Sun Microsystems 2005Q1 manual Consider the following

netstat

tcpListenDrop	=	0	tcpListenDropQ0	=	0
tcpHalfOpenDrop	=	0	tcpOutSackRetrans	=	56

What to look for

•tcpListenDrop - If after several looks at the command output the tcpListenDrop continues to increase, it could indicate a problem with queue size.

Considerations:

•A possible cause of increasing tcpListenDrop is the application throughput being bottlenecked by the number of executing threads. At this point increasing application threads may be a good thing to try.

•Increase queue size. Increase the request queue sizes using ndd. More information on other ndd commands referenced in the Solaris Administration Guide.

ondd -set /dev/tcp tcp_conn_req_max_q <value> ondd -set /dev/tcp tcp_conn_req_max_q0 <value> netstat -a grep <your_hostname> wc -l

Running this command gives a rough count of socket connections on the system. The number of connections open at one time is limited; you can use this tool to look for bottlenecks.

netstat -a grep <your_hostname> wc -l Output #netstat -a wc -l

34567

What to Look For

•socket count - If the number returned is greater than 20,000 then the number of socket connections could be a possible bottleneck.

Consider the following:

•Decrease the point where number of anonymous socket connections start. ondd -set /dev/tcp tcp_smallest_anon_port <value>

•Decrease the time a TCP connection stays in TIME_WAIT. ondd -set /dev/tcp tcp_time_wait_interval <value>

Appendix B Analysis Tools 149