[Gluster-devel] Self-heal with partial files

[Kevan Benson]

Is self heal supposed to work with partial files?  I have an issue where 
self-heal isn't happening on some servers with AFR and unify in a HA 
setup I developed.  Two servers, two clients, all AFR and unify done on 
client side.

If I kill a connection while a large file is being written, the 
glusterfs mount waits the appropriate timeout period (10 seconds in my 
case) and then finishes writing the file to the still active server.  
This results in a full file on one server and a partial file on the 
other (the one I stopped traffic to temporarily to simulate a 
crash/network problem).  If I then enable the disabled server and read 
data from the problematic file, it doesn't self-heal  itself and move 
the full file to the server with the partial file.

Anything written entirely while a server is offline (i.e. the offline 
server has no knowledge of it) is correctly created on read from the 
file, so the problem seems to be related to files that are partially 
written to one server.

Can someone comment on the particular conditions that cause a self 
heal?  Is there something I can do to force it to self heal at this 
point (I repeat that reading data from the file does not work).  I know 
I can use rsync and some foo to fix this, but that becomes less and less 
feasible as the mount size grows and the time for rsync to compare sides 
lengthens.