Sun Microsystems Sun GlassFish Enterprise Server 2.1 Tuning Manual page 96

Tuning for the Solaris OS
Tuning Parameters for Solaris
TABLE 5–1
Parameter
tcp_conn_req_max_q
tcp_conn_req_max_q0
tcp_ip_abort_interval
tcp_keepalive_interval
tcp_rexmit_interval_initial
tcp_rexmit_interval_max
tcp_rexmit_interval_min
tcp_smallest_anon_port
tcp_slow_start_initial
tcp_xmit_hiwat
tcp_recv_hiwat
tcp_conn_hash_size
Sizing the Connection Hash Table
The connection hash table keeps all the information for active TCP connections. Use the
following command to get the size of the connection hash table:
ndd -get /dev/tcp tcp_conn_hash
This value does not limit the number of connections, but it can cause connection hashing to
take longer. The default size is 512.
To make lookups more efficient, set the value to half of the number of concurrent TCP
connections that are expected on the server. You can set this value only in /etc/system, and it
becomes effective at boot time.
Use the following command to get the current number of TCP connections.
netstat -nP tcp|wc -l
96 Sun GlassFish Enterprise Server 2.1 Performance Tuning Guide • January 2009
(Continued)
Scope Default
128
ndd /dev/tcp
1024
ndd /dev/tcp
480000
ndd /dev/tcp
7200000
ndd /dev/tcp
3000
ndd /dev/tcp
240000
ndd /dev/tcp
200
ndd /dev/tcp
32768
ndd /dev/tcp
1
ndd /dev/tcp
8129
ndd /dev/tcp
8129
ndd /dev/tcp
512
ndd /dev/tcp
Tuned Value Comments
1024
4096
60000
900000 For high traffic web sites, lower this
value.
3000 If retransmission is greater than
30-40%, you should increase this
value.
10000
3000
1024 Set on clients too.
2 Slightly faster transmission of small
amounts of data.
32768 Size of transmit buffer.
32768 Size of receive buffer.
8192 Size of connection hash table. See
"Sizing the Connection Hash Table"
on page 96.