This chapter describes some of the Network Cache and Accelerator (NCA) tunable parameters.nca:nca_conn_hash_size nca:nca_conn_req_max_q nca:nca_conn_req_max_q0 nca:nca_ppmax nca:nca_vpmax sq_max_size ge:ge_intr_mode Tunable Parameter For Information Solaris kernel tunables Chapter 2, Solaris Kernel Tunable Parameters NFS tunable parameters Chapter 3, NFS Tunable Parameters Internet Protocol Suite tunable parameters Chapter 4, Internet Protocol Suite Tunable Parameters Setting these parameters is appropriate on a system that is a dedicated web server. These parameters allocate more memory for caching pages. You can set all of the tuning parameters described in this chapter in the /etc/system file.For information on adding tunable parameters to the /etc/system file, see Tuning the Solaris Kernel.DescriptionControls the hash table size in the NCA module for all TCP connections, adjusted to the nearest prime number. Default383 hash table entries Range0 to 201,326,557 Dynamic?No When to ChangeWhen the NCA's TCP hash table is too small to keep track of the incoming TCP connections. This situation causes many TCP connections to be grouped together in the same hashtable entry. This situation is indicated when NCA is receiving many TCP connections, and system performance decreases. Commitment LevelUnstable DescriptionDefines the maximum number of pending TCP connections for NCA to listen on. Default256 connections Range0 to 4,294,967,295 Dynamic?No When to ChangeWhen NCA closes a connection immediately after it is established because it already has too many established TCP connections. If NCA is receiving many TCP connections and can handle a larger load, but is refusing any more connections, increase this parameter. Doing so allows NCA to handle more simultaneous TCP connections. Commitment LevelUnstable DescriptionDefines the maximum number of incomplete (three-way handshake not yet finished) pending TCP connections for NCA to listen on. Default1024 connections Range0 to 4,294,967,295 Dynamic?No When to ChangeWhen NCA refuses to accept any more TCP connections because it already has too many pending TCP connections. If NCA is receiving many TCP connections and can handle a larger load, but is refusing any more connections, increase this parameter. Doing so allows NCA to handle more simultaneous TCP connections. Commitment LevelUnstable DescriptionSpecifies the maximum amount of physical memory (in pages) used by NCA for caching the pages. This value should not be more than 75 percent of total memory. Default25 percent of physical memory Range1 percent to maximum amount of physical memory Dynamic?No When to ChangeWhen using NCA on a system with more than 512 Mbytes of memory. If a system has a lot of physical memory that is not being used, increase this parameter. Then, NCA will efficiently use this memory to cache new objects. As a result, system performance will increase.This parameter should be increased in conjunction with nca_vpmax, unless you have a system with more physical memory than virtual memory (a 32-bit kernel that has greater than 4 Gbytes memory). Use pagesize1 to determine your system's page size. Commitment LevelUnstable DescriptionSpecifies the maximum amount of virtual memory (in pages) used by NCA for caching pages. This value should not be more than 75 percent of the total memory. Default25 percent of virtual memory Range1 percent to maximum amount of virtual memory Dynamic?No When to ChangeWhen using NCA on a system with more than 512 Mbytes of memory. If a system has a lot of virtual memory that is not being used, increase this parameter. Then, NCA will efficiently use this memory to cache new objects. As a result, system performance will increase.This parameter should be increased in conjunction with nca_ppmax. Set this parameter about the same value as nca_vpmax, unless you have a system with more physical memory than virtual memory. Commitment LevelUnstable In addition to setting the NCA parameters, you can do some general system tuning to benefit NCA performance. If you are using gigabit Ethernet (ge driver), you should set the interface in interrupt mode for better results.For example, a system with 4 Gbytes of memory that is booted under 64-bit kernel should have the following parameters set in the /etc/system file. Use pagesize to determine your system's page size.set sq_max_size=0 set ge:ge_intr_mode=1 set nca:nca_conn_hash_size=82500 set nca:nca_conn_req_max_q=100000 set nca:nca_conn_req_max_q0=100000 set nca:nca_ppmax=393216 set nca:nca_vpmax=393216DescriptionSets the depth of the syncq (number of messages) before a destination STREAMS queue generates a QFULL message. Default10000 messages Range0 (unlimited) to MAXINT Dynamic?No When to ChangeWhen NCA is running on a system with a lot of memory, increase this parameter to allow drivers to queue more packets of data. If a server is under heavy load, increase this parameter so that modules and drivers can process more data without dropping packets or getting backlogged.Solaris 8 and later releases – Do not set this parameter to 0 on production systems. If you need to change this parameter, gradually increase this value, and monitor the system.Solaris 7 and earlier releases – Do not set this parameter to 0 on production systems. If you need to change this parameter, gradually increase this value to a maximum of 100, and monitor the system. Commitment LevelUnstable Change HistoryFor information, see sq_max_size (Solaris 9 12/02 Release). DescriptionEnables the ge driver to send packets directly to the upper communication layers rather than queue the packets Default0 (queue packets to upper layers) Range0 (enable) or 1 (disable) Dynamic?No When to ChangeWhen NCA is enabled, set this parameter to 1 so that the packet is delivered to NCA in interrupt mode for faster processing. Commitment LevelUnstable