Re: [Xen-devel] The order of contents saved in "/var/run/xenstored/db" is reversed

[Sunguodong <sunguodong@xxxxxxxxxx>]

> -----Original Message-----
> From: Wei Liu [mailto:wei.liu2@xxxxxxxxxx]
> Sent: Sunday, April 17, 2016 8:21 PM
> To: Sunguodong
> Cc: xen-devel@xxxxxxxxxxxxx; Fanhenglong; Wei Liu
> Subject: Re: [Xen-devel] The order of contents saved in
> "/var/run/xenstored/db" is reversed
> 
> On Sun, Apr 17, 2016 at 10:28:24AM +0000, Sunguodong wrote:
> > Hi all,
> >
> > I have a question about oxenstored, please help if someone knows.
> > Oxenstored saves store information to "/var/run/xenstored/db" when it
> quits, but the contents is reversed.
> > For example,
> > before restart oxenstored, the output of 'xenstore-ls -f' is:
> > ...
> > /local/domain/0/memory/target = "8388608"
> > /local/domain/0/memory/static-max = "4294967292"
> > /local/domain/0/memory/freemem-slack = "0"
> > ...
> > after restart oxenstored, the output is:
> > ...
> > /local/domain/0/memory/freemem-slack = "0"
> > /local/domain/0/memory/static-max = "4294967292"
> > /local/domain/0/memory/target = "8388608"
> > ...
> >
> > I found why when I read the code:
> > When a new element is added to node list, it is added to the head of
> the list, so the newest element will always be saved first, and then
> restored first.
> >
> > Then question is:
> > 1.What is the reason for this, is this done on purpose?
> > 2.What is the impact of doing so if I save the store information in
> the original order(first come first saved, and first saved first
> restored ^_^)?
> >
> 
> Why do you care much about what order they appear in the output? I
I was debugging it, and just confused about that. I was thinking if there
are any features relied on the order and affected when oxenstored restored
in reverse order. 

> don't
> think the tools should make assumption on the order they appear and the
> order doesn't matter.
OK, I get it, thank you.

> 
> In any case, if you need to have consistent view:
> 
>  xenstore-ls -f | sort
> 
> Wei.
> 
> 
> > Looking forward to your reply, thank you!
> >
> > Regards,
> > Jason
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxx
> > http://lists.xen.org/xen-devel
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