Uses of Class
org.apache.hadoop.yarn.exceptions.YarnException

Packages that use YarnException

Package	Description
org.apache.hadoop.yarn.api
org.apache.hadoop.yarn.applications.distributedshell	Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.
org.apache.hadoop.yarn.client.api
org.apache.hadoop.yarn.client.api.async
org.apache.hadoop.yarn.exceptions
org.apache.hadoop.yarn.service.client	Package org.apache.hadoop.yarn.service.client contains classes for YARN Services Client API.
org.apache.hadoop.yarn.util

Uses of YarnException in org.apache.hadoop.yarn.api

Methods in org.apache.hadoop.yarn.api that throw YarnException

Modifier and Type	Method and Description
AllocateResponse	ApplicationMasterProtocol.allocate(AllocateRequest request) The main interface between an ApplicationMaster and the ResourceManager.
CommitResponse	ContainerManagementProtocol.commitLastReInitialization(ContainerId containerId) Commit the Last ReInitialization if possible.
ReservationDeleteResponse	ApplicationClientProtocol.deleteReservation(ReservationDeleteRequest request) The interface used by clients to remove an existing Reservation.
FailApplicationAttemptResponse	ApplicationClientProtocol.failApplicationAttempt(FailApplicationAttemptRequest request) The interface used by clients to request the ResourceManager to fail an application attempt.
FinishApplicationMasterResponse	ApplicationMasterProtocol.finishApplicationMaster(FinishApplicationMasterRequest request) The interface used by an ApplicationMaster to notify the ResourceManager about its completion (success or failed).
KillApplicationResponse	ApplicationClientProtocol.forceKillApplication(KillApplicationRequest request) The interface used by clients to request the ResourceManager to abort submitted application.
GetClusterMetricsResponse	ApplicationClientProtocol.getClusterMetrics(GetClusterMetricsRequest request) The interface used by clients to get metrics about the cluster from the ResourceManager.
GetClusterNodeLabelsResponse	ApplicationClientProtocol.getClusterNodeLabels(GetClusterNodeLabelsRequest request) The interface used by client to get node labels in the cluster
GetClusterNodesResponse	ApplicationClientProtocol.getClusterNodes(GetClusterNodesRequest request) The interface used by clients to get a report of all nodes in the cluster from the ResourceManager.
GetContainerStatusesResponse	ContainerManagementProtocol.getContainerStatuses(GetContainerStatusesRequest request) The API used by the ApplicationMaster to request for current statuses of Containers from the NodeManager.
org.apache.hadoop.yarn.api.protocolrecords.GetLabelsToNodesResponse	ApplicationClientProtocol.getLabelsToNodes(org.apache.hadoop.yarn.api.protocolrecords.GetLabelsToNodesRequest request) The interface used by client to get labels to nodes mappings in existing cluster
GetNewApplicationResponse	ApplicationClientProtocol.getNewApplication(GetNewApplicationRequest request) The interface used by clients to obtain a new ApplicationId for submitting new applications.
GetNewReservationResponse	ApplicationClientProtocol.getNewReservation(GetNewReservationRequest request) The interface used by clients to obtain a new ReservationId for submitting new reservations.
org.apache.hadoop.yarn.api.protocolrecords.GetNodesToLabelsResponse	ApplicationClientProtocol.getNodeToLabels(org.apache.hadoop.yarn.api.protocolrecords.GetNodesToLabelsRequest request) The interface used by client to get node to labels mappings in existing cluster
GetQueueInfoResponse	ApplicationClientProtocol.getQueueInfo(GetQueueInfoRequest request) The interface used by clients to get information about queues from the ResourceManager.
GetQueueUserAclsInfoResponse	ApplicationClientProtocol.getQueueUserAcls(GetQueueUserAclsInfoRequest request) The interface used by clients to get information about queue acls for current user from the ResourceManager.
GetResourceProfileResponse	ApplicationClientProtocol.getResourceProfile(GetResourceProfileRequest request) The interface to get the details for a specific resource profile.
