This introduces two config parameters:

    mds_cache_memory_limit: Sets the soft maximum of the cache to the given
    byte count. (Like mds_cache_size, this doesn't actually limit the maximum
    size of the cache. It just dictates the steady-state size.)

    mds_cache_reservation: This replaces mds_health_cache_threshold everywhere
    except the Beacon heartbeat sent to the mons. The idea here is to specify a
    reservation of memory (5% by default) for operations and the MDS tries to
    always maintain that reservation. So, the MDS will recall caps from clients
    when it begins dipping into its reservation of memory.

mds_cache_size still limits the cache by Inode count but is now by-default 0
(i.e. unlimited). The new preferred way of specifying cache limits is by memory
size. The default is 1GB.

Fixes: http://tracker.ceph.com/issues/20594
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1464976
Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>
(cherry picked from commit 06c94de)

Signed-off-by: Vasu Kulkarni <vasu@redhat.com>

diff --git a/qa/tasks/cephfs/test_client_limits.py b/qa/tasks/cephfs/test_client_limits.py
index 3f8ffa8758f79c221bf4b2eb4a31e3d357708e9e..b06d2a1d233fa0dc5fcecb18fe134942f8171750 100644 (file)
--- a/qa/tasks/cephfs/test_client_limits.py
+++ b/qa/tasks/cephfs/test_client_limits.py
@@ -81,12 +81,12 @@ class TestClientLimits(CephFSTestCase):
             pass
 
         # The remaining caps should comply with the numbers sent from MDS in SESSION_RECALL message,
-        # which depend on the cache size and overall ratio
+        # which depend on the caps outstanding, cache size and overall ratio
         self.wait_until_equal(
             lambda: self.get_session(mount_a_client_id)['num_caps'],
-            int(cache_size * 0.8),
-            timeout=600,
-            reject_fn=lambda x: x < int(cache_size*.8))
+            int(open_files * 0.2),
+            timeout=30,
+            reject_fn=lambda x: x < int(open_files*0.2))
 
     @needs_trimming
     def test_client_pin_root(self):