Symas OpenLDAP Knowledge Base

Release Maintenance Policy


The OpenLDAP Project recently adopted a new release strategy that is more friendly to the needs of the communities that are using its software. The new strategy provides for both a stable long-term release and for a series of shorter-term releases that add new features at the expense of more frequent and sometimes disruptive upgrades.


The OpenLDAP Project has adopted a two-stream release model consisting of a Long Term Support (LTS) release and multiple Feature Releases. To start, OpenLDAP 2.5 will serve as a stable long term base and OpenLDAP 2.6 and later releases will build on that with new features. This means a change to the Project’s single-stream model in which only the current release and one previous release are supported. Instead, the Project will support the current LTS Release and the current Feature Release with some limited overlaps. This allows users to choose whether they want rock-solid set-it-forget-it stability with only patch fixes or to stay at the head of the feature stream in a supported release. Periodically the Project will promote a Feature Release to an LTS Release and the cycle will start all over again.

The Project will continue to use the major.minor.patch release number format.

LTS Releases

The LTS release stream is intended for deployments that prioritize stability over features. A particular LTS release stream is identified by a specific major and a minor release number (e.g., 2.5) and starts at some non-zero patch number, reflecting the point at which the Project deems it ready to serve in an LTS capacity. The patch number increments monotonically with each patch release to indicate the sequence number of the release within that LTS release stream. Patch releases occur approximately four times a year and are restricted to stability, operation, and security fixes. A given LTS release stream is expected to have a life span of approximately five years. When the current LTS release is approximately three years old, the Project will name the new LTS release and will start a two-year end-of-life countdown for the current LTS release. During this period, the Project will fix defects in both LTS releases, but may only apply the most critical patches to the LTS release that is in its end of life stage. Users are encouraged to develop a plan that will help them upgrade quickly to the new LTS release so that they remain on a supported release.

A few other details about LTS releases:

  • Replication WILL work between patch releases of the same LTS release stream. It SHOULD work with releases in other LTS or feature release streams.
  • Databases and configuration files will be usable in binary form with new patch releases without modification, but do not need to be compatible with older patch releases.
  • LTS releases are feature-frozen. If a user needs to use a feature not in an LTS release they’ll need to migrate from the LTS release stream to the feature release stream, accepting the terms of support for the release stream.

Feature Releases

The Feature Release stream is intended for deployments that need to stay abreast of feature and performance enhancements and can tolerate potentially disruptive upgrade cycles every twelve to eighteen months. A feature release is designated by an incremented minor release number (e.g., 2.6 changes to 2.7) and is the primary avenue by which new features are introduced to the supported OpenLDAP release stream. As with LTS releases, the patch number indicates the sequence number within the particular feature release (e.g., 2.7.1, 2.7.2, etc). The Project will apply fixes to the next patch release (e.g., 2.7.3) OR to the next feature release (e.g., 2.8.0), depending on the timing of the Feature Release. Additionally, the Project will apply bug fixes to the current LTS release as appropriate. There will be a brief period during which patches will be applied to both the outgoing and incoming feature releases to allow users to upgrade their deployments.

A few other details about Feature Releases:

  • Replication between various feature releases and LTS releases SHOULD work, but is not required.
  • Database and configuration files SHOULD remain usable in unmodified forms with new feature releases, but it’s not required.
  • The feature release stream will add features and improve performance more frequently than will the LTS release stream. While it will be supported and defects corrected as they come up, the rules are significantly different and users following this stream should be ready to invest more effort in staying current.
  • Bug fixes are ported to the current LTS release as deemed appropriate.

The Project will produce feature releases at a rate of approximately one every twelve to eighteen months. These releases gather new features developed over the course of the year into a single supported release. Periodically the Project will designate a Feature Release as the new LTS release, and provide a two-year support overlap of the two LTS releases. During the last year of support for the earlier LTS release, only critical bugs will be fixed.

The Project has designated OpenLDAP 2.5 as the first LTS release and OpenLDAP 2.6 as the first feature release. This feature release will be followed in about a year by the next feature release, OpenLDAP 2.7.

Updates to the website (download page, etc) corresponding to the new policy have not yet been made but will be coming shortly. This policy supersedes the old policy described in…

– Howard Chu CTO, Symas Corp. Director, Highland Sun Chief Architect, OpenLDAP