geo-rep: Rsync tunables for performance improvements

Flag: --ignore-missing-args
This Rsync flag reduces sync failures if the source file is
unlinked but present in --files-from list. This reduces
Rsync retries in Geo-rep and improves the performance

Flag: --existing
Rsync in Geo-rep never creates target files. Using RPC Geo-rep creates
entry in Slave and rsync --inplace used to prevent creating temporary file
and rename.(To avoid different GFID in Slave). If the entry is missing in
Slave then Geo-rep Rsync gets Permission denied errors when it tries to
create file with name as GFID inside .gfid dir.(Geo-rep rsync syncs data
using GFIDS with aux-gfid-mount)

To disable these flags,

    gluster volume geo-replication <session> config \
        rsync-opt-ignore-missing-args false
    gluster volume geo-replication <session> config \
        rsync-opt-existing false

Thanks Kotresh for finding these awesome tunables.

BUG: 1400924
Change-Id: I6a84fb86a589bf6edc8dfd1086456a84b05a64fc
Signed-off-by: Aravinda VK <avishwan@redhat.com>
Reviewed-on: https://review.gluster.org/16010
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Kotresh HR <khiremat@redhat.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/geo-replication/syncdaemon/resource.py b/geo-replication/syncdaemon/resource.py
index 2fb6d5f1cdf..9cbe92a93c5 100644
--- a/geo-replication/syncdaemon/resource.py
+++ b/geo-replication/syncdaemon/resource.py
@@ -37,7 +37,7 @@ from syncdutils import GsyncdError, select, privileged, boolify, funcode
 from syncdutils import umask, entry2pb, gauxpfx, errno_wrap, lstat
 from syncdutils import NoStimeAvailable, PartialHistoryAvailable
 from syncdutils import ChangelogException, ChangelogHistoryNotAvailable
-from syncdutils import get_changelog_log_level
+from syncdutils import get_changelog_log_level, get_rsync_version
 from syncdutils import CHANGELOG_AGENT_CLIENT_VERSION
 from gsyncdstatus import GeorepStatus
 from syncdutils import get_master_and_slave_data_from_args
@@ -1050,12 +1050,22 @@ class SlaveRemote(object):
         if not files:
             raise GsyncdError("no files to sync")
         logging.debug("files: " + ", ".join(files))
+
+        extra_rsync_flags = []
+        # Performance flag, --ignore-missing-args, if rsync version is
+        # greater than 3.1.0 then include this flag.
+        if boolify(gconf.rsync_opt_ignore_missing_args) and \
+           get_rsync_version(gconf.rsync_command) >= "3.1.0":
+            extra_rsync_flags = ["--ignore-missing-args"]
+
         argv = gconf.rsync_command.split() + \
             ['-aR0', '--inplace', '--files-from=-', '--super',
              '--stats', '--numeric-ids', '--no-implied-dirs'] + \
+            (boolify(gconf.rsync_opt_existing) and ['--existing'] or []) + \
             gconf.rsync_options.split() + \
             (boolify(gconf.sync_xattrs) and ['--xattrs'] or []) + \
             (boolify(gconf.sync_acls) and ['--acls'] or []) + \
+            extra_rsync_flags + \
             ['.'] + list(args)
 
         log_rsync_performance = boolify(gconf.configinterface.get_realtime(