Martin Horozon and Federico Melani from NTT Data present on DevDay at CordaCon 2019. View the presentation.

1. © 2019 NTT DATA Corporation
Information Type:
Company Name: NTT DATA Italia S.p.A
Information Owner:
Taming a Production-Bound Corda Application
23/10/2019
Martin Horozov, Federico Melani
Public
Blockchain

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SPUNTA STAKEHOLDERS
Regulation & association
Corda
Network & Infrastructure
Development
Spunta as-is process
Constraints and advantages from each role
Italian banks

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Reconciliation
• Niche process
• Old regulation
• Bilateral agreements
• Not standardized
Banking industry
• Data format cannot be changed
• Records are batched daily
Back office users
• Different knowledge
• Too specific vs too generic
SPUNTA AS-IS PROCESS

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DESIGN CHOICES
• Multiple applications
• Internal process
• Internal data format
• Internal and customized
rules
• Single distributed application
• Standardized process
• Standardized data format
• Common rules
Dapp standardization
PoC phase: try to use only corda Prod phase: on ledger vs off ledger
Compliance

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• UX
• AngularJS
DESIGN CHOICES
Batch Loading
Ansible
Complete end-to-end application
• Two-party flows
• No AnonymousParty
• No CashState
• No third party contracts
• No exchange of value
• No oracles
• Propose & accept
• Configuration
• Broadcast
• Regulatory rules
• Tx batching
Corda usage
• CorDapp• Swagger
• Spring Boot

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• Massive amount of data (Millions of states & Transactions)
• Can’t fit in a single tx
• Split the commit in multiple txs
• Massive amount of checkpoints
• Solution: keep data in off-ledger table instead of flow
PERFORMANCE

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During the testing phase one of the main challenges was to create a test suite
that can test our CordApp once for all the different Corda interfaces:
1. Unit Tests with Mock Network
2. DriverBasedRun
use Node Driver
3. RealNodeRun
Control and debug nodes in IDE
For example one frequent activity is DB population.
TESTING APPROACH

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CORDAPP SERVICES

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CORDAPP FACADE

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DAO QUERY INTERFACE

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DAO FACADE AND BRIDGE

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CASHDAO VAULT QUERY

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CASHDAO NATIVE QUERY

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FLOW FACADE

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FLOW BRIDGE RPC

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CASH ISSUE FLOW ADAPTER

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UNIT TESTS

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EXAMPLES

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• Production CorDapps needs to reuse the code as much as possible to
garantee a good level of mantainance
• Frameworks like the one we presented can help
• Performance has to consider off-ledger data
• Adapting an old process to a DLT process requires a big effort on
requirements analysis and design
Conclusions

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