The EmbeddedStorageManager is mostly created with factory methods of EmbeddedStorage, where the most common settings, like database directory or the root instance, can be configured.

EmbeddedStorageManager storageManager = EmbeddedStorage.start(
    myRoot,                 // root object of entity graph
    Paths.get("data-dir")    // storage data directory
);

Foundations

To achieve a more detailed customization, you can utilize the EmbeddedStorageFoundation factory type. It holds and creates on demand all the parts that form an EmbeddedStorageManager.

EmbeddedStorageManager storageManager = EmbeddedStorageFoundation.New()
    .setConfiguration(
        StorageConfiguration.Builder()
            .setChannelCountProvider(StorageChannelCountProvider.New(4))
            .setBackupSetup(StorageBackupSetup.New(Paths.get("backupdir")))
            .createConfiguration()
    )
    .createEmbeddedStorageManager();

External Configuration

The artifact storage.embedded.configuration provides a convenience layer for configuration purposes, as well as facilities to read external configuration.

pom.xml
<repositories>
    <repository>
        <id>microstream-releases</id>
        <url>https://repo.microstream.one/repository/maven-public/</url>
    </repository>
</repositories>
<dependencies>
    <dependency>
        <groupId>one.microstream</groupId>
        <artifactId>storage.embedded.configuration</artifactId>
        <version>03.00.00-MS-GA</version>
    </dependency>
</dependencies>

The Configuration type consolidates the most widely used parameters from the storage foundations in one place. It's output is an EmbeddedStorageFoundation from which a EmbeddedStorageManager can be created.

EmbeddedStorageManager storageManager = Configuration.Default()
    .setBaseDirectoryInUserHome("data-dir")
    .setBackupDirectory("backup-dir")
    .setChannelCount(4)
    .createEmbeddedStorageFoundation()
    .createEmbeddedStorageManager();

To read an external configuration use ConfigurationLoader and ConfigurationParser or the Load*() methods of Configuration. Currently XML and INI files are supported.

Configuration configuration = Configuration.LoadXml(
    HelloWorld.class.getResource("/META-INF/microstream/storage.xml")
);

<?xml version="1.0" encoding="UTF-8"?>
<properties>
    <property name="baseDirectory" value ="data" />
    <property name="channelCount" value ="4" />
</properties>

Configuration configuration = Configuration.LoadIni(
    HelloWorld.class.getResource("/META-INF/microstream/storage.ini")
);

baseDirectory = data
channelCount = 4

If you just use Configuration.Load() the default configuration file is used, which is either a file in the classpath root named microstream-storage.properties, or the path configured via the system property microstream.storage.configuration.path.