This small patch changes the balancing computation to work in
parallel, if possible.

While the normal linking is against the single-threaded runtime, if
the code is linked against the multi-threaded one, the balancing will
get a significant speedup (80% efficiency at 4 cores, 60% at 12 cores,
and with GC tweaks it can reach 70%+).

On the single-threaded runtime, due to the fact that we only use the
weak head normal form, it doesn't introduce any extra penalties,
neither in space nor in CPU time (or if there are, they are too small
to detect easily).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Currently, the allocation routines (iterateAlloc and tieredAlloc)
return only the final state of the cluster and the list of allocated
instances. For better visibility in how the cluster resources change,
we compute and return a list of cluster resources at each step, which
should be a good indicator of the cluster state. The cost of the
computation for the new resource when not used is undetectable (< 1%).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This is a cheap way to get back compatibility with Ganeti 2.3 (and
lower) in the RAPI backend. It is however not very safe (the /2/groups
resource could fail due to other reasons), so it is added only
temporarily.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This allows a cluster structure to be easily serialized via "read";
together with the already existing instances of Show, this gives a
poor man's serialization/deserialization implementation.

The patch also exports the compDetailedCV function from Cluster.hs, so
that it can be used by other modules too.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Just another cleanup of duplicate code.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This again abstracts a bit the instance listing. Due to the fact that
I don't want to import Cluster.hs in CLI.hs, we pass the already
generated output. It also moves the instance display to stderr.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Since this bit of code (including the “when (isJust …)” is used in
multiple places, let's abstract it in a function that is used
consistently. One (bad?) side-effect is that all node lists are done
to stderr, including the ones from hbal where it was previously done
to stdout (is that fine?).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This functionality was replicated in multiple places (hbal & hspace),
so we abstract it for better clarity.

Additionally, in hbal we now save the state both before and after
balancing.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

We change processData to just load the data, and return a simpler
type.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This patch converts the backends and mergeData to the new ClusterData
type.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This will be used to hold all the disparate uses of the cluster data:
we have either tuples with these four elements, or functions taking
these four arguments, etc.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This patch moves the allocation policy from hardcoded to be read from
the given specification, and extends the error message for invalid
specifications.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This patch changes the behaviour of the --simulation option to be an
incremental option, where each new use defines a new node group. This
allows simulation of more complex clusters.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

* stable-0.2:
  Move man files to man/ subdirectory

Conflicts (all removed):
        man/hail.1
        man/hbal.1
        man/hscan.1
        man/hspace.1

This is just change on the 0.2 branch to synchronize with the master
branch. It allows automated builds to work better across the two
versions.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Adeodato Simo <dato@google.com>

* devel-0.2:
  Update NEWS file for 0.2.8 release
  hbal: return meaningful exit code for job failures
  Change the balancing function

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Adeodato Simo <dato@google.com>

Currently, LUXI job failures only display a warning message, while
still returning a success exit code. We change hbal to return
true/false from within execJobSet/runJobSet, and add a wrapper for
simpler code.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Adeodato Simo <dato@google.com>

Currently the balancing function is a modified version of the standard
deviation (stddev divided by list length), due to historical reasons.

While this works fine for small clusters, for big clusters it makes
the balancing effect too "weak", and in some cases it refuses to
balance correctly some clusters. It also makes the balancing behaviour
dependant on the cluster size, which is a big no-no.

Therefore we revert to the normal version of standard deviation, and
we also rename the function to reflect what it does. The new version
correctly balances some corner cases that the previous version didn't,
and passes the current balancing unittests.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Adeodato Simo <dato@google.com>

This splits out a bit of code from hspace.hs and moves it into its own
function in Cluster.hs.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This patch changes the allocate mode to respect the alloc_policy for
groups. It does this by changing the sort key from simply the solution
score, to a tuple with two elements: the alloc policy (which is now an
Ord instance) and the solution score. Also, the unallocable groups are
filtered out in the filterMGResults phase.

The patch also slightly enhances the informational message by
including the policy in the group information, to help debugging.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Currently, it's not easy to generate “fake” IAllocator request files
for hail. As such, testing on simulated clusters is hard to do.

To workaround this, we change hail to also take the ‘-t’ and
‘--simulate’ options, so that we can override the cluster data read
from the request. Note that this will not change the request itself
(so for example an evacuation will need to make sure uses the correct
node names), but it's a step forward in testing hail. The other tools
already can use text files which allow for better flexibility.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This will allow reading this attribute via the Rapi/Luxi backends.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Since currently hbal can only work on single groups at a time, we need
to be able to specify the target group when running the live test.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This is the complement to the reading part. Now the live-test works
correctly against clusters with configured exclusion tags.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This means that a file with the correct information is as accurate as
the other backends (Luxi, Rapi). Serialization of tags is in the next
patch.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

The new sepSplit function can split based on empty lines, so we remove
the hackish text splitting from before and simply use sepSplit. This
is needed as the addition of extra sections would have increased the
code linearly, which we don't want :)

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Currently it works on splitting strings by individual chars, but we
can generalise it to split lists by list elements, which means we can
reuse it later in the Text module for splitting both lists of chars by
'|' or lists of lines by empty newlines. The change also makes the
code cleaner (uses “null xs” instead of string-specific “xs == ""”).

Note: I tried to rewrite this in a nicer, functional style using
unfolds, but I failed to account for the final terminator case
(e.g. ab|cd|) resulting in a valid but empty element.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This patch switches from the group index to the group name for the
informational messages in the hail results.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

This should have been in the previous patches, but sent separate for
clarity.

The live-test script is updated to read the first node from the
cluster, now that the text files don't start anymore with the node
data.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>