Novell EDIRECTORY 8.8 - GUIDE, Manual

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Maintaining Novell eDirectory 499
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server by setting the following parameters in the
/etc/opt/novell/eDirectory/conf/
nds.conf
file.
16.2.2 Optimizing eDirectory Cache
Novell eDirectory uses persistent caching so that changes being made to a server are held in a
vector. If the server crashes in the middle of changes, eDirectory will load faster and synchronize the
changes in seconds when the server is brought back up. Novell eDirectory uses a rollback model
with a log file to roll forward transactions in the event of a system failure.
eDirectory settings begin with 16MB of cache, 50% of which is allocated to block caching and the
other 50% is allocated to record cache. After 15 minutes, eDirectory will modify its cache thresholds
to initialize up to 51% of the available free memory for the cache, leaving at least 24 MB for the OS.
This algorithm is used only if the host OS supports the call that enables you to determine the amount
of free memory available.
You can optimize your eDirectory cache in the following ways:
• “Using a Fixed Amount of RAM for Linux and UNIX Systems” on page 499
• “Setting Cache Parameters” on page 501
For more information on optimizing eDirectory cache, refer to Section 16.3, “Improving Bulkload
Performance,” on page 504 .
Using a Fixed Amount of RAM for Linux and UNIX Systems
Although the above algorithm works well for Windows and NetWare, it does not work as well for
Linux and UNIX systems. On Linux and UNIX systems, the free available memory reported by the
OS will be less than other operating systems because of the way the Linux and UNIX uses free
memory for internal caching of file system blocks, frequently run programs, libraries, etc. In
Parameter Description and Recommended Settings
n4u.server.idle-threads Minimum number of threads (regardless of activity)
The value of this parameter should be based on the average client load, in
order to minimize the time required to produce new threads during normal
client activity.
n4u.server.max-threads Maximum number of threads
The value of this parameter should be based on the maximum number of
simultaneous clients that need to be serviced, along with the following
recommendations:
• eDirectory requires a minimum of 16 threads
• One thread for every 255 LDAP connection (Monitor Thread)
• One thread for every four concurrent clients (Worker Thread)
n4u.server.start-threads Number of threads that start when eDirectory starts
The value of this parameter should be based on the average client load, in
order to minimize the time required to produce new threads during normal
client activity.