draft-ietf-netconf-partial-lock-11.txt   rfc5717.txt 
NETCONF B. Lengyel Network Working Group B. Lengyel
Internet-Draft Ericsson Request for Comments: 5717 Ericsson
Intended status: Standards Track M. Bjorklund Category: Standards Track M. Bjorklund
Expires: April 23, 2010 Tail-f Systems Tail-f Systems
October 20, 2009 December 2009
Partial Lock RPC for NETCONF
draft-ietf-netconf-partial-lock-11
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. This document may contain material
from IETF Documents or IETF Contributions published or made publicly
available before November 10, 2008. The person(s) controlling the
copyright in some of this material may not have granted the IETF
Trust the right to allow modifications of such material outside the
IETF Standards Process. Without obtaining an adequate license from
the person(s) controlling the copyright in such materials, this
document may not be modified outside the IETF Standards Process, and
derivative works of it may not be created outside the IETF Standards
Process, except to format it for publication as an RFC or to
translate it into languages other than English.
Internet-Drafts are working documents of the Internet Engineering Partial Lock Remote Procedure Call (RPC) for NETCONF
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Abstract
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The Network Configuration protocol (NETCONF) defines the lock and
http://www.ietf.org/ietf/1id-abstracts.txt. unlock Remote Procedure Calls (RPCs), used to lock entire
configuration datastores. In some situations, a way to lock only
parts of a configuration datastore is required. This document
defines a capability-based extension to the NETCONF protocol for
locking portions of a configuration datastore.
The list of Internet-Draft Shadow Directories can be accessed at Status of This Memo
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 23, 2010. This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Abstract include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the BSD License.
The NETCONF protocol defines the lock and unlock RPCs, used to lock This document may contain material from IETF Documents or IETF
entire configuration datastores. In some situations, a way to lock Contributions published or made publicly available before November
only parts of a configuration datastore is required. This document 10, 2008. The person(s) controlling the copyright in some of this
defines a capability-based extension to the NETCONF protocol for material may not have granted the IETF Trust the right to allow
locking portions of a configuration datastore. modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other
than English.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Definition of Terms . . . . . . . . . . . . . . . . . . . 4 1.1. Definition of Terms . . . . . . . . . . . . . . . . . . . 3
2. Partial Locking Capability . . . . . . . . . . . . . . . . . . 4 2. Partial Locking Capability . . . . . . . . . . . . . . . . . . 3
2.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1. Usage Scenarios . . . . . . . . . . . . . . . . . . . 5 2.1.1. Usage Scenarios . . . . . . . . . . . . . . . . . . . 4
2.2. Dependencies . . . . . . . . . . . . . . . . . . . . . . . 6 2.2. Dependencies . . . . . . . . . . . . . . . . . . . . . . . 5
2.3. Capability Identifier . . . . . . . . . . . . . . . . . . 6 2.3. Capability Identifier . . . . . . . . . . . . . . . . . . 5
2.4. New Operations . . . . . . . . . . . . . . . . . . . . . . 6 2.4. New Operations . . . . . . . . . . . . . . . . . . . . . . 5
2.4.1. <partial-lock> . . . . . . . . . . . . . . . . . . . . 6 2.4.1. <partial-lock> . . . . . . . . . . . . . . . . . . . . 5
2.4.2. <partial-unlock> . . . . . . . . . . . . . . . . . . . 10 2.4.2. <partial-unlock> . . . . . . . . . . . . . . . . . . . 10
2.5. Modifications to Existing Operations . . . . . . . . . . . 11 2.5. Modifications to Existing Operations . . . . . . . . . . . 10
2.6. Interactions with Other Capabilities . . . . . . . . . . . 12 2.6. Interactions with Other Capabilities . . . . . . . . . . . 11
2.6.1. Candidate Configuration Capability . . . . . . . . . . 12 2.6.1. Candidate Configuration Capability . . . . . . . . . . 11
2.6.2. Confirmed Commit Capability . . . . . . . . . . . . . 12 2.6.2. Confirmed Commit Capability . . . . . . . . . . . . . 11
2.6.3. Distinct Startup Capability . . . . . . . . . . . . . 12 2.6.3. Distinct Startup Capability . . . . . . . . . . . . . 11
3. Security Considerations . . . . . . . . . . . . . . . . . . . 12 3. Security Considerations . . . . . . . . . . . . . . . . . . . 12
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
5. Appendix A - XML Schema for Partial Locking (normative) . . 15 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13
6. Appendix B - YANG Module for Partial Locking 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
(non-normative) . . . . . . . . . . . . . . . . . . . . . . . 18 6.1. Normative References . . . . . . . . . . . . . . . . . . . 13
7. Appendix C - Usage Example - Reserving nodes for future 6.2. Informative References . . . . . . . . . . . . . . . . . . 13
editing (non-normative) . . . . . . . . . . . . . . . . . . . 20 Appendix A. XML Schema for Partial Locking (Normative) . . . . . 14
8. Appendix D - Change Log . . . . . . . . . . . . . . . . . . 24 Appendix B. YANG Module for Partial Locking (Non-Normative) . . . 17
8.1. 10-11 . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Appendix C. Usage Example - Reserving Nodes for Future
8.2. 09-10 . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Editing (Non-Normative) . . . . . . . . . . . . . . . 19
8.3. 08-09 . . . . . . . . . . . . . . . . . . . . . . . . . . 24
8.4. 07-08 . . . . . . . . . . . . . . . . . . . . . . . . . . 24
8.5. 06-07 . . . . . . . . . . . . . . . . . . . . . . . . . . 24
8.6. 05-06 . . . . . . . . . . . . . . . . . . . . . . . . . . 24
8.7. 04-05 . . . . . . . . . . . . . . . . . . . . . . . . . . 24
8.8. 03-04 . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.9. 02-03 . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.10. 01-02 . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.11. 00-01 . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.12. -00 . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 27
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28
10.1. Normative References . . . . . . . . . . . . . . . . . . . 28
10.2. Informative References . . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29
1. Introduction 1. Introduction
The [NETCONF] protocol describes the lock and unlock operations that The [NETCONF] protocol describes the lock and unlock operations that
operate on entire configuration datastores. Often, multiple operate on entire configuration datastores. Often, multiple
management sessions need to be able to modify the configuration of a management sessions need to be able to modify the configuration of a
managed device in parallel. In these cases, locking only parts of a managed device in parallel. In these cases, locking only parts of a
configuration datastore is needed. This document defines a configuration datastore is needed. This document defines a
capability based extension to the NETCONF protocol to support partial capability-based extension to the NETCONF protocol to support partial
locking of the NETCONF running datastore using a mechanism based on locking of the NETCONF running datastore using a mechanism based on
the existing XPath filtering mechanisms. the existing XPath filtering mechanisms.
