CavalliumDBEngine/src/main/java/it/cavallium/dbengine/database/disk/OptimisticRocksDBColumn.java
2022-04-06 02:41:32 +02:00

233 lines
7.9 KiB
Java

package it.cavallium.dbengine.database.disk;
import static it.cavallium.dbengine.database.LLUtils.MARKER_ROCKSDB;
import io.micrometer.core.instrument.DistributionSummary;
import io.micrometer.core.instrument.MeterRegistry;
import io.netty5.buffer.api.Buffer;
import io.netty5.buffer.api.BufferAllocator;
import io.netty5.buffer.api.MemoryManager;
import io.netty5.buffer.api.Send;
import it.cavallium.dbengine.database.LLDelta;
import it.cavallium.dbengine.database.LLUtils;
import it.cavallium.dbengine.database.serialization.SerializationException;
import it.cavallium.dbengine.lucene.ExponentialPageLimits;
import it.cavallium.dbengine.rpc.current.data.DatabaseOptions;
import java.io.IOException;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.locks.LockSupport;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.rocksdb.ColumnFamilyHandle;
import org.rocksdb.OptimisticTransactionDB;
import org.rocksdb.ReadOptions;
import org.rocksdb.RocksDBException;
import org.rocksdb.Status.Code;
import org.rocksdb.Transaction;
import org.rocksdb.WriteBatch;
import org.rocksdb.WriteOptions;
import reactor.core.scheduler.Schedulers;
public final class OptimisticRocksDBColumn extends AbstractRocksDBColumn<OptimisticTransactionDB> {
private static final boolean ALWAYS_PRINT_OPTIMISTIC_RETRIES = false;
private final DistributionSummary optimisticAttempts;
public OptimisticRocksDBColumn(OptimisticTransactionDB db,
boolean nettyDirect,
BufferAllocator alloc,
String databaseName,
ColumnFamilyHandle cfh,
MeterRegistry meterRegistry) {
super(db, nettyDirect, alloc, databaseName, cfh, meterRegistry);
this.optimisticAttempts = DistributionSummary
.builder("db.optimistic.attempts.distribution")
.publishPercentiles(0.2, 0.5, 0.95)
.baseUnit("times")
.scale(1)
.publishPercentileHistogram()
.tags("db.name", databaseName, "db.column", columnName)
.register(meterRegistry);
}
@Override
protected boolean commitOptimistically(Transaction tx) throws RocksDBException {
try {
tx.commit();
return true;
} catch (RocksDBException ex) {
var status = ex.getStatus() != null ? ex.getStatus().getCode() : Code.Ok;
if (status == Code.Busy || status == Code.TryAgain) {
return false;
}
throw ex;
}
}
@Override
protected Transaction beginTransaction(@NotNull WriteOptions writeOptions) {
return getDb().beginTransaction(writeOptions);
}
@Override
public void write(WriteOptions writeOptions, WriteBatch writeBatch) throws RocksDBException {
getDb().write(writeOptions, writeBatch);
}
@Override
public @NotNull UpdateAtomicResult updateAtomicImpl(@NotNull ReadOptions readOptions,
@NotNull WriteOptions writeOptions,
Buffer key,
BinarySerializationFunction updater,
UpdateAtomicResultMode returnMode) throws IOException {
long initNanoTime = System.nanoTime();
try {
var cfh = getCfh();
var keyArray = LLUtils.toArray(key);
if (Schedulers.isInNonBlockingThread()) {
throw new UnsupportedOperationException("Called update in a nonblocking thread");
}
try (var tx = beginTransaction(writeOptions)) {
boolean committedSuccessfully;
int retries = 0;
ExponentialPageLimits retryTime = null;
Send<Buffer> sentPrevData;
Send<Buffer> sentCurData;
boolean changed;
do {
var prevDataArray = tx.getForUpdate(readOptions, cfh, keyArray, true);
if (logger.isTraceEnabled()) {
logger.trace(MARKER_ROCKSDB,
"Reading {}: {} (before update)",
LLUtils.toStringSafe(key),
LLUtils.toStringSafe(prevDataArray)
);
}
Buffer prevData;
