org.archive.checkpointing

Interface Checkpointable

All Known Implementing Classes:

AbstractPersistProcessor, AggressiveExtractorHTML, ARCWriterProcessor, BdbCookieStorage, BdbFrontier, BdbModule, BdbServerCache, BdbUriUniqFilter, CandidateScoper, CandidatesProcessor, ContentDigestHistoryLoader, ContentDigestHistoryStorer, ContentExtractor, CrawlController, CrawlerLoggerModule, CrawlMapper, DispositionProcessor, Extractor, ExtractorCSS, ExtractorDOC, ExtractorHTML, ExtractorHTMLForms, ExtractorHTTP, ExtractorImpliedURI, ExtractorJS, ExtractorMultipleRegex, ExtractorPDF, ExtractorSWF, ExtractorUniversal, ExtractorURI, ExtractorXML, FetchDNS, FetchFTP, FetchHistoryProcessor, FetchHTTP, FetchWhois, FormLoginProcessor, FrontierPreparer, HashCrawlMapper, HTTPContentDigest, JerichoExtractorHTML, Kw3WriterProcessor, LexicalCrawlMapper, LinksScoper, LowDiskPauseProcessor, MirrorWriterProcessor, NotOnDomainsDecideRule, NotOnHostsDecideRule, NotSurtPrefixedDecideRule, OnDomainsDecideRule, OnHostsDecideRule, PersistLoadProcessor, PersistLogProcessor, PersistOnlineProcessor, PersistProcessor, PersistStoreProcessor, PreconditionEnforcer, Preselector, Processor, QuotaEnforcer, ReschedulingProcessor, RuntimeLimitEnforcer, Scoper, ScriptedProcessor, StatisticsTracker, SupplementaryLinksScoper, SurtPrefixedDecideRule, TrapSuppressExtractor, WARCWriterProcessor, WriterPoolProcessor

public interface Checkpointable

Interface for objects that can checkpoint their state, possibly but not necessarily into the provided Checkpoint instance, on request.

Contributor:

pjack, gojomo

Method Summary

Methods

Modifier and Type	Method and Description
void	doCheckpoint(Checkpoint checkpointInProgress) Do the actual checkpoint.
void	finishCheckpoint(Checkpoint checkpointInProgress) Cleanup/unlock; need not complete for a checkpoint to be valid.
void	setRecoveryCheckpoint(Checkpoint recoveryCheckpoint) Used to inform a bean that it should restore its state from the given Checkpoint when launched (Lifecycle start()).
void	startCheckpoint(Checkpoint checkpointInProgress) Note a checkpoint is about to begin.

Method Detail

startCheckpoint

void startCheckpoint(Checkpoint checkpointInProgress)

Note a checkpoint is about to begin. Most beans will ignore, but some can use this to wrap up tasks that shouldn't be half-done during a checkpoint (and hold a lock to prevent tasks from beginning during the checkpoint).

Parameters:

checkpointInProgress - Checkpoint

doCheckpoint

void doCheckpoint(Checkpoint checkpointInProgress)
                  throws IOException

Do the actual checkpoint. Beans should ensure any state that they would need to recover gets saved in an appropriate place. A moderate amount of state may be saved as a JSONObject into the Checkpoint (which then keeps it in the checkpoint directory.) Larger amounts of state may be stored in a manner private to the bean, or via other collaborating beans (such as BdbModule) which checkpoint backgin database state.

Parameters:

checkpointInProgress - Checkpoint

Throws:

IOException

finishCheckpoint

void finishCheckpoint(Checkpoint checkpointInProgress)

Cleanup/unlock; need not complete for a checkpoint to be valid.

Parameters:

checkpointInProgress - Checkpoint

setRecoveryCheckpoint

void setRecoveryCheckpoint(Checkpoint recoveryCheckpoint)

Used to inform a bean that it should restore its state from the given Checkpoint when launched (Lifecycle start()). May be autowired or configured after build, but before launch, for example via CheckpointService.setRecoveryCheckpointByName().

Parameters:

recoveryCheckpoint - Checkpoint