private void DownloadDatabase(StoreId localStoreId)
{
try
{
_localDatabase.stopForStoreCopy();
_enableDisableOnStoreCopy.disable();
}
catch (Exception throwable)
{
throw new Exception(throwable);
}
try
{
MemberId source = _selectionStrategy.bestUpstreamDatabase();
AdvertisedSocketAddress fromAddress = _topologyService.findCatchupAddress(source).orElseThrow(() => new TopologyLookupException(source));
_storeCopyProcess.replaceWithStoreFrom(new CatchupAddressProvider_SingleAddressProvider(fromAddress), localStoreId);
}
catch (Exception e) when(e is IOException || e is StoreCopyFailedException || e is UpstreamDatabaseSelectionException || e is TopologyLookupException)
{
_log.warn("Error copying store. Will retry shortly.", e);
return;
}
catch (DatabaseShutdownException e)
{
_log.warn("Store copy aborted due to shutdown.", e);
return;
}
try
{
_localDatabase.start();
_enableDisableOnStoreCopy.enable();
}
catch (Exception throwable)
{
throw new Exception(throwable);
}
_latestTxIdOfUpStream = 0; // we will find out on the next pull request response
_state = TX_PULLING;
_applier.refreshFromNewStore();
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
//ORIGINAL LINE: private void syncStoreWithUpstream(org.neo4j.causalclustering.identity.MemberId source) throws java.io.IOException, org.neo4j.causalclustering.catchup.storecopy.StoreIdDownloadFailedException, org.neo4j.causalclustering.catchup.storecopy.StoreCopyFailedException, org.neo4j.causalclustering.core.state.snapshot.TopologyLookupException, org.neo4j.causalclustering.catchup.storecopy.DatabaseShutdownException
private void SyncStoreWithUpstream(MemberId source)
{
if (_localDatabase.Empty)
{
_debugLog.info("Local database is empty, attempting to replace with copy from upstream server %s", source);
_debugLog.info("Finding store id of upstream server %s", source);
AdvertisedSocketAddress fromAddress = _topologyService.findCatchupAddress(source).orElseThrow(() => new TopologyLookupException(source));
StoreId storeId = _remoteStore.getStoreId(fromAddress);
_debugLog.info("Copying store from upstream server %s", source);
_localDatabase.delete();
_storeCopyProcess.replaceWithStoreFrom(new CatchupAddressProvider_SingleAddressProvider(fromAddress), storeId);
_debugLog.info("Restarting local database after copy.", source);
}
else
{
EnsureSameStoreIdAs(source);
}
}
/// <summary>
/// Tries to catchup this instance by downloading a snapshot. A snapshot consists of both the
/// comparatively small state of the cluster state machines as well as the database store. The
/// store is however caught up using two different approach. If it is possible to catchup by
/// pulling transactions, then this will be sufficient, but if the store is lagging too far
/// behind then a complete store copy will be attempted.
/// </summary>
/// <param name="addressProvider"> Provider of addresses to catchup from. </param>
/// <returns> True if the operation succeeded, and false otherwise. </returns>
/// <exception cref="LifecycleException"> A major database component failed to start or stop. </exception>
/// <exception cref="IOException"> An issue with I/O. </exception>
/// <exception cref="DatabaseShutdownException"> The database is shutting down. </exception>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
//ORIGINAL LINE: boolean downloadSnapshot(org.neo4j.causalclustering.catchup.CatchupAddressProvider addressProvider) throws org.neo4j.kernel.lifecycle.LifecycleException, java.io.IOException, org.neo4j.causalclustering.catchup.storecopy.DatabaseShutdownException
internal virtual bool DownloadSnapshot(CatchupAddressProvider addressProvider)
{
/* Extract some key properties before shutting it down. */
bool isEmptyStore = _localDatabase.Empty;
/*
* There is no reason to try to recover if there are no transaction logs and in fact it is
* also problematic for the initial transaction pull during the snapshot download because the
* kernel will create a transaction log with a header where previous index points to the same
* index as that written down into the metadata store. This is problematic because we have no
* guarantee that there are later transactions and we need at least one transaction in
* the log to figure out the Raft log index (see {@link RecoverConsensusLogIndex}).
*/
if (_commitStateHelper.hasTxLogs(_localDatabase.databaseLayout()))
{
_log.info("Recovering local database");
Ensure(_localDatabase.start, "start local database");
Ensure(_localDatabase.stop, "stop local database");
}
AdvertisedSocketAddress primary;
StoreId remoteStoreId;
try
{
primary = addressProvider.Primary();
remoteStoreId = _remoteStore.getStoreId(primary);
}
catch (Exception e) when(e is CatchupAddressResolutionException || e is StoreIdDownloadFailedException)
{
_log.warn("Store copy failed", e);
return(false);
}
if (!isEmptyStore && !remoteStoreId.Equals(_localDatabase.storeId()))
{
_log.error("Store copy failed due to store ID mismatch");
return(false);
}
Ensure(_suspendOnStoreCopy.disable, "disable auxiliary services before store copy");
Ensure(_localDatabase.stopForStoreCopy, "stop local database for store copy");
_log.info("Downloading snapshot from core server at %s", primary);
/* The core snapshot must be copied before the store, because the store has a dependency on
* the state of the state machines. The store will thus be at or ahead of the state machines,
* in consensus log index, and application of commands will bring them in sync. Any such commands
* that carry transactions will thus be ignored by the transaction/token state machines, since they
* are ahead, and the correct decisions for their applicability have already been taken as encapsulated
* in the copied store. */
CoreSnapshot coreSnapshot;
try
{
coreSnapshot = _catchUpClient.makeBlockingRequest(primary, new CoreSnapshotRequest(), new CatchUpResponseAdaptorAnonymousInnerClass(this));
}
catch (CatchUpClientException e)
{
_log.warn("Store copy failed", e);
return(false);
}
if (!isEmptyStore)
{
StoreId localStoreId = _localDatabase.storeId();
CatchupResult catchupResult;
try
{
catchupResult = _remoteStore.tryCatchingUp(primary, localStoreId, _localDatabase.databaseLayout(), false, false);
}
catch (StoreCopyFailedException e)
{
_log.warn("Failed to catch up", e);
return(false);
}
if (catchupResult == E_TRANSACTION_PRUNED)
{
_log.warn(format("Failed to pull transactions from (%s). They may have been pruned away", primary));
_localDatabase.delete();
isEmptyStore = true;
}
else if (catchupResult != SUCCESS_END_OF_STREAM)
{
_log.warn(format("Unexpected catchup operation result %s from %s", catchupResult, primary));
return(false);
}
}
if (isEmptyStore)
{
try
{
_storeCopyProcess.replaceWithStoreFrom(addressProvider, remoteStoreId);
}
catch (StoreCopyFailedException e)
{
_log.warn("Failed to copy and replace store", e);
return(false);
}
}
/* We install the snapshot after the store has been downloaded,
* so that we are not left with a state ahead of the store. */
_snapshotService.installSnapshot(coreSnapshot);
_log.info("Core snapshot installed: " + coreSnapshot);
/* Starting the database will invoke the commit process factory in
* the EnterpriseCoreEditionModule, which has important side-effects. */
_log.info("Starting local database");
Ensure(_localDatabase.start, "start local database after store copy");
_coreStateMachines.installCommitProcess(_localDatabase.CommitProcess);
Ensure(_suspendOnStoreCopy.enable, "enable auxiliary services after store copy");
return(true);
}
