THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
Status
| Discussion thread | - |
|---|---|
| Vote thread | - |
| JIRA |
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| Release | - |
Motivation
Flink ETL job consumes data from Source Table and produces result to Sink Table after computation. Source Table creates relationship with Sink Table through Flink ETL job. Flink needs a mechanism for users to report these relationships to other systems by customized listeners, such as meta system Datahub [1], Atlas [2] and meta store we mentioned in FLIP-276 [3].
This FLIP aims to introduce listeners for users in Flink, then users can implement them to report the progress of jobs and meta data to external system. Flink SQL and Table api are supported in the first stage, and DataStream will be consider in the future. The main information is as follows
1. Source and Sink information, such as table name, fields, partition keys, primary keys, watermarks, configurations
2. Job information, such as job id/name, execution mode, scheduler type, logical plan
3. Relationship between Source/Sink and jobs, such as source and sink tables for job, fields relationships in job and vertex
4. Job execution information, such as job status changes, vertex status changes, checkpoints
Public Interfaces
JobDeploymentListener
JobDeploymentListener is used to receive events of ddl, job submission, it only supports sql/table jobs in this FLIP.
/**
* Job creation listener, client will create specific event and notify this listener.
*/
@PublicEvolving
public interface JobDeploymentListener {
/* Start the listener. */
void start(Map<String, String> config);
/* Event fired after a catalog has been registered. */
void onRegisterCatalog(CatalogEvent catalogEvent);
void onUnregisterCatalog(UnregisterCatalogEvent catalogEvent);
/* Event fired after a database has been created. */
void onCreateDatabase(DatabaseEvent databaseEvent);
/* Event fired after a database has been dropped. */
void onDropDatabase(DatabaseEvent databaseEvent);
/* Event fired after a table has been created. */
void onCreateTable(CreateTableEvent tableEvent);
/* Event fired after a table has been changed. */
void onAlterTable(AlterTableEvent tableEvent);
/* Event fired after a table has been dropped. */
void onDropTable(DropTableEvent tableEvent);
/* Event fired before a job is submitted to do some validations. */
void onJobPreSubmission(JobSubmissionEvent submitEvent);
/* Event fired after a job is submitted. */
void onJobSubmission(JobSubmissionEvent submitEvent);
/* Event for catalog registration, provides catalog name, default database, database list and properties in the Catalog. */
@PublicEvolving
interface CatalogEvent {
String catalog();
Catalog catalog();
}
/* Event for catalog unregistration. */
@PublicEvolving
interface UnregisterCatalogEvent {
String catalog();
boolean ignoreIfNotExists();
}
/* Event for database creation, provides catalog name, database name, comment and properties of the database. */
@PublicEvolving
interface DatabaseEvent {
String catalog();
String name();
CatalogDatabase database();
boolean ignoreIfExists();
}
/* Event for dropping database. */
@PublicEvolving
interface DropDatabaseEvent {
String catalog();
String name();
boolean ignoreIfExists();
}
/* Table information event, provides column list, primary keys, partition keys, watermarks and properties in the table. The table can be source or sink. */
@PublicEvolving
interface TableEvent {
ObjectIdentifier identifier();
CatalogBaseTable table();
}
/* Event for table creation. */
@PublicEvolving
interface CreateTableEvent extends TableEvent {
boolean ignoreIfExists();
}
/* Event for altering table, provides all information in old table and new table. */
@PublicEvolving
interface AlterTableEvent extends TableEvent {
CreateTableEvent newTable();
boolean ignoreIfExists();
}
/* Event for dropping table. */
@PublicEvolving
interface DropTableEvent {
ObjectIdentifier identifier();
boolean ignoreIfExists();
}
/* Event for before and after job is submitted, provides source tables and sink tables. */
@PublicEvolving
interface JobSubmissionEvent {
JobID jobId();
String jobName();
List<TableEvent> sources();
List<TableEvent> sinks();
}
}
JobExecutionListener
Added JobExecutionListener listens to the status changes in the job. JobManager creates JobEvent for each status when it changes, and notify specific method in JobExecutionListener. Users can implement different listeners according to their needs, such as Datahub listener or Atlas listener.
/**
* When job status is changed in job manager, it will generate job event to notify job execution listener.
