org.apache.bookkeeper.bookie.EntryLogCompactor Maven / Gradle / Ivy
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*
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
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*/
package org.apache.bookkeeper.bookie;
import io.netty.buffer.ByteBuf;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.bookkeeper.bookie.storage.EntryLogScanner;
import org.apache.bookkeeper.bookie.storage.EntryLogger;
import org.apache.bookkeeper.conf.ServerConfiguration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This is the basic entry log compactor to compact entry logs.
* The compaction is done by scanning the old entry log file, copy the active ledgers to the
* current entry logger and remove the old entry log when the scan is over.
*/
public class EntryLogCompactor extends AbstractLogCompactor {
private static final Logger LOG = LoggerFactory.getLogger(EntryLogCompactor.class);
final CompactionScannerFactory scannerFactory = new CompactionScannerFactory();
final EntryLogger entryLogger;
final CompactableLedgerStorage ledgerStorage;
private final int maxOutstandingRequests;
public EntryLogCompactor(
ServerConfiguration conf,
EntryLogger entryLogger,
CompactableLedgerStorage ledgerStorage,
LogRemovalListener logRemover) {
super(conf, logRemover);
this.maxOutstandingRequests = conf.getCompactionMaxOutstandingRequests();
this.entryLogger = entryLogger;
this.ledgerStorage = ledgerStorage;
}
@Override
public boolean compact(EntryLogMetadata entryLogMeta) {
try {
entryLogger.scanEntryLog(entryLogMeta.getEntryLogId(),
scannerFactory.newScanner(entryLogMeta));
scannerFactory.flush();
LOG.info("Removing entry log {} after compaction", entryLogMeta.getEntryLogId());
logRemovalListener.removeEntryLog(entryLogMeta.getEntryLogId());
} catch (LedgerDirsManager.NoWritableLedgerDirException nwlde) {
LOG.warn("No writable ledger directory available, aborting compaction", nwlde);
return false;
} catch (IOException ioe) {
// if compact entry log throws IOException, we don't want to remove that
// entry log. however, if some entries from that log have been re-added
// to the entry log, and the offset updated, it's ok to flush that
LOG.error("Error compacting entry log. Log won't be deleted", ioe);
return false;
}
return true;
}
/**
* A scanner wrapper to check whether a ledger is alive in an entry log file.
*/
class CompactionScannerFactory {
List offsets = new ArrayList();
EntryLogScanner newScanner(final EntryLogMetadata meta) {
return new EntryLogScanner() {
@Override
public boolean accept(long ledgerId) {
return meta.containsLedger(ledgerId);
}
@Override
public void process(final long ledgerId, long offset, ByteBuf entry) throws IOException {
throttler.acquire(entry.readableBytes());
if (offsets.size() > maxOutstandingRequests) {
flush();
}
long entryId = entry.getLong(entry.readerIndex() + 8);
long newoffset = entryLogger.addEntry(ledgerId, entry);
offsets.add(new EntryLocation(ledgerId, entryId, newoffset));
}
};
}
void flush() throws IOException {
if (offsets.isEmpty()) {
if (LOG.isDebugEnabled()) {
LOG.debug("Skipping entry log flushing, as there are no offset!");
}
return;
}
// Before updating the index, we want to wait until all the compacted entries are flushed into the
// entryLog
try {
entryLogger.flush();
ledgerStorage.updateEntriesLocations(offsets);
ledgerStorage.flushEntriesLocationsIndex();
} finally {
offsets.clear();
}
}
}
}