Target
Skill:
After reading this page you
will be able to change the maximum number of entries in your Server's cache.
Factoid:
The
References:
Directory Server Administrator's
Guide: Chapter 10
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Maximum Entries in Cache
This parameter specifies the number of entries the directory server
will maintain in the entry cache. The default value for this parameter
is 1,000. Increasing this number uses more memory but can substantially
improve search performance. The actual amount of memory required per additional
entry depends entirely on the nature of the data you choose to store in
the Directory Server.
While bigger caches are usually better, performance can degrade if dbcachesize
is set too large. If you set the database cache too large and exceed
the physical free memory available, the process will begin to thrash virtual
memory as it writes clean and dirty pages to disk. The result is severe
performance degradation. You can detect this behavior by using one
of the system monitoring tools such as vmstat that provides statistics
for virtual memory usage.
The sample entry below containing person information for Sam Carter
is 387 Bytes.
dn: uid=scarter, ou=People, o=airius.com
cn: Sam Carter
sn: Carter
givenname: Sam
objectclass: top
objectclass: person
objectclass: organizationalPerson
objectclass: inetOrgPerson
ou: Accounting
ou: People
l: Sunnyvale
uid: scarter
mail: scarter@airius.com
telephonenumber: +1 408 555 4798
facsimiletelephonenumber: +1 408 555 9751
roomnumber: 4612
userpassword: sprain
The Directory Server can retrieve data from the entry cache as much as
twice as fast as it can retrieve the same data from the database cache.
Therefore, you will achieve the fastest directory search performance when
all requests are delivered from the entry cache. The actual magnitude
of the performance benefit depends on the complexity of your search and
the type of indexes you maintain.
Tuning the entry cache
You should consider increasing the size of your entry cache
if the following are true:
-
You have memory to spare
-
You use the monitor tool and find that by increasing the entry cache size,
you increase the cache hit ratio
Changing The Maximum Entries In Cache
1. From the Server Manager go to Server Preferences
|Performance Tuning.
2. Change the desired value.
3. Click OK.
4. Click Apply.
5. Click Apply Changes.
6. Stop and then restart the Directory Server.
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