Re: High packet capturing rate in DPDK enabled port

[Stephen Hemminger <stephen@networkplumber.org>]

On Sun, 5 May 2024 13:09:42 +0600
Fuji Nafiul <nafiul.fuji@gmail.com> wrote:

> I have a DPDK-enabled port (Linux server) that serves around 5,000-50,000
> concurrent calls, per packet size of 80 bytes to 200 bytes. so in peak
> time, I require packet capture + file writing speed of around 1GByte/s or 8
> Gbit/sec (at least 0.5Gbyte/s is expected). dpdk official packet capture
> example project "dpdk-dumpcap"'s documentation says it has a capability of
> around 10MByte/s which is far less than required. I implemented a simple
> packet capture and pcap writing code which was able to dump
> around 5000-7000 concurrent call data where I used 1 core and 1 single ring
> of size 4096, and this was all integrated into actual media code (didn't
> use librte_pdump, simply copied to separate rte_ring after capturing
> through rte_eth_rx_burst() and before sending through rte_eth_tx_burst() ).
> I know I can launch this multiple cores and with multiple rings and so on
> but is there any current project which already does this?
> 
> I found a third-party project named "dpdkcap" which says it can support up
> to 10Gbit/s. Has anyone used it and what's the review?
> 
> Or, should I modify the "dpdk-dumpcap" project to my need to
> implement multicore and multi-ring support so I can extend the capability?
> Thanks in advance

The limitations of high speed packet capture is more about speed of writing
to disk. Doing single write per packet is part of the problem. Getting higher
performance requires faster SSD, and using ioring API.

I do not believe that dpdkcap is really supporting writing at 10 Gbit/sec only
that it can capture data on a 10 Gbit/sec device.