internal async Task <Tuple <GossipTableEntry, Dictionary <SiloAddress, GossipTableEntry> > > ReadAllEntriesAsync()
{
var queryResults = await storage.ReadAllTableEntriesForPartitionAsync(this.GlobalServiceId).ConfigureAwait(false);
// organize the returned storage entries by what they represent
GossipTableEntry configInStorage = null;
var gatewayInfoInStorage = new Dictionary <SiloAddress, GossipTableEntry>();
foreach (var x in queryResults)
{
var tableEntry = x.Item1;
if (tableEntry.RowKey.Equals(GossipTableEntry.CONFIGURATION_ROW))
{
configInStorage = tableEntry;
}
else
{
try
{
tableEntry.ParseSiloAddressFromRowKey();
gatewayInfoInStorage.Add(tableEntry.SiloAddress, tableEntry);
}
catch (Exception exc)
{
logger.Error(
(int)TableStorageErrorCode.AzureTable_61,
string.Format("Intermediate error parsing GossipTableEntry: {0}. Ignoring this entry.", tableEntry),
exc);
}
}
}
return(new Tuple <GossipTableEntry, Dictionary <SiloAddress, GossipTableEntry> >(configInStorage, gatewayInfoInStorage));
}
internal async Task <bool> TryUpdateGatewayEntryAsync(GatewayEntry entry, GossipTableEntry row, string eTag)
{
row.Status = entry.Status.ToString();
row.GossipTimestamp = entry.HeartbeatTimestamp;
return(await TryUpdateTableEntryAsync(row, eTag).ConfigureAwait(false));
}
public async Task <IMultiClusterGossipData> Synchronize(IMultiClusterGossipData pushed)
{
logger.Debug("-Synchronize pushed:{0}", pushed);
try
{
// read the entire table from storage
var entriesFromStorage = await tableManager.ReadAllEntriesAsync();
var configInStorage = entriesFromStorage.Item1;
var gatewayInfoInStorage = entriesFromStorage.Item2;
// diff and write back configuration
var configDeltaTask = DiffAndWriteBackConfigAsync(pushed.Configuration, configInStorage);
// diff and write back gateway info for each gateway appearing locally or in storage
var gatewayDeltaTasks = new List <Task <GatewayEntry> >();
var allAddresses = gatewayInfoInStorage.Keys.Union(pushed.Gateways.Keys);
foreach (var address in allAddresses)
{
GatewayEntry pushedInfo = null;
pushed.Gateways.TryGetValue(address, out pushedInfo);
GossipTableEntry infoInStorage = null;
gatewayInfoInStorage.TryGetValue(address, out infoInStorage);
gatewayDeltaTasks.Add(DiffAndWriteBackGatewayInfoAsync(pushedInfo, infoInStorage));
}
// wait for all the writeback tasks to complete
// these are not batched because we want them to fail individually on e-tag conflicts, not all
await configDeltaTask;
await Task.WhenAll(gatewayDeltaTasks);
// assemble delta pieces
var gw = new Dictionary <SiloAddress, GatewayEntry>();
foreach (var t in gatewayDeltaTasks)
{
var d = t.Result;
if (d != null)
{
gw.Add(d.SiloAddress, d);
}
}
var delta = new MultiClusterData(gw, configDeltaTask.Result);
logger.Debug("-Synchronize pulled delta:{0}", delta);
return(delta);
}
catch (Exception e)
{
logger.Info("-Synchronize encountered exception {0}", e);
throw e;
}
}
internal async Task <bool> TryCreateGatewayEntryAsync(GatewayEntry entry)
{
var row = new GossipTableEntry()
{
PartitionKey = GlobalServiceId,
RowKey = GossipTableEntry.ConstructRowKey(entry.SiloAddress, entry.ClusterId),
Status = entry.Status.ToString(),
GossipTimestamp = entry.HeartbeatTimestamp
};
return(await TryCreateTableEntryAsync(row).ConfigureAwait(false));
}
internal async Task <bool> TryCreateConfigurationEntryAsync(MultiClusterConfiguration configuration)
{
if (configuration == null)
{
throw new ArgumentNullException("configuration");
}
var entry = new GossipTableEntry
{
PartitionKey = GlobalServiceId,
RowKey = GossipTableEntry.CONFIGURATION_ROW,
GossipTimestamp = configuration.AdminTimestamp,
Clusters = string.Join(GossipTableEntry.ClustersListSeparator, configuration.Clusters),
Comment = configuration.Comment ?? ""
};
return(await TryCreateTableEntryAsync(entry).ConfigureAwait(false));
}
internal async Task<bool> TryUpdateConfigurationEntryAsync(MultiClusterConfiguration configuration, GossipTableEntry entry, string eTag)
{
if (configuration == null) throw new ArgumentNullException("configuration");
entry.GossipTimestamp = configuration.AdminTimestamp;
entry.Clusters = string.Join(GossipTableEntry.ClustersListSeparator, configuration.Clusters);
entry.Comment = configuration.Comment ?? "";
return (await TryUpdateTableEntryAsync(entry, eTag).ConfigureAwait(false));
}
internal async Task<bool> TryCreateConfigurationEntryAsync(MultiClusterConfiguration configuration)
{
if (configuration == null) throw new ArgumentNullException("configuration");
var entry = new GossipTableEntry
{
PartitionKey = GlobalServiceId,
RowKey = GossipTableEntry.CONFIGURATION_ROW,
GossipTimestamp = configuration.AdminTimestamp,
Clusters = string.Join(GossipTableEntry.ClustersListSeparator, configuration.Clusters),
Comment = configuration.Comment ?? ""
};
return (await TryCreateTableEntryAsync(entry).ConfigureAwait(false));
}
/// <summary>
/// Try once to delete a data entry in the Azure table. Returns false if there is a conflict.