GetAllResourceProfilesResponse	ApplicationClientProtocol.getResourceProfiles(GetAllResourceProfilesRequest request) The interface used by clients to get all the resource profiles that are available on the ResourceManager.
GetAllResourceTypeInfoResponse	ApplicationClientProtocol.getResourceTypeInfo(GetAllResourceTypeInfoRequest request) The interface to get the details for a specific resource profile.
IncreaseContainersResourceResponse	ContainerManagementProtocol.increaseContainersResource(IncreaseContainersResourceRequest request) Deprecated.
ReservationListResponse	ApplicationClientProtocol.listReservations(ReservationListRequest request) The interface used by clients to get the list of reservations in a plan.
ResourceLocalizationResponse	ContainerManagementProtocol.localize(ResourceLocalizationRequest request) Localize resources required by the container.
MoveApplicationAcrossQueuesResponse	ApplicationClientProtocol.moveApplicationAcrossQueues(MoveApplicationAcrossQueuesRequest request) Move an application to a new queue.
RegisterApplicationMasterResponse	ApplicationMasterProtocol.registerApplicationMaster(RegisterApplicationMasterRequest request) The interface used by a new ApplicationMaster to register with the ResourceManager.
ReInitializeContainerResponse	ContainerManagementProtocol.reInitializeContainer(ReInitializeContainerRequest request) ReInitialize the Container with a new Launch Context.
ReleaseSharedCacheResourceResponse	ClientSCMProtocol.release(ReleaseSharedCacheResourceRequest request) The interface used by clients to release a resource with the SharedCacheManager. This method is called once an application is no longer using a claimed resource in the shared cache.
RestartContainerResponse	ContainerManagementProtocol.restartContainer(ContainerId containerId) Restart the container.
RollbackResponse	ContainerManagementProtocol.rollbackLastReInitialization(ContainerId containerId) Rollback the Last ReInitialization if possible.
SignalContainerResponse	ApplicationClientProtocol.signalToContainer(SignalContainerRequest request) The interface used by clients to request the ResourceManager to signal a container.
SignalContainerResponse	ContainerManagementProtocol.signalToContainer(SignalContainerRequest request)
StartContainersResponse	ContainerManagementProtocol.startContainers(StartContainersRequest request) The ApplicationMaster provides a list of StartContainerRequests to a NodeManager to start Containers allocated to it using this interface.
StopContainersResponse	ContainerManagementProtocol.stopContainers(StopContainersRequest request) The ApplicationMaster requests a NodeManager to stop a list of Containers allocated to it using this interface.
SubmitApplicationResponse	ApplicationClientProtocol.submitApplication(SubmitApplicationRequest request) The interface used by clients to submit a new application to the ResourceManager.
ReservationSubmissionResponse	ApplicationClientProtocol.submitReservation(ReservationSubmissionRequest request) The interface used by clients to submit a new reservation to the ResourceManager.
UpdateApplicationPriorityResponse	ApplicationClientProtocol.updateApplicationPriority(UpdateApplicationPriorityRequest request) The interface used by client to set priority of an application.
UpdateApplicationTimeoutsResponse	ApplicationClientProtocol.updateApplicationTimeouts(UpdateApplicationTimeoutsRequest request) The interface used by client to set ApplicationTimeouts of an application.
ContainerUpdateResponse	ContainerManagementProtocol.updateContainer(ContainerUpdateRequest request) The API used by the ApplicationMaster to request for resource update of running containers on the NodeManager.
ReservationUpdateResponse	ApplicationClientProtocol.updateReservation(ReservationUpdateRequest request) The interface used by clients to update an existing Reservation.
UseSharedCacheResourceResponse	ClientSCMProtocol.use(UseSharedCacheResourceRequest request) The interface used by clients to claim a resource with the SharedCacheManager. The client uses a checksum to identify the resource and an ApplicationId to identify which application will be using the resource.

