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>

diff --git a/doc/rados/configuration/filestore-config-ref.rst b/doc/rados/configuration/filestore-config-ref.rst
index 2a5e40eb5080e960ac8f70adc9a909121c2d97ff..bb8926d9849117bb869547ff853ff57681820231 100644 (file)
--- 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 e078547ab3f28752d111cbd662086f60a207b262..e41bc6494d980fff7f0aee02e33ceb4ed648e639 100755 (executable)
--- 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 b553dbfd6893c62721ece8c11a387a4b63d5894e..bf94649e4bedfd7c27b8ad5088698d2add80a336 100644 (file)
--- 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 1a87516a4f53faae4d44847c49aadd952b122bd5..589243e3853731bdf914a376bb86e7569cf1f990 100644 (file)
--- 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