Configure the Management database metadata file

In the first two years of work mainly involved in the configuration Management database (CMDB) system design and development, in the design and development process encountered a lot of data-related issues, just take this opportunity to explain.

Configuration management items and issues with entities. Different configuration items in the configuration management system have different configuration properties, and different configuration entities can be subordinate to one of the properties. If generalize then all of the configuration items will form a chatty table, the table will be very redundant during the development process. Therefore, it is necessary to differentiate in the table design stage, which has undergone three stages, namely table inheritance, attribute map and allocation three stages.

Table inheritance indicates that, during use, different types of configuration items may inherit attributes from the previous parent class, so that the child configuration items can contain the contents and information of the parent configuration item, and that the table is maintained through a common primary key, and later found that the configuration property has a number of drawbacks in table expansion when processing data , any modification of a property may cause the table structure to change.

On this basis, we design an extended property in addition to the previous fixed attribute, which can be dynamically added to a configuration item, and then in-depth consideration, it becomes the structure of the configuration attribute map, the attribute map constructs a unified set of attributes, and the attribute set is divided, so that the attribute belongs to one or more classes , thus forming an association between the attribute and the configuration type. However, the method still exists such as complex configuration, constraint relationship is not strong, property cannot be checked and so on.

Therefore, we build a configuration allocation structure on this basis. The configuration allocation structure is basically the same as the attribute map, the biggest difference is the introduction of configuration categories, configuration templates, configuration rules and configuration constraints four parts. Configuration categories are used to identify inheritance or extension relationships between configuration item types, effectively guaranteeing the transfer of attributes between different types. Configuration templates, which are used to construct the corresponding relationship between configuration categories and configuration properties by configuring the template type on a configuration item, and other types that refer to template properties to some extent to solve the problem of redundant storage of properties between different configuration items of the same type, you can select those configuration categories that have those configuration properties. Configuration constraints are primarily used to configure the validation of properties, to determine whether the type is legitimate, to satisfy a certain logical constraint, such as the current value must be greater than 0 constraints.

Configure the Management database metadata file