The OSDs will heartbeat each other, and report back to the monitors if
any other OSD fails to respond.
An OSD that fails to respond is effectively down, since it's not doing
the things that it's supposed to do. It is possible for this process
to cause problems. For example, I've had some OSDs on
hello, I am running ceph v0.87 for one week, at this week,
many osd have marking down, but I run "ps -ef | grep osd", I can see
the osd process, the osd not really down, then, I check osd log,
I see many logs like "osd.XX from dead osd.YY,marking down",
if the 0.87 will check other osd process ?
