7 INTERNET-DRAFT Howard Y. Chu
8 Intended Category: Standard Track Symas Corporation
9 Expires in six months 1 December 2004
12 Change Sequence Numbers for LDAP
13 <draft-chu-ldap-csn-00.txt>
18 This document is an Internet-Draft and is in full conformance with all
19 provisions of Section 10 of RFC2026.
21 This document is intended to be, after appropriate review and
22 revision, submitted to the RFC Editor as an Standard Track document.
23 Distribution of this memo is unlimited. Technical discussion of this
24 document will take place on the IETF LDAP Extensions mailing list
25 <ldapext@ietf.org>. Please send editorial comments directly to the
26 author <Kurt@OpenLDAP.org>.
28 Internet-Drafts are working documents of the Internet Engineering Task
29 Force (IETF), its areas, and its working groups. Note that other
30 groups may also distribute working documents as Internet-Drafts.
31 Internet-Drafts are draft documents valid for a maximum of six months
32 and may be updated, replaced, or obsoleted by other documents at any
33 time. It is inappropriate to use Internet-Drafts as reference
34 material or to cite them other than as ``work in progress.''
36 The list of current Internet-Drafts can be accessed at
37 <http://www.ietf.org/ietf/1id-abstracts.txt>. The list of
38 Internet-Draft Shadow Directories can be accessed at
39 <http://www.ietf.org/shadow.html>.
41 Copyright (C) The Internet Society (2004). All Rights Reserved.
43 Please see the Full Copyright section near the end of this document
49 This document describes the LDAP/X.500 Change Sequence Number 'CSN'
50 syntax and matching rules and associated attributes. CSNs are used
51 to impose a total ordering upon the sequence of updates applied
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62 1. Background and Intended Use
64 In X.500 Directory Services [X.501], updates to a directory may need
65 to be distributed to multiple servers. The 'modifyTimeStamp' is already
66 defined for recording the time of an update, but it may be inadequate in
67 an environment where multiple servers with loosely synchronized clocks
70 This document describes the 'CSN' syntax which augments a timestamp with
71 additional information to assist in coordinating updates among multiple
72 directory servers. This document describes the 'entryCSN' operational
73 attribute which carries the CSN of the last update applied to an entry
74 and also the 'contextCSN' operational attribute which carries the
75 greatest CSN of all updates applied to a directory context. Directory
76 clients and servers may use these attributes to assist in synchronizing
77 shadowed copies of directory information.
79 This document describes the 'csnMatch' and 'csnOrderingMatch' matching
80 rules corresponding to the 'CSN' syntax.
82 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
83 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
84 document are to be interpreted as described in BCP 14 [RFC2119].
86 Schema definitions are provided using LDAP description formats
87 [RFC2252]. Definitions provided here are formatted (line wrapped) for
91 2. CSN Schema Elements
95 Values in this syntax are encoded according to the following BNF:
97 CSN = timestamp '#' operation-counter '#' replica-id
99 timestamp = <generalizedTimeString as specified in 6.14 of [RFC2252]>
101 operation-counter = 6hex-digit
103 replica-id = 2hex-digit
105 The timestamp SHALL use GMT and SHALL NOT include fractional seconds.
107 The operation-counter is set to zero at the start of each second, and
108 incremented by one for each update operation that occurs within that
111 The replica-id is an identifier that represents a specific Replica in
112 a collection of cooperating servers.
114 The following is a LDAP syntax description [RFC2252] suitable for
115 publication in the subschema.
117 ( IANA-ASSIGNED-OID.1 DESC 'CSN' )
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128 2.2 'csnMatch' Matching Rule
130 The 'csnMatch' matching rule compares an asserted CSN with a stored
131 CSN for equality. Its semantics are same as the octetStringMatch
132 [X.520][RFC2252] matching rule.
134 The following is a LDAP matching rule description [RFC2252] suitable
135 for publication in the subschema.
137 ( IANA-ASSIGNED-OID.2 NAME 'csnMatch'
138 SYNTAX IANA-ASSIGNED-OID.1 )
141 2.3 'csnOrderingMatch' Matching Rule
143 The 'csnOrderingMatch' matching rule compares an asserted CSN
144 with a stored CSN for ordering. Its semantics are the same as the
145 octetStringOrderingMatch [X.520][RFC2252] matching rule.
147 The following is a LDAP matching rule description [RFC2252] suitable
148 for publication in the subschema.
150 ( IANA-ASSIGNED-OID.3 NAME 'csnOrderingMatch'
151 SYNTAX IANA-ASSIGNED-OID.1 )
154 2.4. 'entryCSN' attribute
156 The 'entryCSN' operational attribute provides the CSN of the last
157 update applied to the entry.
159 The following is a LDAP attribute type description [RFC2252] suitable
160 for publication in the subschema.
162 ( IANA-ASSIGNED-OID.4 NAME 'entryCSN'
163 DESC 'CSN of the entry content'
165 ORDERING csnOrderingMatch
169 Chu draft-chu-ldap-csn-00 [Page 3]
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174 SYNTAX IANA-ASSIGNED-OID.1
177 USAGE directoryOperation )
179 Servers SHALL assign a CSN to each entry upon its addition to the
180 directory and provide the entry's CSN as the value of the
181 'entryCSN' operational attribute. The entryCSN attribute SHOULD be
182 updated upon every update of the entry.