if (prevDataArray != null) {
prevData = MemoryManager.unsafeWrap(prevDataArray);
prevDataArray = null;
} else {
prevData = null;
}
try (prevData) {
Buffer prevDataToSendToUpdater;
if (prevData != null) {
prevDataToSendToUpdater = prevData.copy().makeReadOnly();
} else {
prevDataToSendToUpdater = null;
}
@Nullable Buffer newData = applyUpdateAndCloseIfNecessary(updater, prevDataToSendToUpdater);
try (newData) {
var newDataArray = newData == null ? null : LLUtils.toArray(newData);
if (logger.isTraceEnabled()) {
logger.trace(MARKER_ROCKSDB,
"Updating {}. previous data: {}, updated data: {}",
LLUtils.toStringSafe(key),
LLUtils.toStringSafe(prevDataArray),
LLUtils.toStringSafe(newDataArray)
);
}
if (prevData != null && newData == null) {
if (logger.isTraceEnabled()) {
logger.trace(MARKER_ROCKSDB, "Deleting {} (after update)", LLUtils.toStringSafe(key));
}
tx.delete(cfh, keyArray, true);
changed = true;
committedSuccessfully = commitOptimistically(tx);
} else if (newData != null && (prevData == null || !LLUtils.equals(prevData, newData))) {
if (logger.isTraceEnabled()) {
logger.trace(MARKER_ROCKSDB,
"Writing {}: {} (after update)",
LLUtils.toStringSafe(key),
LLUtils.toStringSafe(newData)
);
}
tx.put(cfh, keyArray, newDataArray);
changed = true;
committedSuccessfully = commitOptimistically(tx);
} else {
changed = false;
committedSuccessfully = true;
tx.rollback();
}
sentPrevData = prevData == null ? null : prevData.send();
sentCurData = newData == null ? null : newData.send();
if (!committedSuccessfully) {
tx.undoGetForUpdate(cfh, keyArray);
tx.rollback();
if (sentPrevData != null) {
sentPrevData.close();
}
if (sentCurData != null) {
sentCurData.close();
}
retries++;
if (retries == 1) {
retryTime = new ExponentialPageLimits(0, 2, 2000);
}
long retryNs = 1000000L * retryTime.getPageLimit(retries);
// +- 30%
retryNs = retryNs + ThreadLocalRandom.current().nextLong(-retryNs * 30L / 100L, retryNs * 30L / 100L);
if (retries >= 5 && retries % 5 == 0 || ALWAYS_PRINT_OPTIMISTIC_RETRIES) {
logger.warn(MARKER_ROCKSDB, "Failed optimistic transaction {} (update):"
+ " waiting {} ms before retrying for the {} time", LLUtils.toStringSafe(key), retryNs / 1000000d, retries);
} else if (logger.isDebugEnabled(MARKER_ROCKSDB)) {
logger.debug(MARKER_ROCKSDB, "Failed optimistic transaction {} (update):"
+ " waiting {} ms before retrying for the {} time", LLUtils.toStringSafe(key), retryNs / 1000000d, retries);
}
// Wait for n milliseconds
if (retryNs > 0) {
LockSupport.parkNanos(retryNs);
}
}
}
}
} while (!committedSuccessfully);
if (retries > 5) {
logger.warn(MARKER_ROCKSDB, "Took {} retries to update key {}", retries, LLUtils.toStringSafe(key));
}
recordAtomicUpdateTime(changed, sentPrevData != null, sentCurData != null, initNanoTime);
optimisticAttempts.record(retries);
return switch (returnMode) {
case NOTHING -> {
if (sentPrevData != null) {
sentPrevData.close();
}
if (sentCurData != null) {
sentCurData.close();
}
yield RESULT_NOTHING;
}
case CURRENT -> {
if (sentPrevData != null) {
sentPrevData.close();
}
yield new UpdateAtomicResultCurrent(sentCurData);
}
case PREVIOUS -> {
if (sentCurData != null) {
sentCurData.close();
}
yield new UpdateAtomicResultPrevious(sentPrevData);
}
case BINARY_CHANGED -> new UpdateAtomicResultBinaryChanged(changed);
case DELTA -> new UpdateAtomicResultDelta(LLDelta.of(sentPrevData, sentCurData).send());
};
}
} catch (Throwable ex) {
throw new IOException("Failed to update key " + LLUtils.toStringSafe(key), ex);
}
}
@Override
public boolean supportsTransactions() {
return true;
}
}