replicator: Log rsync file transfers less

- Drop log level for successful rsyncs to debug; ops don't usually care.
- Add an option to skip "send" lines entirely -- in a large cluster,
  during a meaningful expansion, there's too much information getting
  logged; it's just wasting disk space.

Note that we already have similar filtering for directory creation;
that's been present since the initial commit of Swift code.

Drive-by: make it a little more clear that more than one suffix was
likely replicated when logging about success.

Change-Id: I02ba67e77e3378b2c2c8c682d5d230d31cd1bfa9

1 files changed, 7 insertions, 0 deletions

diff --git a/etc/object-server.conf-sample b/etc/object-server.conf-sample
index 9f9f64515..06d3b8770 100644
--- a/etc/object-server.conf-sample
+++ b/etc/object-server.conf-sample
@@ -291,6 +291,13 @@ use = egg:swift#recon
 # ring_check_interval = 15.0
 # recon_cache_path = /var/cache/swift
 #
+# By default, per-file rsync transfers are logged at debug if successful and
+# error on failure. During large rebalances (which both increase the number
+# of diskfiles transferred and increases the likelihood of failures), this
+# can overwhelm log aggregation while providing little useful insights.
+# Change this to false to disable per-file logging.
+# log_rsync_transfers = true
+#
 # limits how long rsync error log lines are
 # 0 means to log the entire line
 # rsync_error_log_line_length = 0