Ticket #1400: NEWS-rst.2.html

File NEWS-rst.2.html, 77.0 KB (added by marlowe, at 2011-05-11T02:32:59Z)

The corresponding HTML file

Line 
1<?xml version="1.0" encoding="utf-8" ?>
2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
3<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
4<head>
5<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
6<meta name="generator" content="Docutils 0.7: http://docutils.sourceforge.net/" />
7<title>User-Visible Changes in Tahoe-LAFS</title>
8<style type="text/css">
9
10/*
11:Author: David Goodger (goodger@python.org)
12:Id: $Id: html4css1.css 6253 2010-03-02 00:24:53Z milde $
13:Copyright: This stylesheet has been placed in the public domain.
14
15Default cascading style sheet for the HTML output of Docutils.
16
17See http://docutils.sf.net/docs/howto/html-stylesheets.html for how to
18customize this style sheet.
19*/
20
21/* used to remove borders from tables and images */
22.borderless, table.borderless td, table.borderless th {
23  border: 0 }
24
25table.borderless td, table.borderless th {
26  /* Override padding for "table.docutils td" with "! important".
27     The right padding separates the table cells. */
28  padding: 0 0.5em 0 0 ! important }
29
30.first {
31  /* Override more specific margin styles with "! important". */
32  margin-top: 0 ! important }
33
34.last, .with-subtitle {
35  margin-bottom: 0 ! important }
36
37.hidden {
38  display: none }
39
40a.toc-backref {
41  text-decoration: none ;
42  color: black }
43
44blockquote.epigraph {
45  margin: 2em 5em ; }
46
47dl.docutils dd {
48  margin-bottom: 0.5em }
49
50/* Uncomment (and remove this text!) to get bold-faced definition list terms
51dl.docutils dt {
52  font-weight: bold }
53*/
54
55div.abstract {
56  margin: 2em 5em }
57
58div.abstract p.topic-title {
59  font-weight: bold ;
60  text-align: center }
61
62div.admonition, div.attention, div.caution, div.danger, div.error,
63div.hint, div.important, div.note, div.tip, div.warning {
64  margin: 2em ;
65  border: medium outset ;
66  padding: 1em }
67
68div.admonition p.admonition-title, div.hint p.admonition-title,
69div.important p.admonition-title, div.note p.admonition-title,
70div.tip p.admonition-title {
71  font-weight: bold ;
72  font-family: sans-serif }
73
74div.attention p.admonition-title, div.caution p.admonition-title,
75div.danger p.admonition-title, div.error p.admonition-title,
76div.warning p.admonition-title {
77  color: red ;
78  font-weight: bold ;
79  font-family: sans-serif }
80
81/* Uncomment (and remove this text!) to get reduced vertical space in
82   compound paragraphs.
83div.compound .compound-first, div.compound .compound-middle {
84  margin-bottom: 0.5em }
85
86div.compound .compound-last, div.compound .compound-middle {
87  margin-top: 0.5em }
88*/
89
90div.dedication {
91  margin: 2em 5em ;
92  text-align: center ;
93  font-style: italic }
94
95div.dedication p.topic-title {
96  font-weight: bold ;
97  font-style: normal }
98
99div.figure {
100  margin-left: 2em ;
101  margin-right: 2em }
102
103div.footer, div.header {
104  clear: both;
105  font-size: smaller }
106
107div.line-block {
108  display: block ;
109  margin-top: 1em ;
110  margin-bottom: 1em }
111
112div.line-block div.line-block {
113  margin-top: 0 ;
114  margin-bottom: 0 ;
115  margin-left: 1.5em }
116
117div.sidebar {
118  margin: 0 0 0.5em 1em ;
119  border: medium outset ;
120  padding: 1em ;
121  background-color: #ffffee ;
122  width: 40% ;
123  float: right ;
124  clear: right }
125
126div.sidebar p.rubric {
127  font-family: sans-serif ;
128  font-size: medium }
129
130div.system-messages {
131  margin: 5em }
132
133div.system-messages h1 {
134  color: red }
135
136div.system-message {
137  border: medium outset ;
138  padding: 1em }
139
140div.system-message p.system-message-title {
141  color: red ;
142  font-weight: bold }
143
144div.topic {
145  margin: 2em }
146
147h1.section-subtitle, h2.section-subtitle, h3.section-subtitle,
148h4.section-subtitle, h5.section-subtitle, h6.section-subtitle {
149  margin-top: 0.4em }
150
151h1.title {
152  text-align: center }
153
154h2.subtitle {
155  text-align: center }
156
157hr.docutils {
158  width: 75% }
159
160img.align-left, .figure.align-left, object.align-left {
161  clear: left ;
162  float: left ;
163  margin-right: 1em }
164
165img.align-right, .figure.align-right, object.align-right {
166  clear: right ;
167  float: right ;
168  margin-left: 1em }
169
170img.align-center, .figure.align-center, object.align-center {
171  display: block;
172  margin-left: auto;
173  margin-right: auto;
174}
175
176.align-left {
177  text-align: left }
178
179.align-center {
180  clear: both ;
181  text-align: center }
182
183.align-right {
184  text-align: right }
185
186/* reset inner alignment in figures */
187div.align-right {
188  text-align: left }
189
190/* div.align-center * { */
191/*   text-align: left } */
192
193ol.simple, ul.simple {
194  margin-bottom: 1em }
195
196ol.arabic {
197  list-style: decimal }
198
199ol.loweralpha {
200  list-style: lower-alpha }
201
202ol.upperalpha {
203  list-style: upper-alpha }
204
205ol.lowerroman {
206  list-style: lower-roman }
207
208ol.upperroman {
209  list-style: upper-roman }
210
211p.attribution {
212  text-align: right ;
213  margin-left: 50% }
214
215p.caption {
216  font-style: italic }
217
218p.credits {
219  font-style: italic ;
220  font-size: smaller }
221
222p.label {
223  white-space: nowrap }
224
225p.rubric {
226  font-weight: bold ;
227  font-size: larger ;
228  color: maroon ;
229  text-align: center }
230
231p.sidebar-title {
232  font-family: sans-serif ;
233  font-weight: bold ;
234  font-size: larger }
235
236p.sidebar-subtitle {
237  font-family: sans-serif ;
238  font-weight: bold }
239
240p.topic-title {
241  font-weight: bold }
242
243pre.address {
244  margin-bottom: 0 ;
245  margin-top: 0 ;
246  font: inherit }
247
248pre.literal-block, pre.doctest-block {
249  margin-left: 2em ;
250  margin-right: 2em }
251
252span.classifier {
253  font-family: sans-serif ;
254  font-style: oblique }
255
256span.classifier-delimiter {
257  font-family: sans-serif ;
258  font-weight: bold }
259
260span.interpreted {
261  font-family: sans-serif }
262
263span.option {
264  white-space: nowrap }
265
266span.pre {
267  white-space: pre }
268
269span.problematic {
270  color: red }
271
272span.section-subtitle {
273  /* font-size relative to parent (h1..h6 element) */
274  font-size: 80% }
275
276table.citation {
277  border-left: solid 1px gray;
278  margin-left: 1px }
279
280table.docinfo {
281  margin: 2em 4em }
282
283table.docutils {
284  margin-top: 0.5em ;
285  margin-bottom: 0.5em }
286
287table.footnote {
288  border-left: solid 1px black;
289  margin-left: 1px }
290
291table.docutils td, table.docutils th,
292table.docinfo td, table.docinfo th {
293  padding-left: 0.5em ;
294  padding-right: 0.5em ;
295  vertical-align: top }
296
297table.docutils th.field-name, table.docinfo th.docinfo-name {
298  font-weight: bold ;
299  text-align: left ;
300  white-space: nowrap ;
301  padding-left: 0 }
302
303h1 tt.docutils, h2 tt.docutils, h3 tt.docutils,
304h4 tt.docutils, h5 tt.docutils, h6 tt.docutils {
305  font-size: 100% }
306
307ul.auto-toc {
308  list-style-type: none }
309
310</style>
311</head>
312<body>
313<div class="document" id="user-visible-changes-in-tahoe-lafs">
314<h1 class="title">User-Visible Changes in Tahoe-LAFS</h1>
315
316<!-- -*- coding: utf-8 -*- -->
317<div class="section" id="release-1-8-2-2011-01-30">
318<h1>Release 1.8.2 (2011-01-30)</h1>
319<div class="section" id="compatibility-and-dependencies">
320<h2>Compatibility and Dependencies</h2>
321<ul class="simple">
322<li>Tahoe is now compatible with Twisted-10.2 (released last month), as
323well as with earlier versions. The previous Tahoe-1.8.1 release
324failed to run against Twisted-10.2, raising an AttributeError on
325StreamServerEndpointService (#1286)</li>
326<li>Tahoe now depends upon the &quot;mock&quot; testing library, and the foolscap
327dependency was raised to 0.6.1 . It no longer requires pywin32
328(which was used only on windows). Future developers should note that
329reactor.spawnProcess and derivatives may no longer be used inside
330Tahoe code.</li>
331</ul>
332</div>
333<div class="section" id="other-changes">
334<h2>Other Changes</h2>
335<ul class="simple">
336<li>the default reserved_space value for new storage nodes is 1 GB (#1208)</li>
337<li>documentation is now in reStructuredText (.rst) format</li>
338<li>&quot;tahoe cp&quot; should now handle non-ASCII filenames</li>
339<li>the unmaintained Mac/Windows GUI applications have been removed (#1282)</li>
340<li>tahoe processes should appear in top and ps as &quot;tahoe&quot;, not
341&quot;python&quot;, on some unix platforms. (#174)</li>
342<li>&quot;tahoe debug trial&quot; can be used to run the test suite (#1296)</li>
343<li>the SFTP frontend now reports unknown sizes as &quot;0&quot; instead of &quot;?&quot;,
344to improve compatibility with clients like FileZilla (#1337)</li>
345<li>&quot;tahoe --version&quot; should now report correct values in situations
346where 1.8.1 might have been wrong (#1287)</li>
347</ul>
348</div>
349</div>
350<div class="section" id="release-1-8-1-2010-10-28">
351<h1>Release 1.8.1 (2010-10-28)</h1>
352<div class="section" id="bugfixes-and-improvements">
353<h2>Bugfixes and Improvements</h2>
354<ul class="simple">
355<li>Allow the repairer to improve the health of a file by uploading some
356shares, even if it cannot achieve the configured happiness
357threshold. This fixes a regression introduced between v1.7.1 and
358v1.8.0. (#1212)</li>
359<li>Fix a memory leak in the ResponseCache which is used during mutable
360file/directory operations. (#1045)</li>
361<li>Fix a regression and add a performance improvement in the
362downloader.  This issue caused repair to fail in some special
363cases. (#1223)</li>
364<li>Fix a bug that caused 'tahoe cp' to fail for a grid-to-grid copy
365involving a non-ASCII filename. (#1224)</li>
366<li>Fix a rarely-encountered bug involving printing large strings to the
367console on Windows. (#1232)</li>
368<li>Perform ~ expansion in the --exclude-from filename argument to
369'tahoe backup'. (#1241)</li>
370<li>The CLI's 'tahoe mv' and 'tahoe ln' commands previously would try to
371use an HTTP proxy if the HTTP_PROXY environment variable was set.
