Tuning Parameters for /etc/system

set rlim_fd_max=value

"Hard” limit on file descriptors that a single process might have open. To override this limit requires superuser privilege. 

set tcp:tcp_conn_hash_size=value

Controls the hash table size in the TCP module for all TCP connections. 

Along with tune_t_flushr, autoup controls the amount of memory examined for dirty pages in each invocation and frequency of file system sync operations. 

set autoup=value

The value of autoup is also used to control whether a buffer is written out from the free list. Buffers marked with the B_DELWRI flag (file content pages that have changed) are written out whenever the buffer has been on the list for longer than autoup seconds. 

Increasing the value of autoup keeps the buffers around for a longer time in memory. 

set tune_t_fsflushr=value

Specifies the number of seconds between fsflush invocations. 

set rechoose_interval=value

Number of clock ticks before a process is deemed to have lost all affinity for the last CPU it ran on. After this interval expires, any CPU is considered a candidate for scheduling a thread. This parameter is relevant only for threads in the timesharing class. Real-time threads are scheduled on the first available CPU. 

ndd -set /dev/tcp tcp_xmit_hiwat 65535 

ndd -set /dev/tcp tcp_recv_hiwat 65535 

The default send window size in bytes. The default receive window size in bytes. 

ndd -set /dev/tcp tcp_cwnd_max 65535 

The maximum value of TCP congestion window (cwnd) in bytes. 

ndd -set /dev/tcp tcp_rexmit_interval_min 3000 

The default minimum retransmission timeout (RTO) value in milliseconds. The calculated RTO for all TCP connections cannot be lower than this value. 

ndd -set /dev/tcp tcp_rexmit_interval_max 10000 

The default maximum retransmission timeout value (RTO) in milliseconds. The calculated RTO for all TCP connections cannot exceed this value. 

ndd -set /dev/tcp tcp_rexmit_interval_initial 3000 

The default initial retransmission timeout value (RTO) in milliseconds 

ndd -set /dev/tcp tcp_time_wait_interval 60000 

The time in milliseconds a TCP connection stays in TIME-WAIT state. Refer to RFC 1122, 4.2.2.13 for more information. 

ndd -set /dev/tcp tcp_keepalive_interval 900000 

The time in milliseconds a TCP connection stays in KEEP-ALIVE state. Refer to RFC 1122, 4.2.2.13 for more information. 

ndd -set /dev/tcp tcp_conn_req_max_q value

The default maximum number of pending TCP connections for a TCP listener waiting to be accepted by accept(SOCKET). 

ndd -set /dev/tcp tcp_conn_req_max_q0 value

The default maximum number of incomplete (three-way handshake not yet finished) pending TCP connections for a TCP listener. 

ndd -set /dev/tcp tcp_ip_abort_interval value

Refer to RFC 793 for more information on TCP three-way handshake. 

ndd -set /dev/tcp tcp_ip_abort_interval value

The default total retransmission timeout value for a TCP connection in milliseconds. For a given TCP connection, if TCP has been re-transmitting for tcp_ip_abort_interval period and it has not received any acknowledgment from the other endpoint during this period, TCP closes this connection.