On 2020/2/18 20:01, Jeff Layton wrote:
On Tue, 2020-02-18 at 15:19 +0800, Xiubo Li wrote:
On 2020/2/17 21:04, Jeff Layton wrote:
On Sun, 2020-02-16 at 01:49 -0500, xiubli@xxxxxxxxxx wrote:
From: Xiubo Li <xiubli@xxxxxxxxxx>
This will simulate pulling the power cable situation, which will
do:
- abort all the inflight osd/mds requests and fail them with -EIO.
- reject any new coming osd/mds requests with -EIO.
- close all the mds connections directly without doing any clean up
and disable mds sessions recovery routine.
- close all the osd connections directly without doing any clean up.
- set the msgr as stopped.
URL: https://tracker.ceph.com/issues/44044
Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
There is no explanation of how to actually _use_ this feature? I assume
you have to remount the fs with "-o remount,halt" ? Is it possible to
reenable the mount as well? If not, why keep the mount around? Maybe we
should consider wiring this in to a new umount2() flag instead?
This needs much better documentation.
In the past, I've generally done this using iptables. Granted that that
is difficult with a clustered fs like ceph (given that you potentially
have to set rules for a lot of addresses), but I wonder whether a scheme
like that might be more viable in the long run.
How about fulfilling the DROP iptable rules in libceph ? Could you
foresee any problem ? This seems the one approach could simulate pulling
the power cable.
Yeah, I've mostly done this using DROP rules when I needed to test things.
But, I think I was probably just guilty of speculating out loud here.
I think doing this by just closing down the sockets is probably fine. I
wouldn't pursue anything relating to to iptables here, unless we have
some larger reason to go that route.
I have digged into the socket and netfilter code today, to do this in
kernel space is kind easy.
Let's have a test if closing socket direct could not work well or as
expected, let's have try that then.
Thanks.
BRs
