spark-webui-BlockStatusListener.adoc

BlockStatusListener Spark Listener

BlockStatusListener is a SparkListener that tracks BlockManagers and the blocks for Storage tab in web UI.

Table 1. BlockStatusListener Registries

Registry	Description
blockManagers	The lookup table for a collection of BlockId and BlockUIData per BlockManagerId.

Caution

FIXME When are the events posted?

Table 2. BlockStatusListener Event Handlers

Event Handler	Description
onBlockManagerAdded	Registers a BlockManager in blockManagers internal registry (with no blocks).
onBlockManagerRemoved	Removes a BlockManager from blockManagers internal registry.
onBlockUpdated	Puts an updated BlockUIData for BlockId for BlockManagerId in blockManagers internal registry. Ignores updates for unregistered BlockManagers or non-StreamBlockIds. For invalid StorageLevels (i.e. they do not use a memory or a disk or no replication) the block is removed.