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Re: back-ndb vs back-sql for exposing one MySQL db?



Gavin Henry wrote:
Hi All,

Here's a quick question, if you need to expose one MySQL db as LDAP for
example, using the existing db that has customer records in it and a 3rd party
application can look up via LDAP, do you use bog standard back-sql or back-ndb
just use one db, as it looks easier to setup?

In asking that question you're assuming that there's no big difference between operating back-sql and back-ndb, but that's not true.

For starters, MySQL supports many different backends (just as OpenLDAP does) and most sites have not been using NDB Cluster as their backend. Migration from one backend to another can require a non-trivial amount of time. The low level features provided by various backends are not all complete; some backends provide SQL functionality that others lack. Setting up and maintaining an NDB cluster also requires a fair amount of expertise.

There are MySQL deployments out there that are already using NDB Cluster of course, and back-ndb would be appropriate for them. But for the majority of MySQL deployments, which aren't already using NDB Cluster, it may not make sense to switch. The MySQL admin has to take a close look at the NDB Cluster feature set vs whatever backend they're currently using to make that decision.

Going by Howards talk at UKUUG 2009:

http://www.ukuug.org/events/spring2009/programme/openldap-mysql.shtml

--
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/