Hyperledger Fabric Composer Overview UW Blockchain Society, 10/29/2018 By Ray Metz, SeattleBlockchainTraining.com http://seattleblockchaintraining.com/outlines/outlines.html

Overview Compare Hyperledger with Blockchain Define Terms Describe features Market Position How do we learn more?

Hyperledger is a Blockchain Basic features of most blockchains, including Hyperledger Back end technology. No front end. Can support multiple client apps. Data is written by multiple parties, this supports decentralization Data is written to disk in an immutable blockchain file format. No deletes. The same data is written to all nodes at once This provides redundancy as well as independence from centralization Drawback: Writing the same data to all nodes is very expensive and slow There is a consensus mechanism for everyone to agree and stay in sync Most blockchains are open source. Anyone can install, or modify the source code independently, but not the ledger without group consensus.

Hyperledger, Fabric, and Composer An umbrella project under the Linux Foundation. www.hyperledger.org Like Linux and Apache foundations, Hyperledger has many products, brands, and components that are not all compatible. Fabric The most popular Hyperledger blockchain. https://www.hyperledger.org/projects/fabric Composer A very popular application that makes Fabric development easier. It is difficult to find examples on the web of using Fabric without Composer. Composer may be merged into Fabric. https://lists.hyperledger.org/g/composer/topic/25106848

Composer Composer is not a blockchain Composer is It’s a client app that connects to Hyperledger Fabric blockchain. The Fabric connection and Composer app can each be cloud or local. IBM Bluemix provides a free cloud Composer environment with both front and back-end components. https://composer-playground.mybluemix.net/ Composer is A javascript based helper environment with its own coding style and objects, separate from Fabric. A limited dev environment A limited test UI. Can execute chaincode, explore data in assets. A sample library of Hyperledger Fabric applications with assets, chaincode, and more. A code migration and deployment tool with import + export features. Not compatible with non-composer Hylerledger Fabric development.

Hyperledger is a Private Blockchain Hyperledger is used by private companies The data in the Ledger is private and not on the Internet. Hyperledger nodes are kept behind corporate firewalls Traditional network VPNs are used to connect multiple companies The “nodes” or “miners” are paid for privately. There is no native coin or currency. You can’t buy Hyperledger coins. Hyperledger has a multi-ledger “channel” security feature, but Composer does not.

Hyperledger features Writes are typically shared by multiple parties. Think partners, customers, or even competitors. Security is defined to manage who has read and write access to what. Security features are very limited. The code in Hyperledger is public and open source www.hyperledger.org - https://github.com/hyperledger https://hyperledger.github.io/composer/latest/installing/installing-index.html Two databases are used in parallel. A ledger database and a world state database. CRUD – Create, Read, Update, Delete. Updates and Deletes are logical in the ledger.

Hyperledger Assets Modeling Hyperledger Assets is similar to SQL or Object Data Modeling Model business appropriate data into rows and column type structures. To make sense for business, the right data has to go to the right place. Bad example: Excel and Hyperledger allow you to input “Happy birthday” and “123 Go!” anywhere, but you don’t enter those in business. It’s up to you to model your data in a useful way. Changing the model once there is already data inside can block it from being viewable. The optional keyword may help during model changes. Firmware / Intel chip example. Word, excel, database, blockchain comparison

Assets Continued Assets are defined in a .cto file, which is a Composer feature Some allowed Data Types are String, Integer, DateTime, Boolean Some SQL ideas are supported Identity, relationship Some object/json/nosql ideas are supported Enum, abstract, concept, array Keep it simple when learning. Think 1-2 assets, 1-4 columns each. In addition to Assets, there are Participants, Transactions, and Events

Chaincode and Smart contracts Chaincode and Smart Contracts is the same thing. Composer chaincode is javascript. There is also Go chaincode without composer. To write data into an Asset, you must use chaincode. There is no API to write directly into an Asset. You can copy Chaincode from Composer examples and modify it. The API calls a Transaction from your .CTO file, and the Transaction references Chaincode.

Hyperledger Nodes Hyperledger has three major node types and some sub types. Client API End users don’t directly connect to Peers. A client API is installed with the appropriate certificate and the Client API makes requests to the peers. Peer Peers are the most similar to typical Blockchain “Nodes”. All Peers keep a copy of the ledger. Some peers can be defined as an “Endorser” Order The Orderer is a unique required Hyperledger Fabric feature. The Order is typically a kafka queueing service that. There is a “solo” service available for single-node setups. Docker: Most Hyperledger nodes run as a Docker instance in production.

Hyperledger and Ethereum Joined each other’s alliances, 10/1/2018 https://www.hyperledger.org/announcements/2018/10/01/enterprise-ethereum- alliance-and-hyperledger-to-advance-the-global-blockchain-business-ecosystem https://entethalliance.org/enterprise-ethereum-alliance-hyperledger-advance- global-blockchain-business-ecosystem/ Latest announcement, 10/26 https://www.hyperledger.org/blog/2018/10/26/hyperledger-fabric-now-supports- ethereum Hyperledger Burrow project https://www.hyperledger.org/projects/hyperledger-burrow

Where do we go from here? Project Manager / Business Analyst / Data Modeler interest: Document Assets and fields for your own use case. If you don’t have a use case, search for and copy an existing one. Plan your nodes. Who would want to run the nodes? Operations interest: Install Hyperledger on your own laptop https://hyperledger-fabric.readthedocs.io/en/latest/build_network.html Who will open firewall ports to the multiple businesses required for multiple nodes? Test on multiple networks and nodes. Security design and testing. How will we deploy design upgrades across multiple corporations? Change Management. Developer interest: Is one Ledger/Channel enough for application security? How do we develop in Go without Composer?

Further Learning Self train https://www.hyperledger.org/projects/fabric BTA Hyperledger certification https://blockchaintrainingalliance.com/ SeattleBlockchainTraining.com short courses (very ad-hoc) Hyperledger Laptop Install Composer and Asset design and deploy http://seattleblockchaintraining.com/outlines/outlines.html Blueberry Consulting Hyperledger lab series with nonprofit opportunities. (under construction)