1.1. Definition of Terms 1.1. Definition of Terms
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in BCP
14, [RFC2119]. 14, [RFC2119].
Additionally the following terms are defined: Additionally, the following terms are defined:
o Instance Identifier: an XPath expression identifying a specific o Instance Identifier: an XPath expression identifying a specific
node in the conceptual XML datastore. It contains an absolute node in the conceptual XML datastore. It contains an absolute
path expression in abbreviated syntax, where predicates are used path expression in abbreviated syntax, where predicates are used
only to specify values for nodes defined as keys to distinguish only to specify values for nodes defined as keys to distinguish
multiple instances. multiple instances.
o Scope of the lock: initially the set of nodes returned by the o Scope of the lock: initially, the set of nodes returned by the
XPath expressions in a successful partial-lock operation. The set XPath expressions in a successful partial-lock operation. The set
might be modified if some of the nodes are deleted by the session might be modified if some of the nodes are deleted by the session
owning the lock. owning the lock.
o Protected area: the set of nodes that are protected from o Protected area: the set of nodes that are protected from
modification by the lock. This set consists of nodes in the scope modification by the lock. This set consists of nodes in the scope
of the lock and nodes in subtrees under them. of the lock and nodes in subtrees under them.
2. Partial Locking Capability 2. Partial Locking Capability
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The :partial-lock capability indicates that the device supports the The :partial-lock capability indicates that the device supports the
locking of its configuration with a more limited scope than a locking of its configuration with a more limited scope than a
complete configuration datastore. The scope to be locked is complete configuration datastore. The scope to be locked is
specified by using restricted or full XPath expressions. Partial specified by using restricted or full XPath expressions. Partial
locking only affects configuration data and only the running locking only affects configuration data and only the running
datastore. The candidate or the start-up datastore are not affected. datastore. The candidate or the start-up datastore are not affected.
The system MUST ensure that configuration resources covered by the The system MUST ensure that configuration resources covered by the
lock are not modified by other NETCONF or non-NETCONF management lock are not modified by other NETCONF or non-NETCONF management
operations such as SNMP and the CLI. operations such as Simple Network Management Protocol (SNMP) and the
Command Line Interface (CLI).
The duration of the partial lock begins when the partial lock is The duration of the partial lock begins when the partial lock is
granted and lasts until (1) either the corresponding <partial-unlock> granted and lasts until (1) either the corresponding <partial-unlock>
operation succeeds or (2) the NETCONF session terminates. operation succeeds or (2) the NETCONF session terminates.
A NETCONF session MAY have multiple parts of the running datastore A NETCONF session MAY have multiple parts of the running datastore
locked using partial lock operations. locked using partial lock operations.
The <partial-lock> operation returns a lock-id to identify each The <partial-lock> operation returns a lock-id to identify each
successfully acquired lock. The lock-id is unique at any given time successfully acquired lock. The lock-id is unique at any given time
for a NETCONF server for all partial-locks granted to any NETCONF or for a NETCONF server for all partial-locks granted to any NETCONF or
non-NETCONF sessions. non-NETCONF sessions.
2.1.1. Usage Scenarios 2.1.1. Usage Scenarios
In the following we describe a few scenarios for partial locking. In the following, we describe a few scenarios for partial locking.
Besides the two described here, there are many other usage scenarios Besides the two described here, there are many other usage scenarios
possible. possible.
2.1.1.1. Multiple managers handling the writable running datastore with 2.1.1.1. Multiple Managers Handling the Writable Running Datastore with
overlapping sections Overlapping Sections
Multiple managers are handling the same NETCONF agent simultaneously. Multiple managers are handling the same NETCONF agent simultaneously.
The agent is handled via the writable running datastore. Each The agent is handled via the writable running datastore. Each
manager has his or her own task, which might involve the modification manager has his or her own task, which might involve the modification
of overlapping sections of the datastore. of overlapping sections of the datastore.
After collecting and analyzing input and preparing the NETCONF After collecting and analyzing input and preparing the NETCONF
operations off-line, the manager locks the areas that are important operations off-line, the manager locks the areas that are important
for his task using one single <partial-lock> operation. The manager for his task using one single <partial-lock> operation. The manager
executes a number of <edit-config> operations to modify the executes a number of <edit-config> operations to modify the
configuration, then releases the partial-lock. The lock should be configuration, then releases the partial-lock. The lock should be
held for the shortest possible time (e.g. seconds rather then held for the shortest possible time (e.g., seconds rather than
minutes). The manager should collect all human input before locking minutes). The manager should collect all human input before locking
anything. As each manager locks only a part of the data model, anything. As each manager locks only a part of the data model,
usually multiple operators can execute the <edit-config> operations usually multiple operators can execute the <edit-config> operations
simultaneously. simultaneously.
2.1.1.2. Multiple managers handling the writable running datastore, 2.1.1.2. Multiple Managers Handling the Writable Running Datastore,
distinct management areas Distinct Management Areas
Multiple managers are handling the same NETCONF agent simultaneously. Multiple managers are handling the same NETCONF agent simultaneously.
The agent is handled via the writable running datastore. The agent's The agent is handled via the writable running datastore. The agent's
data model contains a number of well defined separate areas that can data model contains a number of well-defined separate areas that can
be configured without impacting other areas. An example can be a be configured without impacting other areas. An example can be a
server with multiple applications running on it, or a number of a server with multiple applications running on it, or a number of
network elements with a common NETCONF agent for management. network elements with a common NETCONF agent for management.
Each manager has his or her own task, which does not involve the Each manager has his or her own task, which does not involve the
modification of overlapping sections of the datastore. modification of overlapping sections of the datastore.
The manager locks his area with a <partial-lock> operation, uses a The manager locks his area with a <partial-lock> operation, uses a
number of <edit-config> commands to modify it, later releases the number of <edit-config> commands to modify it, and later releases the
lock. As each manager has his functional area assigned to him, and lock. As each manager has his functional area assigned to him, and
he locks only that area, multiple managers can edit the configuration he locks only that area, multiple managers can edit the configuration
simultaneously. Locks can be held for extended periods (e.g. simultaneously. Locks can be held for extended periods (e.g.,
minutes, hours), as this will not hinder other managers. minutes, hours), as this will not hinder other managers.
This scenario assumes that the global lock operation from [NETCONF] This scenario assumes that the global lock operation from [NETCONF]
is not used. is not used.
2.2. Dependencies 2.2. Dependencies
The device MUST support restricted XPath expressions in the select The device MUST support restricted XPath expressions in the select
element, as described in Section 2.4.1. Optionally, if the :xpath element, as described in Section 2.4.1. Optionally, if the :xpath
capability is also supported (as defined in [NETCONF] chapter 8.9. capability is also supported (as defined in [NETCONF], Section 8.9.
