Package io.debezium.connector.cassandra

Class CommitLogReadHandlerImpl

java.lang.Object

io.debezium.connector.cassandra.CommitLogReadHandlerImpl

All Implemented Interfaces:

org.apache.cassandra.db.commitlog.CommitLogReadHandler

public class CommitLogReadHandlerImpl
extends Object
implements org.apache.cassandra.db.commitlog.CommitLogReadHandler

Handler that implements CommitLogReadHandler interface provided by Cassandra source code. This handler implementation processes each Mutation and invokes one of the registered partition handler for each PartitionUpdate in the Mutation (a mutation could have multiple partitions if it is a batch update), which in turn makes one or more record via the RecordMaker and enqueue the record into the ChangeEventQueue.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	CommitLogReadHandlerImpl.PartitionType	A PartitionType represents the type of a PartitionUpdate.
(package private) static class	CommitLogReadHandlerImpl.RowType	A RowType represents different types of Row-level modifications in a Cassandra table.

Nested classes/interfaces inherited from interface org.apache.cassandra.db.commitlog.CommitLogReadHandler

org.apache.cassandra.db.commitlog.CommitLogReadHandler.CommitLogReadErrorReason, org.apache.cassandra.db.commitlog.CommitLogReadHandler.CommitLogReadException

Field Summary

Fields

Modifier and Type	Field	Description
private static org.slf4j.Logger	LOGGER
private static boolean	MARK_OFFSET
private CommitLogProcessorMetrics	metrics
private OffsetWriter	offsetWriter
private List<io.debezium.connector.base.ChangeEventQueue<Event>>	queues
private RecordMaker	recordMaker
private SchemaHolder	schemaHolder

Constructor Summary

Constructors

Constructor	Description
CommitLogReadHandlerImpl(SchemaHolder schemaHolder, List<io.debezium.connector.base.ChangeEventQueue<Event>> queues, OffsetWriter offsetWriter, RecordMaker recordMaker, CommitLogProcessorMetrics metrics)

Method Summary

Modifier and Type	Method	Description
private static List<Object>	getPartitionKeys(org.apache.cassandra.db.partitions.PartitionUpdate pu)	Given a PartitionUpdate, deserialize the partition key byte buffer into a list of partition key values.
void	handleMutation(org.apache.cassandra.db.Mutation mutation, int size, int entryLocation, org.apache.cassandra.db.commitlog.CommitLogDescriptor descriptor)
private void	handlePartitionDeletion(org.apache.cassandra.db.partitions.PartitionUpdate pu, OffsetPosition offsetPosition, KeyspaceTable keyspaceTable)	Handle a valid deletion event resulted from a partition-level deletion by converting Cassandra representation of this event into a Record object and queue the record to ChangeEventQueue.
private void	handleRowModifications(org.apache.cassandra.db.rows.Row row, CommitLogReadHandlerImpl.RowType rowType, org.apache.cassandra.db.partitions.PartitionUpdate pu, OffsetPosition offsetPosition, KeyspaceTable keyspaceTable)	Handle a valid event resulted from a row-level modification by converting Cassandra representation of this event into a Record object and queue the record to ChangeEventQueue.
void	handleUnrecoverableError(org.apache.cassandra.db.commitlog.CommitLogReadHandler.CommitLogReadException exception)
private void	populateClusteringColumns(RowData after, org.apache.cassandra.db.rows.Row row, org.apache.cassandra.db.partitions.PartitionUpdate pu)
private void	populatePartitionColumns(RowData after, org.apache.cassandra.db.partitions.PartitionUpdate pu)
private void	populateRegularColumns(RowData after, org.apache.cassandra.db.rows.Row row, CommitLogReadHandlerImpl.RowType rowType, KeyValueSchema schema)
private void	process(org.apache.cassandra.db.partitions.PartitionUpdate pu, OffsetPosition offsetPosition, KeyspaceTable keyspaceTable)	Method which processes a partition update if it's valid (either a single-row partition-level deletion or a row-level modification) or throw an exception if it isn't.
boolean	shouldSkipSegmentOnError(org.apache.cassandra.db.commitlog.CommitLogReadHandler.CommitLogReadException exception)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOGGER

private static final org.slf4j.Logger LOGGER

MARK_OFFSET

private static final boolean MARK_OFFSET

See Also:

