geo-rep: checkpointing

- gluster vol geo-rep M S conf checkpoint <LABEL|now>

  sets a checkpoint with LABEL (the keyword "now" is special,
  it's rendered to the label "as of <timestamp of current time>")
  that's used to refer to the checkpoint in the sequel.

  (Technically, gsyncd makes a note of the xtime of master's root
  as of setting the checkpoint, called the "checkpoint target".)

- gluster vol geo-rep M S conf \!checkpoint

  deletes the checkpoint.

- gluster vol geo-rep M S stat

  if status is OK, and there is a checkpoint configured, the checkpoint
  info is appended to status (either "not yet reached", or
  "completed at <timestamp of completion>").

  (Technically, the worker runs a thread that monitors / serializes /
  verifies checkpoint status, and answers checkpoint status requests
  through a UNIX socket; monitoring boils down to querying the xtime
  of slave's root and comparing with the target.)

- gluster vol geo-rep M S conf log-file | xargs grep checkpoint

  displays the checkpoint history. Set, delete and completion events
  are logged properly.

Change-Id: I4398e0819f1504e6e496b4209e91a0e156e1a0f8
BUG: 826512
Signed-off-by: Csaba Henk <csaba@redhat.com>
Reviewed-on: http://review.gluster.com/3491
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/xlators/features/marker/utils/syncdaemon/syncdutils.py b/xlators/features/marker/utils/syncdaemon/syncdutils.py
index f786bc34326..1d4eb20032c 100644
--- a/xlators/features/marker/utils/syncdaemon/syncdutils.py
+++ b/xlators/features/marker/utils/syncdaemon/syncdutils.py
@@ -138,6 +138,12 @@ def finalize(*a, **kw):
                     raise
     if gconf.ssh_ctl_dir and not gconf.cpid:
         shutil.rmtree(gconf.ssh_ctl_dir)
+    if getattr(gconf, 'state_socket', None):
+        try:
+            os.unlink(gconf.state_socket)
+        except:
+            if sys.exc_info()[0] == OSError:
+                pass
     if gconf.log_exit:
         logging.info("exiting.")
     sys.stdout.flush()