IMap.delete operations don't update the LocalMapStats

[rickymemphis]

Hello,

We noticed that the LocalMapStats.getLastUpdateTime() method returns incorrect results when the IMap.delete operations are executed.

Expected behavior
We would expect that the LastUpdateTime metric is updated when entries are removed from a distributed map.
Here is a test that reproduces the issue. Could you please check?

The test is a JUnit5 test executed on a Mac and Java 11.

One of my colleagues reported this issue a while ago, but only part of the problem described was fixed.
The issue I refer to is this

package test;

import static org.junit.jupiter.api.Assertions.assertAll;
import static org.junit.jupiter.api.Assertions.assertTrue;

import com.hazelcast.config.Config;
import com.hazelcast.config.MapConfig;
import com.hazelcast.config.MapStoreConfig;
import com.hazelcast.core.Hazelcast;
import com.hazelcast.core.HazelcastInstance;
import com.hazelcast.map.IMap;
import com.hazelcast.map.MapStore;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

public class TestMap22 {

	private static final String mapName = "testMap" + TestMap22.class.getSimpleName();

	private HazelcastInstance hazelcastInstance;

	private IMap<String, String> iMap;

	private RecordingTimeMapStore store;

	@BeforeEach
	public void setUp() throws Exception {

		// create map store config
		store = new RecordingTimeMapStore();
		MapStoreConfig mapStoreConfig = new MapStoreConfig();
		mapStoreConfig.setEnabled(true);
		mapStoreConfig.setWriteDelaySeconds(1);
		mapStoreConfig.setWriteCoalescing(true);
		mapStoreConfig.setImplementation(store);

		// create config
		Config config = new Config();
		MapConfig mapConfig = config.getMapConfig(mapName);
		mapConfig.setMapStoreConfig(mapStoreConfig);

		// start Hazelcast and init map
		hazelcastInstance = Hazelcast.newHazelcastInstance(config);
		iMap = hazelcastInstance.getMap(mapName);
	}

	@AfterEach
	public void tearDown() throws Exception {
		hazelcastInstance.getLifecycleService().terminate();
	}


	@Test
	public void testDelete() throws InterruptedException {

		iMap.put("k1", "v1");

		long lastUpdateTimeDistributedMap = iMap.getLocalMapStats().getLastUpdateTime();
		long lastUpdateTimeMapStore = store.getLastUpdateTime();
		Thread.sleep(2 * 1000);

		iMap.delete("k1");
		Thread.sleep(5 * 1000);

		assertAll(
				() -> assertTrue(iMap.getLocalMapStats().getLastUpdateTime() - lastUpdateTimeDistributedMap > 0),
				() -> assertTrue(store.getLastUpdateTime() - lastUpdateTimeMapStore > 0)
		);
	}

	@Test
	public void testDelete_nonExistentKey() throws InterruptedException {

		iMap.put("k1", "v1");

		long lastUpdateTimeDistributedMap = iMap.getLocalMapStats().getLastUpdateTime();
		long lastUpdateTimeMapStore = store.getLastUpdateTime();
		Thread.sleep(2 * 1000);

		iMap.delete("nonExistentKey");
		Thread.sleep(5 * 1000);

		assertAll(
				() -> assertTrue(iMap.getLocalMapStats().getLastUpdateTime() - lastUpdateTimeDistributedMap == 0),
				() -> assertTrue(store.getLastUpdateTime() - lastUpdateTimeMapStore == 0)
		);
	}

}

class RecordingTimeMapStore implements MapStore<String, String> {

	private final AtomicLong lastUpdateTime = new AtomicLong();

	@Override
	public void store(String key, String value) {
		lastUpdateTime.set(System.currentTimeMillis());
	}

	@Override
	public void storeAll(Map<String, String> map) {
		lastUpdateTime.set(System.currentTimeMillis());
	}

	@Override
	public void delete(String key) {
		lastUpdateTime.set(System.currentTimeMillis());
	}

	@Override
	public void deleteAll(Collection<String> keys) {
		lastUpdateTime.set(System.currentTimeMillis());
	}

	@Override
	public String load(String key) {
		return null;
	}

	@Override
	public Map<String, String> loadAll(Collection<String> keys) {
		return null;
	}

	@Override
	public Set<String> loadAllKeys() {
		return null;
	}

	public long getLastUpdateTime() {
		return lastUpdateTime.get();
	}

}

[rickymemphis]

Hi Everyone,

I have proposed a solution in this PR

Please let me know what you think about it.

Best,
Riccardo