1STORAGE.CONF(5) InterNetNews Documentation STORAGE.CONF(5)
2
6 storage.conf - Configuration file for storage manager
7
9 The file pathetc/storage.conf contains the rules to be used in
10 assigning articles to different storage methods. These rules determine
11 where incoming articles will be stored.
12 The storage manager is a unified interface between INN and a variety of
14 different storage methods, allowing the news administrator to choose
15 between different storage methods with different trade-offs (or even
16 use several at the same time for different newsgroups, or articles of
17 different sizes). The rest of INN need not care what type of storage
18 method was used for a given article; the storage manager will figure
19 this out automatically when that article is retrieved via the storage
20 API. Note that you may also want to see the options provided in
21 inn.conf(5) regarding article storage.
22 The storage.conf file consists of a series of storage method entries.
24 Blank lines and lines beginning with a number sign ("#") are ignored.
25 The maximum number of characters in each line is 255. The order of
26 entries in this file is important, see below.
27 Each entry specifies a storage method and a set of rules. Articles
29 which match all of the rules of a storage method entry will be stored
30 using that storage method; if an article matches multiple storage
31 method entries, the first one will be used. Each entry is formatted as
32 follows:
33 method <methodname> {
35 class: <storage_class>
36 newsgroups: <wildmat>
37 size: <minsize>[,<maxsize>]
38 expires: <mintime>[,<maxtime>]
39 options: <options>
40 exactmatch: <bool>
41 }
42 If spaces or tabs are included in a value, that value must be enclosed
44 in double quotes (""). If either a number sign ("#") or a double quote
45 are meant to be included verbatim in a value, they should be escaped
46 with "\".
47 <methodname> is the name of a storage method to use for articles which
49 match the rules of this entry. The currently available storage methods
50 are:
51 cnfs
53 timecaf
54 timehash
55 tradspool
56 trash
57 See the "STORAGE METHODS" section below for more details.
59 The meanings of the keys in each storage method entry are as follows:
61 class: <storage_class>
63 An identifier for this storage method entry. <storage_class>
64 should be a number between 0 and 255. It should be unique across
65 all of the entries in this file. It is mainly used for specifying
66 expiration times by storage class as described in expire.ctl(5);
67 "timehash" and "timecaf" will also set the top-level directory in
68 which articles accepted by this storage class are stored. The
69 assignment of a particular number to a storage class is arbitrary
70 but permanent (since it is used in storage tokens). Storage
71 classes can be for instance numbered sequentially in storage.conf.
72 newsgroups: <wildmat>
74 What newsgroups are stored using this storage method. <wildmat> is
75 a uwildmat(3) pattern which is matched against the newsgroups an
76 article is posted to. If storeonxref in inn.conf is true, this
77 pattern will be matched against the newsgroup names in the Xref:
78 header; otherwise, it will be matched against the newsgroup names
79 in the Newsgroups: header (see inn.conf(5) for discussion of the
80 differences between these possibilities). Poison wildmat
81 expressions (expressions starting with "@") are allowed and can be
82 used to exclude certain group patterns: articles crossposted to
83 poisoned newsgroups will not be stored using this storage method.
84 The <wildmat> pattern is matched in order.
85 There is no default newsgroups pattern; if an entry should match
87 all newsgroups, use an explicit "newsgroups: *".
88 size: <minsize>[,<maxsize>]
90 A range of article sizes (in bytes) which should be stored using
91 this storage method. If <maxsize> is 0 or not given, the upper
92 size of articles is limited only by maxartsize in inn.conf. The
93 size: field is optional and may be omitted entirely if you want
94 articles of any size to be stored in this storage method (if, of
95 course, these articles fulfill all the other requirements of this
96 storage method entry). By default, <minsize> is set to 0.
97 expires: <mintime>[,<maxtime>]
99 A range of article expiration times which should be stored using
100 this storage method. Be careful; this is less useful than it may
101 appear at first. This is based only on the Expires: header of the
102 article, not on any local expiration policies or anything in
103 expire.ctl! If <mintime> is non-zero, then this entry will not
104 match any article without an Expires: header. This key is
105 therefore only really useful for assigning articles with requested
106 longer expire times to a separate storage method. Articles only
107 match if the time until expiration (that is to say, the amount of
108 time into the future that the Expires: header of the article
109 requests that it remain around) falls in the interval specified by
110 <mintime> and <maxtime>.
111 The format of these parameters is "0d0h0m0s" (days, hours, minutes,
113 and seconds into the future). If <maxtime> is "0s" or is not
114 specified, there is no upper bound on expire times falling into
115 this entry (note that this key has no effect on when the article
116 will actually be expired, but only on whether or not the article
117 will be stored using this storage method). This field is also
118 optional and may be omitted entirely if you do not want to store
119 articles according to their Expires: header, if any.
