Implement preClose

src/main/java/it/cavallium/dbengine/database/LLKeyValueDatabase.java

@@ -64,5 +64,6 @@ public interface LLKeyValueDatabase extends LLSnapshottable, LLKeyValueDatabaseS
 
 	MeterRegistry getMeterRegistry();
 
+	Mono<Void> preClose();
 	Mono<Void> close();
 }

src/main/java/it/cavallium/dbengine/database/disk/LLLocalKeyValueDatabase.java

@@ -75,6 +75,8 @@ import org.rocksdb.IndexType;
 import org.rocksdb.InfoLogLevel;
 import org.rocksdb.IngestExternalFileOptions;
 import org.rocksdb.LRUCache;
+import org.rocksdb.LogFile;
+import org.rocksdb.MutableDBOptions;
 import org.rocksdb.OptimisticTransactionDB;
 import org.rocksdb.PersistentCache;
 import org.rocksdb.RocksDB;
@@ -317,10 +319,10 @@ public class LLLocalKeyValueDatabase implements LLKeyValueDatabase {
 						// tableOptions.setOptimizeFiltersForMemory(true);
 						columnFamilyOptions.setWriteBufferSize(256 * SizeUnit.MB);
 					}
+				}
 				if (columnOptions.writeBufferSize().isPresent()) {
 					columnFamilyOptions.setWriteBufferSize(columnOptions.writeBufferSize().get());
 				}
-				}
 				tableOptions.setVerifyCompression(false);
 				if (columnOptions.filter().isPresent()) {
 					var filterOptions = columnOptions.filter().get();
@@ -660,12 +662,30 @@ public class LLLocalKeyValueDatabase implements LLKeyValueDatabase {
 		try {
 			ensureOpen();
 			ensureOwned(flushOptions);
-			db.flush(flushOptions);
+			db.flush(flushOptions, List.copyOf(getAllColumnFamilyHandles().values()));
+			db.flushWal(true);
 		} finally {
 			closeLock.unlockRead(closeReadLock);
 		}
 	}
 
+	@Override
+	public Mono<Void> preClose() {
+		return Mono.<Void>fromCallable(() -> {
+			var closeReadLock = closeLock.readLock();
+			try {
+				ensureOpen();
+				try (var fo = new FlushOptions().setWaitForFlush(true)) {
+					flush(fo);
+				}
+				db.cancelAllBackgroundWork(true);
+				return null;
+			} finally {
+				closeLock.unlockRead(closeReadLock);
+			}
+		}).subscribeOn(dbWScheduler);
+	}
+
 	private record RocksLevelOptions(CompressionType compressionType, CompressionOptions compressionOptions) {}
 	private RocksLevelOptions getRocksLevelOptions(DatabaseLevel levelOptions, RocksDBRefs refs) {
 		var compressionType = levelOptions.compression().getType();
@@ -955,7 +975,7 @@ public class LLLocalKeyValueDatabase implements LLKeyValueDatabase {
 					.setWalBytesPerSync(0) // default
 					.setIncreaseParallelism(1)
 					.setDbWriteBufferSize(8 * SizeUnit.MB)
-					.setWalTtlSeconds(0)
+					.setWalTtlSeconds(60)
 					.setWalSizeLimitMB(0)
 					.setMaxTotalWalSize(0) // automatic
 			;
@@ -991,7 +1011,7 @@ public class LLLocalKeyValueDatabase implements LLKeyValueDatabase {
 					.setBytesPerSync(64 * SizeUnit.MB)
 					.setWalBytesPerSync(64 * SizeUnit.MB)
 
-					.setWalTtlSeconds(0) // Auto
+					.setWalTtlSeconds(60) // Auto
 					.setWalSizeLimitMB(0) // Auto
 					.setMaxTotalWalSize(0) // Auto
 			;
@@ -1507,8 +1527,13 @@ public class LLLocalKeyValueDatabase implements LLKeyValueDatabase {
 		return Mono.<Void>fromCallable(() -> {
 			try (var fo = new FlushOptions().setWaitForFlush(true)) {
 				this.flush(fo);
-				return null;
+			} catch (RocksDBException ex) {
+				if (!"ShutdownInProgress".equals(ex.getMessage())) {
+					throw ex;
 				}
+				logger.warn("Shutdown in progress. Flush cancelled", ex);
+			}
+			return null;
 		}).subscribeOn(dbWScheduler);
 	}
 

src/main/java/it/cavallium/dbengine/database/memory/LLMemoryKeyValueDatabase.java

@@ -170,10 +170,14 @@ public class LLMemoryKeyValueDatabase implements LLKeyValueDatabase {
 		return meterRegistry;
 	}
 
+	@Override
+	public Mono<Void> preClose() {
+		return null;
+	}
+
 	@Override
 	public Mono<Void> close() {
-		return Mono
-				.fromRunnable(() -> {
+		return Mono.fromRunnable(() -> {
 			snapshots.forEach((snapshot, dbs) -> dbs.forEach((columnName, db) -> {
 				db.clear();
 			}));

src/main/java/it/cavallium/dbengine/database/remote/LLQuicConnection.java

@@ -398,6 +398,11 @@ public class LLQuicConnection implements LLDatabaseConnection {
 						return meterRegistry;
 					}
 
+					@Override
+					public Mono<Void> preClose() {
+						return null;
+					}
+
 					@Override
 					public Mono<Void> close() {
 						return sendRequest(new CloseDatabase(id)).then();