On Wed, Jun 18, 2008 at 4:30 PM, Patrick McHardy [off-list ref] wrote:

Julius Volz wrote:

quoted

On Wed, Jun 18, 2008 at 4:19 PM, Patrick McHardy [off-list ref] wrote:

quoted

quoted

2) for the service flags, only one bit is set from userspace
(persistent/nonpersistent service). So this might be not too bad to
have as a single Netlink flag attribute.

And this bit can't be unset (or if it currently can't be,
it also wouldn't make sense to be able to unset it)?

It can get unset when editing a persistent service to be
non-persistent, so you would still have to include it in a change
request that doesn't want to unset it. Since it's only one flag
though, it didn't seem too bad to me.

The problem is that its racy. You have to query the current
state before deciding whether to send it or not. And another
process might change it in between. An additional downside
is the overhead for the query itself.

Right, forgot about this issue. Although ipvsadm does no getting and
setting based on the prior value (it only takes the value of the flag
from the command line), there might be other userspace tools who'd
want to use the interface differently.

quoted

An alternative (also, in case of more flags in the future) would be to
put flags into a nested attribute and if this is not supplied from
userspace during an edit operation, the flags will be left untouched.

Then you can't unset them. I'd simply use the flags/mask
scheme.

Ok!

Julius

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