/// </summary>
private async Task <bool> TryDeleteTableEntryAsync(GossipTableEntry data, string etag, [CallerMemberName] string operation = null)
{
return(await TryOperation(() => storage.DeleteTableEntryAsync(data, etag), operation));
}
internal Task <bool> TryDeleteGatewayEntryAsync(GossipTableEntry row, string eTag)
{
return(TryDeleteTableEntryAsync(row, eTag));
}
// compare gatewayInfo with gatewayInfoInStorage, and
// - write gatewayInfo to storage if it is newer (or do nothing on etag conflict)
// - remove expired gateway info from storage
// - return gatewayInfoInStorage if it is newer
internal async Task<GatewayEntry> DiffAndWriteBackGatewayInfoAsync(GatewayEntry gatewayInfo, GossipTableEntry gatewayInfoInStorage)
{
if ((gatewayInfo != null && !gatewayInfo.Expired)
&& (gatewayInfoInStorage == null || gatewayInfoInStorage.GossipTimestamp < gatewayInfo.HeartbeatTimestamp))
{
// push the more recent gateway info to storage
if (gatewayInfoInStorage == null)
{
await tableManager.TryCreateGatewayEntryAsync(gatewayInfo);
}
else
{
await tableManager.TryUpdateGatewayEntryAsync(gatewayInfo, gatewayInfoInStorage, gatewayInfoInStorage.ETag);
}
}
else if (gatewayInfoInStorage != null &&
(gatewayInfo == null || gatewayInfo.HeartbeatTimestamp < gatewayInfoInStorage.GossipTimestamp))
{
var fromstorage = gatewayInfoInStorage.ToGatewayEntry();
if (fromstorage.Expired)
{
// remove gateway info from storage
await tableManager.TryDeleteGatewayEntryAsync(gatewayInfoInStorage, gatewayInfoInStorage.ETag);
}
else
{
// pull the more recent info from storage
return fromstorage;
}
}
return null;
}
internal Task<bool> TryDeleteGatewayEntryAsync(GossipTableEntry row, string eTag)
{
return TryDeleteTableEntryAsync(row, eTag);
}
internal async Task <GossipTableEntry> ReadGatewayEntryAsync(GatewayEntry gateway)
{
var result = await storage.ReadSingleTableEntryAsync(this.GlobalServiceId, GossipTableEntry.ConstructRowKey(gateway.SiloAddress, gateway.ClusterId)).ConfigureAwait(false);
if (result != null)
{
var tableEntry = result.Item1;
try
{
tableEntry.ParseSiloAddressFromRowKey();
return(tableEntry);
}
catch (Exception exc)
{
logger.Error(
(int)TableStorageErrorCode.AzureTable_61,
string.Format("Intermediate error parsing GossipTableEntry: {0}. Ignoring this entry.", tableEntry),
exc);
}
}
return(null);
}
// compare gatewayInfo with gatewayInfoInStorage, and
// - write gatewayInfo to storage if it is newer (or do nothing on etag conflict)
// - remove expired gateway info from storage
// - return gatewayInfoInStorage if it is newer
internal async Task <GatewayEntry> DiffAndWriteBackGatewayInfoAsync(GatewayEntry gatewayInfo, GossipTableEntry gatewayInfoInStorage)
{
if ((gatewayInfo != null && !gatewayInfo.Expired) &&
(gatewayInfoInStorage == null || gatewayInfoInStorage.GossipTimestamp < gatewayInfo.HeartbeatTimestamp))
{
// push the more recent gateway info to storage
if (gatewayInfoInStorage == null)
{
await tableManager.TryCreateGatewayEntryAsync(gatewayInfo);
}
else
{
await tableManager.TryUpdateGatewayEntryAsync(gatewayInfo, gatewayInfoInStorage, gatewayInfoInStorage.ETag);
}
}
else if (gatewayInfoInStorage != null &&
(gatewayInfo == null || gatewayInfo.HeartbeatTimestamp < gatewayInfoInStorage.GossipTimestamp))
{
var fromstorage = gatewayInfoInStorage.ToGatewayEntry();
if (fromstorage.Expired)
{
// remove gateway info from storage
await tableManager.TryDeleteGatewayEntryAsync(gatewayInfoInStorage, gatewayInfoInStorage.ETag);
}
else
{
// pull the more recent info from storage
return(fromstorage);
}
}
return(null);
}
// compare config with configInStorage, and
// - write config to storage if it is newer (or do nothing on etag conflict)
// - return config from store if it is newer
