A data store is simply the storage location of the directory information. Directory information is organized hierarchically, with entries organized in a directory information tree. An entry is identified by its distinguished name (DN) which is a unique key into the database, composed of a sequence of attributes and values which specify the hierarchical location of the entry within the DIT (example, DN: locality=Boston, organizationName=XYZ, country=US). A naming context is a subtree of the directory and is identified by the DN of the subtree. SIMS uses two naming contexts (see Appendix D, "SIMS Directory Schema and Directory Information Tree" for details.)
A data store can contain up to three naming contexts. The DN of these naming contexts are used to identify the data store. The distinguished name of a naming context, or of a subtree of the naming context corresponds to the base DN you specify when you perform an LDAP operation such as a search, or when you configure an LDAP client application.
A data store can contain a mixture of master and replica (slave) naming contexts, some or all of which can be replicated to other servers.
To configure a data store, you must specify the distinguished name of the naming context stored, and the name of the directory where the database files reside. Optional configuration information includes:
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Which attributes are indexed (see"Indexing the Data Store" on page 194 for information about indexing) |
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Congestion thresholds (see "To Create a Data Store" on page 192 for information about the congestion monitoring system and setting thresholds) |
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Cache size (see "To Create a Data Store" on page 192 for information about caching) |
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Naming contexts stored (see "Configuring the Data Store" on page 190) |
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Whether any of the naming contexts held in the data store are replicated to other servers (see "Replication" on page 197) |
"To Create a Data Store" on page 192 gives step-by-step instructions for creating a new data store. "To Modify a Data Store" on page 194 explains how to modify an existing data store.
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To Create a Data Store
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| 1. | In the Admin Console home page, click the Sun Directory Services icon to bring up the LDAP Server property book, choose Ldbm DataStore from the Create pulldown. |
| 2. | Specify the distinguished names of the naming contexts stored in this data store. |
| 3. | Specify the path name to the directory where this database is to be stored. |
| 4. | Specify whether the last modification attributes should be recorded. |
| When this option is enabled, the creator's DN, a creation timestamp, the modifier's DN, and a modification timestamp are added in the entry. This enables you to search the directory for entries created or modified since a particular date or time. This can be useful if you are synchronizing changes across data stores, or you are using partial replication. |
| 5. | Specify the cache size limit, in entries and in bytes. |
| As information is retrieved from the directory it is saved in the cache. When the cache is full, the oldest entry is discarded to make room for new information. Retrieving information from the cache is faster than retrieving entries from the database, but a large cache occupies more memory. Default values for cache size and number of entries are 100,000 bytes and 1000 entries. |
| 6. | Specify congestion thresholds. |
| Congestion thresholds ensure that the directory does not become overloaded, by preventing new operations from starting when there are insufficient resources. |
| Critical specifies the disk space limit at which only search, read, and delete operations are allowed, and add, modify, and modrdn operations are not permitted. The default limit is 200 Kbytes. |
| Congested specifies the disk space limit at which add operations are no longer permitted, though modify, modify RDN (modrdn), search, read, and delete operations are allowed. The default limit is 500 Kbytes. |
| Back-to-normal specifies amount of disk space which must be available before the congested and critical restrictions are lifted. The default limit is 1000 Kbytes. |
| Threshold values are given in the number of Kbytes free on the disk holding the data store. The default location for the data store is /var/opt/SUNWmail/ldap/dbm. |
| 7. | (Optional) Specify which attributes to index in the database. |
| See "To Create or Modify Indexes" on page 196" for details. |
| 8. | In the Naming Contexts section, specify the master and slave subtrees held in this data store. |
| These are naming contexts that are subtrees or objects within the naming context used to name the data store. If you do not specify any naming contexts, the distinguished name of the data store itself is added to the list of master naming contexts automatically, but it is not displayed until you save the naming contexts information. See "Configuring the Data Store" on page 190 for details. |
| a. | Choose Naming Context from the Create menu. |
| b. | Specify the subtree type (subtree or object). |
| c. | Specify the DN of the subtree or object in the Suffix field. |
| d. | Select the mode in the Mode menu. |
| If the naming context is a replica (slave), specify the name of the server from which it is replicated in the Referral field, and specify the DN that slurpd will use when binding to replicate changes from the master. |
| e. | Click OK to save the naming contexts information. |
| 9. | (Optional) Replicate any of the stored naming contexts. |
| See "To Create or Modify Replicas" on page 197 for details. |
| 10. | Click OK in the Create LDBM Data Store window to save the Data Store definition. |
| 11. | Add a directory entry for the root of the data store. |
| See "Adding Entries" on page 94," for details of how to add an entry to the directory. You cannot add any entries to this data store until this root entry exists. |
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To Modify a Data Store |
AdminConsole>SUN Directory Services>LDAP Server property book>Data Store section>data store to modify>Selected pulldown>Modify Data Store
| 1. | In the Admin Console home page, click the Sun Directory Services icon to bring up the LDAP Server property book, then click on the Data Store section. |
| 2. | Select the data store you want to modify from the Data Store list. |
| 3. | Choose Modify Data Store from the Selected pulldown. |
| The data store's property book is displayed, showing the current configuration. You can modify any part of the data store configuration, apart from the distinguished name of the data store naming context. If the data store is empty, you can also modify the distinguished name of the data store naming context. See "To Create a Data Store" on page 192. |