mon: mon_osd_cache_size = 500 (from 10)

10 maps is too small to enable all mon sessions to keep abreast of the
latest maps, especially if OSDs are down for any period of time during an
upgrade.

Note that this is quite a bit larger, but the memory usage of the mon will
scale proportionally to the size of the cluster: 500 small osdmaps is not
a significant amount of RAM, while conversely having a large cache is
most important on a large cluster and those mons will generally have
plenty of RAM available.

Someday we should control this with a memory envelope like we do with the
OSDs, but that remains future work.

Signed-off-by: Sage Weil <sage@redhat.com>
(cherry picked from commit 1ce64292517ac81902715280df988de7805e61bb)

diff --git a/src/common/options.cc b/src/common/options.cc
index 6857b8aa0940066a63f4bef4f14298b3b61a8a40..199bc301e8fd5d8362e31cea985d6d8f56f9c977 100644 (file)
--- a/src/common/options.cc
+++ b/src/common/options.cc
@@ -1184,7 +1184,7 @@ std::vector<Option> get_global_options() {
     /* -- mon: osdmap prune (end) -- */
 
     Option("mon_osd_cache_size", Option::TYPE_INT, Option::LEVEL_ADVANCED)
-    .set_default(10)
+    .set_default(500)
     .set_description(""),
 
     Option("mon_cpu_threads", Option::TYPE_INT, Option::LEVEL_ADVANCED)