XPath Capability), the device MUST also support using any XPath 1.0 "XPath Capability"), the device MUST also support using any XPath 1.0
expression in the select element. expression in the select element.
2.3. Capability Identifier 2.3. Capability Identifier
urn:ietf:params:netconf:capability:partial-lock:1.0 urn:ietf:params:netconf:capability:partial-lock:1.0
2.4. New Operations 2.4. New Operations
2.4.1. <partial-lock> 2.4.1. <partial-lock>
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When a NETCONF session holds a lock on a node, no other session or When a NETCONF session holds a lock on a node, no other session or
non-NETCONF mechanism of the system can change that node or any node non-NETCONF mechanism of the system can change that node or any node
in the hierarchy of nodes beneath it. in the hierarchy of nodes beneath it.
Locking a node protects the node itself and the complete subtree Locking a node protects the node itself and the complete subtree
under the node from modification by others. The set of locked nodes under the node from modification by others. The set of locked nodes
is called the scope of the lock, while all the locked nodes and the is called the scope of the lock, while all the locked nodes and the
nodes in the subtrees under them make up the protected area. nodes in the subtrees under them make up the protected area.
The XPath expressions are evaluated only once at lock time. The XPath expressions are evaluated only once: at lock time.
Thereafter, the scope of the lock is maintained as a set of nodes, Thereafter, the scope of the lock is maintained as a set of nodes,
i.e. the returned nodeset, and not by the XPath expression. If the i.e., the returned nodeset, and not by the XPath expression. If the
configuration data is later altered in a way that would make the configuration data is later altered in a way that would make the
original XPath expressions evaluate to a different set of nodes, this original XPath expressions evaluate to a different set of nodes, this
does not affect the scope of the partial lock. does not affect the scope of the partial lock.
Let's say the agent's data model includes a list of interface nodes. Let's say the agent's data model includes a list of interface nodes.
If the XPath expression in the partial lock operation covers all If the XPath expression in the partial-lock operation covers all
interface nodes at locking, the scope of the lock will be maintained interface nodes at locking, the scope of the lock will be maintained
as the list of interface nodes at the time when the lock was granted. as the list of interface nodes at the time when the lock was granted.
If someone later creates a new interface, this new interface will not If someone later creates a new interface, this new interface will not
be included in the locked-nodes list created previously so the new be included in the locked-nodes list created previously so the new
interface will not be locked. interface will not be locked.
A <partial-lock> operation MUST be handled atomically by the NETCONF A <partial-lock> operation MUST be handled atomically by the NETCONF
server. The server either locks all requested parts of the datastore server. The server either locks all requested parts of the datastore
or none. If during the <partial-lock> operation one of the requested or none. If during the <partial-lock> operation one of the requested
parts cannot be locked, the server MUST unlock all parts that have parts cannot be locked, the server MUST unlock all parts that have
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the scope of the lock are deleted, the lock will still be present. the scope of the lock are deleted, the lock will still be present.
However, its scope will become empty (since the lock will not cover However, its scope will become empty (since the lock will not cover
any nodes). any nodes).
A NETCONF server that supports partial locking MUST be able to grant A NETCONF server that supports partial locking MUST be able to grant
multiple simultaneous partial locks to a single NETCONF session. If multiple simultaneous partial locks to a single NETCONF session. If
the protected area of the individual locks overlap, nodes in the the protected area of the individual locks overlap, nodes in the
common area MUST be protected until all of the overlapping locks are common area MUST be protected until all of the overlapping locks are
released. released.
A partial lock operation MUST fail if: A <partial-lock> operation MUST fail if:
o Any NETCONF session (including the current session) owns the o Any NETCONF session (including the current session) owns the
global lock on the running datastore. global lock on the running datastore.
o Any part of the area to be protected is already locked (or o Any part of the area to be protected is already locked (or
protected by partial locking) by another management session, protected by partial locking) by another management session,
including other NETCONF sessions using <partial-lock> or any other including other NETCONF sessions using <partial-lock> or any other
non-NETCONF management method. non-NETCONF management method.
o The requesting user is not successfully authenticated. o The requesting user is not successfully authenticated.
o The NETCONF server implements access control, and the locking user o The NETCONF server implements access control and the locking user
does not have sufficient access rights. The exact handling of does not have sufficient access rights. The exact handling of
access rights is outside the scope of this document, but it is access rights is outside the scope of this document, but it is
assumed that there is an access control system that MAY deny or assumed that there is an access control system that MAY deny or
allow the partial lock operation. allow the <partial-lock> operation.
The <partial-lock> operation is designed for simplicity, so when a The <partial-lock> operation is designed for simplicity, so when a
partial lock is executed you get what you asked for: a set of nodes partial lock is executed, you get what you asked for: a set of nodes
that are locked for writing. As a consequence users must observe the that are locked for writing.
following:
As a consequence, users must observe the following:
o Locking does not affect read operations. o Locking does not affect read operations.
o If part of the running datastore is locked, this has no effect on o If part of the running datastore is locked, this has no effect on
any unlocked parts of the datastore. If this is a problem (e.g., any unlocked parts of the datastore. If this is a problem (e.g.,
changes depend on data values or nodes outside the protected part changes depend on data values or nodes outside the protected part
of the datastore), these nodes SHOULD be included in the protected of the datastore), these nodes SHOULD be included in the protected
area of the lock. area of the lock.
o Configuration data can be edited both inside and outside the o Configuration data can be edited both inside and outside the
protected area of a lock. It is the responsibility of the NETCONF protected area of a lock. It is the responsibility of the NETCONF
client application to lock all relevant parts of the datastore client application to lock all relevant parts of the datastore
that are crucial for a specific management action. that are crucial for a specific management action.
Note: The <partial-lock> operation does not modify the global <lock> Note: The <partial-lock> operation does not modify the global <lock>
operation defined in the base NETCONF Protocol [NETCONF]. If part of operation defined in the base NETCONF protocol [NETCONF]. If part of
the running datastore is already locked by <partial-lock>, then a the running datastore is already locked by <partial-lock>, then a
global lock for the running datastore MUST fail even if the global global lock for the running datastore MUST fail even if the global
lock is requested by the NETCONF session that owns the partial lock. lock is requested by the NETCONF session that owns the partial lock.
2.4.1.1. Parameters, Result, Examples 2.4.1.1. Parameters, Results, Examples
Parameters: Parameters:
select: One or more 'select' elements, each containing an XPath select: One or more 'select' elements, each containing an XPath
expression. The XPath expression is evaluated in a context where expression. The XPath expression is evaluated in a context
the context node is the root of the server's conceptual data where the context node is the root of the server's
model, and the set of namespace declarations are those in scope conceptual data model, and the set of namespace declarations
on the select element. are those in scope on the select element.
