Paulo Jorge de Melo
2011-Jan-25 13:25 UTC
[Gluster-users] Guideline needed for a xlator project
Greetings, I am having a bit trouble to write a new translator for glusterfs. The main idea is when I try to read a file that not existing in the glusterfs volume, the xlator will look in a predefined local directory and if the file exist will perform the operation as usual but only in the local file. I have read most of the xlators source codes to search for some clues but so far still digging... Any idea??? Thank you Paulo Jorge de Melo
On 01/25/2011 08:25 AM, Paulo Jorge de Melo wrote:> Greetings, > I am having a bit trouble to write a new translator for glusterfs. > The main idea is when I try to read a file that not existing in the > glusterfs volume, the xlator will look in a predefined local directory > and if the file exist will perform the operation as usual but only in > the local file. > > I have read most of the xlators source codes to search for some clues > but so far still digging...I've attached a copy of a document I wrote a while ago when I started writing translators myself. It probably needs some updates, but it should give a decent conceptual overview that will help understand what other translators you look at are doing. I recommend starting with some of the simplest translators, such as performance/* or debug/trace. Stay away from DHT and AFR, which are not only complex generally but each introduce additional layers of control-flow complexity to deal with lookups and transactions respectively. Note that your translator doesn't need to handle all entry points; any you don't specify in your fops table will be set to a default value which just passes through to the first subvolume.