372These now always connect directly to the WAPI, thus avoiding giving
373caps to the HTTP proxy (and also avoiding failures in the case that
374the proxy is failing or requires authentication). (#1253)</li>
375<li>The CLI now correctly reports failure in the case that 'tahoe mv'
376fails to unlink the file from its old location. (#1255)</li>
377<li>'tahoe start' now gives a more positive indication that the node has
378started. (#71)</li>
379<li>The arguments seen by 'ps' or other tools for node processes are now
380more useful (in particular, they include the path of the 'tahoe'
381script, rather than an obscure tool named 'twistd'). (#174)</li>
382</ul>
383</div>
384<div class="section" id="removed-features">
385<h2>Removed Features</h2>
386<ul class="simple">
387<li>The tahoe start/stop/restart and node creation commands no longer
388accept the -m or --multiple option, for consistency between
389platforms.  (#1262)</li>
390</ul>
391</div>
392<div class="section" id="packaging">
393<h2>Packaging</h2>
394<ul class="simple">
395<li>We now host binary packages so that users on certain operating
396systems can install without having a compiler.
397&lt;<a class="reference external" href="http://tahoe-lafs.org/source/tahoe-lafs/deps/tahoe-lafs-dep-eggs/README.html">http://tahoe-lafs.org/source/tahoe-lafs/deps/tahoe-lafs-dep-eggs/README.html</a>&gt;</li>
398<li>Use a newer version of a dependency if needed, even if an older
399version is installed. This would previously cause a VersionConflict
400error. (#1190)</li>
401<li>Use a precompiled binary of a dependency if one with a sufficiently
402high version number is available, instead of attempting to compile
403the dependency from source, even if the source version has a higher
404version number. (#1233)</li>
405</ul>
406</div>
407<div class="section" id="documentation">
408<h2>Documentation</h2>
409<ul class="simple">
410<li>All current documentation in .txt format has been converted to .rst
411format. (#1225)</li>
412<li>Added docs/backdoors.rst declaring that we won't add backdoors to
413Tahoe-LAFS, or add anything to facilitate government access to data.
414(#1216)</li>
415</ul>
416</div>
417</div>
418<div class="section" id="release-1-8-0-2010-09-23">
419<h1>Release 1.8.0 (2010-09-23)</h1>
420<div class="section" id="new-features">
421<h2>New Features</h2>
422<ul class="simple">
423<li>A completely new downloader which improves performance and
424robustness of immutable-file downloads. It uses the fastest K
425servers to download the data in K-way parallel. It automatically
426fails over to alternate servers if servers fail in mid-download. It
427allows seeking to arbitrary locations in the file (the previous
428downloader which would only read the entire file sequentially from
429beginning to end). It minimizes unnecessary round trips and
430unnecessary bytes transferred to improve performance. It sends
431requests to fewer servers to reduce the load on servers (the
432previous one would send a small request to every server for every
433download) (#287, #288, #448, #798, #800, #990, #1170, #1191)</li>
434<li>Non-ASCII command-line arguments and non-ASCII outputs now work on
435Windows. In addition, the command-line tool now works on 64-bit
436Windows. (#1074)</li>
437</ul>
438</div>
439<div class="section" id="id1">
440<h2>Bugfixes and Improvements</h2>
441<ul class="simple">
442<li>Document and clean up the command-line options for specifying the
443node's base directory. (#188, #706, #715, #772, #1108)</li>
444<li>The default node directory for Windows is &quot;.tahoe&quot; in the user's
445home directory, the same as on other platforms. (#890)</li>
446<li>Fix a case in which full cap URIs could be logged. (#685, #1155)</li>
447<li>Fix bug in WUI in Python 2.5 when the system clock is set back to
4481969. Now you can use Tahoe-LAFS with Python 2.5 and set your system
449clock to 1969 and still use the WUI. (#1055)</li>
450<li>Many improvements in code organization, tests, logging,
451documentation, and packaging. (#983, #1074, #1108, #1127, #1129,
452#1131, #1166, #1175)</li>
453</ul>
454</div>
455<div class="section" id="dependency-updates">
456<h2>Dependency Updates</h2>
457<ul class="simple">
458<li>on x86 and x86-64 platforms, pycryptopp &gt;= 0.5.20</li>
459<li>pycrypto 2.2 is excluded due to a bug</li>
460</ul>
461</div>
462</div>
463<div class="section" id="release-1-7-1-2010-07-18">
464<h1>Release 1.7.1 (2010-07-18)</h1>
465<div class="section" id="id2">
466<h2>Bugfixes and Improvements</h2>
467<ul class="simple">
468<li>Fix bug in which uploader could fail with AssertionFailure or report
469that it had achieved servers-of-happiness when it hadn't. (#1118)</li>
470<li>Fix bug in which servers could get into a state where they would
471refuse to accept shares of a certain file (#1117)</li>
472<li>Add init scripts for managing the gateway server on Debian/Ubuntu
473(#961)</li>
474<li>Fix bug where server version number was always 0 on the welcome page
475(#1067)</li>
476<li>Add new command-line command &quot;tahoe unlink&quot; as a synonym for &quot;tahoe
477rm&quot; (#776)</li>
478<li>The FTP frontend now encrypts its temporary files, protecting their
479contents from an attacker who is able to read the disk. (#1083)</li>
480<li>Fix IP address detection on FreeBSD 7, 8, and 9 (#1098)</li>
481<li>Fix minor layout issue in the Web User Interface with Internet
482Explorer (#1097)</li>
483<li>Fix rarely-encountered incompatibility between Twisted logging
484utility and the new unicode support added in v1.7.0 (#1099)</li>
485<li>Forward-compatibility improvements for non-ASCII caps (#1051)</li>
486</ul>
487</div>
488<div class="section" id="code-improvements">
489<h2>Code improvements</h2>
490<ul class="simple">
491<li>Simplify and tidy-up directories, unicode support, test code (#923,
492#967, #1072)</li>
493</ul>
494</div>
495</div>
496<div class="section" id="release-1-7-0-2010-06-18">
497<h1>Release 1.7.0 (2010-06-18)</h1>
498<div class="section" id="id3">
499<h2>New Features</h2>
500<ul class="simple">
501<li>SFTP support
502Your Tahoe-LAFS gateway now acts like a full-fledged SFTP server. It
503has been tested with sshfs to provide a virtual filesystem in Linux.
504Many users have asked for this feature.  We hope that it serves them
505well! See the docs/frontends/FTP-and-SFTP.txt document to get
506started.</li>
507<li>support for non-ASCII character encodings
508Tahoe-LAFS now correctly handles filenames containing non-ASCII
509characters on all supported platforms:</li>
510</ul>
511<blockquote>
512<ul class="simple">
513<li>when reading files in from the local filesystem (such as when you
514run &quot;tahoe backup&quot; to back up your local files to a Tahoe-LAFS
515grid);</li>
516<li>when writing files out to the local filesystem (such as when you
517run &quot;tahoe cp -r&quot; to recursively copy files out of a Tahoe-LAFS
518grid);</li>
519<li>when displaying filenames to the terminal (such as when you run
520&quot;tahoe ls&quot;), subject to limitations of the terminal and locale;</li>
521<li>when parsing command-line arguments, except on Windows.</li>
522</ul>
523</blockquote>
524<ul class="simple">
525<li>Servers of Happiness
526Tahoe-LAFS now measures during immutable file upload to see how well
527distributed it is across multiple servers. It aborts the upload if
528the pieces of the file are not sufficiently well-distributed.
