红帽全球峰会第 6 章 Tuning UDP connections
Tuning RHEL for UDP throughput requires realistic expectations. Unlike TCP, UDP lacks features, such as flow control and congestion control. This makes it difficult to achieve reliable communication and throughput that is close to the maximum speed of the network interface controller (NIC).
6.1. Detecting packet drops
There are multiple levels in the network stack in which the kernel can drop packets. RHEL provides different utilities to display statistics of these levels. Use them to identify potential problems.
Note that you can ignore a very small rate of dropped packets. However, if you encounter a significant rate, consider tuning measures.
The kernel drops network packets if the networking stack cannot handle the incoming traffic.
Procedure
Identify UDP protocol-specific packet drops due to too small socket buffers or slow application processing:
# nstat -az UdpSndbufErrors UdpRcvbufErrors #kernel UdpSndbufErrors 4 0.0 UdpRcvbufErrors 45716659 0.0The second column in the output lists the counters.
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