CDO/Server Configuration Reference

Example

The CDOServerApplication is configured with the cdo-server.xml file. It must be located in the folder that you declare through the system property net4j.config.

Checkout this example from Git and modify it for your needs: http://git.eclipse.org/c/cdo/cdo.git/tree/plugins/org.eclipse.emf.cdo.server.product/config/cdo-server.xml.

The subsequent sections explain the used XML Elements.

Element cdoServer

The root element of the cdo-server.xml file. It can contain zero, one or several acceptor elements and zero, one or several repository elements.

Element acceptor

Defines an IAcceptor instance. Please refer to the Net4j documentation for details about acceptors and connectors.

The type attribute corresponds to the type of an acceptor factory that is contributed via the org.eclipse.net4j.util.factories extension point with a product group of org.eclipse.net4j.acceptors. The remaining attributes depend on the specified type attribute value. The following values are possible with the shipped distribution (subject to user supplied extension):

• tcp: Acceptor for fast, new I/O based socket connections. The following additional attributes are recognized:
  • listenAddr: The network address the server socket shall be bound to. A value of "0.0.0.0" is the default (whole attribute can be omitted) and tells the socket to listen on all available addresses.
  • port: The network port the server socket shall be bound to. A value of "2036" is the default (whole attribute can be omitted).

• jvm: Acceptor for JVM internal (non-socket based ) connections. Currently not supported by the Net4Configurator.

The acceptor element can contain zero or one negotiator element(s).

Please note that the acceptor element is likely to be moved to a separate Net4j configuration file in the future.

Element negotiator

Defines an INegotiator instance to be used by the connectors created by an acceptor (defined by the enclosing acceptor element). Please refer to the Net4j documentation for details about negotiators and the pluggable security concept that can be used for authentication and authorization.

The type attribute corresponds to the type of a negotiator factory that is contributed via the org.eclipse.net4j.util.factories extension point with a product group of org.eclipse.net4j.negotiators. The remaining attributes depend on the specified type attribute value. The following values are possible with the shipped distribution (subject to user supplied extension):

• challenge: Negotiator for simple yet effective and cryptographically secure challenge/response based negotiations. The following additional attributes are recognized:
  • description: The absolute path to a file in the local file system that contains the credentials of the users in the form userid: password.

Element repository

Defines an IRepository instance.

The name attribute uniquely identifies a repository in the scope of a repository configurator.

The repository element can contain several property elements (see below) and must contain exactly one store element.

Property overrideUUID

Specifies a constant UUID for the repository. If omitted the repository will be created with a random UUID. The format of an override UUID is not further specified but should respect the file naming conventions of the used operating system.

Overriding the default random UUID can be useful if you have scripts that operate on the file system folder that is created on the server for each repository and named after the repository UUID.

Property supportingAudits

Specifies whether the repository will support audit views or not. Please note that a repository can only support audit views if its store supports audit views, as well:

Store Implementation	Allowed Values	Default Value
org.eclipse.emf.cdo.server.internal.db.DBStore	true/false	true, if the used mapping strategy supports audits
org.eclipse.emf.cdo.internal.server.mem.MEMStore	true/false	true
org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore	false	false
org.eclipse.emf.cdo.server.internal.objectivity.ObjectivityStore	true/false	false
org.eclipse.emf.cdo.server.internal.db4o.DB4OStore	true/false	false

The shipped DB store does support audit views. Note also that it will not delete or update rows for modified objects if audits are supported. All revised state of the repository will be kept in the DB which can result in databases growing very large!

Property supportingBranches

Specifies whether the repository will support the creation and usage of branches below the always existing main branch or not. Please note that a repository can only support branches if its store supports branches, as well:

Store Implementation	Allowed Values	Default Value
org.eclipse.emf.cdo.server.internal.db.DBStore	true/false	true, if the used mapping strategy supports branches
org.eclipse.emf.cdo.internal.server.mem.MEMStore	true/false	true
org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore	false	false
org.eclipse.emf.cdo.server.internal.objectivity.ObjectivityStore	true/false	false
org.eclipse.emf.cdo.server.internal.db4o.DB4OStore	true/false	false

Also note that branching support always requires auditing support!

Property supportingEcore

Specifies whether the repository will support the storage of instances of the Ecore (meta meta) model or not.

With the advent of the legacy mode (support for models not generated as CDO native models) in CDO 3.0 you can store instances of any model in CDO repositories. Whether these models have been generated for CDO or not only influences their characteristics (scalability, performance, etc.). As a consequence you can also store instances of the Ecore (meta meta) model in CDO Repositories. Since Ecore has always been registered in all package registries the legacy mode would lead to the creation of mapped tables in many types of stores, even if you never planned to store instances of Ecore.

Property serializeCommits

Specifies whether the repository will serialize commit operations by utilizing a lock or not.

Some stores, such as the LissomeStore, require commit operations to be serialized.

Property ensureReferentialIntegrity

Specifies whether the repository will detect and reject commits that would leave stale references in the object graph. Valid values: false (default) or true.

Property allowInterruptRunningQueries

Specifies whether the repository will cancel a scheduled query job if it is alreading running. Some underlying stores (e.g. DBStore with a Derby database) might not be able to deal with this cleanly. For such stores, this parameter can be set to false.

Property idGenerationLocation

Specifies whether the repository will expect clients to generate IDs for new objects or whether it will ask the backend store to generate them. Valid values: STORE (default) or CLIENT.

