Instead of deciding based on secondary node, use the new flag.

This updates the movable flag on instances if they have only one node
(we don't rely on OpMoveInstance) or if they are set so via the command
line options.

This doesn't yet enable the use of the new flag.

This will be used instead of checking for no secondary and for
simplifying 'do not touch' instances.

This adds a short note for the new iallocator mode.

Signed-off-by: Iustin Pop <iustin@google.com>

This patch adds the new request loading/execution (trivial), but the
actual response formatting becomes more difficult as now the response
type differs by request.

Signed-off-by: Iustin Pop <iustin@google.com>

This will be used by the node evacuate IAllocator request type.

Signed-off-by: Iustin Pop <iustin@google.com>

We'll need AllocElement in both Cluster and IAlloc in the future, so we
move it to Node.hs which is imported by both.

Signed-off-by: Iustin Pop <iustin@google.com>

In preparation for multiple responses, we change from Maybe to List
(both used in the container sense).

This allows us to keep the same workflow for all kind of requests.

Signed-off-by: Iustin Pop <iustin@google.com>

Since not all structures will have these keys in the future, we move
them into per-structure keys.

Signed-off-by: Iustin Pop <iustin@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>

This mode restricts the list of instances to be moved to the instances
living on the offline (and drained) nodes.

Signed-off-by: Iustin Pop <iustin@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>

This should be no code change, just reordering of the options.

Signed-off-by: Iustin Pop <iustin@google.com>

In case a secondary node is already N+1 failed, currently the node
selection will accept a node that cannot start (at all) the new instance
as valid. This is wrong, so we add a new simple check to prevent the
case of instance's memory size being higher than the node's free (not
available, which might be lower than 0 for N+1 failures) memory.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This will make it clearer than many if…then choices.

Currently we test each instance for relocation in checkMove; however, it
is a little more clear if we pass only the relocatable instances to
checkMove. The patch also slightly rewrites (indendation/style) the
second half of the checkMove function.

Currently in the balancing function we do two thing:

- take the decision where to do a new balancing round or not
- and actually computing the balancing round

This is not nice, as the two parts are conceptually separate, so this
patch splits the decision on whether to descend or not to a new
function.

It seems that set -e does not affect subshell (only simple commands),
and thus we don't actually get failures from make check being run in a
subshell. Rather than trying to handle this better, we remove the
subshell and invoke make with the required subdirectory.

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>
Signed-off-by: Iustin Pop <iustin@google.com>

This also updates its manpage, some information were really old.

This patch changes from the two separate files to a single file, with
sections separated by a blank line. Currently only the node and instance
data is accepted, later the cluster tags will be read too via this
format.

This makes all the programs accept the new format, but hscan doesn't yet
generate it.

This is in preparation for the text format changes.

We actually use stddev and not the coefficient of variance (as wrongly
noted before), so we update the documentation appropriately.

We also note that the dynamic load values must be pre-normalized, since
we don't do such a normalization in the code.

The live test needs a populated cluster, so let's write this down.

This changes the 'dist' rule to also do a check that the archive can
build all the programs and passes the check test itself, and shows the
sha1sum at the end automatically.

Ganeti/HTools/Version.hs is generated at build time from version (which
is the only one shipped), so it must be removed by the clean rule.

This was found, of all things, via lintian during the Debian packaging…

This increases the priority of fixing N+1 failures compared to balancing
metrics.

* master:
  Use the oper_ram field if available
  rapi, luxi: treat drained nodes as offline

This helps with evacuation/failover of instances on 2-node clusters with
one one offline.

Currently we use the offline instance percentage (with range [0, 1]),
but this is not good, since we want the evacuation of such instances to
have a high priority; therefore we change this to a count of offline
instances, which has higher weight than a metric with range [0, 1].

For the RAPI and LUXI backends, we can get the actual memory usage (if
instances are running) via the oper_ram, whereas backend/memory only
tell what the instance will use at the next boot.

Not using oper_ram means that the node model is flawed and we consider
wrong values for the instance's memory (resulting sometimes in hilarious
values such as x_mem = -700 MB).