write-behind-tools

Write Behind Tools

Tools for write behind queue, which provides following functions

• Get current write behind queue size in the cluster
• Clear retaining data in write behind queue in the cluster

Usage

Use with Apache Maven

Add dependency to pom.xml like this:

<dependency>
  <groupId>io.github.simukappu</groupId>
  <artifactId>write-behind-tools</artifactId>
  <version>1.0.0</version>
</dependency>

Write Behind Tools Processor

Invoke Write Behind Tools Processor from invokeAll method in NamedCache<Object, Object>.
For example, use as follows:

NamedCache<Object, Object> namedCache = CacheFactory.getCache("CacheName");

// Get current write behind queue size in the cluster
{
	// Invoke GetWriteQueueSizeProcessor to all local-storage enabled nodes
	Map<Object, Map.Entry<Integer, Integer>> mapResults = targetCache
			.invokeAll(new AlwaysFilter<Object>(),
					new GetWriteQueueSizeProcessor(targetCacheName));
	
	// Sort result map set by keys
	List<Map.Entry<Integer, Integer>> resultList = new ArrayList<>(
			mapResults.values());
	resultList.sort((a, b) -> a.getKey() - b.getKey());
	
	// Display results
	System.out.println("Size of write behind queue:");
	resultList.forEach(resultEntry -> {
		System.out.println(" " + resultEntry.getValue()
				+ " entries in Node# " + resultEntry.getKey());
	});
}

// Clear retaining data in write behind queue in the cluster
{
	// Invoke ClearWriteQueueProcessor to all local-storage enabled nodes
	Map<Object, Map.Entry<Integer, Integer>> mapResults = targetCache
			.invokeAll(new AlwaysFilter<Object>(),
					new ClearWriteQueueProcessor(targetCacheName));
	
	// Sort result map set by keys
	List<Map.Entry<Integer, Integer>> resultList = new ArrayList<>(
			mapResults.values());
	resultList.sort((a, b) -> a.getKey() - b.getKey());
	
	// Display results
	System.out.println("Removed entries from write behind queue:");
	resultList.forEach(resultEntry -> {
		System.out.println(" " + resultEntry.getValue()
				+ " entries from Node# " + resultEntry.getKey());
	});
}

See Javadoc for more details.

Testing

Just run test.com.simukappu.coherence.writequeue.IntegrationTest as JUnit Test.
You can run this test as stand-alone or multi-processes cluster by running CacheServer before the test.
CacheServer joining this cluster can be started by test.com.simukappu.coherence.writequeue.server.CacheServer.

API Document

https://simukappu.github.io/coherence-tools/write-behind-tools/docs/project-reports.html

License

Apache License