Symas OpenLDAP; Directory Services
Frequently Asked Questions (FAQ)
List of Questions (Click on the "Q" to jump to the answers)
- Q: What is Symas OpenLDAP Directory Services?
- Q: Is the Subscription a License?
- Q: Is Symas OpenLDAP Open Source?
- Q: Isn't Open Source Free?
- Q: Do you have a free version of Symas OpenLDAP?
- Q: We want a Directory Entry for every <insert object here> on the planet. Can Symas OpenLDAP handle that?
- Q: Why doesn't Symas OpenLDAP support Multi-Master operations?
- Q: I don't understand this business of a Subscription for a Master Directory Server including up to two Replica Directory Servers. Can you explain this?
- Q: What contributions has Symas recently made to Open Source Projects that are reflected in the Symas OpenLDAP package?
- Q: I don't care about SSL or Kerberos right now. Can I still use Symas OpenLDAP?
- Q: Which back ends to you support?
- Q: What is back-bdb?
- Q: What is back-hdb?
- Q: How often do you update the Symas OpenLDAP distribution?
- Q: What sort of documentation do you include?
Questions Answered
- Q: What is Symas OpenLDAP Directory Services?
- A: Symas OpenLDAP Directory Services is a distribution of Open Source Directory Services software. The most complete and up-to-date versions of these distributions are available to subscribers under an annual subscription fee. Symas OpenLDAP provides pre-built binary packages tested and ready-to-run for installation on popular platforms using native software installer (package management) technology.
- Q: Is the Subscription a License?
- A: No. The Software is provided under the licenses from the Open Source Projects that developed it. Symas adds no additional licensing to that. The Subscription is a an annual subscription to a collection of commercial services provided by the Symas Corporation: integrating and testing the Open Source software, packaging it into easily installed native packages, keeping the packages current with evolving source code, and of providing technical support. A portion of the cost of the subscription also contributes to on-going development of OpenLDAP.
- Q: Is Symas OpenLDAP Open Source?
- A: Yes. All of the source code in all of the packages in Symas OpenLDAP is readily available for free from the various Open Source Software projects. All of the packages in Symas OpenLDAP are provided with no license fees or royalties. That means it is free as in beer. You are free to modify it and redistribute it under the restrictions of the Open Source licenses of each of the included products. That means it is free as in speech.
- Q: Isn't Open Source Free?
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A: No. Open Source Software is no different than proprietary software when it comes to the costs of the full life cycle: development, maintenance, and support. The Open Source Software model provides community development with free access to the source code without license fees, royalties, or excessive distribution charges. That makes the code appear to be free. However The Open Source Software model is based on volunteer developers who do not provide commercial maintenance and support. Maintenance and support is provided on an ad-hoc basis.
The largest portion of the cost of software development, maintenance, and support comes after development. Some of the maintenance is done by the community without compensation but volunteers often lack the sense of urgency felt by enterprise users. That points to a requirement for professional support and maintenance organizations like the Symas Corporation. Commercial support and maintenance is a long-standing element of the cost of production-grade software products. The Symas OpenLDAP Subscription fee is a fee for those services, not the software, including integrating the packages into one easily installed package, testing it, updating it as needed, and providing technical support.
- Q: Do you have a free version of Symas OpenLDAP?
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A: Yes. Symas OpenLDAP Silver is available for free download upon registration at our download portal. You are welcome to download it and use it subject to the licenses included (from the original Open Source projects). Symas OpenLDAP Silver is not at the same level of currency as Symas OpenLDAP Gold. However, is a terrific platform for study, development, or personal use. Symas offers an inexpensive annual subscription if you decide the Silver edition is adequate but you want Symas's support for your Server(s).
- Q: We want a Directory Entry for every <insert object here> on the planet. Can Symas OpenLDAP handle that?