Element store

Defines an IStore instance. Please refer to CDO Storage Framework for details about stores, store readers and store writers.

The type attribute corresponds to the type of a store factory that is contributed via the org.eclipse.emf.cdo.server.storeFactory extension point. The remaining attributes depend on the specified type attribute value. The following values are possible with the shipped distribution (subject to user supplied extension):

• mem: Store without real persistence. A repository with a mem store can function properly as long as the the server is not restarted. No additional attributes are recognized.
• db: Store that connects via JDBC to a relational database and manages persistent revisions and models through a built-in O/R mapper, see CDO/DB Store. A DB store element can contain the following nested elements:
  • mappingStrategy
  • dbAdapter
  • dataSoure
• hibernate: Store that uses Teneo/Hibernate, see CDO/Hibernate Store.
• objectivity: Store that uses Objectivity/DB, see CDO/Objectivity Store.
• mongodb: Store that uses MongoDB, see CDO/MongoDB Store.
• db4o: Store that uses DB4O, see CDO/DB4O Store.

Property connectionKeepAlivePeriod

Specifies, if the store is a DBStore, at what interval the store will issue an SQL statement to keep the connection to the database alive.

Property readerPoolCapacity

Specifies, if the store is a DBStore, the maximum number of store accessors (JDBC connections) to keep in the reader pool. The default value is 15.

Property writerPoolCapacity

Specifies, if the store is a DBStore, the maximum number of store accessors (JDBC connections) to keep in the writer pool. The default value is 15.

Element mappingStrategy

This element is recognized by DB stores and defines the overall mapping strategy of the built-in O/R mapper.

The type attribute corresponds to the type of a mapping strategy factory that is contributed via the org.eclipse.emf.cdo.server.db.mappingStrategies extension point. The following values are possible with the shipped distribution (subject to user supplied extension):

• horizontal: Mapping strategy that creates one DB table per concrete model class. The following nested property elements are recognized:
  • toManyReferences
  • toOneReferences
  • maxTableNameLength
  • maxFieldNameLength
  • tableNamePrefix
  • qualifiedNames
  • forceNamesWithID

• vertical: Mapping strategy that creates one DB table per class in the model hierarchy. This type is currently not supported. The following nested property elements will be recognized:
  • toManyReferences
  • toOneReferences
  • maxTableNameLength
  • maxFieldNameLength
  • tableNamePrefix
  • qualifiedNames
  • forceNamesWithID

Property toManyReferences

Specifies how the built-in O/R mapper will handle to-many references (collections). The following values are recognized:

• ONE_TABLE_PER_REFERENCE: Each to-many reference of the model will get its own DB table.
• ONE_TABLE_PER_CLASS: All to-many references of a model class will share a single DB table.
• ONE_TABLE_PER_PACKAGE: All to-many references of a model package will share a single DB table.
• ONE_TABLE_PER_REPOSITORY: All to-many references of all model classes i the repository will share a single DB table.
• LIKE_ATTRIBUTES: Collections will be serialized to a BLOB column in the same DB table that the attributes of the containing model class are stored in. This option is currently not supported.

Property toOneReferences

Specifies how the built-in O/R mapper will handle to-one references. The following values are recognized:

• LIKE_ATTRIBUTES: Single references will be stored in a CDOID column in the same DB table that the attributes of the containing model class are stored in. This option is the default option.
• LIKE_TO_MANY_REFERENCES: Single references will be handled in the same way as specified for to-many references. This option is currently not supported.

Property maxTableNameLength

Enables you to override the default value of the chosen DB adapter for the maximum length of table names.

Property maxFieldNameLength

Enables you to override the default value of the chosen DB adapter for the maximum length of column names.

Property tableNamePrefix

Specifies a common fixed prefix for all table names generated by this mapping strategy.

Property qualifiedNames

Specifies whether generated package or class table names are qualified or not.

Property forceNamesWithID

Specifies whether generated names are always suffixed with an internal ID or only in cases where the generated name absolutely needs mangling.

Property fieldConstructionTracking

Specifies whether you want db field construction stacktrace on schema update to have the origin of the nullable index field.

Property objectTypeCacheSize (since cdo.server.db 4.0)

Specifies the size of the object type in-memory cache. Possible configuration values are:

• 0 (zero). Don't use memory caching.
• >0. Use memory caching with the cache size given.

The default is a memory cache size of 10,000,000.

Property columnTypeModifier (since cdo.server.db 4.2)

Specifies the name of a column type modifier.

Property forceIndexes (since cdo.server.db 4.4)

Specifies on what types of structural features additional indexes are to be created. The value is either empty or a | separated list of the following tokens:

• NONE (default)
• ALL (equal to ATTRIBUTE|REFERENCE)
• ATTRIBUTE
• REFERENCE (equal to CONTAINER|CONTAINMENT|XREF)
• CONTAINER
• CONTAINMENT
• XREF

Element dbAdapter

Defines the IDBAdapter instance of the store. Please refer to Net4j DB Framework for details about DB adapters and SQL dialects.

The type attribute corresponds to the name of a DB adapter factory that is contributed via the org.eclipse.net4j.db.dbAdapters extension point. No additional attributes are recognized.

The DB adapter must match the database specified in the dataSource element.

Element dataSource

Defines the DataSource instance of the store.

The class attribute corresponds to the fully qualified name of the data source class. Please refer to your DB manual for details about the supported data sources and their attributes.

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