From: Douglas Fuller <dfuller@redhat.com>
Date: Thu, 28 Jun 2018 14:26:25 +0000 (-0400)
Subject: osd/filestore: Change default filestore_merge_threshold to -1
X-Git-Tag: v13.2.1~71^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F22813%2Fhead;p=ceph.git

osd/filestore: Change default filestore_merge_threshold to -1

Performance evaluations of medium to large size Ceph clusters have
demonstrated negligible performance impact from unnecessarily deep
directory hierarchies but significant performance impact from filestore
split and merge activity. Disable merges by default.

Fixes: http://tracker.ceph.com/issues/24686
Signed-off-by: Douglas Fuller <dfuller@redhat.com>
(cherry picked from commit 75f55f2dfc92a89ec9d821e00effad75839008c9)
---

diff --git a/doc/rados/configuration/filestore-config-ref.rst b/doc/rados/configuration/filestore-config-ref.rst
index 2a5e40eb5080..bb8926d98491 100644
--- a/doc/rados/configuration/filestore-config-ref.rst
+++ b/doc/rados/configuration/filestore-config-ref.rst
@@ -297,7 +297,7 @@ Misc
               NOTE: A negative value means to disable subdir merging
 :Type: Integer
 :Required: No
-:Default: ``10``
+:Default: ``-10``
 
 
 ``filestore split multiple``
diff --git a/qa/standalone/mon/osd-pool-create.sh b/qa/standalone/mon/osd-pool-create.sh
index e078547ab3f2..e41bc6494d98 100755
--- a/qa/standalone/mon/osd-pool-create.sh
+++ b/qa/standalone/mon/osd-pool-create.sh
@@ -213,7 +213,6 @@ function TEST_pool_create_rep_expected_num_objects() {
     setup $dir || return 1
 
     # disable pg dir merge
-    CEPH_ARGS+="--filestore-merge-threshold=-10 "
     export CEPH_ARGS
     run_mon $dir a || return 1
     run_mgr $dir x || return 1
diff --git a/src/common/options.cc b/src/common/options.cc
index 9b9260b42675..3c0023cf3f90 100644
--- a/src/common/options.cc
+++ b/src/common/options.cc
@@ -4554,7 +4554,7 @@ std::vector<Option> get_global_options() {
     .set_description(""),
 
     Option("filestore_merge_threshold", Option::TYPE_INT, Option::LEVEL_DEV)
-    .set_default(10)
+    .set_default(-10)
     .set_description(""),
 
     Option("filestore_split_multiple", Option::TYPE_INT, Option::LEVEL_DEV)
diff --git a/src/sample.ceph.conf b/src/sample.ceph.conf
index 1a87516a4f53..589243e38537 100644
--- a/src/sample.ceph.conf
+++ b/src/sample.ceph.conf
@@ -397,7 +397,7 @@
     # Type: Integer
     # Required: No
     # Default:  10
-    ;filestore merge threshold    = 10
+    ;filestore merge threshold    = -10
 
     # filestore_split_multiple * abs(filestore_merge_threshold) * 16 is the maximum number of files in a subdirectory before splitting into child directories.
     # Type: Integer