529This behavior is controlled by a configuration parameter called
530&quot;servers of happiness&quot;. With the default settings for its erasure
531coding, Tahoe-LAFS generates 10 shares for each file, such that any
5323 of those shares are sufficient to recover the file. The default
533value of &quot;servers of happiness&quot; is 7, which means that Tahoe-LAFS
534will guarantee that there are at least 7 servers holding some of the
535shares, such that any 3 of those servers can completely recover your
536file.  The new upload code also distributes the shares better than the
537previous version in some cases and takes better advantage of
538pre-existing shares (when a file has already been previously
539uploaded). See the architecture.txt document [3] for details.</li>
540</ul>
541</div>
542<div class="section" id="id4">
543<h2>Bugfixes and Improvements</h2>
544<ul class="simple">
545<li>Premature abort of upload if some shares were already present and some servers fail. (#608)</li>
546<li>python ./setup.py install -- can't create or remove files in install directory. (#803)</li>
547<li>Network failure =&gt; internal TypeError. (#902)</li>
548<li>Install of Tahoe on CentOS 5.4. (#933)</li>
549<li>CLI option --node-url now supports https url. (#1028)</li>
550<li>HTML/CSS template files were not correctly installed under Windows. (#1033)</li>
551<li>MetadataSetter does not enforce restriction on setting &quot;tahoe&quot; subkeys.  (#1034)</li>
552<li>ImportError: No module named setuptools_darcs.setuptools_darcs. (#1054)</li>
553<li>Renamed Title in xhtml files. (#1062)</li>
554<li>Increase Python version dependency to 2.4.4, to avoid a critical CPython security bug. (#1066)</li>
555<li>Typo correction for the munin plugin tahoe_storagespace. (#968)</li>
556<li>Fix warnings found by pylint. (#973)</li>
557<li>Changing format of some documentation files. (#1027)</li>
558<li>the misc/ directory was tied up. (#1068)</li>
559<li>The 'ctime' and 'mtime' metadata fields are no longer written except by &quot;tahoe backup&quot;. (#924)</li>
560<li>Unicode filenames in Tahoe-LAFS directories are normalized so that names that differ only in how accents are encoded are treated as the same. (#1076)</li>
561<li>Various small improvements to documentation. (#937, #911, #1024, #1082)</li>
562</ul>
563</div>
564<div class="section" id="removals">
565<h2>Removals</h2>
566<ul class="simple">
567<li>The 'tahoe debug consolidate' subcommand (for converting old
568allmydata Windows client backups to a newer format) has been
569removed.</li>
570</ul>
571</div>
572<div class="section" id="id5">
573<h2>Dependency Updates</h2>
574<ul class="simple">
575<li>the Python version dependency is raised to 2.4.4 in some cases
576(2.4.3 for Redhat-based Linux distributions, 2.4.2 for UCS-2 builds)
577(#1066)</li>
578<li>pycrypto &gt;= 2.0.1</li>
579<li>pyasn1 &gt;= 0.0.8a</li>
580<li>mock (only required by unit tests)</li>
581</ul>
582</div>
583</div>
584<div class="section" id="release-1-6-1-2010-02-27">
585<h1>Release 1.6.1 (2010-02-27)</h1>
586<div class="section" id="bugfixes">
587<h2>Bugfixes</h2>
588<ul>
589<li><p class="first">Correct handling of Small Immutable Directories</p>
590<p>Immutable directories can now be deep-checked and listed in the web
591UI in all cases. (In v1.6.0, some operations, such as deep-check, on
592a directory graph that included very small immutable directories,
593would result in an exception causing the whole operation to abort.)
594(#948)</p>
595</li>
596</ul>
597</div>
598<div class="section" id="usability-improvements">
599<h2>Usability Improvements</h2>
600<ul class="simple">
601<li>Improved user interface messages and error reporting. (#681, #837,
602#939)</li>
603<li>The timeouts for operation handles have been greatly increased, so
604that you can view the results of an operation up to 4 days after it
605has completed. After viewing them for the first time, the results
606are retained for a further day. (#577)</li>
607</ul>
608</div>
609</div>
610<div class="section" id="release-1-6-0-2010-02-01">
611<h1>Release 1.6.0 (2010-02-01)</h1>
612<div class="section" id="id6">
613<h2>New Features</h2>
614<ul>
615<li><p class="first">Immutable Directories</p>
616<p>Tahoe-LAFS can now create and handle immutable directories. (#607,
617#833, #931) These are read just like normal directories, but are
618&quot;deep-immutable&quot;, meaning that all their children (and everything
619reachable from those children) must be immutable objects
620(i.e. immutable or literal files, and other immutable directories).</p>
621<p>These directories must be created in a single webapi call that
622provides all of the children at once. (Since they cannot be changed
623after creation, the usual create/add/add sequence cannot be used.)
624They have URIs that start with &quot;URI:DIR2-CHK:&quot; or &quot;URI:DIR2-LIT:&quot;,
625and are described on the human-facing web interface (aka the &quot;WUI&quot;)
626with a &quot;DIR-IMM&quot; abbreviation (as opposed to &quot;DIR&quot; for the usual
627read-write directories and &quot;DIR-RO&quot; for read-only directories).</p>
628<p>Tahoe-LAFS releases before 1.6.0 cannot read the contents of an
629immutable directory. 1.5.0 will tolerate their presence in a
630directory listing (and display it as &quot;unknown&quot;). 1.4.1 and earlier
631cannot tolerate them: a DIR-IMM child in any directory will prevent
632the listing of that directory.</p>
633<p>Immutable directories are repairable, just like normal immutable
634files.</p>
635<p>The webapi &quot;POST t=mkdir-immutable&quot; call is used to create immutable
636directories. See docs/frontends/webapi.txt for details.</p>
637</li>
638<li><p class="first">&quot;tahoe backup&quot; now creates immutable directories, backupdb has
639dircache</p>
640<p>The &quot;tahoe backup&quot; command has been enhanced to create immutable
641directories (in previous releases, it created read-only mutable
642directories) (#828). This is significantly faster, since it does not
643need to create an RSA keypair for each new directory. Also &quot;DIR-IMM&quot;
644immutable directories are repairable, unlike &quot;DIR-RO&quot; read-only
645mutable directories at present. (A future Tahoe-LAFS release should
646also be able to repair DIR-RO.)</p>
647<p>In addition, the backupdb (used by &quot;tahoe backup&quot; to remember what
648it has already copied) has been enhanced to store information about
649existing immutable directories. This allows it to re-use directories
650that have moved but still contain identical contents, or that have
651been deleted and later replaced. (The 1.5.0 &quot;tahoe backup&quot; command
652could only re-use directories that were in the same place as they
653were in the immediately previous backup.)  With this change, the
654backup process no longer needs to read the previous snapshot out of
655the Tahoe-LAFS grid, reducing the network load considerably. (#606)</p>
656<p>A &quot;null backup&quot; (in which nothing has changed since the previous
657backup) will require only two Tahoe-side operations: one to add an
658Archives/$TIMESTAMP entry, and a second to update the Latest/
659link. On the local disk side, it will readdir() all your local
660directories and stat() all your local files.</p>
661<p>If you've been using &quot;tahoe backup&quot; for a while, you will notice
662that your first use of it after upgrading to 1.6.0 may take a long
663time: it must create proper immutable versions of all the old
664read-only mutable directories. This process won't take as long as
665the initial backup (where all the file contents had to be uploaded
666too): it will require time proportional to the number and size of
667your directories. After this initial pass, all subsequent passes
668should take a tiny fraction of the time.</p>
669<p>As noted above, Tahoe-LAFS versions earlier than 1.5.0 cannot list a
670directory containing an immutable subdirectory. Tahoe-LAFS versions
671earlier than 1.6.0 cannot read the contents of an immutable
672directory.</p>
673<p>The &quot;tahoe backup&quot; command has been improved to skip over unreadable
674objects (like device files, named pipes, and files with permissions
675that prevent the command from reading their contents), instead of
676throwing an exception and terminating the backup process. It also
677skips over symlinks, because these cannot be represented faithfully
678in the Tahoe-side filesystem. A warning message will be emitted each
679time something is skipped. (#729, #850, #641)</p>
680</li>
681<li><p class="first">&quot;create-node&quot; command added, &quot;create-client&quot; now implies
682--no-storage</p>
683<p>The basic idea behind Tahoe-LAFS's client+server and client-only
684processes is that you are creating a general-purpose Tahoe-LAFS
685&quot;node&quot; process, which has several components that can be
686activated. Storage service is one of these optional components, as
687is the Helper, FTP server, and SFTP server. Web gateway
688functionality is nominally on this list, but it is always active; a
689future release will make it optional. There are three special
690purpose servers that can't currently be run as a component in a
691node: introducer, key-generator, and stats-gatherer.</p>
692<p>So now &quot;tahoe create-node&quot; will create a Tahoe-LAFS node process,
693and after creation you can edit its tahoe.cfg to enable or disable
694the desired services. It is a more general-purpose replacement for
695&quot;tahoe create-client&quot;.  The default configuration has storage
696service enabled. For convenience, the &quot;--no-storage&quot; argument makes
697a tahoe.cfg file that disables storage service. (#760)</p>
698<p>&quot;tahoe create-client&quot; has been changed to create a Tahoe-LAFS node
699without a storage service. It is equivalent to &quot;tahoe create-node
700--no-storage&quot;. This helps to reduce the confusion surrounding the
701use of a command with &quot;client&quot; in its name to create a storage
702<em>server</em>. Use &quot;tahoe create-client&quot; to create a purely client-side
703node. If you want to offer storage to the grid, use &quot;tahoe
704create-node&quot; instead.</p>
705<p>In the future, other services will be added to the node, and they
706will be controlled through options in tahoe.cfg . The most important
707of these services may get additional --enable-XYZ or --disable-XYZ
708arguments to &quot;tahoe create-node&quot;.</p>
709</li>
710<li><p class="first">Performance Improvements</p>
711<p>Download of immutable files begins as soon as the downloader has
712located the K necessary shares (#928, #287). In both the previous
713and current releases, a downloader will first issue queries to all
714storage servers on the grid to locate shares before it begins
715downloading the shares. In previous releases of Tahoe-LAFS, download
716would not begin until all storage servers on the grid had replied to
717the query, at which point K shares would be chosen for download from
718among the shares that were located. In this release, download begins
719as soon as any K shares are located. This means that downloads start
720sooner, which is particularly important if there is a server on the
721grid that is extremely slow or even hung in such a way that it will
722never respond. In previous releases such a server would have a
723negative impact on all downloads from that grid. In this release,
724such a server will have no impact on downloads, as long as K shares
725can be found on other, quicker, servers.  This also means that
726downloads now use the &quot;best-alacrity&quot; servers that they talk to, as
727measured by how quickly the servers reply to the initial query. This
728might cause downloads to go faster, especially on grids with
729heterogeneous servers or geographical dispersion.</p>
730</li>
731</ul>
732</div>
733<div class="section" id="minor-changes">
734<h2>Minor Changes</h2>
735<ul class="simple">
736<li>The webapi acquired a new &quot;t=mkdir-with-children&quot; command, to create
737and populate a directory in a single call. This is significantly
738faster than using separate &quot;t=mkdir&quot; and &quot;t=set-children&quot; operations
739(it uses one gateway-to-grid roundtrip, instead of three or
740four). (#533)</li>
741<li>The t=set-children (note the hyphen) operation is now documented in
742docs/frontends/webapi.txt, and is the new preferred spelling of the
743old t=set_children (with an underscore). The underscore version
744remains for backwards compatibility. (#381, #927)</li>
745<li>The tracebacks produced by errors in CLI tools should now be in
746plain text, instead of HTML (which is unreadable outside of a
747browser). (#646)</li>
748<li>The [storage]reserved_space configuration knob (which causes the
749storage server to refuse shares when available disk space drops
750below a threshold) should work on Windows now, not just UNIX. (#637)</li>
751<li>&quot;tahoe cp&quot; should now exit with status &quot;1&quot; if it cannot figure out a
752suitable target filename, such as when you copy from a bare
753filecap. (#761)</li>
754<li>&quot;tahoe get&quot; no longer creates a zero-length file upon error. (#121)</li>
755<li>&quot;tahoe ls&quot; can now list single files. (#457)</li>
756<li>&quot;tahoe deep-check --repair&quot; should tolerate repair failures now,
757instead of halting traversal. (#874, #786)</li>
758<li>&quot;tahoe create-alias&quot; no longer corrupts the aliases file if it had
759previously been edited to have no trailing newline. (#741)</li>
760<li>Many small packaging improvements were made to facilitate the
761&quot;tahoe-lafs&quot; package being included in Ubuntu. Several mac/win32
762binary libraries were removed, some figleaf code-coverage files were
763removed, a bundled copy of darcsver-1.2.1 was removed, and
764additional licensing text was added.</li>
765<li>Several DeprecationWarnings for python2.6 were silenced. (#859)</li>
766<li>The checker --add-lease option would sometimes fail for shares
767stored on old (Tahoe v1.2.0) servers. (#875)</li>
768<li>The documentation for installing on Windows (docs/quickstart.rst)
769has been improved. (#773)</li>
770</ul>
771<p>For other changes not mentioned here, see
772&lt;<a class="reference external" href="http://tahoe-lafs.org/trac/tahoe/query?milestone=1.6.0&amp;keywords=!~news-done">http://tahoe-lafs.org/trac/tahoe/query?milestone=1.6.0&amp;keywords=!~news-done</a>&gt;.