Constant Field Values

queues

private final List<io.debezium.connector.base.ChangeEventQueue<Event>> queues

recordMaker

private final RecordMaker recordMaker

offsetWriter

private final OffsetWriter offsetWriter

schemaHolder

private final SchemaHolder schemaHolder

metrics

private final CommitLogProcessorMetrics metrics

Constructor Detail

CommitLogReadHandlerImpl

CommitLogReadHandlerImpl(SchemaHolder schemaHolder,
                         List<io.debezium.connector.base.ChangeEventQueue<Event>> queues,
                         OffsetWriter offsetWriter,
                         RecordMaker recordMaker,
                         CommitLogProcessorMetrics metrics)

Method Detail

handleMutation

public void handleMutation(org.apache.cassandra.db.Mutation mutation,
                           int size,
                           int entryLocation,
                           org.apache.cassandra.db.commitlog.CommitLogDescriptor descriptor)

Specified by:

handleMutation in interface org.apache.cassandra.db.commitlog.CommitLogReadHandler

handleUnrecoverableError

public void handleUnrecoverableError(org.apache.cassandra.db.commitlog.CommitLogReadHandler.CommitLogReadException exception)
                              throws IOException

Specified by:

handleUnrecoverableError in interface org.apache.cassandra.db.commitlog.CommitLogReadHandler

Throws:

IOException

shouldSkipSegmentOnError

public boolean shouldSkipSegmentOnError(org.apache.cassandra.db.commitlog.CommitLogReadHandler.CommitLogReadException exception)
                                 throws IOException

Specified by:

shouldSkipSegmentOnError in interface org.apache.cassandra.db.commitlog.CommitLogReadHandler

Throws:

IOException

process

private void process(org.apache.cassandra.db.partitions.PartitionUpdate pu,
                     OffsetPosition offsetPosition,
                     KeyspaceTable keyspaceTable)

Method which processes a partition update if it's valid (either a single-row partition-level deletion or a row-level modification) or throw an exception if it isn't. The valid partition update is then converted into a Record and enqueued to the ChangeEventQueue.

handlePartitionDeletion

private void handlePartitionDeletion(org.apache.cassandra.db.partitions.PartitionUpdate pu,
                                     OffsetPosition offsetPosition,
                                     KeyspaceTable keyspaceTable)

Handle a valid deletion event resulted from a partition-level deletion by converting Cassandra representation of this event into a Record object and queue the record to ChangeEventQueue. A valid deletion event means a partition only has a single row, this implies there are no clustering keys. The steps are: (1) Populate the "source" field for this event (2) Fetch the cached key/value schemas from SchemaHolder (3) Populate the "after" field for this event a. populate partition columns b. populate regular columns with null values (4) Assemble a Record object from the populated data and queue the record

handleRowModifications

private void handleRowModifications(org.apache.cassandra.db.rows.Row row,
                                    CommitLogReadHandlerImpl.RowType rowType,
                                    org.apache.cassandra.db.partitions.PartitionUpdate pu,
                                    OffsetPosition offsetPosition,
                                    KeyspaceTable keyspaceTable)

Handle a valid event resulted from a row-level modification by converting Cassandra representation of this event into a Record object and queue the record to ChangeEventQueue. A valid event implies this must be an insert, update, or delete. The steps are: (1) Populate the "source" field for this event (2) Fetch the cached key/value schemas from SchemaHolder (3) Populate the "after" field for this event a. populate partition columns b. populate clustering columns c. populate regular columns d. for deletions, populate regular columns with null values (4) Assemble a Record object from the populated data and queue the record

populatePartitionColumns

private void populatePartitionColumns(RowData after,
                                      org.apache.cassandra.db.partitions.PartitionUpdate pu)

populateClusteringColumns

private void populateClusteringColumns(RowData after,
                                       org.apache.cassandra.db.rows.Row row,
                                       org.apache.cassandra.db.partitions.PartitionUpdate pu)

populateRegularColumns

private void populateRegularColumns(RowData after,
                                    org.apache.cassandra.db.rows.Row row,
                                    CommitLogReadHandlerImpl.RowType rowType,
                                    KeyValueSchema schema)

getPartitionKeys

private static List<Object> getPartitionKeys(org.apache.cassandra.db.partitions.PartitionUpdate pu)

Given a PartitionUpdate, deserialize the partition key byte buffer into a list of partition key values.