*/
@PublicEvolving
public interface JobExecutionListener extends AutoCloseable {
/* Start the listener with job config. */
void start(Map<String, String> config) throws Exception;
/* Event fired after job has been created. */
void onCreated(JobCreatedEvent createdEvent);
/* Event fired after job has beed finished. */
void onFinished(JobFinishedEvent finishedEvent);
/* Event fired after job has beed canceled. */
void onCanceled(JobCanceledEvent canceledEvent);
/* Event fired after job has beed failed. */
void onFailed(JobFailedEvent failedEvent);
/* Event fired after checkpoint has been started. */
void onCheckpointStarted(CheckpointEvent checkpointEvent);
/* Event fired after checkpoint has been completed. */
void onCheckpointCompleted(CheckpointEvent checkpointEvent);
/* Event fired after checkpoint has been aborted. */
void onCheckpointAborted(CheckpointEvent checkpointEvent);
/* Vertex in job plan, provides id, name, parallelism, input edges and output column names. */
@PublicEvolving
interface JobVertexInfo {
String id();
String name();
String operatorName();
String operatorDescription();
int parallelism();
String invokableClassName();
boolean supportsConcurrentExecutionAttempts();
List<JobEdgeInfo> inputs();
List<String> outputColumns();
}
/* Edge in job plan, provides source/target vertex, input columns, distribution, isBroadcast and isForward. */
@PublicEvolving
interface JobEdgeInfo {
JobVertexInfo source();
JobVertexInfo target();
/* Input column names of the edge. */
List<String> inputColumns();
String distribution();
String shipStrategyName();
boolean isBroadcast();
boolean isForward();
String preProcessingOperationName();
String operatorLevelCachingDescription();
}
/* Job scan source vertex, provides source table name, input table columns and source type. */
@PublicEvolving
interface JobScanSourceVertexInfo extends JobVertexInfo {
/* `Catalog.Database.Table` format name. */
String sourceName();
/* Values or Table. */
String type();
/* Columns from source table, detailed information such as column type is provided in {@Code JobCreationListener#onCreateTable}. */
List<String> columns();
/* Source config provides options in source such as source type. */
Map<String, String> config();
}
/* */
@PublicEvolving
interface JobSinkVertexInfo extends JobVertexInfo {
/* `Catalog.Database.Table` format name. */
String sinkName();
/* CollectSink or ModifySink. */
String type();
/* INSERT/UPDATE/DELETE. */
String modifyType();
/* APPEND/RETRACT/UPSERT. */
String updateMode();
/* Columns from sink table, detailed information such as column type is provided in {@Code JobCreationListener#onCreateTable}. */
List<String> columns();
boolean overwrite();
Map<String, String> staticPartitions();
Map<String, String> config();
}
/* Event for job status is changed. */
interface JobBaseEvent {
JobID jobId();
String jobName();
/* Scheduler type such as Default/Adaptive/AdaptiveBatch. */
String scheduler();
/* Job execution mode, PIPELINED/PIPELINED_FORCED/BATCH/BATCH_FORCED. */
ExecutionMode executionMode();
/* BATCH or STREAMING. */
String jobType();
/* Timestamp for current job status. */
long timestamp();
}
@PublicEvolving
interface JobLogicalPlanInfo {
/* Source list. */
List<JobSourceVertex> sources();
/* Sink list. */
List<JobSinkVertex> sinks();
List<JobVertexInfo> getVerticesSortedTopologicallyFromSources();
JobVertexInfo vertex(String id);
}
/* Event for job is created. */
@PublicEvolving
interface JobCreatedEvent extends JobBaseEvent {
JobLogicalPlanInfo plan();
}
/* Event for job is finished. */
@PublicEvolving
interface JobFinishedEvent extends JobBaseEvent { }
/* Event for job is canceled. */
@PublicEvolving
interface JobCanceledEvent extends JobBaseEvent { }
/* Event for job is failed. */
@PublicEvolving
interface JobFailedEvent extends JobBaseEvent {
Throwable exception();
}
/* Event for job checkpoint. */
@PublicEvolving
interface CheckpointEvent extends JobBaseEvent {
long checkpoint();
String externalSavepointLocation();
boolean isPeriodic;
long timestamp();
/* checkpoint or savepoint. */
String snapshotType();
Map<String, String> config();
}
}
Config Customized Listener
Users should add their listener to the classpath of client and flink cluster, and use the following options to add listeners
table.job.deployment.listeners: {job deployment listener class1},{job deployment listener class2}
jobmanager.execution.listeners: {job execution listener class1},{job execution listener class2}
Proposed Changes
Changes for JobDeploymentListener
TableEnvironmentImpl creates customized JobDeploymentListener according to the option table.job.deployment.listeners , and put the listener into CatalogManager and AbstractCatalog. When DDL related operations are executed in CatalogManager and AbstractCatalog , they should notify the listener.
TableEnvironmentImpl will submit the job after it is created, it notifies the listener before and after the job is submitted.
Changes for JobExecutionListener
Flink sql or table jobs are created from Planner which contains exec nodes, then it is converted to Operation , Transformation and StreamGraph. Finally, the jobs are submitted as JobGraph and job managers create ExecutionGraph from it. The operations of source/sink list are as follows.
SourceScan in Planner contains source information such as table name, fields and configurations. But these information is hidden in the Source which is an interface when the SourceScan is converted to Transformation. We should add source information in the conversion of SourceScan->Operation->Transformation->StreamNode.
Similar to sources, Sink and DataStreamSink contain sink information such as table names and configuration. We should add sink information in the conversion of Sink->Operation->Transformation->StreamNode, then we can add Map<JobVertexID, JobSinkVertexInfo> sources in JobGraph and ExecutionGraph too.
After completing the above changes, JobManager can create JobLogicalPlanInfo from JobGraph for JobExecutionListener . When the status of job is changed, DefaultExecutionGraph in JobManager will notify the listener. At the same time, this listener will also listen to the execution of checkpoint. When CheckpointCoordinator starts/completes/aborts a specific checkpoint, it will notify the listener too.
Plan For The Future
- We add column relationships between job vertex in JobLogicalPlanInfo, but it is not supported in Flink at present. We'd like to implement it in the next FLIP.
Source/Sink relationships for SQL/Table jobs are supported,
DataStreamjobs will be supported later.Currently we only supports scan source, lookup join source should be supported later.
Add Job vertex listener for batch mode, such as scheduling and execution status of vertex, execution status of subtask, etc.