184 2.5. 'contextCSN' attribute
186 The 'contextCSN' operational attribute provides the greatest CSN of
187 all the updates applied to a context.
189 The following is a LDAP attribute type description [RFC2252] suitable
190 for publication in the subschema.
192 ( IANA-ASSIGNED-OID.5 NAME 'contextCSN'
193 DESC 'the largest committed CSN of a context'
195 ORDERING csnOrderingMatch
196 SYNTAX IANA-ASSIGNED-OID.1
199 USAGE directoryOperation )
201 Servers SHALL record the greatest CSN of all updates applied to a
202 context in the root entry of the context.
205 3. Security Considerations
208 General LDAP security considerations [RFC3377] apply.
211 4. IANA Considerations
213 4.1. Object Identifier Registration
215 It is requested that IANA register upon Standards Action an LDAP
216 Object Identifier for use in this technical specification.
218 Subject: Request for LDAP OID Registration
219 Person & email address to contact for further information:
220 Howard Chu <hyc@symas.com>
221 Specification: RFC XXXX
222 Author/Change Controller: IESG
224 Identifies the CSN schema elements
227 4.2. Registration of the csnMatch descriptor
229 It is requested that IANA register upon Standards Action the LDAP
230 'csnMatch' descriptor.
232 Subject: Request for LDAP Descriptor Registration
233 Descriptor (short name): csnMatch
234 Object Identifier: IANA-ASSIGNED-OID.2
235 Person & email address to contact for further information:
236 Howard Chu <hyc@symas.com>
238 Specification: RFC XXXX
239 Author/Change Controller: IESG
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246 INTERNET-DRAFT LDAP CSN 1 December 2004
249 4.3. Registration of the csnOrderingMatch descriptor
251 It is requested that IANA register upon Standards Action the LDAP
252 'csnOrderingMatch' descriptor.
254 Subject: Request for LDAP Descriptor Registration
255 Descriptor (short name): csnOrderingMatch
256 Object Identifier: IANA-ASSIGNED-OID.3
257 Person & email address to contact for further information:
258 Howard Chu <hyc@symas.com>
260 Specification: RFC XXXX
261 Author/Change Controller: IESG
264 4.4. Registration of the entryCSN descriptor
266 It is requested that IANA register upon Standards Action the LDAP
267 'entryCSN' descriptor.
269 Subject: Request for LDAP Descriptor Registration
270 Descriptor (short name): entryCSN
271 Object Identifier: IANA-ASSIGNED-OID.4
272 Person & email address to contact for further information:
273 Howard Chu <hyc@symas.com>
274 Usage: Attribute Type
275 Specification: RFC XXXX
276 Author/Change Controller: IESG
279 4.5. Registration of the contextCSN descriptor
281 It is requested that IANA register upon Standards Action the LDAP
282 'contextCSN' descriptor.
284 Subject: Request for LDAP Descriptor Registration
285 Descriptor (short name): contextCSN
286 Object Identifier: IANA-ASSIGNED-OID.5
287 Person & email address to contact for further information:
288 Howard Chu <hyc@symas.com>
289 Usage: Attribute Type
290 Specification: RFC XXXX
291 Author/Change Controller: IESG
296 This document is based on prior work from the IETF LDUP working
297 group including the LDAP Replication Architecture [LDUPMODEL]
298 and the LDAP Content Synchronization Operation [LDUPSYNC].
301 6. Author's Addresses
312 7. Normative References
314 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
315 Requirement Levels", BCP 14 (also RFC 2119), March 1997.
319 Chu draft-chu-ldap-csn-00 [Page 5]
321 INTERNET-DRAFT LDAP CSN 1 December 2004
324 [RFC2252] Wahl, M., A. Coulbeck, T. Howes, and S. Kille,
325 "Lightweight Directory Access Protocol (v3): Attribute
326 Syntax Definitions", RFC 2252, December 1997.
328 [RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access
329 Protocol (v3): Technical Specification", RFC 3377,
332 [X.501] International Telecommunication Union -
333 Telecommunication Standardization Sector, "The Directory
334 -- Models," X.501(1993) (also ISO/IEC 9594-2:1994).
336 [X.520] International Telecommunication Union -
337 Telecommunication Standardization Sector, "The
338 Directory: Selected Attribute Types", X.520(1993) (also
339 ISO/IEC 9594-6:1994).
341 [X.680] International Telecommunication Union -
342 Telecommunication Standardization Sector, "Abstract
343 Syntax Notation One (ASN.1) - Specification of Basic
344 Notation", X.680(1997) (also ISO/IEC 8824-1:1998).
346 [LDUPSYNC] Zeilenga, K. and Choi, J-H "LDAP Content Synchronization
347 Operation", draft-zeilenga-ldup-sync-05.txt, a work in
351 8. Informative References
353 [RFC3383] Zeilenga, K., "IANA Considerations for LDAP", BCP 64
354 (also RFC 3383), September 2002.
356 [LDUPMODEL] Merrellls, J., Srinivasan, U., and Reed, E., "LDAP
357 Replication Architecture", draft-ietf-ldup-model-09.txt.
361 Intellectual Property Rights
363 The IETF takes no position regarding the validity or scope of any
367 Chu draft-chu-ldap-csn-00 [Page 6]
369 INTERNET-DRAFT LDAP CSN 1 December 2004
372 intellectual property or other rights that might be claimed to pertain
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395 Copyright (C) The Internet Society (2004). All Rights Reserved.
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408 or as required to translate it into languages other than English.
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