773To include the tickets mentioned above, go to
774&lt;<a class="reference external" href="http://tahoe-lafs.org/trac/tahoe/query?milestone=1.6.0">http://tahoe-lafs.org/trac/tahoe/query?milestone=1.6.0</a>&gt;.</p>
775</div>
776</div>
777<div class="section" id="release-1-5-0-2009-08-01">
778<h1>Release 1.5.0 (2009-08-01)</h1>
779<div class="section" id="improvements">
780<h2>Improvements</h2>
781<ul class="simple">
782<li>Uploads of immutable files now use pipelined writes, improving
783upload speed slightly (10%) over high-latency connections. (#392)</li>
784<li>Processing large directories has been sped up, by removing a O(N^2)
785algorithm from the dirnode decoding path and retaining unmodified
786encrypted entries.  (#750, #752)</li>
787<li>The human-facing web interface (aka the &quot;WUI&quot;) received a
788significant CSS makeover by Kevin Reid, making it much prettier and
789easier to read. The WUI &quot;check&quot; and &quot;deep-check&quot; forms now include a
790&quot;Renew Lease&quot; checkbox, mirroring the CLI --add-lease option, so
791leases can be added or renewed from the web interface.</li>
792<li>The CLI &quot;tahoe mv&quot; command now refuses to overwrite
793directories. (#705)</li>
794<li>The CLI &quot;tahoe webopen&quot; command, when run without arguments, will
795now bring up the &quot;Welcome Page&quot; (node status and mkdir/upload
796forms).</li>
797<li>The 3.5MB limit on mutable files was removed, so it should be
798possible to upload arbitrarily-sized mutable files. Note, however,
799that the data format and algorithm remains the same, so using
800mutable files still requires bandwidth, computation, and RAM in
801proportion to the size of the mutable file.  (#694)</li>
802<li>This version of Tahoe-LAFS will tolerate directory entries that
803contain filecap formats which it does not recognize: files and
804directories from the future.  This should improve the user
805experience (for 1.5.0 users) when we add new cap formats in the
806future. Previous versions would fail badly, preventing the user from
807seeing or editing anything else in those directories. These
808unrecognized objects can be renamed and deleted, but obviously not
809read or written. Also they cannot generally be copied. (#683)</li>
810</ul>
811</div>
812<div class="section" id="id7">
813<h2>Bugfixes</h2>
814<ul class="simple">
815<li>deep-check-and-repair now tolerates read-only directories, such as
816the ones produced by the &quot;tahoe backup&quot; CLI command. Read-only
817directories and mutable files are checked, but not
818repaired. Previous versions threw an exception when attempting the
819repair and failed to process the remaining contents. We cannot yet
820repair these read-only objects, but at least this version allows the
821rest of the check+repair to proceed. (#625)</li>
822<li>A bug in 1.4.1 which caused a server to be listed multiple times
823(and frequently broke all connections to that server) was
824fixed. (#653)</li>
825<li>The plaintext-hashing code was removed from the Helper interface,
826removing the Helper's ability to mount a
827partial-information-guessing attack. (#722)</li>
828</ul>
829</div>
830<div class="section" id="platform-packaging-changes">
831<h2>Platform/packaging changes</h2>
832<ul class="simple">
833<li>Tahoe-LAFS now runs on NetBSD, OpenBSD, ArchLinux, and NixOS, and on
834an embedded system based on an ARM CPU running at 266 MHz.</li>
835<li>Unit test timeouts have been raised to allow the tests to complete
836on extremely slow platforms like embedded ARM-based NAS boxes, which
837may take several hours to run the test suite. An ARM-specific
838data-corrupting bug in an older version of Crypto++ (5.5.2) was
839identified: ARM-users are encouraged to use recent
840Crypto++/pycryptopp which avoids this problem.</li>
841<li>Tahoe-LAFS now requires a SQLite library, either the sqlite3 that
842comes built-in with python2.5/2.6, or the add-on pysqlite2 if you're
843using python2.4. In the previous release, this was only needed for
844the &quot;tahoe backup&quot; command: now it is mandatory.</li>
845<li>Several minor documentation updates were made.</li>
846<li>To help get Tahoe-LAFS into Linux distributions like Fedora and
847Debian, packaging improvements are being made in both Tahoe-LAFS and
848related libraries like pycryptopp and zfec.</li>
849<li>The Crypto++ library included in the pycryptopp package has been
850upgraded to version 5.6.0 of Crypto++, which includes a more
851efficient implementation of SHA-256 in assembly for x86 or amd64
852architectures.</li>
853</ul>
854</div>
855<div class="section" id="id8">
856<h2>dependency updates</h2>
857<ul class="simple">
858<li>foolscap-0.4.1</li>
859<li>no python-2.4.0 or 2.4.1 (2.4.2 is good) (they contained a bug in base64.b32decode)</li>
860<li>avoid python-2.6 on windows with mingw: compiler issues</li>
861<li>python2.4 requires pysqlite2 (2.5,2.6 does not)</li>
862<li>no python-3.x</li>
863<li>pycryptopp-0.5.15</li>
864</ul>
865</div>
866</div>
867<div class="section" id="release-1-4-1-2009-04-13">
868<h1>Release 1.4.1 (2009-04-13)</h1>
869<div class="section" id="garbage-collection">
870<h2>Garbage Collection</h2>
871<ul>
872<li><p class="first">The big feature for this release is the implementation of garbage
873collection, allowing Tahoe storage servers to delete shares for old
874deleted files. When enabled, this uses a &quot;mark and sweep&quot; process:
875clients are responsible for updating the leases on their shares
876(generally by running &quot;tahoe deep-check --add-lease&quot;), and servers
877are allowed to delete any share which does not have an up-to-date
878lease. The process is described in detail in
879docs/garbage-collection.txt .</p>
880<p>The server must be configured to enable garbage-collection, by
881adding directives to the [storage] section that define an age limit
882for shares. The default configuration will not delete any shares.</p>
883<p>Both servers and clients should be upgraded to this release to make
884the garbage-collection as pleasant as possible. 1.2.0 servers have
885code to perform the update-lease operation but it suffers from a
886fatal bug, while 1.3.0 servers have update-lease but will return an
887exception for unknown storage indices, causing clients to emit an
888Incident for each exception, slowing the add-lease process down to a
889crawl. 1.1.0 servers did not have the add-lease operation at all.</p>
890</li>
891</ul>
892</div>
893<div class="section" id="security-usability-problems-fixed">
894<h2>Security/Usability Problems Fixed</h2>
895<ul class="simple">
896<li>A super-linear algorithm in the Merkle Tree code was fixed, which
897previously caused e.g. download of a 10GB file to take several hours
898before the first byte of plaintext could be produced. The new
899&quot;alacrity&quot; is about 2 minutes. A future release should reduce this
900to a few seconds by fixing ticket #442.</li>
901<li>The previous version permitted a small timing attack (due to our use
902of strcmp) against the write-enabler and lease-renewal/cancel
903secrets. An attacker who could measure response-time variations of
904approximatly 3ns against a very noisy background time of about 15ms
905might be able to guess these secrets. We do not believe this attack
906was actually feasible. This release closes the attack by first
907hashing the two strings to be compared with a random secret.</li>
908</ul>
909</div>
910<div class="section" id="webapi-changes">
911<h2>webapi changes</h2>
912<ul class="simple">
913<li>In most cases, HTML tracebacks will only be sent if an &quot;Accept:
914text/html&quot; header was provided with the HTTP request. This will
915generally cause browsers to get an HTMLized traceback but send
916regular text/plain tracebacks to non-browsers (like the CLI
917clients). More errors have been mapped to useful HTTP error codes.</li>
918<li>The streaming webapi operations (deep-check and manifest) now have a
919way to indicate errors (an output line that starts with &quot;ERROR&quot;
920instead of being legal JSON). See docs/frontends/webapi.txt for
921details.</li>
922<li>The storage server now has its own status page (at /storage), linked
923from the Welcome page. This page shows progress and results of the
924two new share-crawlers: one which merely counts shares (to give an
925estimate of how many files/directories are being stored in the
926grid), the other examines leases and reports how much space would be
927freed if GC were enabled. The page also shows how much disk space is
928present, used, reserved, and available for the Tahoe server, and
929whether the server is currently running in &quot;read-write&quot; mode or
930&quot;read-only&quot; mode.</li>
931<li>When a directory node cannot be read (perhaps because of insufficent
932shares), a minimal webapi page is created so that the &quot;more-info&quot;
933links (including a Check/Repair operation) will still be accessible.</li>
934<li>A new &quot;reliability&quot; page was added, with the beginnings of work on a
935statistical loss model. You can tell this page how many servers you
936are using and their independent failure probabilities, and it will
937tell you the likelihood that an arbitrary file will survive each
938repair period. The &quot;numpy&quot; package must be installed to access this
939page. A partial paper, written by Shawn Willden, has been added to
940docs/proposed/lossmodel.lyx .</li>
941</ul>
942</div>
943<div class="section" id="cli-changes">
944<h2>CLI changes</h2>
945<ul class="simple">
946<li>&quot;tahoe check&quot; and &quot;tahoe deep-check&quot; now accept an &quot;--add-lease&quot;
947argument, to update a lease on all shares. This is the &quot;mark&quot; side
948of garbage collection.</li>
949<li>In many cases, CLI error messages have been improved: the ugly
950HTMLized traceback has been replaced by a normal python traceback.</li>
951<li>&quot;tahoe deep-check&quot; and &quot;tahoe manifest&quot; now have better error
952reporting.  &quot;tahoe cp&quot; is now non-verbose by default.</li>
953<li>&quot;tahoe backup&quot; now accepts several &quot;--exclude&quot; arguments, to ignore
954certain files (like editor temporary files and version-control
955metadata) during backup.</li>
956<li>On windows, the CLI now accepts local paths like &quot;c:dirfile.txt&quot;,
957which previously was interpreted as a Tahoe path using a &quot;c:&quot; alias.</li>
