Tuning the VFS Transport

The Virtual File System (VFS) transport is used by WSO2 ESB to process files in a specified source directory. It supports numerous file systems such as ftp, ftps, sftp, local and samba.

When you work with the VFS transport, you might have a scenario where you need to send large files to a destination. If you use the normal VFS configuration, the memory consumption will be very high since the ESB builds the file inside it. To overcome this issue, WSO2 ESB provides VFS file streaming support. With VFS file streaming, only the stream is passed and therefore memory consumption is less.

Tip: When you transfer a file to a remote FTP location via VFS, the ESB tries to detect the FTP location by navigating from the root folder first. If the ESB does not have at least list permission to the root (/), the file transfer fails.

To use the streaming mode with the VFS transport, follow the steps below:

In <ESB_HOME>/repository/conf/axis2/axis2.xml, in the messageBuilders section, add the binary message builder as follows:
```
<messageBuilder contentType="application/binary" class="org.apache.axis2.format.BinaryBuilder"/>
```
and in the messageFormatters section, add the binary message formatter as follows:
```
<messageFormatter contentType="application/binary" class="org.apache.axis2.format.BinaryFormatter"/>
```
In the proxy service where you use the VFS transport, add the following parameter to enable streaming:
```
<parameter name="transport.vfs.Streaming">true</parameter>
```
In the same proxy service, before the Send mediator, add the following property:
Note

You also need to add the following property if you want to use the VFS transport to transfer files from VFS to VFS.
```
<property name="ClientApiNonBlocking" value="true" scope="axis2" action="remove"/>
```
For more information, see Example 3 of the Send Mediator.

Following is a sample configuration that uses the VFS transport to handle large files:

<definitions xmlns="http://ws.apache.org/ns/synapse">
    <proxy name="StockQuoteProxy" transports="vfs">
        <parameter name="transport.vfs.FileURI">smb://host/test/in</parameter>        
        <parameter name="transport.vfs.ContentType">text/xml</parameter>
        <parameter name="transport.vfs.FileNamePattern">.*\.xml</parameter>
        <parameter name="transport.PollInterval">15</parameter>
        <parameter name="transport.vfs.Streaming">true</parameter>
        <parameter name="transport.vfs.MoveAfterProcess">smb://host/test/original</parameter>            
        <parameter name="transport.vfs.MoveAfterFailure">smb://host/test/original</parameter>          
        <parameter name="transport.vfs.ActionAfterProcess">MOVE</parameter>
        <parameter name="transport.vfs.ActionAfterFailure">MOVE</parameter>
        <target>
             <inSequence>
                <property name="transport.vfs.ReplyFileName"
                          expression="fn:concat(fn:substring-after(get-property('MessageID'), 'urn:uuid:'), '.xml')" scope="transport"/>
                <property action="set" name="OUT_ONLY" value="true"/>
                <property name="ClientApiNonBlocking" value="true" scope="axis2" action="remove"/>
                <send>
                    <endpoint>
                        <address uri="vfs:smb://host/test/out"/> 
                    </endpoint>
                </send>
            </inSequence>
        </target>
        <publishWSDL uri="file:repository/samples/resources/proxy/sample_proxy_1.wsdl"/>
    </proxy>
</definitions>