---
title: changeNumber
description: The set of changes made to a directory server is given by the set of all entries in the changelog, ordered by changeNumber, which strictly increases for a given server.
component: pingds
version: 8.1
page_id: pingds:schemaref:at-changeNumber
canonical_url: https://docs.pingidentity.com/pingds/8.1/schemaref/at-changeNumber.html
---

# changeNumber

The set of changes made to a directory server is given by the set of all entries in the changelog, ordered by `changeNumber`, which strictly increases for a given server.

**Note** The `changeNumber` is unique to a server, and not necessarily shared or synchronized across servers. The change numbers for ForgeRock servers can be synchronized using the `dsrepl reset-change-number` command. ForgeRock servers also provide an alternative `changeLogCookie` attribute, which can be used reliably across a replicated topology.

A client application may synchronize its local copy of directory data by reading the server's changelog for entries where the `changeNumber` is greater than or equal to the last change that the client read from the server. A server can, however, trim its changelog. If the last change read from the changelog is not returned in search results, the client application must fall back to rebuilding its entire copy of directory data.

|                             |                                                                                              |
| --------------------------- | -------------------------------------------------------------------------------------------- |
| *OID*                       | 2.16.840.1.113730.3.1.5                                                                      |
| *Names*                     | changeNumber                                                                                 |
| *Description*               | a number which uniquely identifies a change made to a directory entry                        |
| *Syntax*                    | [Integer](s-Integer.html)                                                                    |
| *Equality matching rule*    | [integerMatch](mr-integerMatch.html)                                                         |
| *Ordering matching rule*    | [integerOrderingMatch](mr-integerOrderingMatch.html)                                         |
| *Substring matching rule*   | [caseExactSubstringsMatch](mr-caseExactSubstringsMatch.html)                                 |
| *Single value*              | true                                                                                         |
| *User modification allowed* | true                                                                                         |
| *Usage*                     | userApplications                                                                             |
| *Origin*                    | [draft-good-ldap-changelog](https://datatracker.ietf.org/doc/html/draft-good-ldap-changelog) |
| *Schema file*               | 03-changelog.ldif                                                                            |
| *Used by*                   | [changeLogEntry](oc-changeLogEntry.html)                                                     |