958<li>The &quot;tahoe restart&quot; command now uses &quot;--force&quot; by default (meaning
959it will start a node even if it didn't look like there was one
960already running).</li>
961<li>The &quot;tahoe debug consolidate&quot; command was added. This takes a series
962of independent timestamped snapshot directories (such as those
963created by the allmydata.com windows backup program, or a series of
964&quot;tahoe cp -r&quot; commands) and creates new snapshots that used shared
965read-only directories whenever possible (like the output of &quot;tahoe
966backup&quot;). In the most common case (when the snapshots are fairly
967similar), the result will use significantly fewer directories than
968the original, allowing &quot;deep-check&quot; and similar tools to run much
969faster. In some cases, the speedup can be an order of magnitude or
970more.  This tool is still somewhat experimental, and only needs to
971be run on large backups produced by something other than &quot;tahoe
972backup&quot;, so it was placed under the &quot;debug&quot; category.</li>
973<li>&quot;tahoe cp -r --caps-only tahoe:dir localdir&quot; is a diagnostic tool
974which, instead of copying the full contents of files into the local
975directory, merely copies their filecaps. This can be used to verify
976the results of a &quot;consolidation&quot; operation.</li>
977</ul>
978</div>
979<div class="section" id="other-fixes">
980<h2>other fixes</h2>
981<ul class="simple">
982<li>The codebase no longer rauses RuntimeError as a kind of
983assert(). Specific exception classes were created for each previous
984instance of RuntimeError.</li>
985</ul>
986<blockquote>
987<dl class="docutils">
988<dt>-Many unit tests were changed to use a non-network test harness,</dt>
989<dd>speeding them up considerably.</dd>
990</dl>
991</blockquote>
992<ul class="simple">
993<li>Deep-traversal operations (manifest and deep-check) now walk
994individual directories in alphabetical order. Occasional turn breaks
995are inserted to prevent a stack overflow when traversing directories
996with hundreds of entries.</li>
997<li>The experimental SFTP server had its path-handling logic changed
998slightly, to accomodate more SFTP clients, although there are still
999issues (#645).</li>
1000</ul>
1001</div>
1002</div>
1003<div class="section" id="release-1-3-0-2009-02-13">
1004<h1>Release 1.3.0 (2009-02-13)</h1>
1005<div class="section" id="checker-verifier-repairer">
1006<h2>Checker/Verifier/Repairer</h2>
1007<ul class="simple">
1008<li>The primary focus of this release has been writing a checker /
1009verifier / repairer for files and directories.  &quot;Checking&quot; is the
1010act of asking storage servers whether they have a share for the
1011given file or directory: if there are not enough shares available,
1012the file or directory will be unrecoverable. &quot;Verifying&quot; is the act
1013of downloading and cryptographically asserting that the server's
1014share is undamaged: it requires more work (bandwidth and CPU) than
1015checking, but can catch problems that simple checking
1016cannot. &quot;Repair&quot; is the act of replacing missing or damaged shares
1017with new ones.</li>
1018<li>This release includes a full checker, a partial verifier, and a
1019partial repairer. The repairer is able to handle missing shares: new
1020shares are generated and uploaded to make up for the missing
1021ones. This is currently the best application of the repairer: to
1022replace shares that were lost because of server departure or
1023permanent drive failure.</li>
1024<li>The repairer in this release is somewhat able to handle corrupted
1025shares. The limitations are:</li>
1026</ul>
1027<blockquote>
1028<ul class="simple">
1029<li>Immutable verifier is incomplete: not all shares are used, and not
1030all fields of those shares are verified. Therefore the immutable
1031verifier has only a moderate chance of detecting corrupted shares.</li>
1032<li>The mutable verifier is mostly complete: all shares are examined,
1033and most fields of the shares are validated.</li>
1034<li>The storage server protocol offers no way for the repairer to
1035replace or delete immutable shares. If corruption is detected, the
1036repairer will upload replacement shares to other servers, but the
1037corrupted shares will be left in place.</li>
1038<li>read-only directories and read-only mutable files must be repaired
1039by someone who holds the write-cap: the read-cap is
1040insufficient. Moreover, the deep-check-and-repair operation will
1041halt with an error if it attempts to repair one of these read-only
1042objects.</li>
1043<li>Some forms of corruption can cause both download and repair
1044operations to fail. A future release will fix this, since download
1045should be tolerant of any corruption as long as there are at least
1046'k' valid shares, and repair should be able to fix any file that is
1047downloadable.</li>
1048</ul>
1049</blockquote>
1050<ul class="simple">
1051<li>If the downloader, verifier, or repairer detects share corruption,
1052the servers which provided the bad shares will be notified (via a
1053file placed in the BASEDIR/storage/corruption-advisories directory)
1054so their operators can manually delete the corrupted shares and
1055investigate the problem. In addition, the &quot;incident gatherer&quot;
1056mechanism will automatically report share corruption to an incident
1057gatherer service, if one is configured. Note that corrupted shares
1058indicate hardware failures, serious software bugs, or malice on the
1059part of the storage server operator, so a corrupted share should be
1060considered highly unusual.</li>
1061<li>By periodically checking/repairing all files and directories,
1062objects in the Tahoe filesystem remain resistant to recoverability
1063failures due to missing and/or broken servers.</li>
1064<li>This release includes a wapi mechanism to initiate checks on
1065individual files and directories (with or without verification, and
1066with or without automatic repair). A related mechanism is used to
1067initiate a &quot;deep-check&quot; on a directory: recursively traversing the
1068directory and its children, checking (and/or verifying/repairing)
1069everything underneath. Both mechanisms can be run with an
1070&quot;output=JSON&quot; argument, to obtain machine-readable check/repair
1071status results. These results include a copy of the filesystem
1072statistics from the &quot;deep-stats&quot; operation (including total number
1073of files, size histogram, etc). If repair is possible, a &quot;Repair&quot;
1074button will appear on the results page.</li>
1075<li>The client web interface now features some extra buttons to initiate
1076check and deep-check operations. When these operations finish, they
1077display a results page that summarizes any problems that were
1078encountered. All long-running deep-traversal operations, including
1079deep-check, use a start-and-poll mechanism, to avoid depending upon
1080a single long-lived HTTP connection. docs/frontends/webapi.txt has
1081details.</li>
1082</ul>
1083</div>
1084<div class="section" id="efficient-backup">
1085<h2>Efficient Backup</h2>
1086<ul>
1087<li><p class="first">The &quot;tahoe backup&quot; command is new in this release, which creates
1088efficient versioned backups of a local directory. Given a local
1089pathname and a target Tahoe directory, this will create a read-only
1090snapshot of the local directory in $target/Archives/$timestamp. It
1091will also create $target/Latest, which is a reference to the latest
1092such snapshot. Each time you run &quot;tahoe backup&quot; with the same source
1093and target, a new $timestamp snapshot will be added. These snapshots
1094will share directories that have not changed since the last backup,
1095to speed up the process and minimize storage requirements. In
1096addition, a small database is used to keep track of which local
1097files have been uploaded already, to avoid uploading them a second
1098time. This drastically reduces the work needed to do a &quot;null backup&quot;
1099(when nothing has changed locally), making &quot;tahoe backup' suitable
1100to run from a daily cronjob.</p>
1101<p>Note that the &quot;tahoe backup&quot; CLI command must be used in conjunction
1102with a 1.3.0-or-newer Tahoe client node; there was a bug in the
11031.2.0 webapi implementation that would prevent the last step (create
1104$target/Latest) from working.</p>
1105</li>
1106</ul>
1107</div>
1108<div class="section" id="large-files">
1109<h2>Large Files</h2>
1110<ul class="simple">
1111<li>The 12GiB (approximate) immutable-file-size limitation is
1112lifted. This release knows how to handle so-called &quot;v2 immutable
1113shares&quot;, which permit immutable files of up to about 18 EiB (about
11143*10^14). These v2 shares are created if the file to be uploaded is
1115too large to fit into v1 shares. v1 shares are created if the file
1116is small enough to fit into them, so that files created with
1117tahoe-1.3.0 can still be read by earlier versions if they are not
1118too large. Note that storage servers also had to be changed to
1119support larger files, and this release is the first release in which
1120they are able to do that. Clients will detect which servers are
1121capable of supporting large files on upload and will not attempt to
1122upload shares of a large file to a server which doesn't support it.</li>
1123</ul>
1124</div>
1125<div class="section" id="ftp-sftp-server">
1126<h2>FTP/SFTP Server</h2>
1127<ul class="simple">
1128<li>Tahoe now includes experimental FTP and SFTP servers. When
1129configured with a suitable method to translate username+password
1130into a root directory cap, it provides simple access to the virtual
1131filesystem. Remember that FTP is completely unencrypted: passwords,
1132filenames, and file contents are all sent over the wire in
1133cleartext, so FTP should only be used on a local (127.0.0.1)
1134connection. This feature is still in development: there are no unit
1135tests yet, and behavior with respect to Unicode filenames is
1136uncertain. Please see docs/frontends/FTP-and-SFTP.txt for
1137configuration details. (#512, #531)</li>
1138</ul>
1139</div>
1140<div class="section" id="id9">
1141<h2>CLI Changes</h2>
1142<ul class="simple">
1143<li>This release adds the 'tahoe create-alias' command, which is a
