Ganeti automatic instance allocation
====================================
-Documents Ganeti version 2.1
+Documents Ganeti version 2.7
.. contents::
Command line interface changes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The node selection options in instanece add and instance replace disks
+The node selection options in instance add and instance replace disks
can be replace by the new ``--iallocator=NAME`` option (shortened to
``-I``), which will cause the auto-assignement of nodes with the
passed iallocator. The selected node(s) will be show as part of the
enabled_hypervisors
the list of enabled hypervisors
+ipolicy
+ the cluster-wide instance policy (for information; the per-node group
+ values take precedence and should be used instead)
+
request
a dictionary containing the details of the request; the keys vary
depending on the type of operation that's being requested, as
alloc_policy
the allocation policy of the node group (consult the semantics of
this attribute in the :manpage:`gnt-group(8)` manpage)
+ ipolicy
+ the instance policy of the node group
instances
a dictionary with the data for the current existing instance on the
cluster, indexed by instance name; the contents are similar to the
instance definitions for the allocate mode, with the addition of:
- admin_up
+ admin_state
if this instance is set to run (but not the actual status of the
instance)
type
the request type; this can be either ``allocate``, ``relocate``,
- ``multi-relocate`` or ``multi-evacuate``. The ``allocate`` request
- is used when a new instance needs to be placed on the cluster. The
- ``relocate`` request is used when an existing instance needs to be
- moved within its node group, while the ``multi-relocate`` one is
- able to relocate multiple instances across multiple node groups. The
- ``multi-evacuate`` protocol requests that the script computes the
- optimal relocate solution for all secondary instances of the given
- nodes.
+ ``change-group`` or ``node-evacuate``. The
+ ``allocate`` request is used when a new instance needs to be placed
+ on the cluster. The ``relocate`` request is used when an existing
+ instance needs to be moved within its node group.
+
+ The ``multi-evacuate`` protocol used to request that the script
+ computes the optimal relocate solution for all secondary instances
+ of the given nodes. It is now deprecated and needs only be
+ implemented if backwards compatibility with Ganeti 2.4 and lower is
+ needed.
+
+ The ``change-group`` request is used to relocate multiple instances
+ across multiple node groups. ``node-evacuate`` evacuates instances
+ off their node(s). These are described in a separate :ref:`design
+ document <multi-reloc-detailed-design>`.
+
+ The ``multi-allocate`` request is used to allocate multiple
+ instances on the cluster. The request is beside of that very
+ similiar to the ``allocate`` one. For more details look at
+ :doc:`Ganeti bulk create <design-bulk-create>`.
For both allocate and relocate mode, the following extra keys are needed
in the ``request`` dictionary:
Relocation:
relocate_from
- a list of nodes to move the instance away from (note that with
- Ganeti 2.0, this list will always contain a single node, the
- current secondary of the instance); type *list of strings*
+ a list of nodes to move the instance away from; for DRBD-based
+ instances, this will contain a single node, the current secondary
+ of the instance, whereas for shared-storage instance, this will
+ contain also a single node, the current primary of the instance;
+ type *list of strings*
-As for ``multi-relocate``, it needs the three following request
-arguments:
+As for ``node-evacuate``, it needs the following request arguments:
instances
- a list of instance names to relocate; type *list of strings*
+ a list of instance names to evacuate; type *list of strings*
+
+ evac_mode
+ specify which instances to evacuate; one of ``primary-only``,
+ ``secondary-only``, ``all``, type *string*
- reloc_mode
- a string indicating the relocation mode; there are three possible
- values for this string: *keep_group*, *change_group*, and
- *any_group*, the semantics or which are explained in :ref:`the
- design document <multi-reloc-detailed-design>`
+``change-group`` needs the following request arguments:
+
+ instances
+ a list of instance names whose group to change; type
+ *list of strings*
target_groups
- this argument is only accepted when ``reloc_mode``, as explained
- above, is *change_group*; if present, it must either be the empty
- list, or contain a list of group UUIDs that should be considered for
- relocating instances to; type *list of strings*
+ must either be the empty list, or contain a list of group UUIDs that
+ should be considered for relocating instances to; type
+ *list of strings*
-Finally, in the case of multi-evacuate, there's one single request
-argument (in addition to ``type``):
+``multi-allocate`` needs the following request arguments:
- evac_nodes
- the names of the nodes to be evacuated; type *list of strings*
+ instances
+ a list of request dicts
Response message
~~~~~~~~~~~~~~~~
entry in the input message, otherwise Ganeti will consider the result
as failed
- for multi-relocate mode, this is a list of lists of serialized
- opcodes. See the :ref:`design document <multi-reloc-result>` for a
- detailed dscription.
+ for the ``node-evacuate`` and ``change-group`` modes, this is a
+ dictionary containing, among other information, a list of lists of
+ serialized opcodes; see the :ref:`design document
+ <multi-reloc-result>` for a detailed description
- for multi-evacuation mode, this is a list of lists; each element of
- the list is a list of instance name and the new secondary node
+ for the ``multi-allocate`` mode this is a tuple of 2 lists, the first
+ being element of the tuple is a list of succeeded allocation, with the
+ instance name as first element of each entry and the node placement in
+ the second. The second element of the tuple is the instance list of
+ failed allocations.
.. note:: Current Ganeti version accepts either ``result`` or ``nodes``
as a backwards-compatibility measure (older versions only supported
}
}
-Input message, node evacuation::
-
- {
- "version": 2,
- ...
- "request": {
- "type": "multi-evacuate",
- "evac_nodes": [
- "node2"
- ],
- }
- }
-
Response messages
~~~~~~~~~~~~~~~~~
projects / ganeti-local / blobdiff