The nodes returned from the select expressions are reported in The nodes returned from the select expressions are reported in the
the rpc-reply message. rpc-reply message.
Each select expression MUST return a node set, and at least one Each select expression MUST return a node set, and at least one of
of the node sets MUST be non-empty. the node sets MUST be non-empty.
If the device supports the :xpath capability, any valid XPath 1.0 If the device supports the :xpath capability, any valid XPath 1.0
expression can be used. If the device does not support the expression can be used. If the device does not support the
:xpath capability, the XPath expression MUST be limited to an :xpath capability, the XPath expression MUST be limited to an
Instance Identifier expression. An Instance Identifier is an Instance Identifier expression. An Instance Identifier is an
absolute path expression in abbreviated syntax, where predicates absolute path expression in abbreviated syntax, where predicates
are used only to specify values for nodes defined as keys to are used only to specify values for nodes defined as keys to
distinguish multiple instances. distinguish multiple instances.
Example: Lock virtual router 1 and interface eth1 Example: Lock virtual router 1 and interface eth1
<nc:rpc <nc:rpc
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message-id="135"> message-id="135">
<lock-id>127</lock-id> <lock-id>127</lock-id>
<locked-node xmlns:rte="http://example.com/ns/route"> <locked-node xmlns:rte="http://example.com/ns/route">
/rte:routing/rte:virtualRouter[rte:routerName='router1'] /rte:routing/rte:virtualRouter[rte:routerName='router1']
</locked-node> </locked-node>
<locked-node xmlns:if="http://example.com/ns/interface"> <locked-node xmlns:if="http://example.com/ns/interface">
/if:interfaces/if:interface[if:id='eth1'] /if:interfaces/if:interface[if:id='eth1']
</locked-node> </locked-node>
</nc:rpc-reply> </nc:rpc-reply>
Note: The XML Schema in [NETCONF] has a known bug which requires the Note: The XML Schema in [NETCONF] has a known bug that requires the
<data> XML element in a <rpc-reply>. This means that the above <data> XML element in a <rpc-reply>. This means that the above
examples will not validate using the XML Schema found in [NETCONF]. examples will not validate using the XML Schema found in [NETCONF].
Positive Response: Positive Response:
If the device was able to satisfy the request, an <rpc-reply> is sent If the device was able to satisfy the request, an <rpc-reply> is sent
with a <lock-id> element (lock identifier) in the <rpc-reply> with a <lock-id> element (lock identifier) in the <rpc-reply>
element. A list of locked nodes is also returned in Instance element. A list of locked nodes is also returned in Instance
Identifier format. Identifier format.
skipping to change at page 10, line 27 skipping to change at page 9, line 34
sessions to an unauthorized client. sessions to an unauthorized client.
If a lock is already held by another session on any node within the If a lock is already held by another session on any node within the
subtrees to be locked, the <error-tag> element is 'lock-denied' and subtrees to be locked, the <error-tag> element is 'lock-denied' and
the <error-info> element includes the <session-id> of the lock owner. the <error-info> element includes the <session-id> of the lock owner.
If the lock is held by a non-NETCONF session, a <session-id> of 0 If the lock is held by a non-NETCONF session, a <session-id> of 0
(zero) SHOULD be included. The same error response is returned if (zero) SHOULD be included. The same error response is returned if
the requesting session already holds the (global) lock for the the requesting session already holds the (global) lock for the
running datastore. running datastore.
If needed the returned session-id may be used to <kill-session> the If needed, the returned session-id may be used to <kill-session> the
NETCONF session holding the lock. NETCONF session holding the lock.
2.4.1.2. Deadlock Avoidance 2.4.1.2. Deadlock Avoidance
As with most locking systems, it is possible that two management As with most locking systems, it is possible that two management
sessions trying to lock different parts of the configuration could sessions trying to lock different parts of the configuration could
become dead-locked. To avoid this situation, clients SHOULD lock become deadlocked. To avoid this situation, clients SHOULD lock
everything they need in one operation. If locking fails, the client everything they need in one operation. If locking fails, the client
MUST back-off, release any previously acquired locks, and SHOULD MUST back-off, release any previously acquired locks, and SHOULD
retry the procedure after waiting some randomized time interval. retry the procedure after waiting some randomized time interval.
2.4.2. <partial-unlock> 2.4.2. <partial-unlock>
The operation unlocks the parts of the running datastore that were The operation unlocks the parts of the running datastore that were
previously locked using <partial-lock> during the same session. The previously locked using <partial-lock> during the same session. The
operation unlocks the parts that are covered by the lock identified operation unlocks the parts that are covered by the lock identified
by the lock-id parameter. In case of multiple potentially by the lock-id parameter. In case of multiple potentially
overlapping locks, only the lock identified by the lock-id is overlapping locks, only the lock identified by the lock-id is
removed. removed.
Parameters: Parameters:
lock-id: Identity of the lock to be unlocked. This lock-id MUST lock-id: Identity of the lock to be unlocked. This lock-id MUST
have been received as a response to a lock request by the manager have been received as a response to a lock request by the
during the current session, and MUST NOT have been sent in a manager during the current session, and MUST NOT have been
previous unlock request. sent in a previous unlock request.
Example: Unlock a previously created lock Example: Unlock a previously created lock
<nc:rpc xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0" <nc:rpc xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0"
xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0"
message-id="136"> message-id="136">
<partial-unlock> <partial-unlock>
<lock-id>127</lock-id> <lock-id>127</lock-id>
</partial-unlock> </partial-unlock>
</nc:rpc> </nc:rpc>
Positive Response: Positive Response:
If the device was able to satisfy the request, an <rpc-reply> is sent If the device was able to satisfy the request, an <rpc-reply> is sent
that contains an <ok> element. A positive response MUST be sent even that contains an <ok> element. A positive response MUST be sent even
if all of the locked parts of the datastore have already been if all of the locked parts of the datastore have already been
deleted. deleted.
Negative Response: Negative Response:
If the <lock-id> parameter does not identify a lock which is owned by If the <lock-id> parameter does not identify a lock that is owned by
the session, an 'invalid-value' error is returned. the session, an 'invalid-value' error is returned.
