Examples with LogVersionedStoreChannel org.neo4j.kernel.impl.transaction.log.LogVersionedStoreChannel used on opensource projects

Example 21 with LogVersionedStoreChannel

use of org.neo4j.kernel.impl.transaction.log.LogVersionedStoreChannel in project neo4j by neo4j.

the class InlinedLogTailScanner method findLogTail.

protected LogTailInformation findLogTail() throws IOException {
    LogFile logFile = logFiles.getLogFile();
    final long highestLogVersion = logFile.getHighestLogVersion();
    long version = highestLogVersion;
    long versionToSearchForCommits = highestLogVersion;
    LogEntryStart latestStartEntry = null;
    long oldestStartEntryTransaction = NO_TRANSACTION_ID;
    long oldestVersionFound = -1;
    byte latestLogEntryVersion = 0;
    boolean startRecordAfterCheckpoint = false;
    boolean corruptedTransactionLogs = false;
    while (version >= logFile.getLowestLogVersion() && version >= INITIAL_LOG_VERSION) {
        log.info("Scanning log file with version %d for checkpoint entries", version);
        oldestVersionFound = version;
        CheckpointInfo latestCheckPoint = null;
        StoreId storeId = StoreId.UNKNOWN;
        try (LogVersionedStoreChannel channel = logFile.openForVersion(version);
            var readAheadChannel = new ReadAheadLogChannel(channel, memoryTracker);
            LogEntryCursor cursor = new LogEntryCursor(logEntryReader, readAheadChannel)) {
            LogHeader logHeader = logFile.extractHeader(version);
            storeId = logHeader.getStoreId();
            LogEntry entry;
            long position = logHeader.getStartPosition().getByteOffset();
            long channelVersion = version;
            while (cursor.next()) {
                entry = cursor.get();
                // Collect data about latest checkpoint
                if (entry instanceof LogEntryInlinedCheckPoint) {
                    latestCheckPoint = new CheckpointInfo((LogEntryInlinedCheckPoint) entry, storeId, new LogPosition(channelVersion, position));
                } else if (entry instanceof LogEntryCommit) {
                    if (oldestStartEntryTransaction == NO_TRANSACTION_ID) {
                        oldestStartEntryTransaction = ((LogEntryCommit) entry).getTxId();
                    }
                } else if (entry instanceof LogEntryStart) {
                    LogEntryStart startEntry = (LogEntryStart) entry;
                    if (version == versionToSearchForCommits) {
                        latestStartEntry = startEntry;
                    }
                    startRecordAfterCheckpoint = true;
                }
                // Collect data about latest entry version, only in first log file
                if (version == versionToSearchForCommits || latestLogEntryVersion == 0) {
                    latestLogEntryVersion = entry.getVersion().version();
                }
                position = channel.position();
                channelVersion = channel.getVersion();
            }
            verifyReaderPosition(version, logEntryReader.lastPosition());
        } catch (Error | ClosedByInterruptException e) {
            // These should not be parsing errors
            throw e;
        } catch (Throwable t) {
            monitor.corruptedLogFile(version, t);
            if (failOnCorruptedLogFiles) {
                throwUnableToCleanRecover(t);
            }
            corruptedTransactionLogs = true;
        }
        if (latestCheckPoint != null) {
            return checkpointTailInformation(highestLogVersion, latestStartEntry, oldestVersionFound, latestLogEntryVersion, latestCheckPoint, corruptedTransactionLogs, storeId);
        }
        version--;
        // if we have found no commits in the latest log, keep searching in the next one
        if (latestStartEntry == null) {
            versionToSearchForCommits--;
        }
    }
    return new LogTailInformation(corruptedTransactionLogs || startRecordAfterCheckpoint, oldestStartEntryTransaction, oldestVersionFound == UNKNOWN, highestLogVersion, latestLogEntryVersion);
}

Example 22 with LogVersionedStoreChannel

use of org.neo4j.kernel.impl.transaction.log.LogVersionedStoreChannel in project neo4j by neo4j.

the class AbstractLogTailScanner method extractFirstTxIdAfterPosition.

/**
 * Extracts txId from first commit entry, when starting reading at the given {@code position}.
 * If no commit entry found in the version, the reader will continue into next version(s) up till
 * {@code maxLogVersion} until finding one.
 *
 * @param initialPosition {@link LogPosition} to start scan from.
 * @param maxLogVersion max log version to scan.
 * @return value object that contains first transaction id of closes commit entry to {@code initialPosition},
 * or {@link InlinedLogTailScanner#NO_TRANSACTION_ID} if not found. And failure flag that will be set to true if
 * there was some exception during transaction log processing.
 * @throws IOException on channel close I/O error.
 */
protected ExtractedTransactionRecord extractFirstTxIdAfterPosition(LogPosition initialPosition, long maxLogVersion) throws IOException {
    long initialVersion = initialPosition.getLogVersion();
    long logVersion = initialVersion;
    var logFile = logFiles.getLogFile();
    while (logVersion <= maxLogVersion) {
        if (logFile.versionExists(logVersion)) {
            LogPosition currentPosition = logVersion != initialVersion ? logFile.extractHeader(logVersion).getStartPosition() : initialPosition;
            try (LogVersionedStoreChannel storeChannel = logFile.openForVersion(logVersion)) {
                storeChannel.position(currentPosition.getByteOffset());
                try (LogEntryCursor cursor = new LogEntryCursor(logEntryReader, new ReadAheadLogChannel(storeChannel, memoryTracker))) {
                    while (cursor.next()) {
                        LogEntry entry = cursor.get();
                        if (entry instanceof LogEntryCommit) {
                            return new InlinedLogTailScanner.ExtractedTransactionRecord(((LogEntryCommit) entry).getTxId());
                        }
                    }
                }
            } catch (Throwable t) {
                monitor.corruptedLogFile(currentPosition.getLogVersion(), t);
                return new InlinedLogTailScanner.ExtractedTransactionRecord(true);
            }
            logVersion = currentPosition.getLogVersion() + 1;
        } else {
            logVersion += 1;
        }
    }
    return new InlinedLogTailScanner.ExtractedTransactionRecord();
}