Package com.linkedin.venice.router.api

Class DictionaryRetrievalService

java.lang.Object

com.linkedin.venice.service.AbstractVeniceService

com.linkedin.venice.router.api.DictionaryRetrievalService

All Implemented Interfaces:

Closeable, AutoCloseable

public class DictionaryRetrievalService
extends AbstractVeniceService

DictionaryRetrievalService runs in a producer-consumer pattern. A thread is created which waits for items to be put in a shared BlockingQueue. There are 2 producers for the store versions to download dictionaries for. 1) Store metadata changed ZK listener. 2) Each failed dictionary fetch request is retried infinitely (till the version is retired). At Router startup, the dictionaries are pre-fetched for currently active versions that require a dictionary. This process is fail-fast and will prevent router start up if any dictionary fetch request fails. When a dictionary is downloaded for a version, it's corresponding version specific compressor is initialized and is maintained by CompressorFactory.

Nested Class Summary

Nested classes/interfaces inherited from class com.linkedin.venice.service.AbstractVeniceService

AbstractVeniceService.ServiceState

Field Summary

Fields inherited from class com.linkedin.venice.service.AbstractVeniceService

logger, serviceState

Constructor Summary

Constructors

Constructor	Description
DictionaryRetrievalService(OnlineInstanceFinder onlineInstanceFinder, VeniceRouterConfig routerConfig, Optional<SSLFactory> sslFactory, ReadOnlyStoreRepository metadataRepository, StorageNodeClient storageNodeClient, CompressorFactory compressorFactory)

Method Summary

Modifier and Type	Method	Description
boolean	startInner()
void	stopInner()

Methods inherited from class com.linkedin.venice.service.AbstractVeniceService

close, getName, isRunning, start, stop

Methods inherited from class java.lang.Object

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

Constructor Details

DictionaryRetrievalService

public DictionaryRetrievalService(OnlineInstanceFinder onlineInstanceFinder,
 VeniceRouterConfig routerConfig,
 Optional<SSLFactory> sslFactory,
 ReadOnlyStoreRepository metadataRepository,
 StorageNodeClient storageNodeClient,
 CompressorFactory compressorFactory)

Parameters:

onlineInstanceFinder - OnlineInstanceFinder used to identify which storage node needs to be queried

routerConfig - common router configuration

sslFactory - if provided, the request will attempt to use ssl when fetching dictionary from the storage nodes

Method Details

startInner

public boolean startInner()

Specified by:

startInner in class AbstractVeniceService

Returns:

true if the service is completely started, false if it is still starting asynchronously (in this case, it is the implementer's responsibility to set AbstractVeniceService.serviceState to AbstractVeniceService.ServiceState.STARTED upon completion of the async work).

stopInner

public void stopInner()
               throws IOException

Specified by:

stopInner in class AbstractVeniceService

Throws:

IOException