FTP Listener and number of connections that are opened

[garuda]

Hello experts.

one of our customer uses BAN control on his ftp - server "ftp.x.com", which means that server is getting blocked in case connection frequency of all clients is higher then 5 times per Minute. Due to this issue, I have the following thoughts. Unfortunately I found nothing in the documentation.


Let`s assume the following jboss-esb.xml of service: "TestService"

<ftp-provider hostname="ftp.test.com" name="FtpGateway">
 <ftp-bus busid="test1">
 <ftp-message-filter directory="/directory1"
 error-directory="/directory1" input-suffix=".xml"
 password="masterpw" post-delete="false"
 post-directory="/directory1" post-suffix=".archived"
 protocol="ftp" read-only="false" username="master" work-suffix=".work"/>
 </ftp-bus>

<ftp-bus busid="test2">
 <ftp-message-filter directory="/directory2"
 error-directory="/directory2" input-suffix=".xml"
 password="masterpw" post-delete="false"
 post-directory="/directory2" post-suffix=".archived"
 protocol="ftp" read-only="false" username="master" work-suffix=".work"/>
 </ftp-bus>
 </ftp-provider>
...
<services>
 <service category="AnyServiceCategory" description="lala" name="TestService">
 <listeners>
 <jms-listener busidref="EdiFTPEsbChannel" maxThreads="1" name="FTP-ESBListener"/>
 <ftp-listener busidref="test_1" is-gateway="true"
 maxThreads="1" name="Listener1" schedule-frequency="300"/>
 <ftp-listener busidref="test_2" is-gateway="true"
 maxThreads="1" name="Listener2" schedule-frequency="300"/>
</service>
</services>
...

How many connections are TestService opened initially and on schedule
time-points ?
- 1 connection for user "master" because initially and / or schedule - frequency is equal for all ftp-listener ?
- 2 connections, one for each ftp-listener (although its the same user and same schedule-frequency)?

Thank you very much for your help.

Best regards,

Dennis

[nl]

One point is, that the RemoteGatewayListener is doing a real login within its init phase (see checkMyParms()):

RemoteFileSystem rfs = RemoteFileSystemFactory.getRemoteFileSystem(ftpEpr, true);

Is this really needed? Wouldn't it be better to make the last argument configurable? Or would it lead to unexpected results?

Regards,

Niels

[nl]

Ok, this seems to be worse than I've thought.

The RemoteGatewayListener is opening a connection on each action.
So if there are n files on the server, it'll need at least

1 (getFileList) + n*2 (getFile + rename/delete) connections.

Isn't it possible to reuse the connection until last file is processed?

[tomeicher]

Well, of course that's doable, but the design of the interfaces and
classes doesn't look like anybody is eager to change all that...

In such cases, I just copy the class in question over to my source tree,
change the package (mind the license header) and implement my
changes.

Holding the connection as a member shouldn't be too hard, but I
guess you must disallow concurrent access somehow...

Cheers, Tom.

[nl]

Hi Tom,

each schedule uses its own Listener (subsequent schedules may share). So what I did is keep the connection as a member at time of onSchedule() Method and close it afterwards, since with finishing this method, all files are being processed.

I also created a JIRA Issue for this (JBESB-2914) since this behaviour is not enterprise ready. Simple FTP is one thing, but think of secure connections...

Regards,

Niels