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Daily Archives: March 19, 2012

Render and Email a Reporting Services Report using .Net

2 Comments Posted by on March 19, 2012

In an earlier post, I had described a customer scenario, where they would want to execute and render a report from a .Net application, and then send the rendered report as an email attachment.

In the previous post, I had talked about how to generate a Tree View of the Report Server Items. In this post, I would be talking mainly about the how to execute a report and render it in a required format. And then send the Report as an email attachment.

The Post, assumes the following

  1. The report which needs to be executed is selected on the Tree View and the report path is passed to the function.
  2. The Report runs with default parameters.
  3. The SMTP mail server is preconfigured.

In order to execute a Report, we need to use the ReportExecutionService() Class, defined in the ReportExecution2005 endpoint for Reporting Services.

I created a new class ExecuteAndRender for this functionality.

The ExecuteAndRender Class, defines and object for the ReportExecutionService() class, in order to execute the methods exposed by Reporting Services.

   1: public ExecuteAndRender()

   2:         {

   3:              rs = new ReportExecutionService();

   4:              rs.Credentials = System.Net.CredentialCache.DefaultCredentials;

   5:              rs.Url = "http://localhost/reportserver/ReportExecution2005.asmx";

   6:         }

Next I created a function RenderReport(string ReportName), this function performance the following tasks

  1. Define the Report Rendering and execution settings.
  2. Calls the ReportExecutionService.LoadReport() to load the report definition.
  3. Defines the report parameters. In this case, since all default values would be used, we do not explicitly define the parameters.
  4. Calls the ReportExecutionService.Render() method to render the report in the desired format.
  5. One the report have been rendered, we create a PDF file for the report.
  6. Then call the AttachAndSendEmail() to send the email. 
   1: public void RenderReport (string ReportName)

   2:         {

   3:             byte[] result = null;

   4:             //string reportPath = "/ReportFolder2";

   5:             string format = "PDF";

   6:             string historyID = null;

   7:             string devInfo = @"<DeviceInfo><Toolbar>False</Toolbar></DeviceInfo>";

   8:  

   9:             //DataSourceCredentials[] credentials = null;

  10:             //string showHideToggle = null;

  11:             string encoding;

  12:             string mimeType;

  13:             string extension;

  14:             Warning[] warnings = null;

  15:             

  16:             //ParameterValue[] reportHistoryParameters = null;

  17:             string[] streamIDs = null;

  18:  

  19:             ExecutionInfo execInfo = new ExecutionInfo();

  20:             ExecutionHeader execHeader = new ExecutionHeader();

  21:  

  22:             rs.ExecutionHeaderValue = execHeader;

  23:             execInfo = rs.LoadReport(ReportName, historyID);

  24:  

  25:             //ReportParameter[] param = execInfo.Parameters;

  26:  

  27:             // Prepare report parameter. Currently the report executes with Default paramerts.

  28:             // Here we retrieve the 

  29:             // But if required the Report Paramaeters can be added.

  30:             

  31:             ParameterValue[] parameters = new ParameterValue[execInfo.Parameters.Length];

  32:  

  33:             rs.SetExecutionParameters(parameters,"en-us");

  34:             String SessionId = rs.ExecutionHeaderValue.ExecutionID;

  35:  

  36:             try

  37:             {

  38:                 result = rs.Render(format, devInfo, out extension, out encoding, out mimeType, out warnings, out streamIDs);

  39:                 execInfo = rs.GetExecutionInfo();

  40:             }

  41:             catch (SoapException e)

  42:             {

  43:                 throw e;

  44:             }

  45:             // Write the contents of the report to an PDF file.

  46:             try

  47:             {

  48:                 FileStream stream = File.Create("report.pdf",result.Length);

  49:                 stream.Write(result, 0, result.Length);

  50:                 stream.Close();

  51:                 ///Now Send the email

  52:                 AttachAndSendEmail("report.pdf");

  53:             }

  54:             catch (Exception e)

  55:             {

  56:                 throw e;

  57:             }

  58:         }

Next, we have the AttachAndSendEmail() function to connect to the SMPT server and send the email. This function achieves the following tasks

  1. Create an SMTP client to connect to the SMTP server.
  2. Create the From and To Addresses for the email.
  3. Creates the MailMessage with the attachment.
  4. And Sends the email. 
   1: public void AttachAndSendEmail(string ReportFileName)

   2:         {

   3:  

