Oracle & tcp.nodelay parameter Oracle Tips by Burleson Consulting

Important Note:  The default value for tcp.nodelay has been permanently changed to tcp.nodelay=yes

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The tcp.nodelay parameter

By default, Oracle*Net waits until the buffer is full before transmitting data; therefore, requests are not always sent immediately to their destinations. This is most commonly found when large amounts of data are streamed from one location to another, and Oracle*Net does not transmit the packet until the buffer is full. Adding a protocol.ora file and specifying a tcp.nodelay to stop buffer flushing delays can sometimes remedy this problem. The parameter can be used both on the client and server. The protocol.ora statement is:

     tcp.nodelay = YES

When this parameter is specified, TCP buffering is skipped so that every request is sent immediately. Slowdowns in the network may be caused by an increase in network traffic due to smaller and more frequent packet transmission.

Oracle-l notes this on tcp.nodelay and it's relationship to the SDU and TDU parameters:

"Setting tcp.nodelay disables the Nagle algorithm in the tcp stack that tries to efficiently balance the data load of a packet with the delay in dispatching it.

Effectively, you're saying "to xxx with optimizing the data payload ... send those babies now!". The complete antithesis of what the SDU/TDU settings are trying to do for you.

You'll end up with a larger number of smaller packets on your WAN, and if it's latency that's your problem, this will make matters worse, not better."

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