1144combination of 'tahoe mkdir' and 'tahoe add-alias'. This also allows
1145you to start using a new tahoe directory without exposing its URI in
1146the argv list, which is publicly visible (through the process table)
1147on most unix systems.  Thanks to Kevin Reid for bringing this issue
1148to our attention.</li>
1149<li>The single-argument form of &quot;tahoe put&quot; was changed to create an
1150unlinked file. I.e. &quot;tahoe put bar.txt&quot; will take the contents of a
1151local &quot;bar.txt&quot; file, upload them to the grid, and print the
1152resulting read-cap; the file will not be attached to any
1153directories. This seemed a bit more useful than the previous
1154behavior (copy stdin, upload to the grid, attach the resulting file
1155into your default tahoe: alias in a child named 'bar.txt').</li>
1156<li>&quot;tahoe put&quot; was also fixed to handle mutable files correctly: &quot;tahoe
1157put bar.txt URI:SSK:...&quot; will read the contents of the local bar.txt
1158and use them to replace the contents of the given mutable file.</li>
1159<li>The &quot;tahoe webopen&quot; command was modified to accept aliases. This
1160means &quot;tahoe webopen tahoe:&quot; will cause your web browser to open to
1161a &quot;wui&quot; page that gives access to the directory associated with the
1162default &quot;tahoe:&quot; alias. It should also accept leading slashes, like
1163&quot;tahoe webopen tahoe:/stuff&quot;.</li>
1164<li>Many esoteric debugging commands were moved down into a &quot;debug&quot;
1165subcommand:</li>
1166</ul>
1167<blockquote>
1168<ul>
1169<li><p class="first">tahoe debug dump-cap</p>
1170</li>
1171<li><p class="first">tahoe debug dump-share</p>
1172</li>
1173<li><p class="first">tahoe debug find-shares</p>
1174</li>
1175<li><p class="first">tahoe debug catalog-shares</p>
1176</li>
1177<li><p class="first">tahoe debug corrupt-share</p>
1178<p>The last command (&quot;tahoe debug corrupt-share&quot;) flips a random bit
1179of the given local sharefile. This is used to test the file
1180verifying/repairing code, and obviously should not be used on user
1181data.</p>
1182</li>
1183</ul>
1184</blockquote>
1185<p>The cli might not correctly handle arguments which contain non-ascii
1186characters in Tahoe v1.3 (although depending on your platform it
1187might, especially if your platform can be configured to pass such
1188characters on the command-line in utf-8 encoding).  See
1189<a class="reference external" href="http://tahoe-lafs.org/trac/tahoe/ticket/565">http://tahoe-lafs.org/trac/tahoe/ticket/565</a> for details.</p>
1190</div>
1191<div class="section" id="web-changes">
1192<h2>Web changes</h2>
1193<ul class="simple">
1194<li>The &quot;default webapi port&quot;, used when creating a new client node (and
1195in the getting-started documentation), was changed from 8123 to
11963456, to reduce confusion when Tahoe accessed through a Firefox
1197browser on which the &quot;Torbutton&quot; extension has been installed. Port
11988123 is occasionally used as a Tor control port, so Torbutton adds
11998123 to Firefox's list of &quot;banned ports&quot; to avoid CSRF attacks
1200against Tor. Once 8123 is banned, it is difficult to diagnose why
1201you can no longer reach a Tahoe node, so the Tahoe default was
1202changed. Note that 3456 is reserved by IANA for the &quot;vat&quot; protocol,
1203but there are argueably more Torbutton+Tahoe users than vat users
1204these days. Note that this will only affect newly-created client
1205nodes. Pre-existing client nodes, created by earlier versions of
1206tahoe, may still be listening on 8123.</li>
1207<li>All deep-traversal operations (start-manifest, start-deep-size,
1208start-deep-stats, start-deep-check) now use a start-and-poll
1209approach, instead of using a single (fragile) long-running
1210synchronous HTTP connection. All these &quot;start-&quot; operations use POST
1211instead of GET. The old &quot;GET manifest&quot;, &quot;GET deep-size&quot;, and &quot;POST
1212deep-check&quot; operations have been removed.</li>
1213<li>The new &quot;POST start-manifest&quot; operation, when it finally completes,
1214results in a table of (path,cap), instead of the list of verifycaps
1215produced by the old &quot;GET manifest&quot;. The table is available in
1216several formats: use output=html, output=text, or output=json to
1217choose one. The JSON output also includes stats, and a list of
1218verifycaps and storage-index strings. The &quot;return_to=&quot; and
1219&quot;when_done=&quot; arguments have been removed from the t=check and
1220deep-check operations.</li>
1221<li>The top-level status page (/status) now has a machine-readable form,
1222via &quot;/status/?t=json&quot;. This includes information about the
1223currently-active uploads and downloads, which may be useful for
1224frontends that wish to display progress information. There is no
1225easy way to correlate the activities displayed here with recent wapi
1226requests, however.</li>
1227<li>Any files in BASEDIR/public_html/ (configurable) will be served in
1228response to requests in the /static/ portion of the URL space. This
1229will simplify the deployment of javascript-based frontends that can
1230still access wapi calls by conforming to the (regrettable)
1231&quot;same-origin policy&quot;.</li>
1232<li>The welcome page now has a &quot;Report Incident&quot; button, which is tied
1233into the &quot;Incident Gatherer&quot; machinery. If the node is attached to
1234an incident gatherer (via log_gatherer.furl), then pushing this
1235button will cause an Incident to be signalled: this means recent log
1236events are aggregated and sent in a bundle to the gatherer. The user
1237can push this button after something strange takes place (and they
1238can provide a short message to go along with it), and the relevant
1239data will be delivered to a centralized incident-gatherer for later
1240processing by operations staff.</li>
1241<li>The &quot;HEAD&quot; method should now work correctly, in addition to the
1242usual &quot;GET&quot;, &quot;PUT&quot;, and &quot;POST&quot; methods. &quot;HEAD&quot; is supposed to return
1243exactly the same headers as &quot;GET&quot; would, but without any of the
1244actual response body data. For mutable files, this now does a brief
1245mapupdate (to figure out the size of the file that would be
1246returned), without actually retrieving the file's contents.</li>
1247<li>The &quot;GET&quot; operation on files can now support the HTTP &quot;Range:&quot;
1248header, allowing requests for partial content. This allows certain
1249media players to correctly stream audio and movies out of a Tahoe
1250grid. The current implementation uses a disk-based cache in
1251BASEDIR/private/cache/download , which holds the plaintext of the
1252files being downloaded. Future implementations might not use this
1253cache. GET for immutable files now returns an ETag header.</li>
1254<li>Each file and directory now has a &quot;Show More Info&quot; web page, which
1255contains much of the information that was crammed into the directory
1256page before. This includes readonly URIs, storage index strings,
1257object type, buttons to control checking/verifying/repairing, and
1258deep-check/deep-stats buttons (for directories). For mutable files,
1259the &quot;replace contents&quot; upload form has been moved here too. As a
1260result, the directory page is now much simpler and cleaner, and
1261several potentially-misleading links (like t=uri) are now gone.</li>
1262<li>Slashes are discouraged in Tahoe file/directory names, since they
1263cause problems when accessing the filesystem through the
1264wapi. However, there are a couple of accidental ways to generate
1265such names. This release tries to make it easier to correct such
1266mistakes by escaping slashes in several places, allowing slashes in
1267the t=info and t=delete commands, and in the source (but not the
1268target) of a t=rename command.</li>
1269</ul>
1270</div>
1271<div class="section" id="id10">
1272<h2>Packaging</h2>
1273<ul class="simple">
1274<li>Tahoe's dependencies have been extended to require the
1275&quot;[secure_connections]&quot; feature from Foolscap, which will cause
1276pyOpenSSL to be required and/or installed. If OpenSSL and its
1277development headers are already installed on your system, this can
1278occur automatically. Tahoe now uses pollreactor (instead of the
1279default selectreactor) to work around a bug between pyOpenSSL and
1280the most recent release of Twisted (8.1.0). This bug only affects
1281unit tests (hang during shutdown), and should not impact regular
1282use.</li>
1283<li>The Tahoe source code tarballs now come in two different forms:
1284regular and &quot;sumo&quot;. The regular tarball contains just Tahoe, nothing
1285else. When building from the regular tarball, the build process will
1286download any unmet dependencies from the internet (starting with the
1287index at PyPI) so it can build and install them. The &quot;sumo&quot; tarball
1288contains copies of all the libraries that Tahoe requires (foolscap,
1289twisted, zfec, etc), so using the &quot;sumo&quot; tarball should not require
1290any internet access during the build process. This can be useful if
1291you want to build Tahoe while on an airplane, a desert island, or
1292other bandwidth-limited environments.</li>
1293<li>Similarly, tahoe-lafs.org now hosts a &quot;tahoe-deps&quot; tarball which
1294contains the latest versions of all these dependencies. This
1295tarball, located at
1296<a class="reference external" href="http://tahoe-lafs.org/source/tahoe/deps/tahoe-deps.tar.gz">http://tahoe-lafs.org/source/tahoe/deps/tahoe-deps.tar.gz</a>, can be
1297unpacked in the tahoe source tree (or in its parent directory), and
1298the build process should satisfy its downloading needs from it
1299instead of reaching out to PyPI.  This can be useful if you want to
1300build Tahoe from a darcs checkout while on that airplane or desert
1301island.</li>
1302<li>Because of the previous two changes (&quot;sumo&quot; tarballs and the
1303&quot;tahoe-deps&quot; bundle), most of the files have been removed from
1304misc/dependencies/ . This brings the regular Tahoe tarball down to
13052MB (compressed), and the darcs checkout (without history) to about
13067.6MB. A full darcs checkout will still be fairly large (because of
1307the historical patches which included the dependent libraries), but
