database systems (Exodus)
• Real-time database systems
• Client-server O-O database systems (Shore)
• Online algorithms, DBMS performance

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Background Info (cont.)

• IBM Almaden Research Staff Member and Manager
  (1995-2000)
• Heterogeneous database systems (Garlic)
• Object middleware (Component Broker)
• Object-relational databases (DB2 UDB)
• Propel Platform Engineering Fellow (2000-?)
• Scalable e-commerce infrastructure (Danube)

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Part Two

• Lessons from the "Road to Propel"

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UW-Madison YearsLesson 1 Awareness is key

• Be plugged in to current technologies issues
• Hardware and OS characteristics
• CPU, memory, disk, and network performance
• Path lengths (e.g., TCP/IP messages)
• DBMS software characteristics
• DBMS internal components
• Layers/calls SQL, records, pages,
• Interactions, e.g., concurrency recovery
• Application characteristics
• Typical workload characteristics
• What systems can or cannot know (when/how)

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UW-Madison YearsLesson 2 Students are the
product

• Having industrial impact is a laudable goal, but
• Its hard (in general) to be fully plugged in
• Details of systems and workloads
• The algorithms may not be the hard part
• More about this shortly
• Students are our biggest accomplishment
• Well-trained students are incredibly valuable
• Systems sense ability to think, learn, adapt
• Im extremely proud of my former students!
• Thats what I miss the most in industry

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UW-Madison YearsThe wake-up call A house of
cards?

• ACL85 Blindly following colleagues
• Ten years later, some papers still using the
  same hardware and software parameters
• RTDBS The blind following the blind?
• We basically stated and then solved these
  research problems ourselves
• SIGMOD-94 The SIGMOD chairs lunchtime analysis
  of SIGMOD paper production
• Not clear to me that most SIGMOD papers in the
  last ten years was such a good thing

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The First TransitionFrom UW-Madison to IBM
Almaden

• Intellectual reasons
• Weary of inventing and then solving problems
• Wanted access to real problems and systems
• Also just needed a change after 12 years
• IBM Almaden reasons
• Terrific environment colleagues for DB
  research
• Development from the safety of a research lab
• Personal reasons
• Wanted to have a life again outside work
• Wanted to live in the Bay area (Silicon Valley)

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IBM Almaden YearsContext Extending DB2 UDB

• From 1996-2000, I worked on adding object
  extensions to SQL and DB2 UDB (V5.2-V7.1)
• Object-relational data model extensions
• Types, OIDs, references, subtables, object views
• Corresponding query language extensions
• Substitutability, path expressions, constraints
  and triggers, type predicates, sub-table access
  rules
• System extensions
• Storage query processing for all of the above
• DB2 UDB work is geographically distributed
• IBM Toronto, Santa Teresa, and Almaden labs

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IBM Almaden YearsLesson 1 Products are hard to
build

• Products are very different than prototypes
• Someone else wrote the first 1M lines of code
• System has many nooks and crannies
• No one person understands the whole thing
• 100 or so people are working on it with you
• You have to do the other 80-90 of the work
• Testing, code reviews, testing, docs, testing,
• System catalogs no big deal, right?
• The engine is just one aspect of a product
• Import/export, bulk load, control center, visual
  explain, query tools, design tools, replication,

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IBM Almaden YearsLesson 1 Products are hard
(cont.)

• Its difficult to make some kinds of changes
• Customers already have terabytes of data
• Data migration is a no-no (at least at IBM ?)
• Catalog migration is a pain and a time sink
• Its not just your own product thats affected
• 3rd-party vendors may also be a factor
• Ex. 1 Physical load utilities (table
  hierarchies)
• Ex. 2 Logical physical database design tools
• Market share standards come into play here

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IBM Almaden YearsLesson 2 Adding to a language
is hard

• SQL is a 25-year old language that was never
  intended to do everything we want it to today
• World was simple tables, basic retrievals
• Various assumptions made for convenience
• Ex. 1 Sub-queries scalar- or table-valued?
• Ex. 2 Nulls inconsistent (e.g., where vs.
  max)
• SQL changes must be monotonic in nature
• Cant change meaning of existing queries (!)
• Extensions must all peacefully co-exist
• Language is getting full (gt 1000 pages)

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IBM Almaden YearsLesson 2 Adding is hard
(cont.)

