Configuration: Persistence

The persistence module allows the transformer to store data in a datastore. The default configuration makes the module load up an in-process sqlite3 database and stores data into a file that can be configured via the persistence.conf configuration file.

For production environments that use a transformer cluster it is advised not to use the sqlite3/filedb persistence as it does not synchronize it's state over the cluster. It is recommended to use the javadb/jdbc layer and connect the persistence module of all transformers in the cluster to a central Database.

Loading Persistence

To load the persitence module add the following to transformer.conf

add-module  persistence 

Options

persistence-filedb-bootstrap

Type: String Array
Default: None

Array of SQL files to be executed when the module loads. This option is only available if enable-file-database is set to true

enable-file-database

Type: Boolean
Default: FALSE

Turn on or off file DB, only when this config option is set to false file database will be disabled

persistence-classid

Type: String
Default: None

When enable-file-database is set to false this option specifies the classid of the java persistence adapter to be loaded and used as a bridge between transformer and a database

Configuration group add-database-params

Start a database params configuration group. This config group gets passed into the persistence implementation loaded and can be used for custom java persistence adapters.

Format:

add-database-params
    init-string         [value]
    driver-name         [value]
    username            [value]
    password            [value]
    extra-params        [values]
end-database-paarms

extra-params

Type: String Array
Default: None

Array of extra arguments to be passed into a custom java persistence adapters. In case of the default Jdbc implementation this takes exactly one argument of type int and specifies number in seconds to wait for a call to Connection.isValid() to return.

init-string

Type: String
Default: None

Initialisation string for the database. For File/SQLite DB this specifies the location where the database file should be stored, for the default JDBC implementation this specifies the JDBC URL.

driver-name

Type: String
Default: None

The Jdbc driver name of the driver to be used by the JDBC default implementation. The driver needs to be made available to transformer.

username

Type: String
Default: None

The username required to authenticate with the database

password

Type: String
Default: None

The password required to authenticate with the database

logfile

Type: String
Default: persistence.log

Logfile

log-level

Type: String
Default: INFO

Logging level of the persistence module.