FSBackend

• FsStateBackend中createKeyedStateBackend是创建了HeapKeyedStateBackend
• FsStateBackend中createOperatorStateBackend是创建了DefaultOperatorStateBackend
• DefaultOperatorStateBackend创建了PartitionableListState， 是State的子类

public interface StateBackend extends java.io.Serializable {default String getName() {return this.getClass().getSimpleName();} CheckpointableKeyedStateBackend createKeyedStateBackend(Environment env,JobID jobID,String operatorIdentifier,TypeSerializer keySerializer,int numberOfKeyGroups,KeyGroupRange keyGroupRange,TaskKvStateRegistry kvStateRegistry,TtlTimeProvider ttlTimeProvider,MetricGroup metricGroup,@Nonnull Collection stateHandles,CloseableRegistry cancelStreamRegistry)throws Exception;OperatorStateBackend createOperatorStateBackend(Environment env,String operatorIdentifier,@Nonnull Collection stateHandles,CloseableRegistry cancelStreamRegistry)throws Exception;/** Whether the state backend uses Flink's managed memory. */default boolean useManagedMemory() {return false;}}

public class FsStateBackend extends AbstractFileStateBackend implements ConfigurableStateBackend {public CheckpointStorageAccess createCheckpointStorage(JobID jobId) throws IOException {checkNotNull(jobId, "jobId");return new FsCheckpointStorageAccess(getCheckpointPath(),getSavepointPath(),jobId,getMinFileSizeThreshold(),getWriteBufferSize());}public  AbstractKeyedStateBackend createKeyedStateBackend(Environment env,JobID jobID,String operatorIdentifier,TypeSerializer keySerializer,int numberOfKeyGroups,KeyGroupRange keyGroupRange,TaskKvStateRegistry kvStateRegistry,TtlTimeProvider ttlTimeProvider,MetricGroup metricGroup,@Nonnull Collection stateHandles,CloseableRegistry cancelStreamRegistry)throws BackendBuildingException {TaskStateManager taskStateManager = env.getTaskStateManager();LocalRecoveryConfig localRecoveryConfig = taskStateManager.createLocalRecoveryConfig();HeapPriorityQueueSetFactory priorityQueueSetFactory =new HeapPriorityQueueSetFactory(keyGroupRange, numberOfKeyGroups, 128);LatencyTrackingStateConfig latencyTrackingStateConfig =latencyTrackingConfigBuilder.setMetricGroup(metricGroup).build();return new HeapKeyedStateBackendBuilder<>( //这里是HeapKeyedStateBackendBuilderkvStateRegistry,keySerializer,env.getUserCodeClassLoader().asClassLoader(),numberOfKeyGroups,keyGroupRange,env.getExecutionConfig(),ttlTimeProvider,latencyTrackingStateConfig,stateHandles,AbstractStateBackend.getCompressionDecorator(env.getExecutionConfig()),localRecoveryConfig,priorityQueueSetFactory,isUsingAsynchronousSnapshots(),cancelStreamRegistry).build();}@Overridepublic OperatorStateBackend createOperatorStateBackend(Environment env,String operatorIdentifier,@Nonnull Collection stateHandles,CloseableRegistry cancelStreamRegistry)throws BackendBuildingException {return new DefaultOperatorStateBackendBuilder(  //这里是DefaultOperatorStateBackendBuilderenv.getUserCodeClassLoader().asClassLoader(),env.getExecutionConfig(),isUsingAsynchronousSnapshots(),stateHandles,cancelStreamRegistry).build();}
}

memory backend

• MemoryStateBackend中createOperatorStateBackend是创建了DefaultOperatorStateBackend
• MemoryStateBackend中createKeyedStateBackend是创建了HeapKeyedStateBackendBackend
• 最终调用了HeapMapState::Create创建state

flink checkpoint

参考资料

https://www.jianshu.com/p/569a7e67c1b3
https://blog.csdn.net/u010942041/article/details/114944767
https://cloud.tencent.com/developer/article/1792720
https://blog.51cto.com/dataclub/5351042
https://www.cnblogs.com/lighten/p/13234350.html
https://cloud.tencent.com/developer/article/1765572
https://blog.csdn.net/m0_63475429/article/details/127417649
https://blog.csdn.net/Direction_Wind/article/details/125646616