• Cool new SQL features are a double-edged sword
• Can add real value for advanced applications
• Consider OLAP, O-R, and temporal extensions
• Different or proprietary bad?
• To 3rd-party vendors, also to nervous customers
• And, tools may hide them anyway
• Query builders, EJB model,
• SQL standardization is an interesting world
• Serious extensions must someday fly with ANSI
  ISO
• SQL standard is in some ways a corporate
  battleground
• Vendors only want the extensions on their radar
  screen

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IBM Almaden YearsLesson 3 Listen to users
needs

• So many features, so little time!
• Potential users help you prioritize your work
• Ex Sub-table triggers constraints in DB2
• They also help you make safe initial decisions
• Ex Internal storage for DB2 table hierarchies
• Potential users can help you see things you might
  otherwise miss (at least initially)
• Ex 1 Advantages of DB2 user-defined OIDs
• Customers already simulate objects today
• Access to system-generated OID values?
• Object caching and efficient write-back
• Ex 2 DB2 object view functionality
• Virtual table hierarchies, same authorization
  model

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The Second TransitionFrom IBM Almaden to Propel

• Some triggering events
• Working on XML middleware layer for DB2 UDB
• After spending nearly 20 years under the hood
• Almaden manager discussions connecting to
  Valley
• Personal belief that this may be a unique time
  for CS
• Call (out of the blue) from Steve Kirsch, CEO
• Given a 4-year paid scholarship to e-school
• Chance to learn about
• Using database system technology
• Web and e-commerce applications
• The startup company experience
• Excellent senior team to learn from at Propel
• Unemployment risk low in Silicon Valley today

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Propel (Web) YearsContext E-commerce
infrastructure

• Propel has three divisions
• E-commerce divison
• Amazon-in-a-box product
• OneID division
• Hosted personal information service
• Platform division
• Infrastructure product for the above (and more)
• Platform Scalable 24x7 e-commerce OS
• Online data management, caching, search, message
  services, deployment, monitoring,

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Propel (Web) Years Context E-C infrastructure
(cont.)
. . .
Firewall
Load Balancer
WebServer
WebServer
WebServer
WebServer
WebServer
. . .
App Server
App Server
AppServer
. . .
Propel Platform
Message Service







Admin MonitoringService
CachingService
ERP Service
OrderMgmtService
PaymentService

Data Management Search Service
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Propel (Web) YearsLesson 1 Standards vs.
innovation

• What a marketing person will likely tell you
  after asking a customer for their input
• Customers want standards-based solutions
• We want DB access via SQL and JDBC
• We want our programmers to use EJBs (J2EE)
• We want to use JSPs for our dynamic pages
• I.e., a typical customer dictionary entry says
• Proprietary see bad
• This poses obvious challenges for innovation!
• Luckily
• XML is also considered standards-based
• Performance, ease of use are still compelling in
  web-land

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Propel (Web) YearsLesson 2 Oracle is a de
facto standard

• Talking to dot-coms with Oracle DBAs is an
  interesting experience for the academic-minded
• Academic point of view
• Whatever its just a database system
• Oracle DBA point of view
• Do my Oracle utilities work with your solution?
• Do my Oracle sequences work with your solution?
• You mean its not Oracle? (said with a whine ?)
• Again, this poses obvious challenges for
  innovation (not to mention other DB vendors!)
• Luckily
• Saying Oracle inside seems to help
• Oracle is not a cheap or limitless solution

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Propel (Web) YearsLesson 3 VCs, dot-coms, and
ASPs

• OracleSunSolaris are to web sites what IBM was
  to corporate IS departments 15 years ago
• Some VC firms prescribe them to dot-coms
• Some IS departments pre-approve (just) them
• They are a favorite managed stack for ASPs
• Thus, todays technology brakes include
• Corporate and VC comfort zones
• ASP system management expertise
• Developer and DBA skill set availability

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Part Three

• Database research in the
• new millennium

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The DB Field Has MaturedBringing a new set of
challenges

• SQL DB systems are becoming a commodity
• ISVs produce DBMS-independent packages
• Ex ERP systems (SAP, Peoplesoft, Baan, )
• SQL ODBC/JDBC is just a given
• New features face a huge uphill battle
• Witness the rate of object-relational adoption
• Hopefully SQL99 will help, but.?
• A SQL DBMS has truly become a component
• Transactional storage for ERP
• On-line data repository for e-commerce
• I.e., just a place to put your data
• So where does that leave our community?

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The DB Field Has MaturedBringing new challenges
(cont.)

• Interesting questions remain! For example
• A good component is easy to manage
• DB systems have way too many knobs
• Theyre virtually impossible to hide as a result
• A good component plugs in well with others
• Better, faster interfaces would be nice
• Cache interaction hooks would be nice
• Workflow hooks would be nice
• (Your application hooks go here)
• XML appears poised for interoperation success
• W3C XML Schema Query standards coming
• Our community should keep playing a big role

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The DB Field Has MaturedBringing new challenges
(cont.)

• Interesting questions remain (cont.)
• Major applications are worth studying
• Ex Kemper, Kossman, et al SAP study
• Sources of typical workload info, database
  characteristics, and feature use (or disuse) info
• Bottom line from a component perspective
• We need to understand how our technologies are
  being utilized (or not) and respond accordingly
• Ex. 1 Queries with parameter markers
• Ex. 2 SQLs approach to authorization
• Ex. 3 Actual usage-driven interoperation hooks
• And, of course, we must continue to innovate!
• Somehow?!?

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E-Commerce DB ResearchA Propel Perspective

• The Propel Platform Not an app server
• Scalable, 24x7 e-commerce infrastructure
• Array of inexpensive Sun or Intel boxes
• Exploitation of low main memory cost
• High-performance and highly available
• Data management and search capabilities
• Transparent data replication partitioning
• Caching of page fragments, objects, and data
• Scalable messaging queuing infrastructure
• Built from best-of-breed components
• XML-enabled (for the future of e-commerce)
• Unified administration and on-line deployment

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E-Commerce DB ResearchProblem 1 Caching

• What to cache and where to cache it?
• Fragments of dynamic HTML pages
• Personalization ruins basic page caching
• Commonly used fragments assured, though
• XML objects used to create HTML fragments
• If applicable, probably less bulky
• Java objects materialized on app servers
• Avoids database re-access cost
• Issues load balancing, memory duplication
• Database objects accessed on DB server(s)
• Lowers database access cost
• Where app servers, DB server(s), or both?

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E-Commerce DB ResearchProblem 1 Caching
(cont.)

• How to keep caches consistent
• Multiple web servers and app servers
• DB rows -gt Java objects -gt XML -gt HTML
• How to uniquely identify objects?
• How to keep track of whats where?
• How to keep track of data dependencies?
• How/when to propagate updates?
• How to maintain consistency?
• In fact, how to define consistency?
• And, just to up the ante a bit further
• Want all this to work across continents!

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E-Commerce DB ResearchProblem 2 Consistency
transactions

• Not all e-commerce data is equally valuable
• Want to trade off reliability performance
• Products hot, may be read-only once deployed
• Shopping carts read/write, best effort
  durability
• Orders also read/write, require full
  durability
• Similar considerations arise w.r.t. consistency
• Would like well-defined choices available
• Auctions okay to bid using slightly outdated
  info
• Orders real-time inventory requires
  transactions
• Need good, architecturally appropriate solutions
• Caching, replication, failover, smart load
  balancing,

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E-Commerce DB ResearchProblem 3 Queries and
search

