/// <summary>
/// A utility method for cleaning up expired sessions that IIS failed to delete. The method performs a scan on the table
/// with a condition that the expiration date is in the past and calls delete on all the keys returned. Scans can be costly on performance
/// so use this method sparingly like a nightly or weekly clean job.
/// </summary>
/// <param name="dbClient">The AmazonDynamoDB client used to find a delete expired sessions.</param>
/// <param name="tableName">The table to search.</param>
public static void DeleteExpiredSessions(IAmazonDynamoDB dbClient, string tableName)
{
Table table = Table.LoadTable(dbClient, tableName, Table.DynamoDBConsumer.SessionStateProvider, DynamoDBEntryConversion.V1);
ScanFilter filter = new ScanFilter();
filter.AddCondition(ATTRIBUTE_EXPIRES, ScanOperator.LessThan, DateTime.Now);
ScanOperationConfig config = new ScanOperationConfig();
config.AttributesToGet = new List <string> {
ATTRIBUTE_SESSION_ID
};
config.Select = SelectValues.SpecificAttributes;
config.Filter = filter;
DocumentBatchWrite batchWrite = table.CreateBatchWrite();
Search search = table.Scan(config);
do
{
List <Document> page = search.GetNextSet();
foreach (var document in page)
{
batchWrite.AddItemToDelete(document);
}
} while (!search.IsDone);
batchWrite.Execute();
}
private void TestMultiTableDocumentBatchWrite(Table hashTable, Table hashRangeTable)
{
var multiTableDocumentBatchWrite = new MultiTableDocumentBatchWrite();
var doc1a = new Document();
doc1a["Id"] = 5101;
doc1a["Data"] = Guid.NewGuid().ToString();
var doc1b = new Document();
doc1b["Id"] = 5102;
doc1b["Data"] = Guid.NewGuid().ToString();
{
var writer = new DocumentBatchWrite(hashTable);
writer.AddDocumentToPut(doc1a);
writer.AddDocumentToPut(doc1b);
multiTableDocumentBatchWrite.AddBatch(writer);
}
var doc2a = new Document();
doc2a["Id"] = 5201;
doc2a["Data"] = Guid.NewGuid().ToString();
var doc2b = new Document();
doc2b["Id"] = 5202;
doc2b["Data"] = Guid.NewGuid().ToString();
{
var writer = new DocumentBatchWrite(hashTable);
writer.AddDocumentToPut(doc2a);
writer.AddDocumentToPut(doc2b);
multiTableDocumentBatchWrite.AddBatch(writer);
}
var doc3a = new Document();
doc3a["Name"] = "Gunnar";
doc3a["Age"] = 77;
doc3a["Job"] = "Retired";
doc3a["Data"] = Guid.NewGuid().ToString();
{
var writer = new DocumentBatchWrite(hashRangeTable);
writer.AddDocumentToPut(doc3a);
multiTableDocumentBatchWrite.AddBatch(writer);
}
multiTableDocumentBatchWrite.Execute();
Document getDoc;
getDoc = hashTable.GetItem(5101);
Assert.AreEqual(doc1a["Data"].AsString(), getDoc["Data"].AsString());
getDoc = hashTable.GetItem(5102);
Assert.AreEqual(doc1b["Data"].AsString(), getDoc["Data"].AsString());
getDoc = hashTable.GetItem(5201);
Assert.AreEqual(doc2a["Data"].AsString(), getDoc["Data"].AsString());
getDoc = hashTable.GetItem(5202);
Assert.AreEqual(doc2b["Data"].AsString(), getDoc["Data"].AsString());
getDoc = hashRangeTable.GetItem("Gunnar", 77);
Assert.AreEqual(doc3a["Data"].AsString(), getDoc["Data"].AsString());
multiTableDocumentBatchWrite = new MultiTableDocumentBatchWrite();
{
var deleteWriter = new DocumentBatchWrite(hashTable);
deleteWriter.AddItemToDelete(doc1a);
deleteWriter.AddItemToDelete(doc1b);
deleteWriter.AddItemToDelete(doc2a);
deleteWriter.AddItemToDelete(doc2b);
multiTableDocumentBatchWrite.AddBatch(deleteWriter);
}
{
var deleteWriter = new DocumentBatchWrite(hashRangeTable);
deleteWriter.AddItemToDelete(doc3a);
multiTableDocumentBatchWrite.AddBatch(deleteWriter);
}
multiTableDocumentBatchWrite.Execute();
}
