rgw: document ops logging setup

Fixes: #3530

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>

2 files changed, 46 insertions, 0 deletions

diff --git a/doc/radosgw/config-ref.rst b/doc/radosgw/config-ref.rst
index f53173e2145..213fa4eb028 100644
--- a/doc/radosgw/config-ref.rst
+++ b/doc/radosgw/config-ref.rst
@@ -202,3 +202,25 @@ set automatically.
 :Description: Whether rgw should use dns cname record of the request hostname field (if hostname is not equal to ``rgw dns name``)
 :Type: Boolean
 :Default: ``false``
+
+
+
+``rgw enable ops log``
+:Description: Whether rgw will log each successful operation
+:Type: Boolean
+:Default: ``true``
+
+``rgw ops log rados``
+:Description: Whether rgw operations logging should be written into the RADOS backend
+:Type: Boolean
+:Default: ``true``
+
+``rgw ops log socket path``
+:Description: The path of a unix domain socket to which operations logging data will be written.
+:Type: String
+:Default: N/A
+
+``rgw ops log data backlog``
+:Description: Total backlog data size for unix domain socket operations logging
+:Type: Integer
+:Default: ``5ul << 20``
diff --git a/doc/radosgw/config.rst b/doc/radosgw/config.rst
index c9605d06cef..32ce66d0426 100644
--- a/doc/radosgw/config.rst
+++ b/doc/radosgw/config.rst
@@ -224,7 +224,31 @@ For details on RADOS Gateway administration, see `radosgw-admin`_.
    in quotes, or simply regenerating the key and ensuring that it 
    does not have an escape character.
 
+Configuring the Operations Logging
+==================================
 
+By default, the RADOS Gateway will log every successful operation in the RADOS backend.
+This means that every request, whether it is a read request or a write request will
+generate a RADOS operation that writes data. This does not come without cost, and may
+affect overall performance. Turning off logging completely can be done by adding the
+following config option to ceph.conf::
+
+        rgw enable ops log = false
+
+Another way to reduce the logging load is to send operations logging data to a unix domain
+socket, instead of writing it to the RADOS backend::
+
+        rgw ops log rados = false
+        rgw enable ops log = true
+        rgw ops log socket path = <path to socket>
+
+When specifying a unix domain socket, it is also possible to specify the maximum amount
+of memory that will be used to keep the data backlog::
+
+        rgw ops log data backlog = <size in bytes>
+
+Any backlogged data in excess to the specified size will be lost, so socket needs to be
+constantly read.
 
 Enabling Swift Access
 =====================