1308a 'lazy' one should now be small.</li>
1309<li>The default &quot;make&quot; target is now an alias for &quot;setup.py build&quot;,
1310which itself is an alias for &quot;setup.py develop --prefix support&quot;,
1311with some extra work before and after (see setup.cfg). Most of the
1312complicated platform-dependent code in the Makefile was rewritten in
1313Python and moved into setup.py, simplifying things considerably.</li>
1314<li>Likewise, the &quot;make test&quot; target now delegates most of its work to
1315&quot;setup.py test&quot;, which takes care of getting PYTHONPATH configured
1316to access the tahoe code (and dependencies) that gets put in
1317support/lib/ by the build_tahoe step. This should allow unit tests
1318to be run even when trial (which is part of Twisted) wasn't already
1319installed (in this case, trial gets installed to support/bin because
1320Twisted is a dependency of Tahoe).</li>
1321<li>Tahoe is now compatible with the recently-released Python 2.6 ,
1322although it is recommended to use Tahoe on Python 2.5, on which it
1323has received more thorough testing and deployment.</li>
1324<li>Tahoe is now compatible with simplejson-2.0.x . The previous release
1325assumed that simplejson.loads always returned unicode strings, which
1326is no longer the case in 2.0.x .</li>
1327</ul>
1328</div>
1329<div class="section" id="grid-management-tools">
1330<h2>Grid Management Tools</h2>
1331<ul class="simple">
1332<li>Several tools have been added or updated in the misc/ directory,
1333mostly munin plugins that can be used to monitor a storage grid.</li>
1334</ul>
1335<blockquote>
1336<ul class="simple">
1337<li>The misc/spacetime/ directory contains a &quot;disk watcher&quot; daemon
1338(startable with 'tahoe start'), which can be configured with a set
1339of HTTP URLs (pointing at the wapi '/statistics' page of a bunch of
1340storage servers), and will periodically fetch
1341disk-used/disk-available information from all the servers. It keeps
1342this information in an Axiom database (a sqlite-based library
1343available from divmod.org). The daemon computes time-averaged rates
1344of disk usage, as well as a prediction of how much time is left
1345before the grid is completely full.</li>
1346<li>The misc/munin/ directory contains a new set of munin plugins
1347(tahoe_diskleft, tahoe_diskusage, tahoe_doomsday) which talk to the
1348disk-watcher and provide graphs of its calculations.</li>
1349<li>To support the disk-watcher, the Tahoe statistics component
1350(visible through the wapi at the /statistics/ URL) now includes
1351disk-used and disk-available information. Both are derived through
1352an equivalent of the unix 'df' command (i.e. they ask the kernel
1353for the number of free blocks on the partition that encloses the
1354BASEDIR/storage directory). In the future, the disk-available
1355number will be further influenced by the local storage policy: if
1356that policy says that the server should refuse new shares when less
1357than 5GB is left on the partition, then &quot;disk-available&quot; will
1358report zero even though the kernel sees 5GB remaining.</li>
1359<li>The 'tahoe_overhead' munin plugin interacts with an
1360allmydata.com-specific server which reports the total of the
1361'deep-size' reports for all active user accounts, compares this
1362with the disk-watcher data, to report on overhead percentages. This
1363provides information on how much space could be recovered once
1364Tahoe implements some form of garbage collection.</li>
1365</ul>
1366</blockquote>
1367</div>
1368<div class="section" id="configuration-changes-single-ini-format-tahoe-cfg-file">
1369<h2>Configuration Changes: single INI-format tahoe.cfg file</h2>
1370<ul class="simple">
1371<li>The Tahoe node is now configured with a single INI-format file,
1372named &quot;tahoe.cfg&quot;, in the node's base directory. Most of the
1373previous multiple-separate-files are still read for backwards
1374compatibility (the embedded SSH debug server and the
1375advertised_ip_addresses files are the exceptions), but new
1376directives will only be added to tahoe.cfg . The &quot;tahoe
1377create-client&quot; command will create a tahoe.cfg for you, with sample
1378values commented out. (ticket #518)</li>
1379<li>tahoe.cfg now has controls for the foolscap &quot;keepalive&quot; and
1380&quot;disconnect&quot; timeouts (#521).</li>
1381<li>tahoe.cfg now has controls for the encoding parameters:
1382&quot;shares.needed&quot; and &quot;shares.total&quot; in the &quot;[client]&quot; section. The
1383default parameters are still 3-of-10.</li>
1384<li>The inefficient storage 'sizelimit' control (which established an
1385upper bound on the amount of space that a storage server is allowed
1386to consume) has been replaced by a lightweight 'reserved_space'
1387control (which establishes a lower bound on the amount of remaining
1388space). The storage server will reject all writes that would cause
1389the remaining disk space (as measured by a '/bin/df' equivalent) to
1390drop below this value. The &quot;[storage]reserved_space=&quot; tahoe.cfg
1391parameter controls this setting. (note that this only affects
1392immutable shares: it is an outstanding bug that reserved_space does
1393not prevent the allocation of new mutable shares, nor does it
1394prevent the growth of existing mutable shares).</li>
1395</ul>
1396</div>
1397<div class="section" id="id11">
1398<h2>Other Changes</h2>
1399<ul class="simple">
1400<li>Clients now declare which versions of the protocols they
1401support. This is part of a new backwards-compatibility system:
1402<a class="reference external" href="http://tahoe-lafs.org/trac/tahoe/wiki/Versioning">http://tahoe-lafs.org/trac/tahoe/wiki/Versioning</a> .</li>
1403<li>The version strings for human inspection (as displayed on the
1404Welcome web page, and included in logs) now includes a platform
1405identifer (frequently including a linux distribution name, processor
1406architecture, etc).</li>
1407<li>Several bugs have been fixed, including one that would cause an
1408exception (in the logs) if a wapi download operation was cancelled
1409(by closing the TCP connection, or pushing the &quot;stop&quot; button in a
1410web browser).</li>
1411<li>Tahoe now uses Foolscap &quot;Incidents&quot;, writing an &quot;incident report&quot;
1412file to logs/incidents/ each time something weird occurs. These
1413reports are available to an &quot;incident gatherer&quot; through the flogtool
1414command. For more details, please see the Foolscap logging
1415documentation. An incident-classifying plugin function is provided
1416in misc/incident-gatherer/classify_tahoe.py .</li>
1417<li>If clients detect corruption in shares, they now automatically
1418report it to the server holding that share, if it is new enough to
1419accept the report.  These reports are written to files in
1420BASEDIR/storage/corruption-advisories .</li>
1421<li>The 'nickname' setting is now defined to be a UTF-8 -encoded string,
1422allowing non-ascii nicknames.</li>
1423<li>The 'tahoe start' command will now accept a --syslog argument and
1424pass it through to twistd, making it easier to launch non-Tahoe
1425nodes (like the cpu-watcher) and have them log to syslogd instead of
1426a local file. This is useful when running a Tahoe node out of a USB
1427flash drive.</li>
1428<li>The Mac GUI in src/allmydata/gui/ has been improved.</li>
1429</ul>
1430</div>
1431</div>
1432<div class="section" id="release-1-2-0-2008-07-21">
1433<h1>Release 1.2.0 (2008-07-21)</h1>
1434<div class="section" id="security">
1435<h2>Security</h2>
1436<ul>
1437<li><p class="first">This release makes the immutable-file &quot;ciphertext hash tree&quot;
1438mandatory.  Previous releases allowed the uploader to decide whether
1439their file would have an integrity check on the ciphertext or not. A
1440malicious uploader could use this to create a readcap that would
1441download as one file or a different one, depending upon which shares
1442the client fetched first, with no errors raised. There are other
1443integrity checks on the shares themselves, preventing a storage
1444server or other party from violating the integrity properties of the
1445read-cap: this failure was only exploitable by the uploader who
1446gives you a carefully constructed read-cap. If you download the file
1447with Tahoe 1.2.0 or later, you will not be vulnerable to this
1448problem. #491</p>
1449<p>This change does not introduce a compatibility issue, because all
1450existing versions of Tahoe will emit the ciphertext hash tree in
1451their shares.</p>
1452</li>
1453</ul>
1454</div>
1455<div class="section" id="dependencies">
1456<h2>Dependencies</h2>
1457<ul class="simple">
1458<li>Tahoe now requires Foolscap-0.2.9 . It also requires pycryptopp 0.5
1459or newer, since earlier versions had a bug that interacted with
1460specific compiler versions that could sometimes result in incorrect
1461encryption behavior. Both packages are included in the Tahoe source
1462tarball in misc/dependencies/ , and should be built automatically
1463when necessary.</li>
1464</ul>
1465</div>
1466<div class="section" id="web-api">
1467<h2>Web API</h2>
1468<ul class="simple">
1469<li>Web API directory pages should now contain properly-slash-terminated
1470links to other directories. They have also stopped using absolute
1471links in forms and pages (which interfered with the use of a
1472front-end load-balancing proxy).</li>
1473<li>The behavior of the &quot;Check This File&quot; button changed, in conjunction
1474with larger internal changes to file checking/verification. The
1475button triggers an immediate check as before, but the outcome is
1476shown on its own page, and does not get stored anywhere. As a
1477result, the web directory page no longer shows historical checker
1478results.</li>
1479<li>A new &quot;Deep-Check&quot; button has been added, which allows a user to
1480initiate a recursive check of the given directory and all files and
1481directories reachable from it. This can cause quite a bit of work,
1482and has no intermediate progress information or feedback about the
1483process. In addition, the results of the deep-check are extremely
1484limited. A later release will improve this behavior.</li>
1485<li>The web server's behavior with respect to non-ASCII (unicode)
1486filenames in the &quot;GET save=true&quot; operation has been improved. To
