Netscape DIRECTORY SERVER 6.0 Installation Manual

Also see for NETSCAPE DIRECTORY SERVER 6.0: Deployment guide Reference Configuration guide

Contents

Netscape DIRECTORY SERVER 6.0 Installation Manual Manual pdf 37 page image

Operating System RequirementsChapter 2 Computer System Requirements 37Set Tuning ParametersThe transmission control blocks (TCBs) store data for each TCP connection. Acontrol block is attached to the TCB hash table for each active connection. If thereare not enough control blocks available when an LDAP connection arrives at theserver via TCP/IP, there is added delay while it waits for additional control blocksto be created. By increasing the TCB timewait table size, you reduce latencyoverhead by allowing more client connections to be serviced faster. To adjust thisvalue, add to the following registry key:HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parametersthe MaxFreeTcbs value of 0xFA0.This example increases the TCB timewait table to 4,000 entries from the default of2,000. Now that the overhead time introduced by TCP has been lowered forDirectory Server, adjust the corresponding hash table that stores the TCBs. Adjustthe hash table by adding to the following registry value:HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parametersthe value of MaxHashTableSize to 0x400.This increases the TCB hash table size from 512 to 1,024, allowing more room forconnection information. TCB information is stored in the nonpaged memory pool.If Directory Server is experiencing memory bottlenecks and more memory cannotbe allotted to the server, lower the above values.On a multiprocessor system, we recommend optimizing the NIC and CPUrelationship. Each LDAP request received over the network generates an interruptto the processor requesting service. If the processor does not consider the request tobe sufficiently urgent, (that is, with a sufficiently high interrupt level), it defers therequest. This deferred interrupt request becomes a Deferred Procedure Call (DPC).As more and more requests come into the server, the number of interrupts andDPCs increases.When an interrupt is sent to a particular CPU and is subsequently deferred,additional server overhead is incurred if this DPC is shipped off to another CPU inthe server (if the server is an SMP capable machine). This is NTs default behaviorand can be costly from a performance perspective. To stop this transfer fromhappening, add to the following registry value:HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NDIS\Parametersthe value of ProcessorAffinityMask to 0.