12:10 p.m.
Wiki: https://fedoraproject.org/wiki/Changes/389_Directory_Server_3.0.0
This is a proposed Change for Fedora Linux.
This document represents a proposed Change. As part of the Changes
process, proposals are publicly announced in order to receive
community feedback. This proposal will only be implemented if approved
by the Fedora Engineering Steering Committee.
== Summary ==
389-ds-base upgrade from version 2.4.4 to the latest upstream version
3.0.0 in Fedora.
Newly created instances now are using LDMB database by default instead
of BerkeleyDB.
== Owner ==
* Name: 389 Directory Server Development Team
* Email: 389-devel (at) lists (dot) fedoraproject (dot) org
Primary contact:
* Name: [[User:progier| Pierre Rogier]]
* Email: progier (at) redhat (dot) com
== Detailed Description ==
Since Fedora 36 (389-ds-base 2.1.0), the 389 Directory Server supports
two kinds of underlying database:
* Berkeley Database (BDB)
* Lightning Memory-Mapped Database Manager (LMDB)
Newly created instances are still created with BDB by default while
libdb is flagged as [[Changes/Libdb deprecated - Fedora Project
Wiki|deprecated since Fedora 33]], this change is about to create
instances with LMDB by default.
== Feedback ==
No feedback yet.
== Benefit to Fedora ==
A step on the way to remove a deprecated piece of software no longer
supported by the upstream community.
(See https://fedoraproject.org/wiki/Changes/Libdb_deprecated)
== Scope ==
The change is quite limited in terms of development and interface
impact, but it impacts a critical component: FreeIPA.
[1] Impact on software that uses generic LDAP interface without any
specific 389DS features (like configuration tools and monitoring
entries):
No interface impact, but there may be some impact in terms of dynamic
(i.e: response time, maximum throughput). Especially if browsing (i.e
VLV) indexes are used on big lists.
[2] Impact on software that explicitly creates 389DS instances (like
FreeIPA) may also have to change the way the database is tuned.
(Especially the database maximum size: `nsslapd-mdb-max-size`)
[3] Impact on software that explicitly uses backend monitoring LDAP
entries: new attributes about LMDB specific data are present.
There are no packages in [3] case and FreeIPA is the only one in [2]
case but there is likely an unknown number of software in [1] case
that use the LDAP interface without needing a specific LDAP server.
So, in summary, the main risk is to see some regression in tests.
* Proposal owners:
Development impact:
- Change of a default value of one parameter of the instance creation
utility (`dscreate`)
- Provide a better visibility of that parameter in configuration tools
(`dscreate` and `dsconf`)
The above changes have already been done to be able to build the test
packages, so the remaining work is to merge the commit in the upstream
branch and rebase it to rawhide.
The larger impact is to determine if there are any regressions while
running 389DS and FreeIPA tests and fix them (with the help of the
FreeIPA team).
* Other developers:
The FreeIPA team is involved to help us diagnose any potential FreeIPA
test regressions.
Other QA teams may also be involved to test that there are no regressions.
* Release engineering: N/A (not needed for this Change): No strong
coordination is needed as only a single group of package is directly
impacted.
* Policies and guidelines: N/A (not needed for this Change)
* Trademark approval: N/A (not needed for this Change)
* Alignment with Community Initiatives:
== Upgrade/compatibility impact ==
No impact on upgrade because existing instances still use the
previously installed backend interface.
There should not be any compatibility issues (bugs excepted) with the
LDAP requests, but performance may be impacted.
There may be issues with applications that explicitly:
* Configure 389 Directory Server instances (like FreeIPA) because the
set of configuration attributes for the backend depends on the
underlying database implementation.
The unused parameters are ignored, so it should not impact the compatibility.
But there is a risk with the new parameters: the "20 GB" default value
for the LMDB database maximum size may not be large enough for the
application's needs.
* Monitor 389 Directory Server backends because the set of attributes
in the monitoring entries also depends on the underlying database
implementation.
More details about these points are described in
[https://www.port389.org/docs/389ds/FAQ/Berkeley-DB-deprecation.html
389 Directory Server FAQ - BerkeleyDB backend deprecation]
== How To Test ==
[https://copr.fedorainfracloud.org/coprs/g/389ds/389-ds-base-freeipa-tests/
COPR project] contains builds that can be tested (F37, F38, F39,
rawhide on x86_64 and s390x).
So you can install them by using:
<pre>
sudo dnf copr enable -y @389ds/389-ds-base-freeipa-tests
sudo dnf install 389-ds-base-3.0.0
</pre>
Then you can create new directory server instances and use them.
== User Experience ==
Prepare for the removal of an obsolete piece of software that is no
longer supported by the upstream community. This process aims to
provide more visibility to its replacement.
== Dependencies ==
All the dependent packages are owned by 389DS and FreeIPA teams:
`dnf repoquery --whatrequires 389-ds-base --recursive`
{| class="wikitable"
|+
|-
! Package !! Owner !! Tests
|-
| 389-ds-base-snmp || 389DS || Tested by 389DS CI test
|-
| cockpit-389-ds || 389DS || Tested by 389DS CI test
|-
| freeipa-fas || FreeIPA || Tested by FreeIPA CI test
|-
| freeipa-healthcheck || FreeIPA || Tested by FreeIPA CI test
|-
| freeipa-server || FreeIPA || Tested by FreeIPA CI test
|-
| freeipa-server-dns || FreeIPA || Tested by FreeIPA CI test
|-
| freeipa-server-trust-ad || FreeIPA || Tested by FreeIPA CI test
|-
| migrationtools || 389DS || Not impacted by the change
|-
| slapi-nis || FreeIPA || Tested by FreeIPA CI test
|}
== Contingency Plan ==
* Contingency mechanism:
* Revert the default backend implementation to Berkeley Database
* If libdb-5.3 or libdb-devel is no longer shipped in Fedora:
The plan is to build libdb static library as part of 389-ds-base build
process and link libback-ldbm statically with it
(as described in
https://docs.fedoraproject.org/en-US/packaging-guidelines/#_statically_li...).
The risk is that we may have to generate patches in case of CVE that
impacts 389-ds or in case of build environment changes until we can
remove the support of the bdb backend. libdb-5.3.28-55.fc38.src shows
that the risk is quite limited (1 cve and one set of patches related
to c99 since 2017).
* Contingency deadline: Fedora 40 beta freeze (2024-02-20)
* Blocks release? No
== Documentation ==
[https://www.port389.org/docs/389ds/FAQ/Berkeley-DB-deprecation.html
Directory Server FAQ - BerkeleyDB backend deprecation]
== Release Notes ==
Need to write release notes for 3.0.0 in
https://www.port389.org/docs/389ds/releases/release-notes.html as
usual for 389DS.
--
Aoife Moloney
Fedora Operations Architect
Fedora Project
Matrix: @amoloney:fedora.im
IRC: amoloney