1 Ganeti-htools release notes
2 ===========================
5 Version 0.2.7 (Thu, 07 Oct 2010)
6 --------------------------------
10 - fixed the error message for hail multi-evacuation mode
11 - improve evacuation mode for offline secondary nodes (ignore available
16 - add a new option ``-S`` to hbal and hspace that saves the cluster
17 state at the end of the processing in the text format used by the
18 ``-t`` option, for later re-processing
19 - a two new options to hbal, -g and --min-gain-limit, that should help
20 in limiting the number of balances steps with a low gain in the final
22 - hbal, when executing jobs, will now wait for the current jobs to
23 finish at the first stop (e.g. ^C); if the user wants immediate exit,
24 another signal should be sent
25 - added “normalized” physical CPU units in hspace output (NPU), which
26 represents units of physical CPUs free/used, based on the max-cpu
30 Version 0.2.6 (Mon, 26 Jul 2010)
31 --------------------------------
33 Exactly three months since the last release. Many internal changes, plus
34 a couple of important changes in the balancing algorithm.
36 First, the balancing may now introduce N+1 errors, if this solves other,
37 more critical problems. For the moment, this means that moving instances
38 away from offline nodes is allowed even if it creates N+1 errors, and
39 that means evacuation can be done in more cases.
41 Second, the scoring for N+1 has changed. In previous versions, it simply
42 counted the number of failing N+1 nodes, which means moving an instance
43 away from a N+1 failed node (but without the node 'clearing' the N+1
44 status) was not reflected in the cluster score. As such, the balancing
45 algorithm managed to clear N+1 errors only sometimes, since usually it
46 takes more than one move for this, and the first prerequisite move was
47 not 'rewarded' appropriately and thus it was not selected. Now, it is
48 possible to fix many more error cases than before: on a simulated 40
49 node cluster full with instances (symmetrically allocated on all nodes),
50 around five nodes can be evacuated before N+1 errors can be solved,
51 whereas 0.2.5 could evacuate at best one node.
53 There were some other internal changes to the scoring algorithm, such
54 that now the metrics have associated weights, and they are not all of
55 the same importance anymore. As of now, the only change is that offline
56 instances have a higher weight, which should favour proper node
59 Among the other changes:
61 - fixed the hspace KM_POOL_* metrics, which were returned as the final
62 state and not as the delta between the initial and final states
63 - fixed hspace handling of N+1 failing clusters: before, it used to
64 generate a 'fake' response, and the structure of this response was not
65 always in sync with the real responses, leading to missing items;
66 currently it proceeds correctly through the code (skipping the
67 computation), and uses the same display mechanisms as the normal case
68 - fixed hscan exit code for RAPI failures: previously it finished with
69 success even if all the clusters failed, which was creating issues
70 with the live-test script; now it exits with exit code 2 for RAPI
71 failures (unfortunately this is still not optimal as LUXI failures
72 will use exit code 1, the same as the command line)
73 - changed the limit values for CPU/disk, which previously were used
74 optionally, whereas now they are always used; the default cpu ratio
75 limit is now 64 VCPUs per PCPU
76 - changed the internal handling of the short name vs. original
77 (Ganeti-provided) name; now internally we always use the full name,
78 and only in display routines we show the shortened (called 'alias')
79 name; as a result, the -O and --excluded-instances options now accept
80 both the full name and the shortened name
81 - changed internal handling of JSON conversions and errors, such that
82 now we show a better context for failure messages, which should help
83 with diagnosing the malformed message
84 - changed the names for a few node fields, and added some more nodes;
85 this is most likely to help with debugging, and not with regular
87 - changed the node fields option to allow the '+' prefix to mean 'extend
88 the default fields list' rather than start from fresh (similar to
89 Ganeti's implementation)
90 - a few internal changes related to the LUXI protocol implementation,
91 which should make it more safe against potential bugs, one
92 optiomization that should help with large messages, and some patches
93 in preparation for potential expansion of the LUXI backend functionality
95 And finally, many improvements on unittests and the live-test
96 script. Test coverage is much enhanced, and the test infrastructure has
97 better error reporting; this should lead down-the-road to better code
101 Version 0.2.5 (Mon, 26 Apr 2010)
102 --------------------------------
104 Some internal cleanup plus a few user-visible changes:
106 - new option for marking instances as 'do-not-move' during rebalancing
107 - allow ``hscan`` to scan the local cluster via Luxi
108 - add more metrics to ``hspace`` which show the delta between original
109 state and final state better (only valid for tiered allocation)
112 Version 0.2.4 (Mon, 22 Feb 2010)
113 --------------------------------
115 Two improvements for node evacuation:
117 - hbal takes a new parameter ``--evac-mode`` that restricts the
118 instances to be moved to the ones on offline/drained nodes, which
119 should reduce the work done
120 - hail supports the new ``multi-evacuate`` mode of the IAllocator