internal async Task <MultiClusterConfiguration> DiffAndWriteBackConfigAsync(MultiClusterConfiguration config, GossipTableEntry configInStorage)
{
// interpret empty admin timestamp by taking the azure table timestamp instead
// this allows an admin to inject a configuration by editing table directly
if (configInStorage != null && configInStorage.GossipTimestamp == default(DateTime))
{
configInStorage.GossipTimestamp = configInStorage.Timestamp.UtcDateTime;
}
if (config != null &&
(configInStorage == null || configInStorage.GossipTimestamp < config.AdminTimestamp))
{
// push the more recent configuration to storage
if (configInStorage == null)
{
await tableManager.TryCreateConfigurationEntryAsync(config);
}
else
{
await tableManager.TryUpdateConfigurationEntryAsync(config, configInStorage, configInStorage.ETag);
}
}
else if (configInStorage != null &&
(config == null || config.AdminTimestamp < configInStorage.GossipTimestamp))
{
// pull the more recent configuration from storage
return(configInStorage.ToConfiguration());
}
return(null);
}
internal async Task<bool> TryCreateGatewayEntryAsync(GatewayEntry entry)
{
var row = new GossipTableEntry()
{
PartitionKey = GlobalServiceId,
RowKey = GossipTableEntry.ConstructRowKey(entry.SiloAddress, entry.ClusterId),
Status = entry.Status.ToString(),
GossipTimestamp = entry.HeartbeatTimestamp
};
return (await TryCreateTableEntryAsync(row).ConfigureAwait(false));
}
internal async Task<bool> TryUpdateGatewayEntryAsync(GatewayEntry entry, GossipTableEntry row, string eTag)
{
row.Status = entry.Status.ToString();
row.GossipTimestamp = entry.HeartbeatTimestamp;
return (await TryUpdateTableEntryAsync(row, eTag).ConfigureAwait(false));
}
internal async Task <bool> TryUpdateConfigurationEntryAsync(MultiClusterConfiguration configuration, GossipTableEntry entry, string eTag)
{
if (configuration == null)
{
throw new ArgumentNullException("configuration");
}
entry.GossipTimestamp = configuration.AdminTimestamp;
entry.Clusters = string.Join(GossipTableEntry.ClustersListSeparator, configuration.Clusters);
entry.Comment = configuration.Comment ?? "";
return(await TryUpdateTableEntryAsync(entry, eTag).ConfigureAwait(false));
}
/// <summary>
/// Try once to delete a data entry in the Azure table. Returns false if there is a conflict.
/// </summary>
private async Task<bool> TryDeleteTableEntryAsync(GossipTableEntry data, string etag, [CallerMemberName]string operation = null)
{
return await TryOperation(() => storage.DeleteTableEntryAsync(data, etag), operation);
}
// compare config with configInStorage, and
// - write config to storage if it is newer (or do nothing on etag conflict)
// - return config from store if it is newer
internal async Task<MultiClusterConfiguration> DiffAndWriteBackConfigAsync(MultiClusterConfiguration config, GossipTableEntry configInStorage)
{
// interpret empty admin timestamp by taking the azure table timestamp instead
// this allows an admin to inject a configuration by editing table directly
if (configInStorage != null && configInStorage.GossipTimestamp == default(DateTime))
configInStorage.GossipTimestamp = configInStorage.Timestamp.UtcDateTime;
if (config != null &&
(configInStorage == null || configInStorage.GossipTimestamp < config.AdminTimestamp))
{
// push the more recent configuration to storage
if (configInStorage == null)
await tableManager.TryCreateConfigurationEntryAsync(config);
else
await tableManager.TryUpdateConfigurationEntryAsync(config, configInStorage, configInStorage.ETag);
}
else if (configInStorage != null &&
(config == null || config.AdminTimestamp < configInStorage.GossipTimestamp))
{
// pull the more recent configuration from storage
return configInStorage.ToConfiguration();
}
return null;
}