corda/docs/source/node-database.rst

Node database

Default in-memory database

By default, nodes store their data in an H2 database. You can connect directly to a running node's database to see its stored states, transactions and attachments as follows:

• Enable the H2 database access in the node configuration using the following syntax:

  h2Settings {
      address: "localhost:0"
  }

• Download the last stable h2 platform-independent zip, unzip the zip, and navigate in a terminal window to the unzipped folder

• Change directories to the bin folder: cd h2/bin

• Run the following command to open the h2 web console in a web browser tab:

  • Unix: sh h2.sh
  • Windows: h2.bat

• Find the node's 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

• Paste this string into the JDBC URL field and click Connect, using the default username (sa) and no password.

You will be presented with a web interface that shows the contents of your node's storage and vault, and provides an interface for you to query them using SQL.

The default behaviour is to expose the H2 database on localhost. This can be overridden in the node configuration using h2Settings.address and specifying the address of the network interface to listen on, or simply using 0.0.0.0:0 to listen on all interfaces.

PostgreSQL

Nodes can also be configured to use PostgreSQL 9.6, using PostgreSQL JDBC Driver 42.1.4.

Warning

This is an experimental community contribution. The Corda continuous integration pipeline does not run unit tests or integration tests of this feature.

Configuration

Here is an example node configuration for PostgreSQL:

dataSourceProperties = {
    dataSourceClassName = "org.postgresql.ds.PGSimpleDataSource"
    dataSource.url = "jdbc:postgresql://[HOST]:[PORT]/postgres"
    dataSource.user = [USER]
    dataSource.password = [PASSWORD]
}
database = {
    transactionIsolationLevel = READ_COMMITTED
    schema = [SCHEMA]
}

Note that:

• The database.schema property is optional
• The value of database.schema is not wrapped in double quotes and Postgres always treats it as a lower-case value (e.g. AliceCorp becomes alicecorp)
• If you provide a custom database.schema, its value must either match the dataSource.user value to end up on the standard schema search path according to the PostgreSQL documentation, or the schema search path must be set explicitly for the user.

SQLServer

Nodes also have untested support for Microsoft SQL Server 2017, using Microsoft JDBC Driver 6.2 for SQL Server.

Warning

This is an experimental community contribution, and is currently untested. We welcome pull requests to add tests and additional support for this feature.

Configuration

Here is an example node configuration for SQLServer:

dataSourceProperties = {
    dataSourceClassName = "com.microsoft.sqlserver.jdbc.SQLServerDataSource"
    dataSource.url = "jdbc:sqlserver://[HOST]:[PORT];databaseName=[DATABASE_NAME]"
    dataSource.user = [USER]
    dataSource.password = [PASSWORD]
}
database = {
    transactionIsolationLevel = READ_COMMITTED
    schema = [SCHEMA]
}
jarDirs = ["[FULL_PATH]/sqljdbc_6.2/enu/"]

Note that:

• The database.schema property is optional and is ignored as of release 3.1.

* Ensure the directory referenced by jarDirs contains only one JDBC driver JAR file; by the default,

sqljdbc_6.2/enu/contains two JDBC JAR file for different Java versions.

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