1487achieve maximum compatibility with variously buggy web browsers, the
1488server does not try to figure out the character set of the inbound
1489filename. It just echoes the same bytes back to the browser in the
1490Content-Disposition header. This seems to make both IE7 and Firefox
1491work correctly.</li>
1492</ul>
1493</div>
1494<div class="section" id="id12">
1495<h2>Checker/Verifier/Repairer</h2>
1496<ul>
1497<li><p class="first">Tahoe is slowly acquiring convenient tools to check up on file
1498health, examine existing shares for errors, and repair files that
1499are not fully healthy. This release adds a mutable
1500checker/verifier/repairer, although testing is very limited, and
1501there are no web interfaces to trigger repair yet. The &quot;Check&quot;
1502button next to each file or directory on the wapi page will perform
1503a file check, and the &quot;deep check&quot; button on each directory will
1504recursively check all files and directories reachable from there
1505(which may take a very long time).</p>
1506<p>Future releases will improve access to this functionality.</p>
1507</li>
1508</ul>
1509</div>
1510<div class="section" id="operations-packaging">
1511<h2>Operations/Packaging</h2>
1512<ul class="simple">
1513<li>A &quot;check-grid&quot; script has been added, along with a Makefile
1514target. This is intended (with the help of a pre-configured node
1515directory) to check upon the health of a Tahoe grid, uploading and
1516downloading a few files. This can be used as a monitoring tool for a
1517deployed grid, to be run periodically and to signal an error if it
1518ever fails. It also helps with compatibility testing, to verify that
1519the latest Tahoe code is still able to handle files created by an
1520older version.</li>
1521<li>The munin plugins from misc/munin/ are now copied into any generated
1522debian packages, and are made executable (and uncompressed) so they
1523can be symlinked directly from /etc/munin/plugins/ .</li>
1524<li>Ubuntu &quot;Hardy&quot; was added as a supported debian platform, with a
1525Makefile target to produce hardy .deb packages. Some notes have been
1526added to docs/debian.txt about building Tahoe on a debian/ubuntu
1527system.</li>
1528<li>Storage servers now measure operation rates and
1529latency-per-operation, and provides results through the /statistics
1530web page as well as the stats gatherer. Munin plugins have been
1531added to match.</li>
1532</ul>
1533</div>
1534<div class="section" id="other">
1535<h2>Other</h2>
1536<ul class="simple">
1537<li>Tahoe nodes now use Foolscap &quot;incident logging&quot; to record unusual
1538events to their NODEDIR/logs/incidents/ directory. These incident
1539files can be examined by Foolscap logging tools, or delivered to an
1540external log-gatherer for further analysis. Note that Tahoe now
1541requires Foolscap-0.2.9, since 0.2.8 had a bug that complained about
1542&quot;OSError: File exists&quot; when trying to create the incidents/
1543directory for a second time.</li>
1544<li>If no servers are available when retrieving a mutable file (like a
1545directory), the node now reports an error instead of hanging
1546forever. Earlier releases would not only hang (causing the wapi
1547directory listing to get stuck half-way through), but the internal
1548dirnode serialization would cause all subsequent attempts to
1549retrieve or modify the same directory to hang as well. #463</li>
1550<li>A minor internal exception (reported in logs/twistd.log, in the
1551&quot;stopProducing&quot; method) was fixed, which complained about
1552&quot;self._paused_at not defined&quot; whenever a file download was stopped
1553from the web browser end.</li>
1554</ul>
1555</div>
1556</div>
1557<div class="section" id="release-1-1-0-2008-06-11">
1558<h1>Release 1.1.0 (2008-06-11)</h1>
1559<div class="section" id="cli-new-alias-model">
1560<h2>CLI: new &quot;alias&quot; model</h2>
1561<ul class="simple">
1562<li>The new CLI code uses an scp/rsync -like interface, in which
1563directories in the Tahoe storage grid are referenced by a
1564colon-suffixed alias. The new commands look like:</li>
1565</ul>
1566<blockquote>
1567<ul class="simple">
1568<li>tahoe cp local.txt tahoe:virtual.txt</li>
1569<li>tahoe ls work:subdir</li>
1570</ul>
1571</blockquote>
1572<ul class="simple">
1573<li>More functionality is available through the CLI: creating unlinked
1574files and directories, recursive copy in or out of the storage grid,
1575hardlinks, and retrieving the raw read- or write- caps through the
1576'ls' command. Please read docs/CLI.txt for complete details.</li>
1577</ul>
1578</div>
1579<div class="section" id="wapi-new-pages-new-commands">
1580<h2>wapi: new pages, new commands</h2>
1581<ul class="simple">
1582<li>Several new pages were added to the web API:</li>
1583</ul>
1584<blockquote>
1585<ul class="simple">
1586<li>/helper_status : to describe what a Helper is doing</li>
1587<li>/statistics : reports node uptime, CPU usage, other stats</li>
1588<li>/file : for easy file-download URLs, see #221</li>
1589<li>/cap == /uri : future compatibility</li>
1590</ul>
1591</blockquote>
1592<ul class="simple">
1593<li>The localdir=/localfile= and t=download operations were
1594removed. These required special configuration to enable anyways, but
1595this feature was a security problem, and was mostly obviated by the
1596new &quot;cp -r&quot; command.</li>
1597<li>Several new options to the GET command were added:</li>
1598</ul>
1599<blockquote>
1600<ul>
1601<li><p class="first">t=deep-size : add up the size of all immutable files reachable from the directory</p>
1602</li>
1603<li><dl class="first docutils">
1604<dt>t=deep-stats <span class="classifier-delimiter">:</span> <span class="classifier">return a JSON-encoded description of number of files, size</span></dt>
1605<dd><p class="first last">distribution, total size, etc</p>
1606</dd>
1607</dl>
1608</li>
1609</ul>
1610</blockquote>
1611<ul class="simple">
1612<li>POST is now preferred over PUT for most operations which cause
1613side-effects.</li>
1614<li>Most wapi calls now accept overwrite=, and default to overwrite=true</li>
1615<li>&quot;POST /uri/DIRCAP/parent/child?t=mkdir&quot; is now the preferred API to
1616create multiple directories at once, rather than ...?t=mkdir-p .</li>
1617<li>PUT to a mutable file (&quot;PUT /uri/MUTABLEFILECAP&quot;, &quot;PUT
1618/uri/DIRCAP/child&quot;) will modify the file in-place.</li>
1619<li>more munin graphs in misc/munin/</li>
1620</ul>
1621<blockquote>
1622<ul class="simple">
1623<li>tahoe-introstats</li>
1624<li>tahoe-rootdir-space</li>
1625<li>tahoe_estimate_files</li>
1626<li>mutable files published/retrieved</li>
1627<li>tahoe_cpu_watcher</li>
1628<li>tahoe_spacetime</li>
1629</ul>
1630</blockquote>
1631</div>
1632<div class="section" id="new-dependencies">
1633<h2>New Dependencies</h2>
1634<ul class="simple">
1635<li>zfec 1.1.0</li>
1636<li>foolscap 0.2.8</li>
1637<li>pycryptopp 0.5</li>
1638<li>setuptools (now required at runtime)</li>
1639</ul>
1640</div>
1641<div class="section" id="new-mutable-file-code">
1642<h2>New Mutable-File Code</h2>
1643<ul class="simple">
1644<li>The mutable-file handling code (mostly used for directories) has
1645been completely rewritten. The new scheme has a better API (with a
1646modify() method) and is less likely to lose data when several
1647uncoordinated writers change a file at the same time.</li>
1648<li>In addition, a single Tahoe process will coordinate its own
1649writes. If you make two concurrent directory-modifying wapi calls to
1650a single tahoe node, it will internally make one of them wait for
1651the other to complete. This prevents auto-collision (#391).</li>
1652<li>The new mutable-file code also detects errors during publish
1653better. Earlier releases might believe that a mutable file was
1654published when in fact it failed.</li>
1655</ul>
1656</div>
1657<div class="section" id="other-features">
1658<h2>other features</h2>
1659<ul class="simple">
1660<li>The node now monitors its own CPU usage, as a percentage, measured
1661every 60 seconds. 1/5/15 minute moving averages are available on the
1662/statistics web page and via the stats-gathering interface.</li>
1663<li>Clients now accelerate reconnection to all servers after being
1664offline (#374). When a client is offline for a long time, it scales
1665back reconnection attempts to approximately once per hour, so it may
1666take a while to make the first attempt, but once any attempt
1667succeeds, the other server connections will be retried immediately.</li>
1668<li>A new &quot;offloaded KeyGenerator&quot; facility can be configured, to move
1669RSA key generation out from, say, a wapi node, into a separate
1670process. RSA keys can take several seconds to create, and so a wapi
1671node which is being used for directory creation will be unavailable
1672for anything else during this time. The Key Generator process will
1673pre-compute a small pool of keys, to speed things up further. This
1674also takes better advantage of multi-core CPUs, or SMP hosts.</li>
1675<li>The node will only use a potentially-slow &quot;du -s&quot; command at startup
1676(to measure how much space has been used) if the &quot;sizelimit&quot;
1677parameter has been configured (to limit how much space is
1678used). Large storage servers should turn off sizelimit until a later
1679release improves the space-management code, since &quot;du -s&quot; on a
1680terabyte filesystem can take hours.</li>
1681<li>The Introducer now allows new announcements to replace old ones, to
1682avoid buildups of obsolete announcements.</li>
1683<li>Immutable files are limited to about 12GiB (when using the default
16843-of-10 encoding), because larger files would be corrupted by the
1685four-byte share-size field on the storage servers (#439). A later
1686release will remove this limit. Earlier releases would allow &gt;12GiB
1687uploads, but the resulting file would be unretrievable.</li>
1688<li>The docs/ directory has been rearranged, with old docs put in
1689docs/historical/ and not-yet-implemented ones in docs/proposed/ .</li>
1690<li>The Mac OS-X FUSE plugin has a significant bug fix: earlier versions
1691would corrupt writes that used seek() instead of writing the file in
1692linear order.  The rsync tool is known to perform writes in this
1693order. This has been fixed.</li>
1694</ul>
1695</div>
1696</div>
1697</div>
1698</body>
1699</html>