tcp parameters tuning for JDB access to Oracle

[Dharshana Jayasuriya]

Hi All,

We have a Oracle 8.1.7 database in HP-UX 11.0 and trying to access this database using JDBC over the network. It seems the queries take unusually long time. Keeping the network delays and traffic congestion issues aside, is there something I can do to tune up the tcp/ip related params in HP-UX using ndd ?

Which parameters should be tuned to which values ?

Following are some params with their respective values (they are actually deafult values) at the moment.
tcp_conn_request_max 20
tcp_syn_rcvd_max 500
tcp_time_wait_interval 60,000
tcp_xmt_hiwater_def 32768
tcp_recv_hiwater_def 32768.

All comments and suggestions are very much appreciated.

[rick jones]

It is unlikely that you would need t change any of them. The one most likely to require changes would be tcp_conn_request_max - but that only if you see an increasing number of connections dropped due to full queue in the output of netstat -p tcp.

Changing the TIME_WAIT interval is generally not advised.

The tcp_syn_rcvd_max is only to deal with DOS situations, and the hiwaters would only need to be changed if your queries ever tried to dump more than 32KB (actually 64KB given how the stack works) at a time into the connection.

It might be interesting to take a tcpdump (www.tcpdump.org) trace of one or more transactions against the database and see what it looks like.