From 75f55f2dfc92a89ec9d821e00effad75839008c9 Mon Sep 17 00:00:00 2001
From: Douglas Fuller <dfuller@redhat.com>
Date: Thu, 28 Jun 2018 10:26:25 -0400
Subject: [PATCH] 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>
---
 doc/rados/configuration/filestore-config-ref.rst | 2 +-
 qa/standalone/mon/osd-pool-create.sh             | 1 -
 src/common/options.cc                            | 2 +-
 src/sample.ceph.conf                             | 2 +-
 4 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/doc/rados/configuration/filestore-config-ref.rst b/doc/rados/configuration/filestore-config-ref.rst
index 2a5e40eb5080e..bb8926d984911 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 e078547ab3f28..e41bc6494d980 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 b553dbfd6893c..bf94649e4bedf 100644
--- a/src/common/options.cc
+++ b/src/common/options.cc
@@ -4622,7 +4622,7 @@ 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 1a87516a4f53f..589243e385373 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
-- 
2.39.5