121 protocol, that will be released in a minor release on the Ganeti 2.1
125 Version 0.2.3 (Thu, 4 Feb 2010)
126 --------------------------------
130 - Fixes selection of secondary node: previously, if the cluster had
131 many N+1 failures, a N+1 failed node could be selected as secondary
132 even if it did not have enough memory to allow the instance to be
133 migrated/failed over to it; this is bad for automated tools, since
134 we can get the cluster in an unhealthy state
135 - Switch the text backend to a single input file, that is generated
136 now by hscan and shouldn't be generated manually via
137 gnt-node/instance list anymore; this allows richer information to be
138 kept in the file, and simplifies a little the internals of the text
142 Version 0.2.2 (Tue, 29 Dec 2009)
143 --------------------------------
145 Small release, 0.2.1 was broken and thus this was released earlier:
147 - Release 0.2.1 broke the LUXI backend due to a typo, fixed
148 - Added a live-test script that should catch errors like the above one
149 in the future (needs a working, non-empty cluster)
150 - Changed RAPI and LUXI backends to treat drained nodes as offline,
151 similar to the IAllocator backend change in 0.2.0 (which was wrongly
152 marked as affecting all backends)
153 - Changed the metrics for offline instances and N1 score from percent to
154 count, in order to increase the priority of evacuations
155 - Added a new metric (offline primary instances) which should fix the
156 evacuation of a offline node in a 2-node cluster
159 Version 0.2.1 (Wed, 2 Dec 2009)
160 --------------------------------
162 - Added instance exclusion defined via instance tags
163 - Fixed the output of hspace to be again parseable from the shell
166 Version 0.2.0 (Tue, 10 Nov 2009)
167 --------------------------------
169 A significant release, with a few new major features:
171 - Added direct execution of the hbal solution when using the Luxi
172 backend; the steps for each instance moves are submitted as a single
173 jobs, and the different jobs are submitted as groups in order to
174 parallelise the execution of moves
175 - Added support for balancing based on dynamic utilisation data for
176 instances, fed in via a text file; by default, all instances are
177 considered equal and this change also improves the equalisation of
178 secondary instances per node
179 - Added support for tiered capacity calculation in hspace, where we
180 start from a maximum instance spec and decrease the spec when we run
181 out of resources; this should give a better measure of available
182 capacity on 'fragmented' clusters; this is done separately from the
183 current fixed-mode computation
185 Also there have been many minor improvements:
187 - Added option for showing instances (“--print-instances”), similar to
188 the print nodes option
189 - Added support for customising the node list via an argument to the
190 print nodes option in the form of a comma-separated list of field
191 names; currently the field names are not documented, expecting further
192 changes in a next release
193 - Enhanced the error reporting in the Luxi and Rapi backends
194 - Changed the handling of drained nodes, now being treated the same as
195 offline nodes, for Ganeti 2.0.4+ compatibility
196 - A number of internal changes, simplifying code and merging some
198 - Simplify the build system in relation to creation of archives
201 Version 0.1.8 (Tue, 29 Sep 2009)
202 --------------------------------
204 - Brown-paper-bag release fixing haddock issues
207 Version 0.1.7 (Mon, 28 Sep 2009)
208 --------------------------------
210 - Fixed a bug in the Luxi backend for big responses
211 - Fixed test suite exit code in presence of test failures
212 - Changed the migrate operation to run instead failover for instances
213 which were marked as not running in the input data (this could have
214 been changed since then, but it's better than today's always migrate)
215 - Added support for 'cheap' moves only (only migrate/failover) in
217 - Added support for building without curl (thus no RAPI backend)
220 Version 0.1.6 (Wed, 19 Aug 2009)
221 --------------------------------
223 - Added support for Luxi (the native Ganeti protocol)
224 - Added support for simulated clusters (for hspace only)
225 - Added timeouts for the RAPI backend
226 - Fixed a few inconsistencies in the command line handling
227 - Fixed handling of errors while loading data
228 - The 'network' is a new dependency due to the Luxi addition
231 Version 0.1.5 (Thu, 09 Jul 2009)
232 --------------------------------
234 - Removed obsolete hn1 program; this allowed removal of a lot of
236 - Lots of changes in hspace: the output now is a shell fragment in order
237 for script to source it or parse it easier; added failure reasons;
238 optimised to use less memory for large clusters
239 - Optimized the scoring algorithm (used by all tools) so that now
240 computations should be faster
243 Version 0.1.4 (Tue, 16 Jun 2009)
244 --------------------------------
246 - Added CPU count/ratio of virtual-to-physical CPUs to the cluster
247 scoring methods; this means that now the balancer, the iallocator
248 plugin and so on will try to keep the VCPU-to-PCPU ratio equal across
250 - Fixed some hscan bugs
251 - Fixed the way iallocator reads the total disk size (was broken and it
252 was always falling back to summing the disk sizes)
253 - Internals: fixed most compile-time warnings
256 Version 0.1.3 (Fri, 05 Jun 2009)
257 --------------------------------
259 - Fix a bug in the ReplacePrimary instance moves, affecting most of the
263 Version 0.1.2 (Tue, 02 Jun 2009)