Uses of YarnException in org.apache.hadoop.yarn.applications.distributedshell

Methods in org.apache.hadoop.yarn.applications.distributedshell that throw YarnException

Modifier and Type	Method and Description
void	ApplicationMaster.run() Main run function for the application master
boolean	Client.run() Main run function for the client

Uses of YarnException in org.apache.hadoop.yarn.client.api

Methods in org.apache.hadoop.yarn.client.api that throw YarnException

Modifier and Type	Method and Description
abstract int	AppAdminClient.actionCancelUpgrade(String appName) Cancels the upgrade of the service.
abstract int	AppAdminClient.actionCleanUp(String appName, String userName) Operation to be performed by the RM after an application has completed.
abstract int	AppAdminClient.actionDestroy(String appName) Remove the specification and all application data for a YARN application.
abstract int	AppAdminClient.actionFlex(String appName, Map<String,String> componentCounts) Change the number of running containers for a component of a YARN application / long-running service.
abstract int	AppAdminClient.actionLaunch(String fileName, String appName, Long lifetime, String queue) Launch a new YARN application.
abstract int	AppAdminClient.actionSave(String fileName, String appName, Long lifetime, String queue) Save the specification for a YARN application / long-running service.
abstract int	AppAdminClient.actionStart(String appName) Start a YARN application from a previously saved specification.
abstract int	AppAdminClient.actionStop(String appName) Stop a YARN application (attempt to stop gracefully before killing the application).
abstract int	AppAdminClient.actionUpgradeComponents(String appName, List<String> components) Upgrade components of a long running service.
abstract int	AppAdminClient.actionUpgradeExpress(String appName, File fileName) Express upgrade a long running service.
abstract int	AppAdminClient.actionUpgradeInstances(String appName, List<String> componentInstances) Upgrade component instances of a long running service.
abstract AllocateResponse	AMRMClient.allocate(float progressIndicator) Request additional containers and receive new container allocations.
abstract void	TimelineClient.cancelDelegationToken(Token<TimelineDelegationTokenIdentifier> timelineDT) Cancel a timeline delegation token.
abstract void	NMClient.commitLastReInitialization(ContainerId containerId) Commit last reInitialization of the specified container.
abstract YarnClientApplication	YarnClient.createApplication() Obtain a YarnClientApplication for a new application, which in turn contains the ApplicationSubmissionContext and GetNewApplicationResponse objects.
abstract GetNewReservationResponse	YarnClient.createReservation() Obtain a GetNewReservationResponse for a new reservation, which contains the ReservationId object.
abstract ReservationDeleteResponse	YarnClient.deleteReservation(ReservationDeleteRequest request) The interface used by clients to remove an existing Reservation.
abstract int	AppAdminClient.enableFastLaunch(String destinationFolder) Upload AM dependencies to HDFS.
abstract void	YarnClient.failApplicationAttempt(ApplicationAttemptId applicationAttemptId) Fail an application attempt identified by given ID.
abstract List<QueueInfo>	YarnClient.getAllQueues() Get information (QueueInfo) about all queues, recursively if there is a hierarchy
abstract Token<AMRMTokenIdentifier>	YarnClient.getAMRMToken(ApplicationId appId) Get the AMRM token of the application.
abstract ApplicationAttemptReport	YarnClient.getApplicationAttemptReport(ApplicationAttemptId applicationAttemptId) Get a report of the given ApplicationAttempt.
abstract ApplicationAttemptReport	AHSClient.getApplicationAttemptReport(ApplicationAttemptId applicationAttemptId) Get a report of the given ApplicationAttempt.
abstract List<ApplicationAttemptReport>	YarnClient.getApplicationAttempts(ApplicationId applicationId) Get a report of all (ApplicationAttempts) of Application in the cluster.
abstract List<ApplicationAttemptReport>	AHSClient.getApplicationAttempts(ApplicationId applicationId) Get a report of all (ApplicationAttempts) of Application in the cluster.
abstract ApplicationReport	YarnClient.getApplicationReport(ApplicationId appId) Get a report of the given Application.
abstract ApplicationReport	AHSClient.getApplicationReport(ApplicationId appId) Get a report of the given Application.
abstract List<ApplicationReport>	YarnClient.getApplications() Get a report (ApplicationReport) of all Applications in the cluster.