2.5. Modifications to Existing Operations 2.5. Modifications to Existing Operations
A successful partial lock will cause a subsequent operation to fail A successful partial lock will cause a subsequent operation to fail
if that operation attempts to modify nodes in the protected area of if that operation attempts to modify nodes in the protected area of
the lock and is executed in a NETCONF session other than the session the lock and is executed in a NETCONF session other than the session
that has been granted the lock. The <error-tag> 'in-use' and the that has been granted the lock. The <error-tag> 'in-use' and the
<error-app-tag> 'locked' is returned. All operations that modify the <error-app-tag> 'locked' is returned. All operations that modify the
running datastore are affected, including: <edit-config>, <copy- running datastore are affected, including: <edit-config>, <copy-
config>, <delete-config>, <commit> and <discard-changes>. If partial config>, <delete-config>, <commit>, and <discard-changes>. If
lock prevents <edit-config> modifying some data, but the operation partial lock prevents <edit-config> from modifying some data, but the
includes the continue-on-error option, modification of other parts of operation includes the continue-on-error option, modification of
the datastore, which are not protected by partial locking, might other parts of the datastore, which are not protected by partial
still succeed. locking, might still succeed.
If the datastore contains nodes locked by partial lock, this will If the datastore contains nodes locked by partial lock, this will
cause the (global) <lock> operation to fail. The <error-tag> element cause the (global) <lock> operation to fail. The <error-tag> element
'lock-denied' and an <error-info> element including the <session-id> 'lock-denied' and an <error-info> element including the <session-id>
of the lock owner will be returned. If the lock is held by a non- of the lock owner will be returned. If the lock is held by a non-
NETCONF session, a <session-id> of 0 (zero) is returned. NETCONF session, a <session-id> of 0 (zero) is returned.
All of these operations are affected only if they are targeting the All of these operations are affected only if they are targeting the
running datastore. running datastore.
2.6. Interactions with Other Capabilities 2.6. Interactions with Other Capabilities
2.6.1. Candidate Configuration Capability 2.6.1. Candidate Configuration Capability
The candidate datastore can not be locked using the <partial-lock> The candidate datastore cannot be locked using the <partial-lock>
operation. operation.
2.6.2. Confirmed Commit Capability 2.6.2. Confirmed Commit Capability
If: If:
o a partial lock is requested for the running datastore, and o a partial lock is requested for the running datastore, and
o the NETCONF server implements the :confirmed-commit capability, o the NETCONF server implements the :confirmed-commit capability,
and and
o there was a recent confirmed <commit> operation where the o there was a recent confirmed <commit> operation where the
confirming <commit> operation has not been received confirming <commit> operation has not been received
then the lock MUST be denied, because if the confirmation does not then the lock MUST be denied, because if the confirmation does not
arrive, the running datastore MUST be rolled back to its state before arrive, the running datastore MUST be rolled back to its state before
the commit. The NETCONF server might therefore need to modify the the commit. The NETCONF server might therefore need to modify the
configuration. configuration.
In this case the <error-tag> 'in-use' and the <error-app-tag>
In this case, the <error-tag> 'in-use' and the <error-app-tag>
'outstanding-confirmed-commit' is returned. 'outstanding-confirmed-commit' is returned.
2.6.3. Distinct Startup Capability 2.6.3. Distinct Startup Capability
The startup datastore can not be locked using the <partial-lock> The startup datastore cannot be locked using the <partial-lock>
operation. operation.
3. Security Considerations 3. Security Considerations
The same considerations are relevant as for the base NETCONF Protocol The same considerations are relevant as for the base NETCONF protocol
[NETCONF]. <partial-lock> and <partial-unlock> RPCs MUST only be [NETCONF]. <partial-lock> and <partial-unlock> RPCs MUST only be
allowed for an authenticated user. <partial-lock> and <partial- allowed for an authenticated user. <partial-lock> and <partial-
unlock> RPCs SHOULD only be allowed for an authorized user. However unlock> RPCs SHOULD only be allowed for an authorized user. However,
as NETCONF access control is not standardized and not a mandatory as NETCONF access control is not standardized and not a mandatory
part of a NETCONF implementation, it is strongly recommended, but part of a NETCONF implementation, it is strongly recommended, but
OPTIONAL. (although nearly all implementations include some kind of OPTIONAL (although nearly all implementations include some kind of
access control) access control).
A lock (either a partial lock or a global lock) might prevent other A lock (either a partial lock or a global lock) might prevent other
users from configuring the system. The following mechanisms are in users from configuring the system. The following mechanisms are in
place to prevent the misuse of this possibility: place to prevent the misuse of this possibility:
A user, that is not successfully authenticated, MUST NOT be A user, that is not successfully authenticated, MUST NOT be
granted a partial lock. granted a partial lock.
Only an authorized user SHOULD be able to request a partial lock. Only an authorized user SHOULD be able to request a partial lock.
The partial lock is automatically released when a session is The partial lock is automatically released when a session is
terminated regardless of how the session ends. terminated regardless of how the session ends.
The <kill-session> operation makes it possible to terminate other The <kill-session> operation makes it possible to terminate other
users's sessions. users' sessions.
The NETCONF server MAY log partial lock requests in an audit The NETCONF server MAY log partial lock requests in an audit
trail. trail.
A lock that is hung for some reason (e.g., a broken TCP connection A lock that is hung for some reason (e.g., a broken TCP connection
that the server has not yet recognised) can be released using another that the server has not yet recognized) can be released using another
NETCONF session by explicitly killing the session owning that lock NETCONF session by explicitly killing the session owning that lock
using the <kill-session> operation. using the <kill-session> operation.
Partial locking is not an authorization mechanism; it SHOULD NOT be Partial locking is not an authorization mechanism; it SHOULD NOT be
used to provide security or access control. Partial locking SHOULD used to provide security or access control. Partial locking SHOULD
only be used as a mechanism for providing consistency when multiple only be used as a mechanism for providing consistency when multiple
managers are trying to configure the node. It is vital that users managers are trying to configure the node. It is vital that users
easily understand the exact scope of a lock. This is why the scope easily understand the exact scope of a lock. This is why the scope
is determined when granting a lock and is not modified thereafter. is determined when granting a lock and is not modified thereafter.
4. IANA Considerations 4. IANA Considerations
This document registers one capability identifier URN from the This document registers one capability identifier URN from the
"Network Configuration Protocol (NETCONF) Capability URNs" registry, "Network Configuration Protocol (NETCONF) Capability URNs" registry,
and one URI for the NETCONF XML namespace in the "IETF XML registry" and one URI for the NETCONF XML namespace in the "IETF XML registry"
[RFC3688]. Note that the capability URN is compliant to [NETCONF] [RFC3688]. Note that the capability URN is compliant to [NETCONF],
section 10.3. Section 10.3.
Index Capability Identifier
------------- ---------------------------------------------------
:partial-lock urn:ietf:params:netconf:capability:partial-lock:1.0
+---------------+---------------------------------------------------+
| Index | Capability Identifier |
+---------------+---------------------------------------------------+
| :partial-lock | urn:ietf:params:netconf:capability:partial-lock:1 |
| | .0 |
+---------------+---------------------------------------------------+
URI: urn:ietf:params:xml:ns:netconf:partial-lock:1.0 URI: urn:ietf:params:xml:ns:netconf:partial-lock:1.0
Registrant Contact: The IESG. Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace. XML: N/A, the requested URI is an XML namespace.