264 --------------------------------
266 - Add a new program, “hspace”, which computes the free space on a
267 cluster (based on a given instance spec)
268 - Improvements in API docs and partially in the user docs
269 - Started adding unittests
272 Version 0.1.1 (Tue, 26 May 2009)
273 --------------------------------
275 - Add a new program, “hail”, which is an iallocator plugin and can
276 allocate/relocate instances
277 - Experimental support for non-mirrored instances (hail supports them,
278 hbal should no longer abort when it finds such instances and simply
280 - The RAPI port and/or scheme can be overriden now, and even “file://”
281 schemes can be used if the message body has been saved under the
283 - Lots of code reorganization, esp. rewritten loading pipeline
284 - Better data checking and better error messages in case validation
285 fails; tools now consider nodes with error in input data (‘?’ returned
286 by ganeti) as offline
287 - Small enhancement to the makefile for simpler packaging
290 Version 0.1.0 (Tue, 19 May 2009)
291 --------------------------------
293 - Drop compatibility with Ganeti 1.2
294 - Add a new minimum score option (with a very low default), should help
295 with very good clusters (but is still not optimal)
296 - Add a --quiet option to hbal
297 - Add support for reading offline nodes directly from the cluster
300 Version 0.0.8 (Tue, 21 Apr 2009)
301 --------------------------------
303 - hbal: prevent mismatches in wrong node names being passed to -O, by
304 aborting in this case
305 - add the ability to write the commands (-C) to a script via (-C<file>),
306 so that it can be later executed directly; this has also changed the
307 commands to include the ncessary -f flags to skip confirmations
308 - add checks for extra argument in hbal and hn1, so that unintended
310 - raise the accepted “missing” memory limit to 512MB, to cover usual Xen
314 Version 0.0.7 (Mon, 23 Mar 2009)
315 --------------------------------
317 - added support for offline nodes, which are not used as targets for
318 instance relocation and if they hold instances the hbal algorithm will
319 attempt to relocate these away
320 - added support for offline instances, which now will no longer skew the
321 free memory estimation of nodes; the algorithm will no longer create
322 conditions for N+1 failures when such instances are later started
323 - implemented a complete model of node resources, in order to prevent an
324 unintended re-occurrence of cases like the offline instance were we
325 miscalculate some node resource; this gives warning now in case the
326 node reported free disk or free memory deviates by more than a set
327 amount from the expected value
328 - a new tool *hscan* that can generate the input text-file for the other
329 tools by collection via RAPI
330 - some small changes to the build system to make it more friendly; also
331 included the generated documentation in the source archive
334 Version 0.0.6 (Mon, 16 Mar 2009)
335 --------------------------------
337 - re-factored the hbal algorithm to make it stable in the sense that it
338 gives the same solution when restarted from the middle; barring
339 rounding of disk/memory and incomplete reporting from Ganeti (for
340 1.2), it should be now feasible to rely on its output without
341 generating moves ad infinitum
342 - the hbal algorithm now uses two more variables: the node N+1 failures
343 and the amount of reserved memory; the first of which tries to ‘fix’
344 the N+1 status, the latter tries to distribute secondaries more
346 - the hbal algorithm now uses two more moves at each step:
347 replace+failover and failover+replace (besides the original failover,
348 replace, and failover+replace+failover)
349 - slightly changed the build system to embed GIT version/tags into the
350 binaries so that we know for a binary from which tree it was done,
351 either via ‘--version’ or via “strings hbal|grep version”
352 - changed the solution list and in general the hbal output to be more
353 clear by default, and changed “gnt-instance failover” to “gnt-instance
355 - added man pages for the two binaries
358 Version 0.0.5 (Mon, 09 Mar 2009)
359 --------------------------------
361 - a few small improvements for hbal (possibly undone by later changes),
362 hbal is now quite faster
363 - fix documentation building
364 - allow hbal to work on non N+1 compliant clusters, but without
365 guarantees that the end cluster will be compliant; in any case, this
366 should give a smaller number of nodes that are not compliant if the
367 cluster state permits it
368 - strip common domain suffix from nodes and instances, so that output is
369 shorter and hopefully clearer
372 Version 0.0.4 (Sun, 15 Feb 2009)
373 --------------------------------
375 - better balancing algorithm in hbal
376 - implemented an RAPI collector, now the cluster data can be gathered
377 automatically via RAPI and doesn't need manual export of node and
381 Version 0.0.3 (Wed, 28 Jan 2009)
382 --------------------------------
384 - initial release of the hbal, a cluster rebalancing tool
385 - input data format changed due to hbal requirements
388 Version 0.0.2 (Tue, 06 Jan 2009)
389 --------------------------------
391 - fix handling of some common cases (cluster N+1 compliant from the
392 start, too big depth given, failure to compute solution)
393 - add option to print the needed command list for reaching the proposed
397 Version 0.0.1 (Tue, 06 Jan 2009)
398 --------------------------------
400 - initial release of hn1 tool
402 .. vim: set textwidth=72 :
projects / ganeti-local / blob