BizTalk Custom Pipeline Component System.OutOfMemoryException - biztalk

Question

I'm currently developing a BizTalk Custom Send Pipeline that accepts an xml file and converts it to Excel. Unfortunately, after deploying the pipeline, I'm receiving a System.OutOfMemoryException. I've included the code for Execute Method of IComponent interface. All suggestions are welcome.
public Microsoft.BizTalk.Message.Interop.IBaseMessage Execute(IPipelineContext pContext, Microsoft.BizTalk.Message.Interop.IBaseMessage inmsg)
{
MemoryStream outMemStream = new MemoryStream();
try
{
if (inmsg.BodyPart.Data != null)
{
// Read the source message coming from the messaging engine and convert it to memory stream
byte[] buffer = new byte[16 * 1024];
using (MemoryStream ms = new MemoryStream())
{
int read;
while ((read = inmsg.BodyPart.Data.Read(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
}
buffer = ms.ToArray();
}
if (buffer != null)
{
var binaryWriter = new BinaryWriter(outMemStream);
binaryWriter.Write(buffer);
}
OpenXMLOffice oOffice = new OpenXMLOffice();
outMemStream.Position = 0;
oOffice.XMLToExcel(outMemStream, TemporaryFileLocation);
inmsg.BodyPart.Data.Position = 0;
inmsg.BodyPart.Data = outMemStream;
pContext.ResourceTracker.AddResource(outMemStream);
}
return inmsg;
}
catch (Exception ex)
{
throw new ApplicationException(String.Format("Error converting XML to Excel:{0} - Stack Trace: {1}", ex.Message, ex.StackTrace));
}
}
Here is the most recent error received:
Log Name: Application
Source: BizTalk Server
Date: 2/14/2012 9:29:00 AM
Event ID: 5754
Task Category: BizTalk Server
Level: Error
Keywords: Classic
User: N/A
Computer: IASDev-PC
Description:
A message sent to adapter "FILE" on send port "ExcelSendPort" with URI "C:\SeleneFTPFile\Excel\%MessageID%.xml" is suspended.
Error details: There was a failure executing the send pipeline: "IAS.SeleneFTPFile.ExcelEncodePipeline, IAS.SeleneFTPFile, Version=1.0.0.0, Culture=neutral, PublicKeyToken=2add433e7764165f" Source: "Excel File Encoder" Send Port: "ExcelSendPort" URI: "C:\SeleneFTPFile\Excel\%MessageID%.xml" Reason: Error converting XML to Excel:Exception of type 'System.OutOfMemoryException' was thrown. - Stack Trace: at System.IO.MemoryStream.set_Capacity(Int32 value)
at System.IO.MemoryStream.EnsureCapacity(Int32 value)
at System.IO.MemoryStream.Write(Byte[] buffer, Int32 offset, Int32 count)
at IAS.SeleneFTPFile.Components.ExcelPipeline.EncodeExcel.Execute(IPipelineContext pContext, IBaseMessage inmsg)
MessageId: {ED37CDD1-EF0C-46E7-9519-061AF3D4F8A4}
InstanceID: {B0E448B3-3DAD-4E52-8F87-07C5D5AA5224}

Answer 1

You could try pre-allocating the MemoryStream buffer (as suggested here). The error message states that it can't allocate enough memory for the line when performing the buffered write (ms.Write(buffer, 0, read);).
using (MemoryStream ms = new MemoryStream(buffer.Length))
The other issue you have is that your buffer could overflow - producing this exact error when the MemoryStream is written to (ms.Write(buffer, 0, read)).
byte[] buffer = new byte[2 * 1024 * 1024]; // try increasing to 2MB buffer

Answer 2

Even I face the same issue. I can find that the reason is the stream position does not advance and remains at 0 for the inmsg.BodyPart.Data stream, even after the below statement executes:
read = inmsg.BodyPart.Data.Read(buffer, 0, buffer.Length)