private void DeleteOldEntities()
{
var storageAccount = this.storageAccountFactory.GetStorageAccount();
Debug.Assert(null == storageAccount);
// Create a table client
CloudTableClient tableClient = AzureTableCommon.CreateNewTableClient(storageAccount);
// Create a new table service context
CloudTableClient tableServiceContext = tableClient;
// Figure out the timestamp before which all entities will be deleted
DateTime cutoffTime = DateTime.UtcNow.Add(-this.entityDeletionAge);
// Delete the entities in batches. Do this in a loop until our query
// for "delete-eligible" entities yields no results.
TableContinuationToken continuationToken = null;
do
{
QueryAndDeleteEntityBatch(storageAccount, tableServiceContext, cutoffTime, ref continuationToken);
if (this.stopping)
{
this.traceSource.WriteInfo(
this.logSourceId,
"The consumer is being stopped. Therefore, no more old entities will be deleted in this pass.");
break;
}
} while (null != continuationToken);
}
public void OnEtwEventDeliveryStart()
{
this.perfHelper.TableUploadPeriodBegin();
var storageAccount = this.tableUploadSettings.StorageAccountFactory.GetStorageAccount();
Debug.Assert(null == storageAccount);
// Create a table client
CloudTableClient tableClient = AzureTableCommon.CreateNewTableClient(storageAccount);
// Create new table service contexts using the new credentials
for (int i = 0; i < this.batchConcurrencyCount; i++)
{
Debug.Assert(null == this.tableClients[i]);
this.tableClients[i] = tableClient;
}
}
private void CreateTableWorker(CloudStorageAccount storageAccount)
{
// Create the table client object
CloudTableClient cloudTableClient = AzureTableCommon.CreateNewTableClient(storageAccount);
// Create the table
#if DotNetCoreClrLinux
cloudTableClient.GetTableReference(this.tableUploadSettings.TableName).CreateIfNotExistsAsync().Wait();
#else
cloudTableClient.GetTableReference(this.tableUploadSettings.TableName).CreateIfNotExists();
#endif
// Create an array of table service context objects
this.availableIndexes = new Stack <int>();
this.tableClients = new CloudTableClient[this.batchConcurrencyCount];
for (int i = 0; i < this.batchConcurrencyCount; i++)
{
this.availableIndexes.Push(i);
}
}
private void QueryAndDeleteEntityBatch(CloudStorageAccount storageAccount, CloudTableClient tableServiceContext, DateTime cutoffTime, ref TableContinuationToken continuationToken)
{
TableContinuationToken initialContinuationToken = continuationToken;
continuationToken = null;
this.traceSource.WriteInfo(this.logSourceId, "Deleting table entries older than {0}.", cutoffTime);
// Create a query object
TableQuery <TableEntity> query = this.queryCreationMethod(cutoffTime);
TableQuerySegment <TableEntity> resultSegment;
try
{
this.perfHelper.ExternalOperationBegin(
ExternalOperationTime.ExternalOperationType.TableQuery,
0);
// Execute the query
#if DotNetCoreClr
resultSegment = tableServiceContext.GetTableReference(this.tableName).ExecuteQuerySegmentedAsync(query, initialContinuationToken).Result;
#else
resultSegment = tableServiceContext.GetTableReference(this.tableName).ExecuteQuerySegmented(query, initialContinuationToken);
#endif
this.perfHelper.ExternalOperationEnd(
ExternalOperationTime.ExternalOperationType.TableQuery,
0);
}
catch (Exception e)
{
AzureTableCommon.TableServiceExceptionAction action = AzureTableCommon.ProcessTableServiceQueryException(
this.traceSource,
this.logSourceId,
e,
AzureTableCommon.TableServiceAction.QueryEntitiesForDeletion);
// Give up on this batch
Debug.Assert(AzureTableCommon.TableServiceExceptionAction.Abort == action);
return;
}
continuationToken = resultSegment.ContinuationToken;
if (!resultSegment.Results.Any())
{
// Query did not give us any entities to delete. Nothing more to
// be done here.
return;
}
this.perfHelper.BatchQueriedFromAzureTable((ulong)resultSegment.Results.Count());
// Create a table client
CloudTableClient tableClient = AzureTableCommon.CreateNewTableClient(storageAccount);
// Walk through the query results
var entitiesToDelete = new List <TableEntity>();
string partitionKey = String.Empty;
foreach (var entity in resultSegment.Results)
{
// Azure table service requires all entities in a batched transaction to
// have the same parition key. Hence if the partition key for this entity
// is not the same as that of the entities we already added to the batch,
// then delete those entities first and add this one to a new batch.
if ((false == String.IsNullOrEmpty(partitionKey)) &&
(false == entity.PartitionKey.Equals(partitionKey)))
{
DeleteEntityBatch(tableClient, entitiesToDelete);
// Clear for the next batch
entitiesToDelete.Clear();
}
// Record the partition key for the current batch
partitionKey = entity.PartitionKey;
entitiesToDelete.Add(entity);
// If we have reached that maximum entity count for a batch, then
// delete those entities.
if (entitiesToDelete.Count == AzureTableCommon.MaxEntitiesInBatch)
{
DeleteEntityBatch(tableClient, entitiesToDelete);
// Clear for the next batch
entitiesToDelete.Clear();
}
}
if (entitiesToDelete.Any())
{
DeleteEntityBatch(tableClient, entitiesToDelete);
}
}