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389_Directory_Server_3.0.0

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:


Current status

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 deprecated since Fedora 33, this change is about to create instances with LMDB by default.


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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.

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 389 Directory Server FAQ - BerkeleyDB backend deprecation

How To Test

COPR project contains builds that can be tested (F37, F38, F39, rawhide on x86_64 and s390x).

So you can install them by using: 

sudo dnf copr enable -y @389ds/389-ds-base-freeipa-tests
sudo dnf install 389-ds-base-3.0.0

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

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_linking_executables). 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

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.

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