[ceph-users] What goes in the monitor database?
bryanh at giraffe-data.com
Sat Nov 4 13:35:41 PDT 2017
Hi. Can anyone give me a rough idea of what the monitor database is for? I'm
curious about how it is behaving in an experimental system I set up.
I have a single monitor and a single client that just connects once a second
and does a "status" command. There is one OSD and one MDS in there too. This
is a Hammer system with a LevelDB key-value store. This produces a fair
amount of activity in the database; it looks like about 25K of updates for
every "status" transaction. The database compacts periodically and over the
longrun, does not grow in size.
Using ceph_kvstore_tool after shutting down the monitor, I see hundreds of
So what does the monitor have to store to do a "status" command?
I've seen clues that the activity has to do with Paxos elections, but I'm
fuzzy on why elections would be happening or why they would need a persistent
Bryan Henderson San Jose, California
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