120 A <mintime> value greater than "0s" implies that this storage
122 method won't match any article without an Expires: header.
123 options: <options>
125 This key is for passing special options to storage methods that
126 require them (currently only "cnfs"). See the "STORAGE METHODS"
127 section below for a description of its use.
128 exactmatch: <bool>
130 If this key is set to true, all the newsgroups in the Newsgroups:
131 header of incoming articles will be examined to see if they match
132 newsgroups patterns. (Normally, any non-zero number of matching
133 newsgroups is sufficient, provided no newsgroup matches a poison
134 wildmat as described above.) This is a boolean value; "true",
135 "yes" and "on" are usable to enable this key. The case of these
136 values is not significant. The default is false.
137 If an article matches all of the constraints of an entry, it is stored
139 via that storage method and is associated with that <storage_class>.
140 This file is scanned in order and the first matching entry is used to
141 store the article.
142 If an article does not match any entry, either by being posted to a
144 newsgroup which does not match any of the <wildmat> patterns or by
145 being outside the size and expires ranges of all entries whose
146 newsgroups pattern it does match, the article is not stored and is
147 rejected by innd. When this happens, the error message:
148 cant store article: no matching entry in storage.conf
150 is logged to syslog. If you want to silently drop articles matching
152 certain newsgroup patterns or size or expires ranges, assign them to
153 the "trash" storage method rather than having them not match any
154 storage method entry.
155
157 Currently, there are five storage methods available. Each method has
158 its pros and cons; you can choose any mixture of them as is suitable
159 for your environment. Note that each method has an attribute
160 EXPENSIVESTAT which indicates whether checking the existence of an
161 article is expensive or not. This is used to run expireover(8).
162 cnfs
164 The "cnfs" storage method stores articles in large cyclic buffers
165 (CNFS stands for Cyclic News File System). Articles are stored in
166 CNFS buffers in arrival order, and when the buffer fills, it wraps
167 around to the beginning and stores new articles over the top of the
168 oldest articles in the buffer. The expire time of articles stored
169 in CNFS buffers is therefore entirely determined by how long it
170 takes the buffer to wrap around, which depends on how quickly data
171 is being stored in it. (This method is therefore said to have
172 self-expire functionality.) EXPENSIVESTAT is false for this
173 method.
174 CNFS has its own configuration file, cycbuff.conf, which describes
176 some subtleties to the basic description given above. Storage
177 method entries for the "cnfs" storage method must have an options:
178 field specifying the metacycbuff into which articles matching that
179 entry should be stored; see cycbuff.conf(5) for details on
180 metacycbuffs.
181 Advantages: By far the fastest of all storage methods (except for
183 "trash"), since it eliminates the overhead of dealing with a file
184 system and creating new files. Unlike all other storage methods,
185 it does not require manual article expiration. With CNFS, the
186 server will never throttle itself due to a full spool disk, and
187 groups are restricted to just the buffer files given so that they
188 can never use more than the amount of disk space allocated to them.
189 Disadvantages: Article retention times are more difficult to
191 control because old articles are overwritten automatically.
192 Attacks on Usenet, such as flooding or massive amounts of spam, can
193 result in wanted articles expiring much faster than intended (with
194 no warning).
195 timecaf
197 This method stores multiple articles in one file, whose name is
198 based on the article's arrival time and the storage class. The
199 file name will be:
200 <patharticles>/timecaf-nn/bb/aacc.CF
202 where "nn" is the hexadecimal value of <storage_class>, "bb" and
204 "aacc" are the hexadecimal components of the arrival time, and "CF"
205 is a hardcoded extension. (The arrival time, in seconds since the
206 epoch, is converted to hexadecimal and interpreted as 0xaabbccdd,
207 with "aa", "bb", and "cc" used to build the path.) This method
208 does not have self-expire functionality (meaning expire has to run
209 periodically to delete old articles). EXPENSIVESTAT is false for
210 this method.
211 Advantages: It is roughly four times faster than "timehash" for
213 article writes, since much of the file system overhead is bypassed,
214 while still retaining the same fine control over article retention
215 time.
216 Disadvantages: Using this method means giving up all but the most
218 careful manually fiddling with the article spool; in this aspect,
219 it looks like "cnfs". As one of the newer and least widely used
220 storage types, "timecaf" has not been as thoroughly tested as the
221 other methods.
222 timehash
224 This method is very similar to "timecaf" except that each article
225 is stored in a separate file. The name of the file for a given
226 article will be:
227 <patharticles>/time-nn/bb/cc/yyyy-aadd
229 where "nn" is the hexadecimal value of <storage_class>, "yyyy" is a
231 hexadecimal sequence number, and "bb", "cc", and "aadd" are
232 components of the arrival time in hexadecimal (the arrival time is
233 interpreted as documented above under "timecaf"). This method does
234 not have self-expire functionality. EXPENSIVESTAT is true for this
235 method.
