internal virtual void CheckDataConsistencyWithMaster(URI availableMasterId, Master master, StoreId storeId, TransactionIdStore transactionIdStore)
{
TransactionId myLastCommittedTxData = transactionIdStore.LastCommittedTransaction;
long myLastCommittedTx = myLastCommittedTxData.TransactionIdConflict();
HandshakeResult handshake;
try
{
using (Response <HandshakeResult> response = master.Handshake(myLastCommittedTx, storeId))
{
handshake = response.ResponseConflict();
RequestContextFactory.Epoch = handshake.Epoch();
}
}
catch (BranchedDataException e)
{
// Rethrow wrapped in a branched data exception on our side, to clarify where the problem originates.
throw new BranchedDataException("The database stored on this machine has diverged from that " + "of the master. This will be automatically resolved.", e);
}
catch (Exception e)
{
// Checked exceptions will be wrapped as the cause if this was a serialized
// server-side exception
if (e.InnerException is MissingLogDataException)
{
/*
* This means the master was unable to find a log entry for the txid we just asked. This
* probably means the thing we asked for is too old or too new. Anyway, since it doesn't
* have the tx it is better if we just throw our store away and ask for a new copy. Next
* time around it shouldn't have to even pass from here.
*/
throw new StoreOutOfDateException("The master is missing the log required to complete the " + "consistency check", e.InnerException);
}
throw e;
}
long myChecksum = myLastCommittedTxData.Checksum();
if (myChecksum != handshake.TxChecksum())
{
string msg = "The cluster contains two logically different versions of the database.. This will be " +
"automatically resolved. Details: I (server_id:" + Config.get(ClusterSettings.server_id) +
") think checksum for txId (" + myLastCommittedTx + ") is " + myChecksum +
", but master (server_id:" + getServerId(availableMasterId) + ") says that it's " +
handshake.TxChecksum() + ", where handshake is " + handshake;
throw new BranchedDataException(msg);
}
MsgLog.info("Checksum for last committed tx ok with lastTxId=" + myLastCommittedTx + " with checksum=" + myChecksum);
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
//ORIGINAL LINE: public void migrate(org.neo4j.io.layout.DatabaseLayout directoryLayout, org.neo4j.io.layout.DatabaseLayout migrationLayout, org.neo4j.kernel.impl.util.monitoring.ProgressReporter progressReporter, String versionToMigrateFrom, String versionToMigrateTo) throws java.io.IOException
public override void Migrate(DatabaseLayout directoryLayout, DatabaseLayout migrationLayout, ProgressReporter progressReporter, string versionToMigrateFrom, string versionToMigrateTo)
{
// Extract information about the last transaction from legacy neostore
File neoStore = directoryLayout.MetadataStore();
long lastTxId = MetaDataStore.getRecord(_pageCache, neoStore, MetaDataStore.Position.LAST_TRANSACTION_ID);
TransactionId lastTxInfo = ExtractTransactionIdInformation(neoStore, lastTxId);
LogPosition lastTxLogPosition = ExtractTransactionLogPosition(neoStore, directoryLayout, lastTxId);
// Write the tx checksum to file in migrationStructure, because we need it later when moving files into storeDir
WriteLastTxInformation(migrationLayout, lastTxInfo);
WriteLastTxLogPosition(migrationLayout, lastTxLogPosition);
if (versionToMigrateFrom.Equals("vE.H.0"))
{
// NOTE for 3.0 here is a special case for vE.H.0 "from" record format.
// Legend has it that 3.0.5 enterprise changed store format without changing store version.
// This was done to cheat the migrator to avoid doing store migration since the
// format itself was backwards compatible. Immediately a problem was detected:
// if a user uses 3.0.5 for a while and then goes back to a previous 3.0.x patch release
// the db wouldn't recognize it was an incompatible downgrade and start up normally,
// but read records with scrambled values and pointers, sort of.
//
// This condition has two functions:
// 1. preventing actual store migration between vE.H.0 --> vE.H.0b
// 2. making vE.H.0b used in any migration where either vE.H.0 or vE.H.0b is the existing format,
// this because vE.H.0b is a superset of vE.H.0 and sometimes (for 3.0.5) vE.H.0
// actually means vE.H.0b (in later version).
//
// In later versions of neo4j there are better mechanics in place so that a non-migration like this
// can be performed w/o special casing. To not require backporting that functionality
// this condition is here and should be removed in 3.1.
versionToMigrateFrom = "vE.H.0b";
}
RecordFormats oldFormat = selectForVersion(versionToMigrateFrom);
RecordFormats newFormat = selectForVersion(versionToMigrateTo);
if (FormatFamily.isHigherFamilyFormat(newFormat, oldFormat) || (FormatFamily.isSameFamily(oldFormat, newFormat) && IsDifferentCapabilities(oldFormat, newFormat)))
{
// TODO if this store has relationship indexes then warn user about that they will be incorrect
// after migration, because now we're rewriting the relationship ids.
