During the first stages of cluster planning the most important service that needs to be considered is the LDAP directory. The LDAP server will be a part of the cluster back-end section and will be set to make use of the high-availability clustering ability.
The directory services are required for routing and authentication purposes. Without it, the proxies cannot route traffic to the designated node that stores an account. There are two situations a cluster engineer can encounter while setting up a cluster:
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No LDAP / Active Directory service is available and needs to be set up.
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A directory already exists and the cluster must be built around it.
Although a directory service is highly recommended, a local file can be used to route traffic in the back-end. Using a local file can slow a cluster very much and the proxies will require updates each time the configuration changes. More details on this topic are available in the "Axigen Mapping System" chapter.
Setting up a new directory service for the cluster
This type of setup can be created quite fast. The directory service must be installed and configured according to the cluster requirements, using the recommended default values, to be integrated as smoothly as possible with Axigen. Once the service is running, the next phase of cluster deployment should start and the proxies set in place.
Other fields can be added to the directory entries if the need arises. Axigen does not require exclusive access to any value or field, but merely relies on it to perform its tasks.
Integrating an existing directory service with the cluster
The toughest configuration scenario is the use of an already existing directory service within the cluster environment. There are special requirements that must be dealt with, such as directory and entry structure, as well as the information provided to the mail server during normal operation. However, in most cases, to the existing entries some new fields need to be added and the already existing ones need to fit perfectly into the default entry model used by Axigen mail server. If Axigen and another application require the same field to have different types of values, then another, custom field, must be added to the entry structure to allow Axigen to behave as expected.
Axigen can integrate with almost any type of entry structure used by a directory service. The only drawback here is that fields must be added to every entry of the directory that Axigen will use and this can prove very difficult with some setups.