Running the demos

The Corda repository contains a number of demo programs demonstrating Corda’s functionality:

  1. The Trader Demo, which shows a delivery-vs-payment atomic swap of commercial paper for cash
  2. The IRS Demo, which shows two nodes establishing an interest rate swap and performing fixings with a rates oracle
  3. The Attachment Demo, which demonstrates uploading attachments to nodes
  4. The SIMM Valuation Demo, which shows two nodes agreeing on a portfolio and valuing the initial margin using the Standard Initial Margin Model
  5. The Notary Demo, which shows three different types of notaries and a single node getting multiple transactions notarised.
  6. The Bank of Corda Demo, which shows a node acting as an issuer of assets (the Bank of Corda) while remote client applications request issuance of some cash on behalf of a node called Big Corporation

If any of the demos don’t work, please raise an issue on GitHub.

Note

If you are running the demos from the command line in Linux (but not macOS), you may have to install xterm.

Note

If you would like to see flow activity on the nodes type in the node terminal flow watch.

Trader demo

This demo brings up four nodes: Bank A, Bank B, Bank Of Corda, and a notary/network map node that they all use. Bank A will be the buyer, and requests some cash from the Bank of Corda in order to acquire commercial paper from Bank B, the seller.

To run from the command line in Unix:

  1. Run ./gradlew samples:trader-demo:deployNodes to create a set of configs and installs under samples/trader-demo/build/nodes
  2. Run ./samples/trader-demo/build/nodes/runnodes to open up four new terminals with the four nodes
  3. Run ./gradlew samples:trader-demo:runBuyer to instruct the buyer node to request issuance of some cash from the Bank of Corda node

4. Run ./gradlew samples:trader-demo:runSeller to trigger the transaction. If you entered flow watch you can see flows running on both sides of transaction. Additionally you should see final trade information displayed to your terminal.

To run from the command line in Windows:

  1. Run gradlew samples:trader-demo:deployNodes to create a set of configs and installs under samples\trader-demo\build\nodes
  2. Run samples\trader-demo\build\nodes\runnodes to open up four new terminals with the four nodes
  3. Run gradlew samples:trader-demo:runBuyer to instruct the buyer node to request issuance of some cash from the Bank of Corda node

4. Run gradlew samples:trader-demo:runSeller to trigger the transaction. If you entered flow watch you can see flows running on both sides of transaction. Additionally you should see final trade information displayed to your terminal.

IRS demo

This demo brings up three nodes: Bank A, Bank B and a node that simultaneously runs a notary, a network map and an interest rates oracle. The two banks agree on an interest rate swap, and then do regular fixings of the deal as the time on a simulated clock passes.

To run from the command line in Unix:

  1. Run ./gradlew samples:irs-demo:deployNodes to install configs and a command line tool under samples/irs-demo/build
  2. Run ./gradlew samples:irs-demo:installDist
  3. Move to the samples/irs-demo/build directory
  4. Run ./nodes/runnodes to open up three new terminals with the three nodes (you may have to install xterm).

To run from the command line in Windows:

  1. Run gradlew samples:irs-demo:deployNodes to install configs and a command line tool under samples\irs-demo\build
  2. Run gradlew samples:irs-demo:installDist
  3. Move to the samples\irs-demo\build directory
  4. Run nodes\runnodes to open up three new terminals with the three nodes.

This demo also has a web app. To use this, run nodes and then navigate to http://localhost:10007/web/irsdemo and http://localhost:10010/web/irsdemo to see each node’s view of the ledger.

To use the web app, click the “Create Deal” button, fill in the form, then click the “Submit” button. You can then use the time controls at the top left of the home page to run the fixings. Click any individual trade in the blotter to view it.

Note

The IRS web UI currently has a bug when changing the clock time where it may show no numbers or apply fixings inconsistently. The issues will be addressed in a future milestone release. Meanwhile, you can take a look at a simpler oracle example https://github.com/corda/oracle-example

Attachment demo

This demo brings up three nodes, and sends a transaction containing an attachment from one to the other.

To run from the command line in Unix:

  1. Run ./gradlew samples:attachment-demo:deployNodes to create a set of configs and installs under samples/attachment-demo/build/nodes
  2. Run ./samples/attachment-demo/build/nodes/runnodes to open up three new terminal tabs/windows with the three nodes and webserver for BankB
  3. Run ./gradlew samples:attachment-demo:runRecipient, which will block waiting for a trade to start
  4. Run ./gradlew samples:attachment-demo:runSender in another terminal window to send the attachment. Now look at the other windows to see the output of the demo

To run from the command line in Windows:

  1. Run gradlew samples:attachment-demo:deployNodes to create a set of configs and installs under samples\attachment-demo\build\nodes
  2. Run samples\attachment-demo\build\nodes\runnodes to open up three new terminal tabs/windows with the three nodes and webserver for BankB
  3. Run gradlew samples:attachment-demo:runRecipient, which will block waiting for a trade to start
  4. Run gradlew samples:attachment-demo:runSender in another terminal window to send the attachment. Now look at the other windows to see the output of the demo

Notary demo

This demo shows a party getting transactions notarised by either a single-node or a distributed notary service. All versions of the demo start two counterparty nodes. One of the counterparties will generate transactions that transfer a self-issued asset to the other party and submit them for notarisation. The Raft version of the demo will start three distributed notary nodes. The BFT SMaRt version of the demo will start four distributed notary nodes.