   4:             SmtpClient client = new SmtpClient("Address of the SMTP Server", 25);

   5:             client.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;

   6:  

   7:             MailAddress from = new MailAddress("<from Address here>","<DisplayNamehere>",

   8:                             System.Text.Encoding.UTF8);

   9:  

  10:             MailAddress to = new MailAddress("<To Address here>","<DisplayNamehere>",

  11:                 System.Text.Encoding.UTF8);

  12:  

  13:  

  14:             MailMessage msg = new MailMessage(from,to);

  15:             msg.Subject = "Report Attached " + DateTime.Now.ToString();

  16:             msg.Body = "Report From Report Server";

  17:             msg.BodyEncoding = System.Text.Encoding.UTF8;

  18:             msg.Attachments.Add(new Attachment(ReportFileName));

  19:  

  20:             try

  21:             {

  22:                 client.Send(msg);

  23:             }

  24:             catch (System.Net.Mail.SmtpException e)

  25:             { throw e; }

  26:         }

 

This code sends the messages in an synchronous manner. In case if required, SMTPClient.SendAsync method can also be used.

Reporting Services, SQL Server , , ,

Target_Recovery_Time – Indirect Checkpoint SQL Server 2012

2 Comments Posted by on March 19, 2012

SQL Server 2012, introduces a new Database level option “Target_Recovery_Time” to better control and predict the time it takes during Recovery for the Database. The reason for this option was simple, the “Recovery Interval” option in sp_configure was really not reliable enough.

Before we talk about the new option, lets talk a bit about the older option.

With the Recovery interval option (set in minutes, default is 0), SQL Server would schedule the Database checkpoints in such a way that the time taken to recover the database is similar to what is specified in the Recovery Interval setting. What happens in the background is that SQL Server tries to schedule the checkpoint based on the number of DML operations that are taking place, but fails to take into consideration the number of DB Pages being modified by these operations.

As shown in the Video, SQL Server first calculates the Checkpoint interval for the Database number of DML operations and the value of “Recovery Interval” option.

When the first transaction completes (which modifies about 160 pages) and the subsequent fires, we flush all these 160 pages to the disk an move the Min_Recovery_LSN forward to the checkpoint LSN. This Min Recovery LSN is the what is used during the Database recovery, to Predict what operations are to be repeated in the Redo Phase of Recovery. During the Second Transaction (which is modifying close to 12K pages), if there were no problems, during checkpoint we would have flushed these 12K pages to the disk, which would result in a spike in the Disk Write Activity. Assuming that there was a crash, just before the Checkpoint happened (the transaction did commit), because of the large amount of pages which needs to be loaded and modified, the time to recover the database might vary and would be unpredictable.

The current Checkpoint algorithm induces the following problems, which are indeed the reason why the new Database was introduced.

  • Massive spikes in the Disk Write activity, during checkpoint.
  • Unpredictable recovery times for the Database.

The idea was to smooth out the disk write activity, so that we no longer see the massive spikes and to also have better predictability of the recovery time of a database.

The new database option can be set using the following Command. 

   1: ALTER DATABASE [CheckpointDB] SET TARGET_RECOVERY_TIME = 10 SECONDS 

   2: GO

or it can be set using the Database Properties window in SSMS.

image

When the new database option is set, SQL Server performs two things,

  • First it  introduces a background task to continuously flush the Dirty buffers from the disk. What SQL actually does is it calculates a min number of Dirty buffers it would keep. Every time this threshold is exceeded, the background process (called the background Recovery writer) kicks in and flushes the dirty buffers to the disk.
  • Continously move the Min_Recovery_LSN forwards to the LSN, which was most recently flushed. Since the Min_Recovery LSN is continuously moving forward, in case of a crash happens, the amount of work done during the Recovery would be small.

The video, below illustrates how this is happens.

With the new setting, the writes are no longer in spikes (smoothens out because of the background recovery writer) and the amount of work which needs to be done during the Recovery Phase is also reduced, providing more accurate estimations of the Recovery Time for the Database.

Word of Caution

If you set the Target_Recovery_Time to a very small number (like 1 sec) on an OLTP environment, SQL Server might just throttle the disk with the massive amount of Write operations which needs to be done as part of the Background Recovery Writes. Set this option, only after carefully examining the workload pattern and your SLA commitments. Most often the older “Recovery Interval” option from sp_configure works well.

I would like to thank my friend Parikshit Savjani, for his help with the Videos.

Performance, SQL Engine, SQL Server ,