// Some form of migration is required (a fallback/catch-all option)
MigrateWithBatchImporter(directoryLayout, migrationLayout, lastTxId, lastTxInfo.Checksum(), lastTxLogPosition.LogVersion, lastTxLogPosition.ByteOffset, progressReporter, oldFormat, newFormat);
}
// update necessary neostore records
LogPosition logPosition = ReadLastTxLogPosition(migrationLayout);
UpdateOrAddNeoStoreFieldsAsPartOfMigration(migrationLayout, directoryLayout, versionToMigrateTo, logPosition);
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
//ORIGINAL LINE: private void updateOrAddNeoStoreFieldsAsPartOfMigration(org.neo4j.io.layout.DatabaseLayout migrationStructure, org.neo4j.io.layout.DatabaseLayout sourceDirectoryStructure, String versionToMigrateTo, org.neo4j.kernel.impl.transaction.log.LogPosition lastClosedTxLogPosition) throws java.io.IOException
private void UpdateOrAddNeoStoreFieldsAsPartOfMigration(DatabaseLayout migrationStructure, DatabaseLayout sourceDirectoryStructure, string versionToMigrateTo, LogPosition lastClosedTxLogPosition)
{
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final java.io.File storeDirNeoStore = sourceDirectoryStructure.metadataStore();
File storeDirNeoStore = sourceDirectoryStructure.MetadataStore();
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final java.io.File migrationDirNeoStore = migrationStructure.metadataStore();
File migrationDirNeoStore = migrationStructure.MetadataStore();
fileOperation(COPY, _fileSystem, sourceDirectoryStructure, migrationStructure, Iterables.iterable(DatabaseFile.METADATA_STORE), true, ExistingTargetStrategy.SKIP);
MetaDataStore.setRecord(_pageCache, migrationDirNeoStore, MetaDataStore.Position.UPGRADE_TRANSACTION_ID, MetaDataStore.getRecord(_pageCache, storeDirNeoStore, MetaDataStore.Position.LAST_TRANSACTION_ID));
MetaDataStore.setRecord(_pageCache, migrationDirNeoStore, MetaDataStore.Position.UPGRADE_TIME, DateTimeHelper.CurrentUnixTimeMillis());
// Store the checksum of the transaction id the upgrade is at right now. Store it both as
// LAST_TRANSACTION_CHECKSUM and UPGRADE_TRANSACTION_CHECKSUM. Initially the last transaction and the
// upgrade transaction will be the same, but imagine this scenario:
// - legacy store is migrated on instance A at transaction T
// - upgraded store is copied, via backup or HA or whatever to instance B
// - instance A performs a transaction
// - instance B would like to communicate with A where B's last transaction checksum
// is verified on A. A, at this point not having logs from pre-migration era, will need to
// know the checksum of transaction T to accommodate for this request from B. A will be able
// to look up checksums for transactions succeeding T by looking at its transaction logs,
// but T needs to be stored in neostore to be accessible. Obviously this scenario is only
// problematic as long as we don't migrate and translate old logs.
TransactionId lastTxInfo = ReadLastTxInformation(migrationStructure);
MetaDataStore.setRecord(_pageCache, migrationDirNeoStore, MetaDataStore.Position.LAST_TRANSACTION_CHECKSUM, lastTxInfo.Checksum());
MetaDataStore.setRecord(_pageCache, migrationDirNeoStore, MetaDataStore.Position.UPGRADE_TRANSACTION_CHECKSUM, lastTxInfo.Checksum());
MetaDataStore.setRecord(_pageCache, migrationDirNeoStore, MetaDataStore.Position.LAST_TRANSACTION_COMMIT_TIMESTAMP, lastTxInfo.CommitTimestamp());
MetaDataStore.setRecord(_pageCache, migrationDirNeoStore, MetaDataStore.Position.UPGRADE_TRANSACTION_COMMIT_TIMESTAMP, lastTxInfo.CommitTimestamp());
// add LAST_CLOSED_TRANSACTION_LOG_VERSION and LAST_CLOSED_TRANSACTION_LOG_BYTE_OFFSET to the migrated
// NeoStore
MetaDataStore.setRecord(_pageCache, migrationDirNeoStore, MetaDataStore.Position.LAST_CLOSED_TRANSACTION_LOG_VERSION, lastClosedTxLogPosition.LogVersion);
MetaDataStore.setRecord(_pageCache, migrationDirNeoStore, MetaDataStore.Position.LAST_CLOSED_TRANSACTION_LOG_BYTE_OFFSET, lastClosedTxLogPosition.ByteOffset);
// Upgrade version in NeoStore
MetaDataStore.setRecord(_pageCache, migrationDirNeoStore, MetaDataStore.Position.STORE_VERSION, MetaDataStore.versionStringToLong(versionToMigrateTo));
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
//ORIGINAL LINE: void writeLastTxInformation(org.neo4j.io.layout.DatabaseLayout migrationStructure, org.neo4j.kernel.impl.store.TransactionId txInfo) throws java.io.IOException
internal virtual void WriteLastTxInformation(DatabaseLayout migrationStructure, TransactionId txInfo)
{
WriteTxLogCounters(_fileSystem, LastTxInformationFile(migrationStructure), txInfo.TransactionIdConflict(), txInfo.Checksum(), txInfo.CommitTimestamp());
}
