| Severe SQL*NET performance issues are encountered. [message #53220] |
Wed, 04 September 2002 11:56  |
Nic Otempi
Messages: 1
Registered: September 2002
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Junior Member |
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Currently one of issues we are trying to figure out is why there is a big difference in Latency between a sqlnet ping compare to a regular server ping.
For example a regular ping between a client in Austin, TX to database server in SanJose,CA is taking about 60MS. But a sqlnet ping between same clients is taking 3 to 4 times longer.
Questions:
1)why there is a big difference in latency between two pings?
2) Is there anybody encountered similar problems before?
3) What are some performance recommendations to reduce sqlnet latency?
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| Re: Severe SQL*NET performance issues are encountered. [message #53221 is a reply to message #53220] |
Wed, 04 September 2002 12:18  |
SKS
Messages: 26
Registered: February 2002
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Junior Member |
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When tnsping is issued from the command line, a lookup on the Oracle Net Alias is performed. This can occur using a local file called TNSNAMES.ORA or using a Naming Service like Oracle Names or LDAP. The purpose is to get the host name and port number the target Listener is listening on. Once the host name and port number is acquired, a TCP connection is opened to
the target host and port the Oracle Listener is on. To open this TCP connection, the host name must be resolved to the IP address of the destination host. TCP/IP then performs the three-way handshake to complete the connection.
Ping uses IP and thus does not require TCP's three-way handshake. When ping operates, it only sends one IP packet and receives only one. This is fewer packets, by quite a bit, then Oracle's tnsping creates.
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