get_versions()¶

Returns all available versions of the plugin. Depending on the plugin, this version may map directly to the HDFS version, or it may not; check your plugin’s documentation. It is responsibility of the plugin to make sure that all required images for each hadoop version are available, as well as configs and whatever else that plugin needs to create the Hadoop cluster.

Returns: list of strings representing plugin versions

Example return value: [“1.2.1”, “2.3.0”, “2.4.1”]

get_configs( hadoop_version )¶

Lists all configs supported by the plugin with descriptions, defaults, and targets for which this config is applicable.

Returns: list of configs

Example return value: ((“JobTracker heap size”, “JobTracker heap size, in MB”, “int”, “512”, “mapreduce”, “node”, True, 1))

get_node_processes( hadoop_version )¶

Returns all supported services and node processes for a given Hadoop version. Each node process belongs to a single service and that relationship is reflected in the returned dict object. See example for details.

Returns: dictionary having entries (service -> list of processes)

Example return value: {“mapreduce”: [“tasktracker”, “jobtracker”], “hdfs”: [“datanode”, “namenode”]}

get_required_image_tags( hadoop_version )¶

Lists tags that should be added to OpenStack Image via Image Registry. Tags are used to filter Images by plugin and hadoop version.

Returns: list of tags

Example return value: [“tag1”, “some_other_tag”, …]

validate( cluster )¶

Validates a given cluster object. Raises a SaharaException with a meaningful message in the case of validation failure.

Returns: None

Example exception: <NotSingleNameNodeException {code=’NOT_SINGLE_NAME_NODE’, message=’Hadoop cluster should contain only 1 NameNode instance. Actual NN count is 2’ }>

validate_scaling( cluster, existing, additional )¶

To be improved.

Validates a given cluster before scaling operation.

Returns: list of validation_errors

update_infra( cluster )¶

This method is no longer used now that Sahara utilizes Heat for OpenStack resource provisioning, and is not currently utilized by any plugin.

Returns: None

configure_cluster( cluster )¶

Configures cluster on the VMs provisioned by sahara. In this function the plugin should perform all actions like adjusting OS, installing required packages (including Hadoop, if needed), configuring Hadoop, etc.

Returns: None

start_cluster( cluster )¶

Start already configured cluster. This method is guaranteed to be called only on a cluster which was already prepared with configure_cluster(…) call.

Returns: None

scale_cluster( cluster, instances )¶

Scale an existing cluster with additional instances. The instances argument is a list of ready-to-configure instances. Plugin should do all configuration operations in this method and start all services on those instances.

Returns: None

get_edp_engine( cluster, job_type )¶

Returns an EDP job engine object that supports the specified job_type on the given cluster, or None if there is no support. The EDP job engine object returned must implement the interface described in Elastic Data Processing (EDP) SPI. The job_type is a String matching one of the job types listed in Job Types.

Returns: an EDP job engine object or None

decommission_nodes( cluster, instances )¶

Scale cluster down by removing a list of instances. The plugin should stop services on the provided list of instances. The plugin also may need to update some configurations on other instances when nodes are removed; if so, this method must perform that reconfiguration.

Returns: None

on_terminate_cluster( cluster )¶

When user terminates cluster, sahara simply shuts down all the cluster VMs. This method is guaranteed to be invoked before that, allowing the plugin to do some clean-up.

Returns: None

get_open_ports( node_group )¶

When user requests sahara to automatically create a security group for the node group (auto_security_group property set to True), sahara will call this plugin method to get a list of ports that need to be opened.

Returns: list of ports to be open in auto security group for the given node group

get_edp_job_types( versions )¶

Optional method, which provides the ability to see all supported job types for specified plugin versions.

Returns: dict with supported job types for specified versions of plugin

recommend_configs( self, cluster, scaling=False )¶

Optional method, which provides recommendations for cluster configuration before creating/scaling operation.

get_image_arguments( self, hadoop_version ):¶

Optional method, which gets the argument set taken by the plugin’s image generator, or NotImplemented if the plugin does not provide image generation support. See Image Generation.

Returns: A sequence with items of type sahara.plugins.images.ImageArgument.

pack_image( self, hadoop_version, remote, reconcile=True, … ):¶

Optional method which packs an image for registration in Glance and use by Sahara. This method is called from the image generation CLI rather than from the Sahara api or engine service. See Image Generation.

Returns: None (modifies the image pointed to by the remote in-place.)

validate_images( self, cluster, reconcile=True, image_arguments=None ):¶

Validates the image to be used to create a cluster, to ensure that it meets the specifications of the plugin. See Image Generation.

Returns: None; may raise a sahara.plugins.exceptions.ImageValidationError