com.canto.cumulus.server.esp.modules.dbmirror

Interface DBMirrorWorker

public interface DBMirrorWorker

This interface specifies all the methods you need to implement to enable your esp to actually work as a mirroring esp. All the methods in this interface are directly called by the server.

The mirroring process works by mirroring relational tables. There are two table types to support:

• Named Tables
• Cue Tables

Named Tables always have two columns, one with a string as the primary key (RECORD_NAME) and a second one holding binary data (RECORD_DATA).
The table must be able to store large binary data values.
There are two Named Tables for a mirroring process needed, called MASTER_TABLE and MISC_TABLE.

Cue Tables are dynamically created and persists of one to many columns. The primary key is an int value.

When initializing the mirroring the Named Tables MASTER_TABLE and MISC_TABLE need to be created automatically by the mirroring esp. The Cue Tables are created on the fly. Cue Table definitions are added to the MASTER_TABLE and need to be parsed to update the according Cue Table itself as well.

Method Summary

Methods

Modifier and Type	Method and Description
void	addTableEntry(MirroringTask task) Add the specified entry to the table.
void	deleteTableEntry(MirroringTask task) Remove the specified entry from the according table.
void	prepareMirroring() Prepare the start of a new mirroring process.
void	prepareMirroringFinished(MirroringTask task) Finish preparing the mirror.
void	rebuild(DBRebuild rebuild) Start a rebuild from the mirrored information.
void	startMirroring(boolean isInitCall) Start the mirroring process by creating all the needed connections and checking the needed resources.
void	stopMirroring() Release all resources to stop mirroring.
void	updateTableEntry(MirroringTask task) Update the specified entry in the according table.

Method Detail

startMirroring

void startMirroring(boolean isInitCall)

Start the mirroring process by creating all the needed connections and checking the needed resources. This method gets always called before the mirroring process starts or is resumed.

prepareMirroring

void prepareMirroring()
                      throws MirroringException

Prepare the start of a new mirroring process.

Create the two tables that are always needed for any Cumulus database that are called MASTER_TABLE and MISC_TABLE. Both tables are Named Tables and need two columns: RECORD_NAME (String) and RECORD_DATA (Binary)

Throws:

MirroringException - when an error occured

prepareMirroringFinished

void prepareMirroringFinished(MirroringTask task)
                              throws MirroringException

Finish preparing the mirror.

This method is called after all table entries are made after calling prepareMirroring().

Parameters:

task - the entry specifying the values and the table to work on

Throws:

MirroringException - when an error occured

Since:

7.1

addTableEntry

void addTableEntry(MirroringTask task)
                   throws MirroringException

Add the specified entry to the table.

Parameters:

task - the entry specifying the values and the table to work on

Throws:

MirroringException - when an error occured

updateTableEntry

void updateTableEntry(MirroringTask task)
                      throws MirroringException

Update the specified entry in the according table.

Parameters:

task - the entry specifying the values and the table to work on

Throws:

MirroringException - when an error occured

deleteTableEntry

void deleteTableEntry(MirroringTask task)
                      throws MirroringException

Remove the specified entry from the according table.

Parameters:

task - the entry specifying the values and the table to work on

Throws:

MirroringException - when an error occured

stopMirroring

void stopMirroring()

Release all resources to stop mirroring. This method gets called when the mirroring is disabled for the Cumulus catalog but also when the Cumulus server shuts down.

rebuild

void rebuild(DBRebuild rebuild)
             throws MirroringException

Start a rebuild from the mirrored information. This method is called without a previous call to #startMirroring(). Therefore you will need to connect to your backend system at the beginning of your implementation. Rebuilding must happen in a specific order. You will need to provide the Cumulus Server with the needed information in the specified order.
The order is:

• Rebuild the MASTER_TABLE
• Rebuild the MISC_TABLE
• Rebuild all Cue Tables

Rebuilding a table has several steps:

• Call DBRebuild.beginTable(int, String, int) to let the Cumulus server know about a new table
• Call DBRebuild.addTableEntry(String, com.canto.cumulus.utils.JPack) (for Named Tables) or DBRebuild.addTableEntry(int, com.canto.cumulus.utils.JPack) (for Cue Tables) for all table entries
• Call DBRebuild.endTable() to let the Cumulus server know that a table is completely processed.

After all tables have been processed this method is left and all the needed resources are freed.

Parameters:

rebuild - allows callback into the server to write the mirrored information back into the Cumulus catalog.

Throws:

MirroringException