PennDOT ATX Project ATAM

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PennDOT ATX Project ATAM

• Team Stalagmite
• Dan Abramovich
• Jeff Ditillo
• Andrew Guletsky
• Oksana Schubert
• Alexey Stolpovskikh
• Dehua Zhang

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Agenda

• Introduction
• Problem space Quality attributes Utility tree
• Architectural views and discussion
• Deployment and logical views
• Run-time views for major system parts
• Transaction processing
• JBoss-based redundancy
• Security
• Administration
• Reports
• Prototypes discussion
• Views are preceded by key decisions/facts to
  guide discussion

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Problem Space

• Problem description
• New solution for PennDOT on-line vehicle title
  and registration services
• Major stakeholders
• PennDOT
• ATX (our clients)
• Participating companies
• Business drivers
• Improve PennDOTs business processes
• Allow ATX to become PennDOTs Business Partner

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Quality Attributes

• Security
• Allow good guys to get in
• Keep bad guys out
• Put blinders on clients to only see allowed
  information
• Support user roles to limit functionality
• Availability
• Failover
• Recover from errors
• Modifiability
• Extend the system easily
• Update transaction descriptions, op. codes and
  fees without code changes
• Performance
• Provide reasonable user experience for many
  concurrent clients

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Utility Tree
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Deployment ViewsKey decisions/facts

• Requires minimum 2 computers
• AppServer and DB servers combined
• Requires at least 4 computes for high
  availability/performance
• Replicated DB exposes one virtual IP address
• Gatekeeper exposes one IP address
• Replication and redundancy transparent to ATX

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Deployment View
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High Availability Deployment View
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Logical ViewKey decisions/facts

• Separate Admin and Client interfaces
• Flexible location of Database layer
• Either co-located with AppServer or separate
• Most data storage managed by AppServer container
• Secure channel between client and server
• Role-based authentication and authorization
• Server blade requirements
• Each needs WebSphere MQ client
• Full state replication between blades
• Requirement for replicated file storage (MSCS)

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Logical View
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Run-time View Transaction Processing Key
decisions/facts

• IN and OUT queues hosted by PennDOT
• Transaction descriptions promote Modifiability
• Remedy risk of not having Gatekeeper access
• Make adding new transactions easy
• Clients manage transaction boundaries
• Insure that only successful transactions are
  acknowledges to PennDOT
• JMS and MDBs used for GK communication

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Run-time View Transaction Processing
Transactions e-v-e-r-y-w-h-e-r-e

• Problems solved by transaction description
• AAMVA record layout layout, field dependency,
  and format
• Database storage common and unique parts
• Transaction control flow
• Client sends request to PennDOT (via ATX)
• ATX receives asynchronous reply
• Stores reply in DB record
• Client polls for result and discovers DB record
• Client acknowledges receipt
• DB record deleted
• Message committed on Gatekeepers OUT queue

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Run-time View Transaction Processing
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Run-time View RedundancyKey decisions/facts

• Achieves redundancy via client-hosted proxy
• Proxy is supplied by JBoss and free for us
• Proxy is aware of all server blades
• Proxy will failover in case of timeouts
• State replicated between servers in real time
  (with very small latency)

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Run-time View Redundancy
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Run-time View SecurityKey decisions/facts

• Container provides security/authentication
  infrastructure
• Supports security plug-ins
• Requires deployment text files
• Allows for custom security proxies to validate
  parameters
• Covers both client and admin interfaces

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Run-time View Security
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Run-time View AdministrationKey decisions/facts

• Manages 4 functional areas
• Accounts
• Add/delete users add/delete locations
  assign/modify user privileges
• Transaction descriptions
• If/when changed by PennDOT
• Fees
• Set/update PCCS discounts, PennDOT charges
• Reports
• ltMore details latergt

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Run-time View Administration
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Run-time View ReportingKey decisions/facts

• Report solution is implemented by JasperReports
  (free COTS)
• Report viewers hosted by admin interface and
  client
• Supports custom datasources to massage
  transaction records
• Scheduler is implemented by COTS
• Final choice TBD

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Run-time View Reporting
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Prototypes Update

• Security
• SSL, login module and custom security proxy ()
• Entity bean performance with large records
• No performance bottlenecks ()
• Transactional (lazy) replication on DB (-)
• JasperReports
• Support for datasources ()
• Difficult to create report templates (-)
• Present trade-off to the client (other candidate
  commercial Crystal Reports)

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Prototypes Update (contd)

• Gatekeeper simulator
• Requires update with AAMVA records (?)
• Miniature transaction processor
• JMS and MDB to communicate with WebSphere MQ ()
• Performance questions under stress (-)
• Entity bean primary key auto-increment issue
• JBoss 3.2.0 native support ()
• Need JDBC 3.x compatible driver (-)
• Potentially switch from MS SQL to MySQL

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QA