org.apache.sling.distribution.journal.bookkeeper

Class BookKeeper

java.lang.Object

org.apache.sling.distribution.journal.bookkeeper.BookKeeper

All Implemented Interfaces:

Closeable, AutoCloseable

public class BookKeeper
extends Object
implements Closeable

Keeps track of offset and processed status and manages coordinates the import/retry handling. The offset store is identified by the agentName only. With non clustered publish instances deployment, each instance stores the offset in its own node store, thus avoiding mix ups. Moreover, when cloning an instance from a node store, the cloned instance will implicitly recover the offsets and start from the last processed offset. With clustered publish instances deployment, only one Subscriber agent must run on the cluster in order to avoid mix ups. The clustered and non clustered publish instances use cases can be supported by only running the Subscriber agent on the leader instance.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BookKeeper.PackageStatus

Field Summary

Fields

Modifier and Type	Field and Description
static int	COMMIT_AFTER_NUM_SKIPPED
static String	KEY_OFFSET
static String	STORE_TYPE_STATUS

Constructor Summary

Constructors

Constructor and Description
BookKeeper(org.apache.sling.api.resource.ResourceResolverFactory resolverFactory, DistributionMetricsService distributionMetricsService, org.apache.sling.distribution.journal.bookkeeper.PackageHandler packageHandler, org.osgi.service.event.EventAdmin eventAdmin, Consumer<org.apache.sling.distribution.journal.messages.PackageStatusMessage> sender, Consumer<org.apache.sling.distribution.journal.messages.LogMessage> logSender, BookKeeperConfig config)
BookKeeper(org.apache.sling.api.resource.ResourceResolverFactory resolverFactory, DistributionMetricsService distributionMetricsService, org.apache.sling.distribution.journal.bookkeeper.PackageHandler packageHandler, org.osgi.service.event.EventAdmin eventAdmin, Consumer<org.apache.sling.distribution.journal.messages.PackageStatusMessage> sender, Consumer<org.apache.sling.distribution.journal.messages.LogMessage> logSender, BookKeeperConfig config, org.apache.sling.distribution.ImportPostProcessor importPostProcessor)

Method Summary

Modifier and Type	Method and Description
void	close()
PackageRetries	getPackageRetries()
int	getRetries(String pubAgentName)
void	importPackage(org.apache.sling.distribution.journal.messages.PackageMessage pkgMsg, long offset, long createdTime) We aim at processing the packages exactly once.
long	loadOffset()
void	markStatusSent()
void	removePackage(org.apache.sling.distribution.journal.messages.PackageMessage pkgMsg, long offset)
boolean	sendStoredStatus(int retry)
boolean	shouldCommitSkipped()
void	skipPackage(long offset)

Methods inherited from class java.lang.Object

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

Field Detail

STORE_TYPE_STATUS

public static final String STORE_TYPE_STATUS

See Also:

Constant Field Values

KEY_OFFSET

public static final String KEY_OFFSET

See Also:

Constant Field Values

COMMIT_AFTER_NUM_SKIPPED

public static final int COMMIT_AFTER_NUM_SKIPPED

See Also:

Constant Field Values

Constructor Detail

BookKeeper

public BookKeeper(org.apache.sling.api.resource.ResourceResolverFactory resolverFactory,
                  DistributionMetricsService distributionMetricsService,
                  org.apache.sling.distribution.journal.bookkeeper.PackageHandler packageHandler,
                  org.osgi.service.event.EventAdmin eventAdmin,
                  Consumer<org.apache.sling.distribution.journal.messages.PackageStatusMessage> sender,
                  Consumer<org.apache.sling.distribution.journal.messages.LogMessage> logSender,
                  BookKeeperConfig config)

BookKeeper

public BookKeeper(org.apache.sling.api.resource.ResourceResolverFactory resolverFactory,
                  DistributionMetricsService distributionMetricsService,
                  org.apache.sling.distribution.journal.bookkeeper.PackageHandler packageHandler,
                  org.osgi.service.event.EventAdmin eventAdmin,
                  Consumer<org.apache.sling.distribution.journal.messages.PackageStatusMessage> sender,
                  Consumer<org.apache.sling.distribution.journal.messages.LogMessage> logSender,
                  BookKeeperConfig config,
                  org.apache.sling.distribution.ImportPostProcessor importPostProcessor)

Method Detail

importPackage

public void importPackage(org.apache.sling.distribution.journal.messages.PackageMessage pkgMsg,
                          long offset,
                          long createdTime)
                   throws org.apache.sling.distribution.common.DistributionException

We aim at processing the packages exactly once. Processing the packages exactly once is possible with the following conditions I. The package importer is configured to disable auto-committing changes. II. A single commit aggregates three content updates C1. install the package C2. store the processing status C3. store the offset processed Some package importers require auto-saving or issue partial commits before failing. For those packages importers, we aim at processing packages at least once, thanks to the order in which the content updates are applied.

Throws:

org.apache.sling.distribution.common.DistributionException

removePackage

public void removePackage(org.apache.sling.distribution.journal.messages.PackageMessage pkgMsg,
                          long offset)
                   throws org.apache.sling.api.resource.LoginException,
                          org.apache.sling.api.resource.PersistenceException

Throws:

org.apache.sling.api.resource.LoginException

org.apache.sling.api.resource.PersistenceException

skipPackage

public void skipPackage(long offset)
                 throws org.apache.sling.api.resource.LoginException,
                        org.apache.sling.api.resource.PersistenceException

Throws:

org.apache.sling.api.resource.LoginException

org.apache.sling.api.resource.PersistenceException

shouldCommitSkipped

public boolean shouldCommitSkipped()

sendStoredStatus

public boolean sendStoredStatus(int retry)

Returns:

true if the status has been sent ; false otherwise.

markStatusSent

public void markStatusSent()

loadOffset

public long loadOffset()

getRetries

public int getRetries(String pubAgentName)

getPackageRetries

public PackageRetries getPackageRetries()

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException