topic Re: WCM FTP deployment in Alfresco Archive

WCM FTP deployment

rscheele — Tue, 27 May 2008 13:30:08 GMT

Hello,i have some web space where i can upload files using ftp. Using Alfresco Deployment, i can define a File Server Receiver (FSR) which connects to a remote server using RMI. I don't understand RMI and i wouldn't know if my web server supports it, but the most obvious way for me would be to conne

Re: WCM FTP deployment

pmonks — Tue, 27 May 2008 16:07:48 GMT

The FileSystem Receiver is a separate process that would be installed on your web server. It acts as an RMI server and the main ("authoring") instance of Alfresco connects to it (as an RMI client) whenever deployment is initiated.

There's an enhancement request in JIRA to allow the over-the-wire protocol used for deployment to be pluggable (see http://issues.alfresco.com/browse/ETWOTWO-436), but I don't think FTP would be sufficient (deployment requires more than just remote file I/O APIs, which is all that FTP provides).

Cheers,
Peter

Re: WCM FTP deployment

pmonks — Tue, 27 May 2008 16:20:29 GMT

That said, you could implement a custom FSR deployment runnable that acts as an FTP client and pushes deployment deltas over to an FTP server. In this model the FSR itself doesn't have to run on your web server (it would probably run on the same server as the Alfresco authoring instance).

The interface you'd implement to do this is called "FSDeploymentRunnable".

Cheers,
Peter

Re: WCM FTP deployment

pmonks — Tue, 27 May 2008 16:45:52 GMT

And just to follow up again (last time, I promise! :wink, you actually don't have to write Java code to do this. FSRs can invoke custom shell scripts, so you could simply write a shell script that invokes an FTP client, providing it with the FTP commands (put, mkdir, delete, etc.) equivalent to the operations listed in the deployment delta's manifest.

Cheers,
Peter

Re: WCM FTP deployment

rscheele — Thu, 29 May 2008 07:42:53 GMT

Thnx for your helpful words. I don't fully understand why deployment should be more than file transfer in some occassions, eg mine where i just place the web content on the www root of my web server. I only have file access, how should i setup that interface? I do not have root access to that server (virtualised web server)

Re: WCM FTP deployment

pmonks — Thu, 29 May 2008 18:02:03 GMT

The Alfresco deployment functionality only sends deltas (ie. files that are new, updated or deleted since the last deployment) and in order to calculate the delta it needs to know which revision (if any) the target (whether an ASR or FSR) is currently at. FTP (and other file transfer oriented protocols) don't support that kind of "API call", so they can't be used (at least not exclusively) for deployment.

Based on your description, I'd go with the "FSR + custom shell script" approach. You'd install an FSR on the same server as the Alfresco authoring instance and configure it to call your custom shell script whenever deployment is initiated. The shell script would read the deployment manifest (which describes the delta that's being deployed as a list of file / operation pairs) and then perform the equivalent FTP operations against the (remote) web server machine. The net result is that the web server machine doesn't need anything more than an FTP server running on it in order to support deployment.

It would also be fantastic if you could submit the shell script back to the community once you've implemented it (since it should be pretty reusable). Probably the best place to put it is the "wcm-deployment" forge project (http://forge.alfresco.com/projects/wcm-deployment/) - I can set you up with commit privileges for that project if you'd like.

Cheers,
Peter

Re: WCM FTP deployment

boneill — Fri, 04 Jul 2008 06:49:12 GMT

Does anyone know if the custom shell script for FTP deployment using an FSR ever get written. I currently have a requirement for the same functionality (FTP changed pages to a site hosted by an ISP). Or, is there a new way to do this since this post.

Re: WCM FTP deployment

tommorris — Fri, 04 Jul 2008 13:51:36 GMT

Something that I've tried with some success is using the FSR to deploy to a local space,
and then trigger (the post-deploy trigger action is defined in a context.xml) a batch file to push the files to the remote web-server.
I'd recommend using RSync (on top of Cygwin on a Windows server) to push just the deltas, across to a listening RSync daemon.
You can execute RSync over SSL too. (Incidentally, if you're using SSL, you could use SFTP too).

Re: WCM FTP deployment

pmonks — Fri, 04 Jul 2008 14:40:57 GMT

One of the nice things about rsync is that it uses block-level deltas, so when used on top of the directory tree deltas that Alfresco calculates you get a really specific set of deltas (only the files that are new / modified / deleted are replicated, and for updated files only those blocks that have changed are replicated).

The only thing I'm not sure about is how rsync handles deletes - if the manifest calculated by Alfresco includes a delete, does rsync correctly replicate it?

Cheers,
Peter

Re: WCM FTP deployment

tommorris — Fri, 04 Jul 2008 14:58:50 GMT

Yes, it does handle deletes.
And you're right about the sub-file diffs.

Re: WCM FTP deployment

pmonks — Fri, 04 Jul 2008 15:10:54 GMT

The only caveat to using rsync is that I've found it to be quite chatty, so if you're running it over a low bandwidth or high latency connection, you may find you're better off using vanilla FTP (which seems to be better behaved on those kinds of connections). It seems a bit counter intuitive that a "dumb" protocol such as FTP can be more performant in some cases, but I guess calculating which blocks have changed is an (I/O and network) expensive operation.

Cheers,
Peter

Re: WCM FTP deployment

tommorris — Fri, 04 Jul 2008 15:14:29 GMT

I think you're probably right Peter.
BTW: You can can also configure rsync to perform file-level diffs - maybe that speeds things up a bit.

Re: WCM FTP deployment

boneill — Sun, 06 Jul 2008 11:41:21 GMT

Hi guys,
Thanks alot for the suggestions. I will look into rsynch. It sounds like the right solution for this problem. While I am on the subject, where do you download the FSR softeware from.

Regards