5. Appendix A - XML Schema for Partial Locking (normative) 5. Acknowledgements
Thanks to Andy Bierman, Sharon Chisholm, Phil Shafer, David
Harrington, Mehmet Ersue, Wes Hardaker, Juergen Schoenwaelder, Washam
Fan, and many other members of the NETCONF WG for providing important
input to this document.
6. References
6.1. Normative References
[NETCONF] Enns, R., "NETCONF Configuration Protocol", RFC 4741,
December 2006.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
6.2. Informative References
[YANG] Bjorklund, M., "YANG - A data modeling language for
NETCONF", Work in Progress, December 2009.
Appendix A. XML Schema for Partial Locking (Normative)
The following XML Schema defines the <partial-lock> and <partial- The following XML Schema defines the <partial-lock> and <partial-
unlock> operations: unlock> operations:
-- RFC Ed.: Insert license information for code as appropriate
<CODE BEGINS> <CODE BEGINS>
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0" xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0"
xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0"
targetNamespace="urn:ietf:params:xml:ns:netconf:partial-lock:1.0" targetNamespace="urn:ietf:params:xml:ns:netconf:partial-lock:1.0"
elementFormDefault="qualified" attributeFormDefault="unqualified"> elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:annotation> <xs:annotation>
<xs:documentation> <xs:documentation>
Schema defining the partial-lock and unlock operations. Schema defining the partial-lock and unlock operations.
organization "IETF NETCONF Working Group" organization "IETF NETCONF Working Group"
contact contact
Netconf Working Group Netconf Working Group
Mailing list: netconf@ietf.org Mailing list: netconf@ietf.org
Web: http://www.ietf.org/html.charters/netconf-charter.html Web: http://www.ietf.org/html.charters/netconf-charter.html
Balazs Lengyel Balazs Lengyel
balazs.lengyel@ericsson.com" balazs.lengyel@ericsson.com
revision 2009-10-19 revision 2009-10-19
description Initial version, published as RFC yyyy. description Initial version, published as RFC 5717.
-- RFC Ed.: replace yyyy with actual RFC number and remove this note. </xs:documentation>
</xs:documentation> </xs:annotation>
</xs:annotation>
<xs:import namespace="urn:ietf:params:xml:ns:netconf:base:1.0" <xs:import namespace="urn:ietf:params:xml:ns:netconf:base:1.0"
schemaLocation="urn:ietf:params:xml:ns:netconf:base:1.0"/> schemaLocation="urn:ietf:params:xml:ns:netconf:base:1.0"/>
<xs:simpleType name="lock-id-type"> <xs:simpleType name="lock-id-type">
<xs:annotation> <xs:annotation>
<xs:documentation> <xs:documentation>
A number identifying a specific A number identifying a specific
partial-lock granted to a session. partial-lock granted to a session.
It is allocated by the system, and SHOULD It is allocated by the system, and SHOULD
be used in the unlock operation. be used in the unlock operation.
</xs:documentation> </xs:documentation>
</xs:annotation> </xs:annotation>
<xs:restriction base="xs:unsignedInt"/> <xs:restriction base="xs:unsignedInt"/>
</xs:simpleType> </xs:simpleType>
<xs:complexType name="partialLockType"> <xs:complexType name="partialLockType">
<xs:annotation> <xs:annotation>
<xs:documentation> <xs:documentation>
A NETCONF operation that locks parts of A NETCONF operation that locks parts of
the running datastore. the running datastore.
</xs:documentation> </xs:documentation>
</xs:annotation> </xs:annotation>
<xs:complexContent> <xs:complexContent>
<xs:extension base="nc:rpcOperationType"> <xs:extension base="nc:rpcOperationType">
<xs:sequence> <xs:sequence>
<xs:element name="select" type="xs:string" <xs:element name="select" type="xs:string"
maxOccurs="unbounded"> maxOccurs="unbounded">
<xs:annotation> <xs:annotation>
<xs:documentation> <xs:documentation>
XPath expression that specifies the scope XPath expression that specifies the scope
of the lock. An Instance Identifier of the lock. An Instance Identifier
expression must be used unless the :xpath expression must be used unless the :xpath
capability is supported in which case any capability is supported in which case any
XPath 1.0 expression is allowed. XPath 1.0 expression is allowed.
</xs:documentation> </xs:documentation>
</xs:annotation> </xs:annotation>
</xs:element> </xs:element>
</xs:sequence> </xs:sequence>
</xs:extension> </xs:extension>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
<xs:complexType name="partialUnLockType"> <xs:complexType name="partialUnLockType">
<xs:annotation> <xs:annotation>
<xs:documentation> <xs:documentation>
A NETCONF operation that releases a previously acquired A NETCONF operation that releases a previously acquired
partial-lock. partial-lock.
</xs:documentation> </xs:documentation>
</xs:annotation> </xs:annotation>
<xs:complexContent> <xs:complexContent>
<xs:extension base="nc:rpcOperationType"> <xs:extension base="nc:rpcOperationType">
<xs:sequence> <xs:sequence>
<xs:element name="lock-id" type="lock-id-type"> <xs:element name="lock-id" type="lock-id-type">
<xs:annotation> <xs:annotation>
<xs:documentation> <xs:documentation>
Identifies the lock to be released. MUST Identifies the lock to be released. MUST
be the value received in the response to be the value received in the response to
the partial-lock operation. the partial-lock operation.
</xs:documentation> </xs:documentation>
</xs:annotation> </xs:annotation>
</xs:element> </xs:element>
</xs:sequence> </xs:sequence>
</xs:extension> </xs:extension>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
<!-- <partial-lock> operation --> <!-- <partial-lock> operation -->
<xs:element name="partial-lock" type="partialLockType" <xs:element name="partial-lock" type="partialLockType"
substitutionGroup="nc:rpcOperation"/> substitutionGroup="nc:rpcOperation"/>
<!-- <partial-unlock> operation --> <!-- <partial-unlock> operation -->
<xs:element name="partial-unlock" type="partialUnLockType" <xs:element name="partial-unlock" type="partialUnLockType"
substitutionGroup="nc:rpcOperation"/> substitutionGroup="nc:rpcOperation"/>
<!-- reply to <partial-lock> --> <!-- reply to <partial-lock> -->
<xs:complexType name="contentPartInPartialLockReplyType"> <xs:complexType name="contentPartInPartialLockReplyType">
<xs:annotation> <xs:annotation>
<xs:documentation> <xs:documentation>
The content of the reply to a successful The content of the reply to a successful
partial-lock request MUST conform to this complex type. partial-lock request MUST conform to this complex type.