abstract List<ApplicationReport>	AHSClient.getApplications() Get a report (ApplicationReport) of all Applications in the cluster.
abstract List<ApplicationReport>	YarnClient.getApplications(EnumSet<YarnApplicationState> applicationStates) Get a report (ApplicationReport) of Applications matching the given application states in the cluster.
List<ApplicationReport>	YarnClient.getApplications(GetApplicationsRequest request) Get a list of ApplicationReports that match the given GetApplicationsRequest.
abstract List<ApplicationReport>	YarnClient.getApplications(Set<String> applicationTypes) Get a report (ApplicationReport) of Applications matching the given application types in the cluster.
abstract List<ApplicationReport>	YarnClient.getApplications(Set<String> applicationTypes, EnumSet<YarnApplicationState> applicationStates) Get a report (ApplicationReport) of Applications matching the given application types and application states in the cluster.
abstract List<ApplicationReport>	YarnClient.getApplications(Set<String> applicationTypes, EnumSet<YarnApplicationState> applicationStates, Set<String> applicationTags) Get a report (ApplicationReport) of Applications matching the given application types, application states and application tags in the cluster.
abstract List<ApplicationReport>	YarnClient.getApplications(Set<String> queues, Set<String> users, Set<String> applicationTypes, EnumSet<YarnApplicationState> applicationStates) Get a report (ApplicationReport) of Applications matching the given users, queues, application types and application states in the cluster.
abstract List<QueueInfo>	YarnClient.getChildQueueInfos(String parent) Get information (QueueInfo) about all the immediate children queues of the given queue
abstract List<NodeLabel>	YarnClient.getClusterNodeLabels() The interface used by client to get node labels in the cluster
abstract ContainerReport	YarnClient.getContainerReport(ContainerId containerId) Get a report of the given Container.
abstract ContainerReport	AHSClient.getContainerReport(ContainerId containerId) Get a report of the given Container.
abstract List<ContainerReport>	YarnClient.getContainers(ApplicationAttemptId applicationAttemptId) Get a report of all (Containers) of ApplicationAttempt in the cluster.
abstract List<ContainerReport>	AHSClient.getContainers(ApplicationAttemptId applicationAttemptId) Get a report of all (Containers) of ApplicationAttempt in the cluster.
abstract ContainerStatus	NMClient.getContainerStatus(ContainerId containerId, NodeId nodeId) Query the status of a container.
abstract Token<TimelineDelegationTokenIdentifier>	TimelineClient.getDelegationToken(String renewer) Get a delegation token so as to be able to talk to the timeline server in a secure way.
abstract String	AppAdminClient.getInstances(String appName, List<String> components, String version, List<String> containerStates)
abstract Map<String,Set<NodeId>>	YarnClient.getLabelsToNodes() The interface used by client to get labels to nodes mapping in existing cluster
abstract Map<String,Set<NodeId>>	YarnClient.getLabelsToNodes(Set<String> labels) The interface used by client to get labels to nodes mapping for specified labels in existing cluster
abstract List<NodeReport>	YarnClient.getNodeReports(NodeState... states) Get a report of nodes (NodeReport) in the cluster.
abstract Map<NodeId,Set<String>>	YarnClient.getNodeToLabels() The interface used by client to get node to labels mappings in existing cluster
abstract List<QueueUserACLInfo>	YarnClient.getQueueAclsInfo() Get information about acls for current user on all the existing queues.
abstract QueueInfo	YarnClient.getQueueInfo(String queueName) Get information (QueueInfo) about a given queue.
abstract Resource	YarnClient.getResourceProfile(String profile) Get the details of a specific resource profile from the RM.
abstract Map<String,Resource>	YarnClient.getResourceProfiles() Get the resource profiles available in the RM.
abstract List<org.apache.hadoop.yarn.api.records.ResourceTypeInfo>	YarnClient.getResourceTypeInfo() Get available resource types supported by RM.
abstract Token	YarnClient.getRMDelegationToken(Text renewer) Get a delegation token so as to be able to talk to YARN using those tokens.
abstract List<QueueInfo>	YarnClient.getRootQueueInfos() Get information (QueueInfo) about top level queues.
abstract String	AppAdminClient.getStatusString(String appIdOrName) Get detailed app specific status string for a YARN application.
abstract YarnClusterMetrics	YarnClient.getYarnClusterMetrics() Get metrics (YarnClusterMetrics) about the cluster.
