io.druid.storage.cassandra

Class CassandraDataSegmentPusher

java.lang.Object

io.druid.storage.cassandra.CassandraStorage

io.druid.storage.cassandra.CassandraDataSegmentPusher

All Implemented Interfaces:

DataSegmentPusher

public class CassandraDataSegmentPusher
extends CassandraStorage
implements DataSegmentPusher

Cassandra Segment Pusher

Author:

boneill42

Constructor Summary

Constructors

Constructor and Description
CassandraDataSegmentPusher(CassandraDataSegmentConfig config, com.fasterxml.jackson.databind.ObjectMapper jsonMapper)

Method Summary

Modifier and Type	Method and Description
String	getPathForHadoop()
String	getPathForHadoop(String dataSource) Deprecated.
Map<String,Object>	makeLoadSpec(URI uri)
DataSegment	push(File indexFilesDir, DataSegment segment, boolean replaceExisting) Pushes index files and segment descriptor to deep storage.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.druid.segment.loading.DataSegmentPusher

getAllowedPropertyPrefixesForHadoop, getDefaultStorageDir, getStorageDir, makeIndexPathName

Constructor Detail

CassandraDataSegmentPusher

@Inject
public CassandraDataSegmentPusher(CassandraDataSegmentConfig config,
                                          com.fasterxml.jackson.databind.ObjectMapper jsonMapper)

Method Detail

getPathForHadoop

public String getPathForHadoop()

Specified by:

getPathForHadoop in interface DataSegmentPusher

getPathForHadoop

@Deprecated
public String getPathForHadoop(String dataSource)

Deprecated.

Specified by:

getPathForHadoop in interface DataSegmentPusher

push

public DataSegment push(File indexFilesDir,
                        DataSegment segment,
                        boolean replaceExisting)
                 throws IOException

Description copied from interface: DataSegmentPusher

Pushes index files and segment descriptor to deep storage.

Specified by:

push in interface DataSegmentPusher

Parameters:

indexFilesDir - directory containing index files

segment - segment descriptor

replaceExisting - overwrites existing objects if true, else leaves existing objects unchanged on conflict. The behavior of the indexer determines whether this should be true or false. For example, since Tranquility does not guarantee that replica tasks will generate indexes with the same data, the first segment pushed should be favored since otherwise multiple historicals may load segments with the same identifier but different contents which is a bad situation. On the other hand, indexers that maintain exactly-once semantics by storing checkpoint data can lose or repeat data if it fails to write a segment because it already exists and overwriting is not permitted. This situation can occur if a task fails after pushing to deep storage but before writing to the metadata storage, see: https://github.com/druid-io/druid/issues/5161. If replaceExisting is true, existing objects MUST be overwritten, since failure to do so will break exactly-once semantics. If replaceExisting is false, existing objects SHOULD be prioritized but it is acceptable if they are overwritten (deep storages may be eventually consistent or otherwise unable to support transactional writes).

Returns:

segment descriptor

Throws:

IOException

makeLoadSpec

public Map<String,Object> makeLoadSpec(URI uri)

Specified by:

makeLoadSpec in interface DataSegmentPusher