From: Zac Dover Date: Thu, 30 May 2024 13:28:56 +0000 (+1000) Subject: doc/cephfs: edit front matter in mantle.rst X-Git-Tag: v17.2.8~340^2 X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=3f940065bde70be1ac4c9e46bfa58e5ebab70c32;p=ceph.git doc/cephfs: edit front matter in mantle.rst Improve the structure and grammar of the front matter in the doc/cephfs/mantle.rst file. Signed-off-by: Zac Dover (cherry picked from commit 559d4849ecd6f93b5812f3d8d0448115c5b5beab) --- diff --git a/doc/cephfs/mantle.rst b/doc/cephfs/mantle.rst index 064408f712a7a..97d98aa7d7f4a 100644 --- a/doc/cephfs/mantle.rst +++ b/doc/cephfs/mantle.rst @@ -6,20 +6,25 @@ Mantle Mantle is for research and development of metadata balancer algorithms, not for use on production CephFS clusters. -Multiple, active MDSs can migrate directories to balance metadata load. The -policies for when, where, and how much to migrate are hard-coded into the -metadata balancing module. Mantle is a programmable metadata balancer built -into the MDS. The idea is to protect the mechanisms for balancing load -(migration, replication, fragmentation) but stub out the balancing policies -using Lua. Mantle is based on [1] but the current implementation does *NOT* -have the following features from that paper: +Mantle is a programmable metadata balancer that is built into the MDS. + +By default (without Mantle), multiple, active MDSs can migrate directories to +balance metadata load. The policies for when, where, and how much to migrate +are hard-coded into the metadata balancing module. + +Mantle works by protecting the mechanisms for balancing load (migration, +replication, fragmentation) while suppressing the balancing policies using Lua. +Mantle is based on [1] but the current implementation does *NOT* have the +following features from that paper: 1. Balancing API: in the paper, the user fills in when, where, how much, and - load calculation policies; currently, Mantle only requires that Lua policies - return a table of target loads (e.g., how much load to send to each MDS) -2. "How much" hook: in the paper, there was a hook that let the user control - the fragment selector policy; currently, Mantle does not have this hook -3. Instantaneous CPU utilization as a metric + load calculation policies. Currently, Mantle requires only that Lua policies + return a table of target loads (for example, how much load to send to each + MDS) +2. The "how much" hook: in the paper, there was a hook that allowed the user to + control the "fragment selector policy". Currently, Mantle does not have this + hook. +3. "Instantaneous CPU utilization" as a metric. [1] Supercomputing '15 Paper: http://sc15.supercomputing.org/schedule/event_detail-evid=pap168.html