abstract void	NMClient.increaseContainerResource(Container container) Deprecated.
abstract int	AppAdminClient.initiateUpgrade(String appName, String fileName, boolean autoFinalize) Initiate upgrade of a long running service.
abstract void	YarnClient.killApplication(ApplicationId applicationId) Kill an application identified by given ID.
abstract void	YarnClient.killApplication(ApplicationId applicationId, String diagnostics) Kill an application identified by given ID.
abstract ReservationListResponse	YarnClient.listReservations(ReservationListRequest request) The interface used by clients to get the list of reservations in a plan.
abstract void	YarnClient.moveApplicationAcrossQueues(ApplicationId appId, String queue) Attempts to move the given application to the given queue.
abstract void	TimelineClient.putDomain(ApplicationAttemptId appAttemptId, TimelineDomain domain) Send the information of a domain to the timeline server.
abstract void	TimelineClient.putDomain(TimelineDomain domain) Send the information of a domain to the timeline server.
abstract TimelinePutResponse	TimelineClient.putEntities(ApplicationAttemptId appAttemptId, TimelineEntityGroupId groupId, TimelineEntity... entities) Send the information of a number of conceptual entities to the timeline server.
abstract TimelinePutResponse	TimelineClient.putEntities(TimelineEntity... entities) Send the information of a number of conceptual entities to the timeline server.
abstract RegisterApplicationMasterResponse	AMRMClient.registerApplicationMaster(String appHostName, int appHostPort, String appTrackingUrl) Register the application master.
RegisterApplicationMasterResponse	AMRMClient.registerApplicationMaster(String appHostName, int appHostPort, String appTrackingUrl, Map<Set<String>,PlacementConstraint> placementConstraints) Register the application master.
abstract void	NMClient.reInitializeContainer(ContainerId containerId, ContainerLaunchContext containerLaunchContex, boolean autoCommit) Re-Initialize the Container.
abstract void	SharedCacheClient.release(ApplicationId applicationId, String resourceKey) The method to release a resource with the SharedCacheManager. This method is called once an application is no longer using a claimed resource in the shared cache.
abstract long	TimelineClient.renewDelegationToken(Token<TimelineDelegationTokenIdentifier> timelineDT) Renew a timeline delegation token.
abstract void	NMClient.restartContainer(ContainerId containerId) Restart the specified container.
abstract void	NMClient.rollbackLastReInitialization(ContainerId containerId) Rollback last reInitialization of the specified container.
abstract void	YarnClient.signalToContainer(ContainerId containerId, SignalContainerCommand command) Signal a container identified by given ID.
abstract Map<String,ByteBuffer>	NMClient.startContainer(Container container, ContainerLaunchContext containerLaunchContext) Start an allocated container.
abstract void	NMClient.stopContainer(ContainerId containerId, NodeId nodeId) Stop an started container.
abstract ApplicationId	YarnClient.submitApplication(ApplicationSubmissionContext appContext) Submit a new application to YARN. It is a blocking call - it will not return ApplicationId until the submitted application is submitted successfully and accepted by the ResourceManager.
abstract ReservationSubmissionResponse	YarnClient.submitReservation(ReservationSubmissionRequest request) The interface used by clients to submit a new reservation to the ResourceManager.
abstract void	AMRMClient.unregisterApplicationMaster(FinalApplicationStatus appStatus, String appMessage, String appTrackingUrl) Unregister the application master.
abstract Priority	YarnClient.updateApplicationPriority(ApplicationId applicationId, Priority priority) The interface used by client to set priority of an application
UpdateApplicationTimeoutsResponse	YarnClient.updateApplicationTimeouts(UpdateApplicationTimeoutsRequest request)
abstract void	NMClient.updateContainerResource(Container container) Update the resources of a container.
abstract ReservationUpdateResponse	YarnClient.updateReservation(ReservationUpdateRequest request) The interface used by clients to update an existing Reservation.
abstract URL	SharedCacheClient.use(ApplicationId applicationId, String resourceKey) The method to claim a resource with the SharedCacheManager. The client uses a checksum to identify the resource and an ApplicationId to identify which application will be using the resource.

