org.apache.geode.cache.snapshot

Interface RegionSnapshotService<K,V>

Type Parameters:

K - the cache entry key type

V - the cache entry value type

public interface RegionSnapshotService<K,V>

Allows a snapshot of region data to be imported and exported. Example usage:

 // obtain a snapshot
 RegionSnapshot snapshot = region.getSnapshotService();

 // export the snapshot, every region in the cache will be exported
 snapshot.save(new File("snapshot.gfd"), SnapshotOptions.GEMFIRE);

 // import the snapshot file, updates any existing entries in the region
 snapshot.load(new File("snapshot.gfd"), SnapshotOptions.GEMFIRE);
 

When parallel export is used, the file name will be modified to include a unique identifier for the member that created the file, so providing a file location of "snapshot.gfd" would result in creation of multiple files with the format "snapshot-unique_id.gfd". When loading files from a parallel export, a directory can be given instead of a single file and all snapshot files in that directory will be loaded.

 // import directory of snapshot files
 snapshot.load(new File("snapshotDir"), SnapshotOptions.GEMFIRE);
 

The default behavior is to perform all I/O operations on the node where the snapshot operations are invoked. This will involve either collecting or dispersing data over the network if the region is a partitioned region. The snapshot behavior can be changed using SnapshotOptions. For example:

 RegionSnapshotService snapshot = region.getSnapshotService();
 SnapshotFilter filter = new SnapshotFilter() {
   public boolean accept(Entry$lt;K, V$gt; entry) {
     return true;
   }
 };

 SnapshotOptions$lt;Object, Object$gt; options = snapshot.createOptions();
 options.setFilter(filter);

 snapshot.save(new File("snapshot.gfd"), SnapshotFormat.GEMFIRE, options);
 

Note that the snapshot does not provide a consistency guarantee. Updates to data during the course of import/export operations could result data inconsistencies.

Since:

GemFire 7.0

See Also:

Region.getSnapshotService(), SnapshotOptions

Field Summary

Fields

Modifier and Type	Field and Description
static String	SNAPSHOT_FILE_EXTENSION File extension for snapshot files

Method Summary

Modifier and Type	Method and Description
SnapshotOptions<K,V>	createOptions() Creates a SnapshotOptions object configured with default settings.
void	load(File snapshot, SnapshotOptions.SnapshotFormat format) Imports the snapshot file into the specified region.
void	load(File snapshot, SnapshotOptions.SnapshotFormat format, SnapshotOptions<K,V> options) Imports the snapshot file into the specified region by applying user-configured options.
void	save(File snapshot, SnapshotOptions.SnapshotFormat format) Exports the region data into the snapshot file.
void	save(File snapshot, SnapshotOptions.SnapshotFormat format, SnapshotOptions<K,V> options) Exports the region data into the snapshot file by applying user-configured options.

Field Detail

SNAPSHOT_FILE_EXTENSION

static final String SNAPSHOT_FILE_EXTENSION

File extension for snapshot files

See Also:

Constant Field Values

Method Detail

createOptions

SnapshotOptions<K,V> createOptions()

Creates a SnapshotOptions object configured with default settings. The options can be used to configure snapshot behavior.

Returns:

the default options

save

void save(File snapshot,
          SnapshotOptions.SnapshotFormat format)
   throws IOException

Exports the region data into the snapshot file.

Parameters:

snapshot - the snapshot file (must end in .gfd)

format - the snapshot format

Throws:

IOException - error writing snapshot

save

void save(File snapshot,
          SnapshotOptions.SnapshotFormat format,
          SnapshotOptions<K,V> options)
   throws IOException

Exports the region data into the snapshot file by applying user-configured options.

Parameters:

snapshot - the snapshot file (must end in .gfd)

format - the snapshot format

options - the snapshot options

Throws:

IOException - error writing snapshot

load

void load(File snapshot,
          SnapshotOptions.SnapshotFormat format)
   throws IOException,
          ClassNotFoundException

Imports the snapshot file into the specified region. The snapshot parameter can be either a single snapshot file or a directory containing snapshot files. If a single file, it must end in the snapshot file extension (.gfd) to be imported. If a directory, only files in the directory that end in .gfd will be loaded.

Prior to loading data, the region should have been created and any necessary serializers (either DataSerializer or PdxSerializer) and Instantiators should have been registered.

Parameters:

snapshot - the snapshot file (ending in .gfd) or a directory of .gfd snapshot files

format - the snapshot file format

Throws:

IOException - Unable to import data

ClassNotFoundException - Unable to import data

load

void load(File snapshot,
          SnapshotOptions.SnapshotFormat format,
          SnapshotOptions<K,V> options)
   throws IOException,
          ClassNotFoundException

Imports the snapshot file into the specified region by applying user-configured options. The snapshot parameter can be either a single snapshot file or a directory containing snapshot files. If a single file, it must end in the snapshot file extension (.gfd) to be imported. If a directory, only files in the directory that end in .gfd will be loaded.

Prior to loading data, the region should have been created and any necessary serializers (either DataSerializer or PdxSerializer) and Instantiators should have been registered.

Parameters:

snapshot - the snapshot file (ending in .gfd) or a directory of .gfd snapshot files

format - the snapshot file format

options - the snapshot options

Throws:

IOException - Unable to import data

ClassNotFoundException - Unable to import data