geo-rep: Fix Rsync hang issue

When rsync is executed using Python subprocess, by default
stdout of subprocess will be None. With the log rsync performance
patch stdout is assigned to PIPE. Rsync writes to that PIPE
whenever it syncs files. If log_rsync_performance is disabled
then nobody will consume stdout and that gets full. Rsync hangs
if PIPE is full.

log_rsync_performance option is introduced with patch 10070

With this patch stdout=PIPE only if log_rsync_performance is
enabled. Also removed -v option from Rsync.

Thanks Venky and Kotresh for RCA.

BUG: 1219444
Change-Id: I4b06ca2ebdcb93ac8319f60bc637182fb3d38091
Original-Author: Aravinda VK <avishwan@redhat.com>
Reviewed-on: http://review.gluster.org/10556
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Reviewed-on: http://review.gluster.org/10634
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/geo-replication/syncdaemon/resource.py b/geo-replication/syncdaemon/resource.py
index 2a04d632091..71fcc8c798f 100644
--- a/geo-replication/syncdaemon/resource.py
+++ b/geo-replication/syncdaemon/resource.py
@@ -904,14 +904,22 @@ class SlaveRemote(object):
             raise GsyncdError("no files to sync")
         logging.debug("files: " + ", ".join(files))
         argv = gconf.rsync_command.split() + \
-            ['-avR0', '--inplace', '--files-from=-', '--super',
+            ['-aR0', '--inplace', '--files-from=-', '--super',
              '--stats', '--numeric-ids', '--no-implied-dirs'] + \
             gconf.rsync_options.split() + \
             (boolify(gconf.sync_xattrs) and ['--xattrs'] or []) + \
             (boolify(gconf.sync_acls) and ['--acls'] or []) + \
             ['.'] + list(args)
-        po = Popen(argv, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
-                   stderr=subprocess.PIPE)
+
+        if gconf.log_rsync_performance:
+            # use stdout=PIPE only when log_rsync_performance enabled
+            # Else rsync will write to stdout and nobody is their
+            # to consume. If PIPE is full rsync hangs.
+            po = Popen(argv, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                       stderr=subprocess.PIPE)
+        else:
+            po = Popen(argv, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
+
         for f in files:
             po.stdin.write(f)
             po.stdin.write('\0')