Uses of YarnException in org.apache.hadoop.yarn.client.api.async

Methods in org.apache.hadoop.yarn.client.api.async that throw YarnException

Modifier and Type	Method and Description
abstract RegisterApplicationMasterResponse	AMRMClientAsync.registerApplicationMaster(String appHostName, int appHostPort, String appTrackingUrl) Registers this application master with the resource manager.
RegisterApplicationMasterResponse	AMRMClientAsync.registerApplicationMaster(String appHostName, int appHostPort, String appTrackingUrl, Map<Set<String>,PlacementConstraint> placementConstraints) Register the application master.
void	AMRMClientAsync.registerTimelineV2Client(org.apache.hadoop.yarn.client.api.TimelineV2Client timelineClient) Register TimelineClient to AMRMClient.
abstract void	AMRMClientAsync.unregisterApplicationMaster(FinalApplicationStatus appStatus, String appMessage, String appTrackingUrl) Unregister the application master.

Uses of YarnException in org.apache.hadoop.yarn.exceptions

Subclasses of YarnException in org.apache.hadoop.yarn.exceptions

Modifier and Type	Class and Description
class	ApplicationAttemptNotFoundException This exception is thrown on (GetApplicationAttemptReportRequest) API when the Application Attempt doesn't exist in Application History Server or ApplicationMasterProtocol.allocate(AllocateRequest) if application doesn't exist in RM.
class	ApplicationIdNotProvidedException Exception to be thrown when Client submit an application without providing ApplicationId in ApplicationSubmissionContext.
class	ApplicationNotFoundException This exception is thrown on (GetApplicationReportRequest) API when the Application doesn't exist in RM and AHS
class	ConfigurationException This exception is thrown on unrecoverable configuration errors.
class	ContainerNotFoundException This exception is thrown on (GetContainerReportRequest) API when the container doesn't exist in AHS
class	YARNFeatureNotEnabledException This exception is thrown when a feature is being used which is not enabled yet.

Uses of YarnException in org.apache.hadoop.yarn.service.client

Methods in org.apache.hadoop.yarn.service.client with annotations of type with type parameters of type that implement declared as with annotations of type with type parameters of type with annotations of type with annotations of type with type parameters of type that return that return types with arguments of type with parameters of type with type arguments of type that throw with annotations of type with annotations of type with parameters of type with type arguments of type that throw YarnException

Modifier and Type	Method and Description
int	ServiceClient.actionBuild(Service service)
int	ServiceClient.actionCancelUpgrade(String appName)
int	ServiceClient.actionCleanUp(String appName, String userName)
ApplicationId	ServiceClient.actionCreate(Service service)
int	ServiceClient.actionDestroy(String serviceName)
int	ServiceClient.actionFlex(String serviceName, Map<String,String> componentCountStrings)
int	ServiceClient.actionLaunch(String fileName, String serviceName, Long lifetime, String queue)
int	ServiceClient.actionSave(String fileName, String serviceName, Long lifetime, String queue)
int	ServiceClient.actionStart(String serviceName)
ApplicationId	ServiceClient.actionStartAndGetId(String serviceName)
int	ServiceClient.actionStop(String serviceName)
int	ServiceClient.actionStop(String serviceName, boolean waitForAppStopped)
int	ServiceClient.actionUpgrade(Service service, List<Container> compInstances)
int	ServiceClient.actionUpgradeComponents(String appName, List<String> components)
int	ServiceClient.actionUpgradeExpress(Service service)
int	ServiceClient.actionUpgradeExpress(String appName, File path)
int	ServiceClient.actionUpgradeInstances(String appName, List<String> componentInstances)
protected Path	ServiceClient.addJarResource(String serviceName, Map<String,LocalResource> localResources)
protected org.apache.hadoop.yarn.service.ClientAMProtocol	ServiceClient.createAMProxy(String serviceName, ApplicationReport appReport)
int	ServiceClient.enableFastLaunch(String destinationFolder)
Map<String,Long>	ServiceClient.flexByRestService(String serviceName, Map<String,Long> componentCounts)
ApplicationId	ServiceClient.getAppId(String serviceName)
Container[]	ServiceClient.getContainers(String appName, List<String> components, String version, List<ContainerState> containerStates)
String	ServiceClient.getInstances(String appName, List<String> components, String version, List<String> containerStates)
Service	ServiceClient.getStatus(String serviceName)
String	ServiceClient.getStatusString(String appIdOrName)
int	ServiceClient.initiateUpgrade(Service service)
int	ServiceClient.initiateUpgrade(String appName, String fileName, boolean autoFinalize)
Service	ServiceClient.loadAppJsonFromLocalFS(String fileName, String serviceName, Long lifetime, String queue)
String	ServiceClient.updateLifetime(String serviceName, long lifetime)

Uses of YarnException in org.apache.hadoop.yarn.util

Methods in org.apache.hadoop.yarn.util that throw YarnException

Modifier and Type	Method and Description
void	ResourceCalculatorProcessTree.initialize() Initialize the object.