</xs:documentation> </xs:documentation>
</xs:annotation> </xs:annotation>
<xs:sequence> <xs:sequence>
<xs:element name="lock-id" type="lock-id-type"> <xs:element name="lock-id" type="lock-id-type">
<xs:annotation> <xs:annotation>
<xs:documentation> <xs:documentation>
Identifies the lock to be released. Must be the value Identifies the lock to be released. Must be the value
received in the response to a partial-lock operation. received in the response to a partial-lock operation.
</xs:documentation> </xs:documentation>
</xs:annotation> </xs:annotation>
</xs:element> </xs:element>
<xs:element name="locked-node" type="xs:string" <xs:element name="locked-node" type="xs:string"
maxOccurs="unbounded"> maxOccurs="unbounded">
<xs:annotation> <xs:annotation>
<xs:documentation> <xs:documentation>
List of locked nodes in the running datastore. List of locked nodes in the running datastore.
</xs:documentation> </xs:documentation>
</xs:annotation> </xs:annotation>
</xs:element> </xs:element>
</xs:sequence> </xs:sequence>
</xs:complexType> </xs:complexType>
</xs:schema> </xs:schema>
<CODE ENDS> <CODE ENDS>
6. Appendix B - YANG Module for Partial Locking (non-normative) Appendix B. YANG Module for Partial Locking (Non-Normative)
The following YANG module defines the <partial-lock> and <partial- The following YANG module defines the <partial-lock> and <partial-
unlock> operations. The YANG language is defined in unlock> operations. The YANG language is defined in [YANG].
[I-D.ietf-netmod-yang].
-- RFC Ed.: Insert license information for code as appropriate
<CODE BEGINS> <CODE BEGINS>
module ietf-netconf-partial-lock { module ietf-netconf-partial-lock {
namespace urn:ietf:params:xml:ns:netconf:partial-lock:1.0; namespace urn:ietf:params:xml:ns:netconf:partial-lock:1.0;
prefix pl; prefix pl;
organization "IETF Network Configuration (netconf) Working Group"; organization "IETF Network Configuration (netconf) Working Group";
contact contact
skipping to change at page 18, line 36 skipping to change at page 17, line 34
Balazs Lengyel Balazs Lengyel
Ericsson Ericsson
balazs.lengyel@ericsson.com"; balazs.lengyel@ericsson.com";
description description
"This YANG module defines the <partial-lock> and "This YANG module defines the <partial-lock> and
<partial-unlock> operations."; <partial-unlock> operations.";
revision 2009-10-19 { revision 2009-10-19 {
description description
"Initial version, published as RFC yyyy."; "Initial version, published as RFC 5717.";
// RFC Ed.: replace yyyy with actual RFC number & remove this note.
} }
typedef lock-id-type { typedef lock-id-type {
type uint32; type uint32;
description description
"A number identifying a specific partial-lock granted to a session. "A number identifying a specific partial-lock granted to a session.
It is allocated by the system, and SHOULD be used in the It is allocated by the system, and SHOULD be used in the
partial-unlock operation."; partial-unlock operation.";
} }
skipping to change at page 19, line 17 skipping to change at page 18, line 14
"XPath expression that specifies the scope of the lock. "XPath expression that specifies the scope of the lock.
An Instance Identifier expression MUST be used unless the An Instance Identifier expression MUST be used unless the
:xpath capability is supported, in which case any XPath 1.0 :xpath capability is supported, in which case any XPath 1.0
expression is allowed."; expression is allowed.";
} }
} }
output { output {
leaf lock-id { leaf lock-id {
type lock-id-type; type lock-id-type;
description description
"Identifies the lock, if granted. The lock-id SHOULD be "Identifies the lock, if granted. The lock-id SHOULD be
used in the partial-unlock rpc."; used in the partial-unlock rpc.";
} }
leaf-list locked-node { leaf-list locked-node {
type instance-identifier; type instance-identifier;
min-elements 1; min-elements 1;
description description
"List of locked nodes in the running datastore"; "List of locked nodes in the running datastore";
} }
} }
} }
rpc partial-unlock { rpc partial-unlock {
description description
"A NETCONF operation that releases a previously acquired "A NETCONF operation that releases a previously acquired
partial-lock."; partial-lock.";
input { input {
leaf lock-id { leaf lock-id {
type lock-id-type; type lock-id-type;
description description
"Identifies the lock to be released. MUST be the value "Identifies the lock to be released. MUST be the value
received in the response to a partial-lock operation."; received in the response to a partial-lock operation.";
} }
} }
} }
} }
<CODE ENDS> <CODE ENDS>
7. Appendix C - Usage Example - Reserving nodes for future editing Appendix C. Usage Example - Reserving Nodes for Future Editing
(non-normative) (Non-Normative)
Partial lock cannot be used to lock non-existent nodes, which would Partial lock cannot be used to lock non-existent nodes, which would
effectively attempt to reserve them for future use. To guarantee effectively attempt to reserve them for future use. To guarantee
that a node cannot be created by some other session, the parent node that a node cannot be created by some other session, the parent node
should be locked, the top level node of the new subtree created, and should be locked, the top-level node of the new subtree created, and
then locked with another <partial-lock> operation. After this, the then locked with another <partial-lock> operation. After this, the
lock on the parent node should be removed. lock on the parent node should be removed.
In this chapter an example illustrating the above is given. In this section, an example illustrating the above is given.
We want to create <user> Joe under <users>, and start editing it. We want to create <user> Joe under <users>, and start editing it.
Editing might take a number of minutes. We want to immediately lock Editing might take a number of minutes. We want to immediately lock
Joe so no one will touch it before we are finished with the editing. Joe so no one will touch it before we are finished with the editing.
We also want to minimize locking other parts of the running datastore We also want to minimize locking other parts of the running datastore
as multiple managers might be adding users near simultaneously. as multiple managers might be adding users near simultaneously.
First we check what users are already defined. First, we check what users are already defined.
Step 1 - Read existing users Step 1 - Read existing users
<rpc message-id="101" <rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get-config> <get-config>
<source> <source>
<running/> <running/>
</source> </source>
<filter type="subtree"> <filter type="subtree">
skipping to change at page 21, line 21 skipping to change at page 20, line 21
<users> <users>
<user> <user>
<name>fred</name> <name>fred</name>
<phone>8327</phone> <phone>8327</phone>
</user> </user>
</users> </users>
</top> </top>
</data> </data>
</rpc-reply> </rpc-reply>
We want to add the new user "Joe" and immediately lock him using We want to add the new user Joe and immediately lock him using
partial locking. The way to do this, is to first lock all <user> partial locking. The way to do this, is to first lock all <user>
nodes by locking the <users> node. nodes by locking the <users> node.