The output will display a list of notarised transaction IDs and corresponding signer public keys. In the Raft distributed notary, every node in the cluster can service client requests, and one signature is sufficient to satisfy the notary composite key requirement. In the BFT SMaRt distributed notary, three signatures are required. You will notice that successive transactions get signed by different members of the cluster (usually allocated in a random order).

To run the Raft version of the demo from the command line in Unix:

  1. Run ./gradlew samples:notary-demo:deployNodes, which will create all three types of notaries’ node directories with configs under samples/notary-demo/build/nodes/nodesRaft (nodesBFT and nodesSingle for BFT and Single notaries).
  2. Run ./samples/notary-demo/build/nodes/nodesRaft/runnodes, which will start the nodes in separate terminal windows/tabs. Wait until a “Node started up and registered in ...” message appears on each of the terminals
  3. Run ./gradlew samples:notary-demo:notarise to make a call to the “Party” node to initiate notarisation requests In a few seconds you will see a message “Notarised 10 transactions” with a list of transaction ids and the signer public keys

To run from the command line in Windows:

  1. Run gradlew samples:notary-demo:deployNodes, which will create all three types of notaries’ node directories with configs under samples/notary-demo/build/nodes/nodesRaft (nodesBFT and nodesSingle for BFT and Single notaries).
  2. Run samples\notary-demo\build\nodes\nodesRaft\runnodes, which will start the nodes in separate terminal windows/tabs. Wait until a “Node started up and registered in ...” message appears on each of the terminals
  3. Run gradlew samples:notary-demo:notarise to make a call to the “Party” node to initiate notarisation requests In a few seconds you will see a message “Notarised 10 transactions” with a list of transaction ids and the signer public keys

To run the BFT SMaRt notary demo, use nodesBFT instead of nodesRaft in the path (you will see messages from notary nodes trying to communicate each other sometime with connection errors, that’s normal). For a single notary node, use nodesSingle.

Notary nodes store consumed states in a replicated commit log, which is backed by a H2 database on each node. You can ascertain that the commit log is synchronised across the cluster by accessing and comparing each of the nodes’ backing stores by using the H2 web console:

  • Firstly, download H2 web console (download the “platform-independent zip”), and start it using a script in the extracted folder: h2/bin/h2.sh (or h2\bin\h2 for Windows)

  • If you are uncertain as to which version of h2 to install or if you have connectivity issues, refer to build.gradle located in the node directory and locate the compile step for com.h2database. Use a client of the same major version - even if still in beta.

  • The H2 web console should start up in a web browser tab. To connect we first need to obtain a JDBC connection string. Each node outputs its connection string in the terminal window as it starts up. In a terminal window where a node is running, look for the following string:

    Database connection url is              : jdbc:h2:tcp://10.18.0.150:56736/node

    You can use the string on the right to connect to the h2 database: just paste it into the JDBC URL field and click Connect. You will be presented with a web application that enumerates all the available tables and provides an interface for you to query them using SQL

  • The committed states are stored in the NOTARY_COMMITTED_STATES table. Note that the raw data is not human-readable, but we’re only interested in the row count for this demo

Bank Of Corda demo

This demo brings up three nodes: a notary, a node acting as the Bank of Corda that accepts requests for issuance of some asset and a node acting as Big Corporation which requests issuance of an asset (cash in this example).

Upon receipt of a request the Bank of Corda node self-issues the asset and then transfers ownership to the requester after successful notarisation and recording of the issue transaction on the ledger.

Note

The Bank of Corda is somewhat like a “Bitcoin faucet” that dispenses free bitcoins to developers for testing and experimentation purposes.

To run from the command line in Unix:

  1. Run ./gradlew samples:bank-of-corda-demo:deployNodes to create a set of configs and installs under samples/bank-of-corda-demo/build/nodes
  2. Run ./samples/bank-of-corda-demo/build/nodes/runnodes to open up three new terminal tabs/windows with the three nodes
  3. Run ./gradlew samples:bank-of-corda-demo:runRPCCashIssue to trigger a cash issuance request
  4. Run ./gradlew samples:bank-of-corda-demo:runWebCashIssue to trigger another cash issuance request. Now look at your terminal tab/window to see the output of the demo

To run from the command line in Windows:

  1. Run gradlew samples:bank-of-corda-demo:deployNodes to create a set of configs and installs under samples\bank-of-corda-demo\build\nodes
  2. Run samples\bank-of-corda-demo\build\nodes\runnodes to open up three new terminal tabs/windows with the three nodes
  3. Run gradlew samples:bank-of-corda-demo:runRPCCashIssue to trigger a cash issuance request
  4. Run gradlew samples:bank-of-corda-demo:runWebCashIssue to trigger another cash issuance request. Now look at the your terminal tab/window to see the output of the demo

Note

To verify that the Bank of Corda node is alive and running, navigate to the following URL: http://localhost:10007/api/bank/date

Note

The Bank of Corda node explicitly advertises with a node service type as follows: advertisedServices = ["corda.issuer.USD"] This allows for 3rd party applications to perform actions based on Node Type. For example, the Explorer tool only allows nodes of this type to issue and exit cash.

