Service manual

How Searches Use Cache
114 Sun ONE Directory Server Installation and Tuning Guide • June 2003
1. Attempts to retrieve the entry having the specified base DN from the entry
cache.
If the entry is found there, Directory Server checks whether the candidate entry
matches the filter providedfor the search.
If the entry matches, Directory Server then quickly returns the formatted,
cached entry to the client application.
2. Attempts to retrieve the entry from the database cache.
If the entry is found there, Directory Server copies the entry to the entry cache
for the suffix, and then proceeds as if the entry had been found in the entry
cache.
3. Attempts to retrieve the entry from the database itself.
If the entry is found there, Directory Server copies the entry to the database
cache, then proceeds as if the entry had been found in the database cache.
Subtree and One-Level Search Process
Also as shown in Figure 6-2 on page 113, searches on a subtree or a level of a tree
involve additional processing to handle sets of entries. To process such searches,
Directory Server:
1. Attempts to build a set of candidate entries that match the filter from indexes
in the database cache.
If no appropriate index is present, the set of candidate entries must be
generated from the relevant entries in the database itself.
2. Handles each candidate entry by:
a. Performing a base search to retrieve the entry.
b. Checking whether the entry matches the filter provided for the search.
c. Returning the entry to the client application if the entry matches the filter.
In this way, Directory Server avoids constructing the set in memory.
Ideally, you know what searches to expect before tuning Directory Server. In
practice, verify assumptions through empirical testing.