public void CorrectlyGeneratesRanges()
{
foreach (var numShards in Enumerable.Range(2, 10000))
{
var ranges = Int32RangeGenerator.GetRanges(numShards);
Assert.IsNotNull(ranges);
Assert.AreEqual(numShards, ranges.Count);
var actualFirstRange = ranges.First();
Assert.AreEqual(1, actualFirstRange.Key);
Assert.AreEqual(int.MinValue, actualFirstRange.Value.LowValue);
for (int shardNum = 2; shardNum < ranges.Count; shardNum++)
{
var previousRange = ranges[shardNum - 1];
var actualRange = ranges[shardNum];
Assert.AreEqual(previousRange.HighValue, actualRange.LowValue);
}
var actualLastRange = ranges.Last();
Assert.AreEqual(ranges.Count, actualLastRange.Key);
Assert.AreEqual(int.MaxValue, actualLastRange.Value.HighValue);
var actualNextToLastRange = ranges[ranges.Count - 1];
Assert.AreEqual(actualNextToLastRange.HighValue, actualLastRange.Value.LowValue);
}
}
public void CorrectlyGeneratesRangeForOneShard()
{
var ranges = Int32RangeGenerator.GetRanges(1);
Assert.IsNotNull(ranges);
Assert.AreEqual(1, ranges.Count);
var actualFullRange = ranges.Single();
Assert.AreEqual(1, actualFullRange.Key);
Assert.AreEqual(int.MinValue, actualFullRange.Value.LowValue);
Assert.AreEqual(int.MaxValue, actualFullRange.Value.HighValue);
}
public void ThrowsExceptionForNumShardsLessThan1()
{
Int32RangeGenerator.GetRanges(0);
}
public void AddInt32RangeMapShards(AddInt32RangeMapShardsArgs args)
{
args.Validate();
var shardRanges = Int32RangeGenerator.GetRanges(args.ShardLocations.Locations.Length);
// sanity checks
if (shardRanges.Count != args.ShardLocations.Locations.Length)
{
throw new Exception($"The number of locations ({args.ShardLocations.Locations.Length}) does not match the number of generated shard ranges ({shardRanges.Count}).");
}
if (shardRanges[1].LowValue != int.MinValue)
{
throw new Exception($"Expected the first shard range low value to be int.MinValue, but it is {shardRanges[1].LowValue}.");
}
if (shardRanges[shardRanges.Count].HighValue != int.MaxValue)
{
throw new Exception($"Expected the last shard range high value to be int.MaxValue, but it is {shardRanges[shardRanges.Count].HighValue}.");
}
// now that we're sure everything is as expected, let's proceed...
var shardManagementService = new ShardMapManagementService(args.ConnectionString);
var keyType = typeof(int).Name;
var connectionString = new SqlConnectionStringBuilder(args.ConnectionString);
for (int i = 0; i < args.ShardLocations.Locations.Length - 1; i++)
{
var shardNumber = (i + 1);
var location = args.ShardLocations.Locations[i];
var range = shardRanges[shardNumber];
Log.Information(
LoggingMessageTemplates.AddRangeMapShard,
shardNumber,
location.DatabaseName,
location.ServerName,
keyType,
range.LowValue,
range.HighValue,
args.MapName,
connectionString.InitialCatalog,
connectionString.DataSource);
shardManagementService.AddRangeMapShard(
args.MapName,
range.LowValue,
range.HighValue,
location.ServerName,
location.DatabaseName);
}
var lastLocation = args.ShardLocations.Locations.Last();
var lastRange = shardRanges.Last();
Log.Information(
LoggingMessageTemplates.AddRangeMapShard,
lastRange.Key,
lastLocation.DatabaseName,
lastLocation.ServerName,
keyType,
lastRange.Value.LowValue,
"+infinity",
args.MapName,
connectionString.InitialCatalog,
connectionString.DataSource);
shardManagementService.AddRangeMapShard(
args.MapName,
lastRange.Value.LowValue,
lastLocation.ServerName,
lastLocation.DatabaseName);
}