236 Advantages: Heavy traffic groups do not cause bottlenecks, and a
238 fine control of article retention time is still possible.
239 Disadvantages: The ability to easily find all articles in a given
241 newsgroup and manually fiddle with the article spool is lost, and
242 INN still suffers from speed degradation due to file system
243 overhead (creating and deleting individual files is a slow
244 operation).
245 tradspool
247 Traditional spool, or "tradspool", is the traditional news article
248 storage format. Each article is stored in an individual text file
249 named:
250 <patharticles>/news/group/name/nnnnn
252 where "news/group/name" is the name of the newsgroup to which the
254 article was posted with each period changed to a slash, and "nnnnn"
255 is the sequence number of the article in that newsgroup. For
256 crossposted articles, the article is linked into each newsgroup to
257 which it is crossposted (using either hard or symbolic links).
258 This is the way versions of INN prior to 2.0 stored all articles,
259 as well as being the article storage format used by C News and
260 earlier news systems. This method does not have self-expire
261 functionality. EXPENSIVESTAT is true for this method.
262 Advantages: It is widely used and well-understood; it can read
264 article spools written by older versions of INN and it is
265 compatible with all third-party INN add-ons. This storage
266 mechanism provides easy and direct access to the articles stored on
267 the server and makes writing programs that fiddle with the news
268 spool very easy, and gives fine control over article retention
269 times.
270 Disadvantages: It takes a very fast file system and I/O system to
272 keep up with current Usenet traffic volumes due to file system
273 overhead. Groups with heavy traffic tend to create a bottleneck
274 because of inefficiencies in storing large numbers of article files
275 in a single directory. It requires a nightly expire program to
276 delete old articles out of the news spool, a process that can slow
277 down the server for several hours or more.
278 trash
280 This method silently discards all articles stored in it. Its only
281 real uses are for testing and for silently discarding articles
282 matching a particular storage method entry (for whatever reason).
283 Articles stored in this method take up no disk space and can never
284 be retrieved, so this method has self-expire functionality of a
285 sort. EXPENSIVESTAT is false for this method.
286
288 The following sample storage.conf file would store all articles posted
289 to alt.binaries.* in the "BINARIES" CNFS metacycbuff, all articles over
290 roughly 50 KB in any other hierarchy in the "LARGE" CNFS metacycbuff,
291 all other articles in alt.* in one timehash class, and all other
292 articles in any newsgroups in a second timehash class, except for the
293 internal.* hierarchy which is stored in traditional spool format.
294 method tradspool {
296 class: 1
297 newsgroups: internal.*
298 }
299 method cnfs {
300 class: 2
301 newsgroups: alt.binaries.*
302 options: BINARIES
303 }
304 method cnfs {
305 class: 3
306 newsgroups: *
307 size: 50000
308 options: LARGE
309 }
310 method timehash {
311 class: 4
312 newsgroups: alt.*
313 }
314 method timehash {
315 class: 5
316 newsgroups: *
317 }
318 Notice that the last storage method entry will catch everything. This
320 is a good habit to get into; make sure that you have at least one
321 catch-all entry just in case something you did not expect falls through
322 the cracks. Notice also that the special rule for the internal.*
323 hierarchy is first, so it will catch even articles crossposted to
324 alt.binaries.* or over 50 KB in size.
325 As for poison wildmat expressions, if you have for instance an article
327 crossposted between misc.foo and misc.bar, the pattern:
328 misc.*,!misc.bar
330 will match that article whereas the pattern:
332 misc.*,@misc.bar
334 will not match that article. An article posted only to misc.bar will
336 fail to match either pattern.
337 Usually, high-volume groups and groups whose articles do not need to be
339 kept around very long (binaries groups, *.jobs*, news.lists.filters,
340 etc.) are stored in CNFS buffers. Use the other methods (or CNFS
341 buffers again) for everything else. However, it is as often as not
342 most convenient to keep in "tradspool" special hierarchies like local
343 hierarchies and hierarchies that should never expire or through the
344 spool of which you need to go manually.
345
347 Written by Katsuhiro Kondou <kondou@nec.co.jp> for InterNetNews.
348 Rewritten into POD by Julien Elie.
349 $Id: storage.conf.pod 8357 2009-02-27 17:56:00Z iulius $
351
353 cycbuff.conf(5), expire.ctl(5), expireover(8), inn.conf(5), innd(8),
354 uwildmat(3).
355INN 2.5.2 2010-08-11 STORAGE.CONF(5)