Sizing Guide for Netscape Directory Server 

The purpose of this guide is to offer a starting point for sizing server hardware for Netscape Director Server.  This is a simple guide, not a recipe book and is by no means comprehensive.  Only that major topics such as class of machine, amount of memory, amount of disk, and number of CPUs are covered.  For best results, use this guide in conjunction with advice from your friendly Netscape System Engineer.

What systems are supported?

 
Vendor
Architecture
Operating System
Digital Alpha Digital Unix 4.0
Hewlett-Packard PA HP-UX 10.2, 11.0
IBM RS/6000 AIX 4.1.5, 4.2
Intel 486, Pentium Windows NT 3.51, 4.0
SGI MIPS IRIX 6.2
Sun SPARC Solaris 2.5.1, 2.6
 

How much memory is recommended?

Memory is used by Directory Server to run the server process and to cache directory data.  Caching is the major consumer of memory.  Refer to the Directory Server Performance Tuning Primer for more detailed recommendations on optimizing memory usage for performance.  When calculating the amount of memory you require, it is helpful to think of memory in terms of usage you can control, variable memory, and usage you cannot, fixed memory.

Variable memory consumers

db cache - This cache is part of the Directory Server back-end.  The default setting is 10 MB but it can be increased up to 2 GB assuming enough free memory is available.  The general rule for setting this value is no more than 75% of free memory when all systems on your hardware are running.

entry cache - This cache stores directory entries in the Directory Server front-end.  The default setting is 1,000 entries therefore its actual size in bytes will depend on the size of your average directory entry.  Assuming you are storing only text data, your average entry size will likely be somewhere between 0.5 and 1 KB.  The fastest directory search performance is achieved when all requests are delivered out of the entry cache.

Fixed memory consumers

directory server process - This is the amount of memory the Directory Server uses to run.

any other processes on same box - This is the memory that may be used by other servers and applications that you are running on the same hardware.  For example, you may be running a Messaging Server that is configured for a local Directory Server.

How much disk is recommended?

Disk space requirements are driven by two factors, the number and size of your directory entries, and the number and type of indexes you choose to maintain.  Liberally allocate disk space.  The table below provides some estimates for the amount of disk you will need given the size of your directory.
 
Directory Size 
(entries)
Memory
Disk
Database
Indexes
minimum
 64 MB
 100 MB
50,000
256 MB
1 GB
100,000
512 MB
2 GB
250,000
768 MB
2 GB
500,000
1 GB
3 GB
1,000,000
1 GB
6 GB
3,000,000
2 GB
9 GB
10,000,000
2 GB
 4 GB
10 GB
24,000,000
2 GB
8 GB
22 GB
The numbers in the table above will vary with entry size.  The actual amount of disk required per additional entry depends entirely on the nature of the data you choose to store in the Directory Server.  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

How many CPUs are recommended?

There is no CPU requirement for Netscape Directory Server.  We have tested Directory Server 4.0 on machines with up to 10 CPUs.  As a general rule of thumb, you should buy as many CPUs as required to get the performance you need.  Faster CPUs will also produce higher performance.

What are some sample configurations for Solaris and NT?

Solaris

Hardware Sun ES450 Sun E3000 Sun E6000
CPU 2 x 296 MHz 2 x 167 MHz 8 x ?
Memory 1 GB 512 MB 2 GB
Disk ? 12 GB (fraction) 30 GB

Windows NT

Hardware Compaq Proliant Compaq Proliant Compaq Proliant
CPU 2 x PentiumPro 200 MHz 1 x PentiumPro 200 MHz 4 x PentiumII Xeon 400 MHz
Memory 256 MB 768 MB 1 GB
Disk 768 MB 4 GB 46 GB