And also a couple of functions for describing a given solution; these
will be used in the future instead of the ones currently in hail.

The patch also enhances the description of failure messages.

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

Tuples are good for two, three, at most four elements. Beyond that, the
continuous pattern matching and construction/deconstruction becomes
tedious.

Since in the future we'll probably keep more information in the
AllocSolution type, we change it now from a triple to a "real" data
type. We also do some cleanups: adding a real emptyAlloc value, instead
of the previous hardcoded ones, and add some more comments on how we do
the multi-evacuation.

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

Since we added the score to AllocElement, we don't need to wrap
AllocElement in yet another tuple, just to attach the cluster score. So
we simplify the AllocSolution type.

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

AllocElement, a type used as a result of allocations, holds the status
of the nodes after the allocation. In most cases, we'll compare this
allocation result with others, to see which allocation decision makes
the most sense. This comparison is done via the cluster score.

However, if we later need to redo this computation, as part of other
comparisons, we'd need to evaluate it again, etc. So it's easier to just
compute the score at the place where we compute the node list in the
initial step.

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

Actually, this just moves the functions from the QC module to Types, and
removes a duplicate entry from Cluster.

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

This improves on the previous change. Currently, the node and instance
lists shipped around during data loading are (again) association lists.
For instances it's not a big issue, but the node list is rewritten
continuously while we assign instances to nodes, and that is very slow.
The code was originally written for small (10-20 node) clusters, and
today with multinodes… :)

Rewriting to use Node.List/Instance.List makes a bit of a messy patch,
but it allows to remove some custom functions for assoc. list
processing, and also some custom unittests.

At the end, the load time is almost halved, and we spend time now just
in the string parsing code (which is, as we know, slow…).

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

When loading big clusters, the association lists become a bit slow, so
we'll replace this with a simple Map String Int; the change is trivial
and can be reverted easily, while it brings up a good speedup in the
data loading.

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

The type alias NameAssoc has been introduced a long time ago, but there
are some few not-yet-converted cases. In preparation for changes to that
type, let's make sure we use it consistently.

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

On a single-group cluster, we proceed as before. On multi-group
clusters, we require selection of the desired group (currently via UUID
only).

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

This splits a top-level cluster information into the component node
groups. Instance go to the group of their primary node, but otherwise we
don't disallow split instances.

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>

Since some of the functions we export from Container.hs are 1:1
identical to IntMap, we can just export the originals and remove the
wrappers. This reduces the code we need to unittest.

Furthermore, we add two simple unittest for the two non-trivial
functions that we do have in Container.hs.

And finally, we remove the 'remove' function, since it's not used, and
thus bring code coverage very close to 100%.

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>

For now, we don't support instances allocated across two groups, and we
will reject such clusters. The isClusterConsistent function will return
a list of inconsistent instances, potentially allowing operation without
touch them (but only the rest).

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

Unittests included. The function will be needed for consistency checks
in the algorithms.

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

This is to pottentially allow easier changes later.

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

This depends on future support from Ganeti (2.4+).

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

This makes the code incompatible with JSON files from Ganeti pre-2.4.

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

Compatibility with old text files is kept by using the default UUID if
the file (or even some records) don't have a UUID.

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

This makes the code incompatible with Ganeti pre-2.4.

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

This is not used anywhere yet, and the backend are all just adding the
default UUID, not the real one.

The patch also allows displaying the group UUID in the node list.

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

This will be used as a placeholder for the cases when we need a UUID
(any UUID), but we don't have one handy.

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

This does just two passes, instead of three, over the list. This reduces
the overall runtime well enough (~25%) in some tests, but it's not
reproducible using profiling, so I don't know how much the function
itself is being sped-up.

Note: this is written via `seq`s, and not BangPatterns. Since it's just
one case, adding BangPatterns just for it wasn't a big gain.

Thanks to Lécz Balázs for the impetus to improve this!

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

Currently, hbal does a one-two signal handling, where the first signal
causes graceful termination, and the second one an immediate on (either
SIGINT or SIGTERM can be used, interchangeably). However, this poses a
timing problem: if two programs want to send a graceful termination
request, they cannot do that without careful coordination.

To fix this, we change to code to handle the signal separately: SIGINT
(^C) sends graceful termination, while SIGTERM sends immediate
termination. This should allow easier controlling of hbal.

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

While we don't actually have IO code in the Simu loader, we do have the
same interface. So we move the code again to a separate parseData
function which is exported.

The change is similar to the text loader change.

This change, which will be followed by similar changes in the other
loaders, splits the parsing of the data from the actual loading from
disk. Since the parsing doesn't usually involve IO actions, we will be
able to better test the parsing. The loading becomes a smaller part of
the code and thus inability to test it has a smaller impact.

This break compatibility with Ganeti pre-2.3.

* devel-0.2:
  Fix tag exclusion weight

Currently, the tag exclusion metric has a weight of one, which means
there might be cases where we won't move instances around because it
upsets the cluster metrics. However, we do want to make a higher effort
for cleaning up tag collisions, so we increase the weight to an
empirically-determined value of 2.

Pandoc 1.5.x uses the locale information to parse its input files (only
1.5, pre and post version use always UTF-8). Hence we need to enforce a
UTF-8 locale for proper parsing of input files.

This simplifies the maintenance of the man pages, and unifies the rst-to-*
converter to pandoc.

This is a work in progress, will be modified along with the progress
of Ganeti 2.3.

Currently, the key metrics/tiered spec computations show the virtual cpu
count. However, since we do have a maximum ration Vcpu/Pcpu, we can also
show the “normalized” cpu count, i.e. the equivalent physical cpu count
corresponding to the virtual ones.