/// <summary>
/// Initiates a schema agreement check.
/// <para/>
/// Schema changes need to be propagated to all nodes in the cluster.
/// Once they have settled on a common version, we say that they are in agreement.
/// <para/>
/// This method does not perform retries so
/// <see cref="ProtocolOptions.MaxSchemaAgreementWaitSeconds"/> does not apply.
/// </summary>
/// <returns>True if schema agreement was successful and false if it was not successful.</returns>
public async Task <bool> CheckSchemaAgreementAsync()
{
if (Hosts.Count == 1)
{
// If there is just one node, the schema is up to date in all nodes :)
return(true);
}
try
{
var queries = new[]
{
ControlConnection.QueryAsync(SelectSchemaVersionLocal),
ControlConnection.QueryAsync(SelectSchemaVersionPeers)
};
await Task.WhenAll(queries).ConfigureAwait(false);
return(CheckSchemaVersionResults(queries[0].Result, queries[1].Result));
}
catch (Exception ex)
{
Logger.Error("Error while checking schema agreement.", ex);
}
return(false);
}
/// <summary>
/// Refresh the partition map for all tables.
/// </summary>
internal async Task RefreshPartitionMap()
{
if (!Configuration.Policies.LoadBalancingPolicy.RequiresPartitionMap)
{
return;
}
var addressToHosts = new Dictionary <IPAddress, Host>();
foreach (var host in AllHosts())
{
addressToHosts.Add(host.Address.Address, host);
}
var rows = await ControlConnection.QueryAsync(SelectPartitions);
var splitsSource = new Dictionary <string, List <PartitionMetadata> >();
foreach (var row in rows)
{
var keyspace = row.GetValue <string>("keyspace_name");
var tableName = row.GetValue <string>("table_name");
var fullTableName = keyspace + "." + tableName;
var replicas = row.GetValue <IDictionary <IPAddress, string> >("replica_addresses");
var hosts = new List <Host>(replicas.Count);
foreach (var entry in replicas)
{
Host host;
if (!addressToHosts.TryGetValue(entry.Key, out host))
{
continue;
}
var role = entry.Value;
if (role == "LEADER")
{
hosts.Insert(0, host);
}
else if (role == "READ_REPLICA" || role == "FOLLOWER")
{
hosts.Add(host);
}
}
var startKey = BytesToHashCode(row.GetValue <byte[]>("start_key"));
var endKey = BytesToHashCode(row.GetValue <byte[]>("end_key"));
List <PartitionMetadata> partitions;
if (!splitsSource.TryGetValue(fullTableName, out partitions))
{
partitions = new List <PartitionMetadata>();
splitsSource.Add(fullTableName, partitions);
}
partitions.Add(new PartitionMetadata(startKey, endKey, hosts));
}
var splits = new Dictionary <string, TableSplitMetadata>();
foreach (var entry in splitsSource)
{
splits.Add(entry.Key, new TableSplitMetadata(entry.Value));
}
TableSplitMetadata = splits;
}
