6.3. Manually Setting the Entry Cache Size

The entry cache is used to store directory entries that are used during search and read operations. Setting the entry cache to a size that enables Directory Server to store all records has the highest performance impact on search operations.
If entry caching is not configured, Directory Server reads the entry from the id2entry.db database file and converts the DNs from the on-disk format to the in-memory format. Entries that are stored in the cache enable the server to skip the disk I/O and conversion steps.

Note

Instead of manually setting the entry cache size Red Hat recommends the auto-sizing feature for optimized settings based on the hardware resources. For details, see Section 6.1.1, “Manually Re-enabling the Database and Entry Cache Auto-sizing”.

6.3.1. Manually Setting the Entry Cache Size Using the Command Line

To manually set the entry cache size using the command line:
  1. Disable automatic cache tuning:
    # dsconf -D "cn=Directory Manager" ldap://server.example.com backend config set --cache-autosize=0
  2. Display the suffixes and their corresponding back end:
    # dsconf -D "cn=Directory Manager" ldap://server.example.com suffix list
    dc=example,dc=com (userroot)
    This command displays the name of the back end database next to each suffix. You require the suffix's database name in the next step.
  3. Set the entry cache size for the database:
    # dsconf -D "cn=Directory Manager" ldap://server.example.com backend suffix set --cache-memsize=2147483648 userRoot
    This command sets the entry cache to 2 gigabytes.
  4. Restart the Directory Service instance:
    # dsctl instance_name restart

6.3.2. Manually Setting the Entry Cache Size Using the Web Console

To manually set the entry cache size using the Web Console:
  1. Open the Directory Server user interface in the web console. For details, see Logging Into Directory Server Using the Web Console section in the Red Hat Directory Server Administration Guide.
  2. Select the instance.
  3. On the Database tab, select Global Database Configuration.
  4. Disable Automatic Cache Tuning.
  5. Click Save Configuration.
  6. Click the Actions button, and select Restart Instance.
  7. Set the size of the database cache in the Entry Cache Size (bytes) field.
  8. Click Save Configuration.
  9. Click the Actions button, and select Restart Instance.