public OperationalDatabases GetOperationalDatabases(Statement statement)
{
OperationalDatabases databases = new OperationalDatabases
{
OtherCandidates = new List <Database>()
};
try
{
String databaseSet = statement.DatabaseSet;
var master = DALBootstrap.DatabaseSets[databaseSet].DatabaseWrappers.Where(item => item.DatabaseType == DatabaseType.Master).Single();
var slaves = DALBootstrap.DatabaseSets[databaseSet].DatabaseWrappers.Where(item => item.DatabaseType == DatabaseType.Slave)
.OrderByDescending(p => p.Ratio).ToList();
if (slaves != null && slaves.Count > 0)
{
databases.FirstCandidate = slaves[0].Database;
slaves.RemoveAt(0);
slaves.ForEach(p => databases.OtherCandidates.Add(p.Database));
databases.OtherCandidates.Add(master.Database);
}
}
catch
{
throw;
}
return(databases);
}
/// <summary>
/// 读写分离规则
/// </summary>
/// <param name="statement"></param>
/// <returns></returns>
public OperationalDatabases GetOperationalDatabases(Statement statement)
{
OperationalDatabases databases = new OperationalDatabases
{
OtherCandidates = new List <Database>()
};
try
{
String databaseSet = statement.DatabaseSet;
var master = DALBootstrap.DatabaseSets[databaseSet].DatabaseWrappers.Single(item => item.DatabaseType == DatabaseType.Master);
var slaves = DALBootstrap.DatabaseSets[databaseSet].DatabaseWrappers.Where(item => item.DatabaseType == DatabaseType.Slave)
.ToList();
Int32 count = slaves.Count();
if (statement.OperationType == OperationType.Read && count > 0)
{
Random random = new Random();
//如果多于1个Slave，随机选择一个
int index = random.Next(0, count);
for (Int32 i = 0; i < count; i++)
{
if (i == index)
{
databases.FirstCandidate = slaves.ElementAt(index).Database;
}
else
{
databases.OtherCandidates.Add(slaves.ElementAt(i).Database);
}
}
//将主库加入作为最后的备选
databases.OtherCandidates.Add(master.Database);
}
else
{
databases.FirstCandidate = master.Database;
databases.OtherCandidates.Add(count > 0 ? slaves.ElementAt(0).Database:null);
}
}
catch (Exception ex)
{
throw new DalException(ex.Message + Environment.NewLine + ex.StackTrace);
}
return(databases);
}
public T ExecuteWithHa <T>(Func <Database, T> func, OperationalDatabases databases)
{
T result = default(T);
BitArray bitArray = (databases.OtherCandidates != null && databases.OtherCandidates.Count > 0) ? new BitArray(databases.OtherCandidates.Count) : null;
var currentOperateDatabase = databases.FirstCandidate;
Int32 retryTimes = RetryFailOverTimes;
try
{
ExecutorManager.Executor.Daemon();
//被Mark Down了，且当前Request没有放行
while (haBean.EnableHA && retryTimes > 0 && !currentOperateDatabase.Available)
{
var fallbackDatabase = FallToNextDatabase(currentOperateDatabase, databases.OtherCandidates, bitArray);
if (fallbackDatabase == currentOperateDatabase)
{
throw new DalMarkDownException(String.Format(Resources.DBMarkDownException, currentOperateDatabase.AllInOneKey));
}
currentOperateDatabase = fallbackDatabase;
retryTimes--;
}
if (!currentOperateDatabase.Available)
{
throw new DalMarkDownException(String.Format(Resources.DBMarkDownException, currentOperateDatabase.AllInOneKey));
}
result = func(currentOperateDatabase);
}
catch (DalMarkDownException)
{
throw;
}
catch (DbException ex)
{
if (!haBean.EnableHA)
{
throw;
}
var exception = ex;
Boolean failoverSucceed = false;
String databaseSet = currentOperateDatabase.DatabaseSetName;
String allInOneKey = currentOperateDatabase.AllInOneKey;
while (retryTimes > 0)
{
retryTimes--;
try
{
Boolean failoverNecessary = SatisfyRetryFailOverCondition(exception);
if (!failoverNecessary)
{
throw;
}
var failoverDatabase = FallToNextDatabase(currentOperateDatabase, databases.OtherCandidates, bitArray);
if (failoverDatabase == null)
{
throw;
}
allInOneKey = failoverDatabase.AllInOneKey;
result = func(failoverDatabase);
failoverSucceed = true;
}
catch (DbException exp)
{
exception = exp;
failoverSucceed = false;
}
if (failoverSucceed)
{
LogManager.Logger.MetricsFailover(databaseSet, allInOneKey);
break;
}
}
if (!failoverSucceed)
{
throw;
}
}
return(result);
}