• W3Cs XML Schema recommendation
• How to store richly typed XML data?
• Sparse/variant data, repeating elements,
  subtyping, text,
• Would like to map it into (object-?) relational
  databases
• W3Cs XML Query recommendation
• How to process XML queries efficiently?
• SQL-appropriate processing model
• Pushdown and other optimizations
• How to handle search-oriented queries
• Want transaction-consistent text indexing
• Also want relevance ranking and various IR
  goodies

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E-Commerce DB ResearchProblem 4 Content
management

• E-commerce sites are rich in content
• HTML fragments (e.g., logos and other goodies)
• Images (e.g., pictures of products)
• Text (e.g., descriptions of products)
• Database data (e.g., product attributes,
  pricing)
• JSP pages (e.g., a product page)
• Personalization rules (i.e., what to show me)
• Business logic (i.e., Java code)
• Data -gt object mappings (e.g., Java classes)
• And the list goes on

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E-Commerce DB ResearchProblem 4 Content mgmt.
(cont.)

• This poses a number of problems
• Versioning of file-based artifacts
• Not unlike CAD or document versioning
• Multiple editors working on the content base
• Several companies do this (e.g., Interwoven)
• Versioning of DB-based artifacts
• Not clear how to handle integrate this part
• No winning solutions out there yet (that I know
  of)
• Versioning of code-based artifacts
• How to keep all this stuff mutually consistent?
• And, how to deploy online in a 24x7 world?

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E-Commerce DB ResearchProblem 5 The sun never
sets anymore

• The web brings a clear need for 24x7 solutions
• Asynchronous replication techniques
• Online schema evolution (w/replication)
• Online data loading and deployment
• Online management of rolling history data
• Design for administration/monitoring is also key
• Online backup/restore
• Failure performance monitoring
• Would like system to be self-tuning
  self-scaling
• Reassign boxes between services as needed
• Even give and take boxes from ASP infrastructure

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The Propel PlatformWere attacking all of these
issues

• Programming model
• Objects with (truly!) universal OIDs
• Java classes, derived from XML Schema objects
• Caching
• Multilevel cache hierarchy (w/partitioning)
• Mini-caches, global cache, MM-DBMS, DB-DBMS
• Consistency and transactions
• Can trade off ACID-ity vs. performance
• Queries and search
• XML-based query language, integrated search
• Transparency for cached, partitioned,
  replicated data

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The Propel PlatformWere attacking all of these
issues (cont.)

• Platform message system
• Truly scalable IPC for Platform components
• Hides a number of painful details
• Load balancing failover
• System monitoring
• Also supports persistent message queueing
• Content management
• Currently focused on deployment problems
• Partnering (sigh!) for content management
• System monitoring and administration
• Separate software stack with agents everywhere
• JSP-based console to oversee integrate
  activities

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ConclusionLessons from the "Road to Propel"

• UW-Madison lessons Know what matters!
• Awareness is key
• Students are the product
• IBM Almaden lessons Whats really hard?
• Products are hard to build
• Adding to a language is hard
• Listen to users needs
• Propel lessons Commoditization brings
  roadblocks.
• Standards vs. innovation
• Oracle is a de facto standard
• Dot-coms, VCs, and ASPs

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ConclusionDB research in the new millennium

• SQL databases are becoming commodity parts
• ISVs strive for DBMS vendor-independence
• This makes (visible) innovation hard
• Lots of interesting research questions, though
• Component hooks, usage scenarios, XML,
• E-commerce problems are ripe for the picking
• Examples that have arisen at Propel include
• Caching, transactions consistency
• Queries and search
• Content management
• Online everything for a 24x7 world

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ConclusionSome operational recommendations

• Understand the real problems out there
• Industrial friends can be very helpful
• Your students will benefit tremendously
• So will the companies who hire them
• Recognize that commoditization is happening
• Consider working within the constraints that it
  brings
• Many important open problems remain
• E-commerce is a fun/interesting example here
• Also keep in mind what really matters
• Its actually not any of this stuff, in the
  end!