In the window you run the command you should see (in case of Web, RPC is simmilar):

  • Requesting Cash via Web ...
  • Successfully processed Cash Issue request

If you want to see flow activity enter in node’s shell flow watch. It will display all state machines running currently on the node.

Launch the Explorer application to visualize the issuance and transfer of cash for each node:

./gradlew tools:explorer:run (on Unix) or gradlew tools:explorer:run (on Windows)

Using the following login details:

  • For the Bank of Corda node: localhost / port 10006 / username bankUser / password test
  • For the Big Corporation node: localhost / port 10009 / username bigCorpUser / password test

See https://docs.corda.net/node-explorer.html for further details on usage.

SIMM and Portfolio Demo - aka the Initial Margin Agreement Demo

Background and SIMM Introduction

This app is a demonstration of how Corda can be used for the real world requirement of initial margin calculation and agreement; featuring the integration of complex and industry proven third party libraries into Corda nodes.

SIMM is an acronym for “Standard Initial Margin Model”. It is effectively the calculation of a “margin” that is paid by one party to another when they agree a trade on certain types of transaction. This margin is paid such that, in the event of one of the counterparties suffering a credit event (a financial term and a polite way to say defaulting, not paying the debts that are due, or potentially even bankruptcy), then the party that is owed any sum already has some of the amount that it should have been paid. This payment to the receiving party is a preventative measure in order to reduce the risk of a potentially catastrophic default domino effect that caused the Great Financial Crisis, as it means that they can be assured that if they need to pay another party, they will have a proportion of the funds that they have been relying on.

To enact this, in September 2016, the ISDA committee - with full backing from various governing bodies - issued a ruling on what is known as the ISDA SIMM ™ model, a way of fairly and consistently calculating this margin. Any parties wishing to trade a financial product that is covered under this ruling would, independently, use this model and calculate their margin payment requirement, agree it with their trading counterparty and then pay (or receive, depending on the results of this calculation) this amount. In the case of disagreement that is not resolved in a timely fashion, this payment would increase and so therefore it is in the parties’ interest to reach agreement in as short as time frame as possible.

To be more accurate, the SIMM calculation is not performed on just one trade - it is calculated on an aggregate of intermediary values (which in this model are sensitivities to risk factors) from a portfolio of trades; therefore the input to a SIMM is actually this data, not the individual trades themselves.

Also note that implementations of the SIMM are actually protected and subject to license restrictions by ISDA (this is due to the model itself being protected). We were fortunate enough to technically partner with OpenGamma who allowed us to demonstrate the SIMM process using their proprietary model. In the source code released, we have replaced their analytics engine with very simple stub functions that allow the process to run without actually calculating correct values, and can easily be swapped out in place for their real libraries.

What happens in the demo (notionally)

Preliminaries
  • Ensure that there are a number of live trades with another party financial products that are covered under the ISDA SIMM agreement (if none, then use the demo to enter some simple trades as described below).
Initial Margin Agreement Process
  • Agree that one will be performing the margining calculation against a portfolio of trades with another party, and agree the trades in that portfolio. In practice, one node will start the flow but it does not matter which node does.
  • Individually (at the node level), identify the data (static, reference etc) one will need in order to be able to calculate the metrics on those trades
  • Confirm with the other counterparty the dataset from the above set
  • Calculate any intermediary steps and values needed for the margin calculation (ie sensitivities to risk factors)
  • Agree on the results of these steps
  • Calculate the initial margin
  • Agree on the calculation of the above with the other party
  • In practice, pay (or receive) this margin (omitted for the sake of complexity for this example)

Demo execution (step by step)

To run from the command line in Unix:

  1. Deploy the nodes using ./gradlew samples:simm-valuation-demo:deployNodes
  2. Run the nodes using ./samples/simm-valuation-demo/build/nodes/runnodes

To run from the command line in Windows:

  1. Deploy the nodes using gradlew samples:simm-valuation-demo:deployNodes
  2. Run the nodes using samples\simm-valuation-demo\build\nodes\runnodes

Then, for both Unix and Windows:

  1. Browse to http://localhost:10005/web/simmvaluationdemo
  2. Select the counterparty (i.e. Bank B)
  3. Enter at least 3 trades - via the “Create New Trade” tab
  4. On the “Agree Valuations” tab, click the “Start Calculations” button

Additionally, you can confirm that these trades are not visible from Bank C’s node and are visible to Bank B.

Please note that any URL path information after simmvaluationdemo should not be bookmarked or navigated to directly, as it is only provided for aesthetic purposes.