mon: disabled rocksdb compression when used as the backend

This significantly reduced CPU utilization on the bigbang scale
testing cluster at CERN.  Note that it is already disabled for
leveldb by default (in ceph_mon.cc).

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/common/config_opts.h b/src/common/config_opts.h
index d3fa4e00f00fee6bdd22818c9f216c62ba79dac7..ec57ee959df3412d1b256678b0672fbbbf8af5a4 100644 (file)
--- a/src/common/config_opts.h
+++ b/src/common/config_opts.h
@@ -760,7 +760,7 @@ OPTION(keyvaluestore_rocksdb_options, OPT_STR, "")
 // rocksdb options that will be used for omap(if omap_backend is rocksdb)
 OPTION(filestore_rocksdb_options, OPT_STR, "")
 // rocksdb options that will be used in monstore
-OPTION(mon_rocksdb_options, OPT_STR, "")
+OPTION(mon_rocksdb_options, OPT_STR, "compression=kNoCompression")
 
 /**
  * osd_*_priority adjust the relative priority of client io, recovery io,