From: Josh Durgin <jdurgin@redhat.com>
Date: Sat, 3 Mar 2018 02:37:15 +0000 (-0500)
Subject: PendingReleaseNotes: note about changing omap backend to rocksdb
X-Git-Tag: v10.2.11~32^2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=b991c334bb5826fc28170861884a040a3c5f4a77;p=ceph.git

PendingReleaseNotes: note about changing omap backend to rocksdb

Signed-off-by: Josh Durgin <jdurgin@redhat.com>
---

diff --git a/PendingReleaseNotes b/PendingReleaseNotes
index c0abc91883d1a..d134ac86ad2b2 100644
--- a/PendingReleaseNotes
+++ b/PendingReleaseNotes
@@ -15,3 +15,10 @@
 * The RBD C API's rbd_discard method and the C++ API's Image::discard method
   now enforce a maximum length of 2GB. This restriction prevents overflow of
   the result code.
+
+* New OSDs will now use rocksdb for omap data by default, rather than
+  leveldb. omap is used by RGW bucket indexes and CephFS directories,
+  and when a single leveldb grows to 10s of GB with a high write or
+  delete workload, it can lead to high latency when leveldb's
+  single-threaded compaction cannot keep up. rocksdb supports multiple
+  threads for compaction, which avoids this problem.