applications • It keeps metadata about application execution, such as pointers to completed checkpoints. • A high-availability mode migrates the responsibility and metadata for a job to another JobManager consensus services, e.g. leader election • The JobManager writes the JobGraph and all required metadata, such as the application’s JAR file, into a remote persistent storage system • Zookeeper also restore, reads are sequential within each key-group, and often across multiple key-groups • The metadata of key-group-to-subtask assignments are small. No need to maintain explicit lists of key-groups

the elements of the window, and a Collector to emit results. • A Context gives access to the metadata of the window (start and end timestamps in the case of a time window), the current processing Exception; public abstract class Context implements Serializable { // Returns the metadata of the window public abstract W window(); // Returns the current processing time

memory is dominated by the metaspace, the size of which is unlimited by default and holds class metadata as well as static content. There is a JIRA Ticket6 to limit the size to 250 megabyte by default

PartitionOBucket级C 并DMerge-On-Rea- Mkh取 支持I量P取便于进一 步数RTransform I量h Apache Iceberg asic Data Metadata Database Table Partition Spec Manifest File TableMetadata Snapshot Current Table Version