On Mon, Sep 21, 2009 at 3:14 PM, Iustin Pop <[email protected]> wrote: > > --- > doc/design-2.1.rst | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 51 insertions(+), 0 deletions(-) > > diff --git a/doc/design-2.1.rst b/doc/design-2.1.rst > index 2bc9810..36213d8 100644 > --- a/doc/design-2.1.rst > +++ b/doc/design-2.1.rst > @@ -434,6 +434,57 @@ handle both cases. The default kvm vif script will be > changed to do so. (Xen > doesn't have a ganeti provided script, so nothing will be done for that > hypervisor) > > +Introducting persistent UUIDs > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + > +Current state and shortcomings > +++++++++++++++++++++++++++++++ > + > +Some objects in the Ganeti configurations are tracked by their name > +while also supporting renames. This creates an extra difficulty, > +because neither Ganeti nor external management tools can then track > +the actual entity, and due to the name change it behaves like a new > +one. > + > +Proposed changes part 1 > ++++++++++++++++++++++++ > + > +We will change Ganeti to use UUIDs for entity tracking, but in a > +staggered way. In 2.1, we will simply add an “uuid” attribute to each > +of the instances, nodes and cluster itself. This will be reported on > +instance creation for nodes, and on node adds for the nodes. It will > +be of course avaiblable for querying via the OpQueryNodes/Instance and > +cluster information, and via RAPI as well. > + > +Note that Ganeti will not provide any way to change this attribute. > + > +Upgrading from Ganeti 2.0 will add automatically uuids to all entities > +missing them. > +
Looks good. Also, can at least some of these information (eg: uuid to name mapping for nodes) be exported by ssconf? > + > +Proposed changes part 2 > ++++++++++++++++++++++++ > + > +In the next release (e.g. 2.2), the tracking of objects will change > +from the name to the UUID internally, and externally Ganeti will > +accept both forms of identification; e.g. an RAPI call would be made > +either against ``/2/instances/foo.bar`` or against > +``/2/instances/bb3b2e42…``. > + > +Another change here is that node identification (during cluster > +operations/queries like master startup, “am I the master?” and > +similar) could be done via UUIDs which is more stable than the current > +hostname-based scheme. > + > +Internal tracking refers to the way the configuration is stored; a > +DRBD disk of an instance refers to the node name (so that IPs can be > +changed easily), but this is still a problem for name changes; thus > +these will be changed to point to the node name to ease renames. > + > +The advantages of this change (after the second round of changes), if > +that node rename becomes trivial, whereas today node rename would > +require a complete lock of all instances. > + > > Automated disk repairs infrastructure > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > -- > 1.6.3.3 > > -- Guido Trotter Google - Sysops Team Google Ireland Ltd. : Registered in Ireland with company number 368047. Gordon House, Barrow Street, Dublin 4, Ireland.