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A: Yes. Symas OpenLDAP is probably your best choice today because of its comprehensive and native support for 64-bit systems (HP, IBM, Sun, and Intel architectures). The size of your directory should be limited only by the size of the disks on which you manage it. If you want very high performance access to Directories with millions or hundreds of millions of entries, you need hardware configurations with large storage (memory, RAM) that the Directory and database can use for cacheing. Symas OpenLDAP supports the very largest 64-bit computing platforms that make Directories with fast response to random queries over tens of millions of entries possible.
- Q: Why doesn't Symas OpenLDAP support Multi-Master operations?
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A: Good question. OpenLDAP 2.4 which will be the basis of Symas OpenLDAP 4 will support Multi-Master operations. This support is being added at Symas's expense to provide this controversial capability without the update collision detection problems prevalent in other commercial implementations. There's quite a history to that question and OpenLDAP and Symas have, for some time, thought there are good reasons to avoid Multi-Master operations on an LDAP Directory.
See this FAQ entry at OpenLDAP.org for the project's official position and a link to an IETF draft for further discussion.
Symas OpenLDAP with MirrorMode replication of the production Master Directory Server and a fail-over plan should provide all the advantages perceived of multi-master mode.
Multi-Master operations only make technical sense when provisioning (data entry and maintenance) centers are widely distributed and connected to the main directory by poor network connections.
Otherwise, Multi-Master operations merely add complexity and overhead which increases the processing required at each Master Directory Server.
- Q: I don't understand this business of a Subscription for a Master Directory Server including up to two Replica Directory Servers. Can you explain this?
-
A: No. After a few years of trying to explain it to people, we dropped that pricing scheme.
Subscriptions for Symas OpenLDAP are now annual by server.
There are no additional costs based on numbers of entries or processors running in the server.
- Q: What contributions has Symas recently made to Open Source Projects that are reflected in the Symas OpenLDAP package?
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A: OpenLDAP and Cyrus SASL include significant contributions from Symas, especially in these areas:
- Database Backend Architecture
- The
syncrepl sync replication architecture (now an Internet Standard)
- MirrorMode and Multi-Master capabilities
- Configuration Backend
- Overlay interface and initial overlays
- slapd performance optimization,
- back-bdb and back-hdb architecture,
- SASL authentication and authorization integration,
- TLS/SSL support, and
- GSSAPI/Kerberos V support
- Q: I don't care about SSL or Kerberos right now. Can I still use Symas OpenLDAP?
- A: Yes. Symas OpenLDAP also supports simple (cleartext password) authentication, which does not require SSL or Kerberos.
- Q: Which back ends to you support?
- A: The Symas OpenLDAP LDAP server features the newly-developed
back-bdb, back-hdb, and back-mdb backends as well as the more traditional back-ldbm configured to use the Berkeley DB package. Symas OpenLDAP also supports the monitor backend which provides performance data through LDAP, back-ldap which provides access to other directores and several others. Other backends may be made available based on customer demand.
- Q: What is back-bdb?
- A: Back-bdb is a back end that is optimized for the Berkeley DB and takes advantage of its page locking features to improve concurrency. Load times are substantially improved and database sizes are halved. This backend is now part of the standard OpenLDAP distribution, and is featured in Symas OpenLDAP.
- Q: What is back-hdb?
- A: Back-hdb is a back end that is based on back-bdb, but which organizes its data in a true hierarchical fashion. Because of this, back-hdb supports the subtree rename operation, allowing subtrees to be quickly and efficiently moved within the same database (a requirement of the LDAPv3 standard which most other Directory Services packages fail to provide). Another advantage of back-hdb is that its hierarchical design makes for higher write throughput. This is especially good for applications that frequently modify the LDAP database. This backend is now part of the standard OpenLDAP distribution, and is featured in Symas OpenLDAP.
- Q: How often do you update the Symas OpenLDAP distribution?
- A: Symas OpenLDAP releases will track the most recent Symas-recommended OpenLDAP releases. We will also update the distribution for important bug-fixes. Symas tries to balance the need for currency with the need for stability and produce a small number of updates over the course of a year.
- Q: What sort of documentation do you include?
- A: Symas OpenLDAP includes basic "Install it and get it running" documentation that covers installation of Symas OpenLDAP in its basic configuration.
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