Note that if we would lock all the <user> nodes using the select Note that if we would lock all the <user> nodes using the select
expression '/usr:top/usr:users/usr:user' ; this would not lock the expression '/usr:top/usr:users/usr:user'; this would not lock the new
new user "Joe", which we will create after locking. So we rather user Joe, which we will create after locking. So we rather have to
have to lock the <users> node. lock the <users> node.
Step 3 - Lock users Step 3 - Lock users
<nc:rpc <nc:rpc
xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0"
xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0" xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0"
message-id="102"> message-id="102">
<partial-lock> <partial-lock>
<select xmlns:usr="http://example.com/users"> <select xmlns:usr="http://example.com/users">
/usr:top/usr:users /usr:top/usr:users
skipping to change at page 22, line 17 skipping to change at page 21, line 17
<nc:rpc-reply <nc:rpc-reply
xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0"
xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0" xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0"
message-id="102"> message-id="102">
<lock-id>1</lock-id> <lock-id>1</lock-id>
<locked-node xmlns:usr="http://example.com/users"> <locked-node xmlns:usr="http://example.com/users">
/usr:top/usr:users /usr:top/usr:users
</locked-node> </locked-node>
</nc:rpc-reply> </nc:rpc-reply>
Next we create user Joe. Joe is protected by the lock received above, Next we create user Joe. Joe is protected by the lock received
as it is under the sub-tree rooted at the <users> node. above, as it is under the subtree rooted at the <users> node.
Step 5 - Create user Joe Step 5 - Create user Joe
<rpc message-id="103" <rpc message-id="103"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-config> <edit-config>
<target> <target>
<running/> <running/>
</target> </target>
<config> <config>
skipping to change at page 23, line 19 skipping to change at page 22, line 19
xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0" xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0"
message-id="104"> message-id="104">
<partial-lock> <partial-lock>
<select xmlns:usr="http://example.com/users"> <select xmlns:usr="http://example.com/users">
/usr:top/usr:users/user[usr:name="Joe"]" /usr:top/usr:users/user[usr:name="Joe"]"
</select> </select>
</partial-lock> </partial-lock>
</nc:rpc> </nc:rpc>
The NETCONF server grants the partial lock. The scope of this second The NETCONF server grants the partial lock. The scope of this second
lock includes only the <user> node with name Joe. The lock protects lock includes only the <user> node with name Joe. The lock protects
all data below this particular <user> node. all data below this particular <user> node.
Step 7 - Receive lock Step 7 - Receive lock
<nc:rpc-reply <nc:rpc-reply
xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0"
xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0" xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0"
message-id="104"> message-id="104">
<lock-id>2</lock-id> <lock-id>2</lock-id>
<locked-node xmlns:usr="http://example.com/users"> <locked-node xmlns:usr="http://example.com/users">
/usr:top/usr:users/user[usr:name="Joe"]" /usr:top/usr:users/user[usr:name="Joe"]"
</locked-node> </locked-node>
</nc:rpc-reply> </nc:rpc-reply>
The scope of the second lock is the <user> node Joe. It protects this The scope of the second lock is the <user> node Joe. It protects
<user> node and any data below it (e.g. phone number). At this point this <user> node and any data below it (e.g., phone number). At this
of time these nodes are protected both by the first and second lock. point of time, these nodes are protected both by the first and second
Next we unlock the other <user>s and the <users> node, to allow other lock. Next, we unlock the other <user>s and the <users> node, to
managers to work on them. We still keep the second lock, so the allow other managers to work on them. We still keep the second lock,
<user> node Joe and the sub-tree below is still protected. so the <user> node Joe and the subtree below is still protected.
Step 8 - Release lock on <users> Step 8 - Release lock on <users>
<nc:rpc xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0" <nc:rpc xmlns="urn:ietf:params:xml:ns:netconf:partial-lock:1.0"
xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0"
message-id="105"> message-id="105">
<partial-unlock> <partial-unlock>
<lock-id>1</lock-id> <lock-id>1</lock-id>
</partial-unlock> </partial-unlock>
</nc:rpc> </nc:rpc>
8. Appendix D - Change Log
8.1. 10-11
Minor clarifications
8.2. 09-10
Clarifications
Only the running datastore can be locked
8.3. 08-09
Clarifications
8.4. 07-08
Clarifications
8.5. 06-07
Changed XSD and YANG to allow additional proprietary datastores to be
locked.
8.6. 05-06
Added usage example
Clarified error messages
Clarified interaction with edit-config continue-on-error
Improved YANG: indentation, canonical order, contact info
Added usage example in appendix C
Synchronized YANG and XSD
8.7. 04-05
Language and editorial updates
all app-tags are with dashes without spaces
Added usage scenarios
Changed encoding
Clarified definitions, separated scope of lock and protected area
8.8. 03-04
Minor clarifications
Added list of locked-nodes to the output of partial-lock.
Added <target> wrapper around datastore names.
Allowed atomic/one operation locking of datastore parts in multiple
datastores.
Improved English (hopefully)
Removed the <data> element from rpc-reply following the text of
rfc4741.
8.9. 02-03
Minor clarifications
Same descriptions in XSD and YANG.
8.10. 01-02
Made XSD normative
Clarified that no specific access control is assumed.
Clarified that non-existing nodes are NOT covered by the lock, even
if they where existing and covered by the lock when it was originally
granted.
Some rewording
Added app-tags for two of the error cases.
Made YANG an informative reference
Enhanced security considerations.
8.11. 00-01
Added YANG module.
8.12. -00
Created from draft-lengyel-ngo-partial-lock-01.txt
9. Acknowledgements
Thanks to Andy Bierman, Sharon Chisholm, Phil Shafer , David
Harrington, Mehmet Ersue, Wes Hardaker, Juergen Schoenwaelder, Washam
Fan and many other members of the NETCONF WG for providing important
input to this document.
10. References
10.1. Normative References
[NETCONF] Enns, R., "NETCONF Configuration Protocol", RFC 4741,
December 2006.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
10.2. Informative References
[I-D.ietf-netmod-yang]
Bjorklund, M., "YANG - A data modeling language for
NETCONF", draft-ietf-netmod-yang-07 (work in progress),
July 2009.
Authors' Addresses Authors' Addresses
Balazs Lengyel Balazs Lengyel
Ericsson Ericsson
Email: balazs.lengyel@ericsson.com EMail: balazs.lengyel@ericsson.com
Martin Bjorklund Martin Bjorklund
Tail-f Systems Tail-f Systems
Email: mbj@tail-f.com EMail: mbj@tail-f.com
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