iperf 测试网络性能指标
背景
Iperf是一个网络性能测试工具, 主要应用于LINUX服务器下面。可以测量最大TCP和UDP带宽，具有多种参数和特性。
可以记录带宽，延迟抖动和数据包丢失，最大组和MTU等统计信息，通过这些信息可以发现网络问题，检查网络质量，定位网络瓶颈。Iperf在linux和windows平台均有二进制版本供自由使用。
对于需要大量网络交互的产品，例如Greenplum，网络性能指标是一个很重要的指标。
iperf使用方法
安装在需要测试网络的两台主机上。
git clone https://github.com/esnet/iperf.git
cd iperf
切换到最新的稳定分支后安装
git checkout 3.1-STABLE
./configure --prefix=/home/digoal/iperfhome
make
make install
将so加入
$ sudo vi /etc/ld.so.conf
/home/digoal/iperfhome/lib
# ldconfig
# ldconfig -p |grep iperf
测试
1. 服务端
./iperfhome/bin/iperf3 -p 8181 -f M -i 3 -B 0.0.0.0 -V --logfile /tmp/iperf.log -s -D
tail -f -n 1 /tmp/iperf.log
2. 客户端
通过-M 指定测试的TCP包大小。
./iperfhome/bin/iperf3 -c xxx.xxx.xxx.xxx -p 8181 -b 0 -t 100 -P 64 -i 3 -M 90
有必要的话，可以指定并行度，测试tcp或udp, 缓冲区的大小，TCP窗口的大小，MTU大小，堵塞控制算法等等。
3. 观察
通过sar -n DEV 1 10000可以观察服务端以及客户端的接收和发送pps, 带宽等信息。
$ sar -n TCP | EDEV ...
4. 其他软件
$ iptraf
$ qperf
参考
1. help
./iperfhome/bin/iperf3 --help
Usage: iperf [-s|-c host] [options]
iperf [-h|--help] [-v|--version]
Server or Client:
-p, --port # server port to listen on/connect to
-f, --format [kmgKMG] format to report: Kbits, Mbits, KBytes, MBytes
-i, --interval # seconds between periodic bandwidth reports
-F, --file name xmit/recv the specified file
-A, --affinity n/n,m set CPU affinity
-B, --bind <host> bind to a specific interface
-V, --verbose more detailed output
-J, --json output in JSON format
--logfile f send output to a log file
-d, --debug emit debugging output
-v, --version show version information and quit
-h, --help show this message and quit
Server specific:
-s, --server run in server mode
-D, --daemon run the server as a daemon
-I, --pidfile file write PID file
-1, --one-off handle one client connection then exit
Client specific:
-c, --client <host> run in client mode, connecting to <host>
-u, --udp use UDP rather than TCP
-b, --bandwidth #[KMG][/#] target bandwidth in bits/sec (0 for unlimited)
(default 1 Mbit/sec for UDP, unlimited for TCP)
(optional slash and packet count for burst mode)
-t, --time # time in seconds to transmit for (default 10 secs)
-n, --bytes #[KMG] number of bytes to transmit (instead of -t)
-k, --blockcount #[KMG] number of blocks (packets) to transmit (instead of -t or -n)
-l, --len #[KMG] length of buffer to read or write
(default 128 KB for TCP, 8 KB for UDP)
--cport <port> bind to a specific client port (TCP and UDP, default: ephemeral port)
-P, --parallel # number of parallel client streams to run
-R, --reverse run in reverse mode (server sends, client receives)
-w, --window #[KMG] set window size / socket buffer size
-C, --congestion <algo> set TCP congestion control algorithm (Linux and FreeBSD only)
-M, --set-mss # set TCP/SCTP maximum segment size (MTU - 40 bytes)
-N, --no-delay set TCP/SCTP no delay, disabling Nagle's Algorithm
-4, --version4 only use IPv4
-6, --version6 only use IPv6
-S, --tos N set the IP 'type of service'
-L, --flowlabel N set the IPv6 flow label (only supported on Linux)
-Z, --zerocopy use a 'zero copy' method of sending data
-O, --omit N omit the first n seconds
-T, --title str prefix every output line with this string
--get-server-output get results from server
--udp-counters-64bit use 64-bit counters in UDP test packets
[KMG] indicates options that support a K/M/G suffix for kilo-, mega-, or giga-
iperf3 homepage at: http://software.es.net/iperf/
Report bugs to: https://github.com/esnet/iperf
2. 帮助文档
man man1/iperf3.1
IPERF(1) User Manuals IPERF(1)
NAME
iperf3 - perform network throughput tests
SYNOPSIS
iperf3 -s [ options ]
iperf3 -c server [ options ]
DESCRIPTION
iperf3 is a tool for performing network throughput measurements. It can test either TCP or UDP throughput. To perform an iperf3 test the user must establish both a server and a client.
GENERAL OPTIONS
-p, --port n
set server port to listen on/connect to to n (default 5201)
-f, --format
[kmKM] format to report: Kbits, Mbits, KBytes, MBytes
-i, --interval n
pause n seconds between periodic bandwidth reports; default is 1, use 0 to disable
-F, --file name
client-side: read from the file and write to the network, instead of using random data; server-side: read from the network and write to the file, instead of throwing the data away
-A, --affinity n/n,m
Set the CPU affinity, if possible (Linux and FreeBSD only). On both the client and server you can set the local affinity by using the n form of this argument (where n is a CPU number). In addition,
on the client side you can override the server’s affinity for just that one test, using the n,m form of argument. Note that when using this feature, a process will only be bound to a single CPU (as
opposed to a set containing potentialy multiple CPUs).
-B, --bind host
bind to a specific interface
-V, --verbose
give more detailed output
-J, --json
output in JSON format
--logfile file
send output to a log file.
-d, --debug
emit debugging output. Primarily (perhaps exclusively) of use to developers.
-v, --version
show version information and quit
-h, --help
show a help synopsis
SERVER SPECIFIC OPTIONS
-s, --server
run in server mode
-D, --daemon
run the server in background as a daemon
-I, --pidfile file
write a file with the process ID, most useful when running as a daemon.
-1, --one-off
handle one client connection, then exit.
CLIENT SPECIFIC OPTIONS
-c, --client host
run in client mode, connecting to the specified server
--sctp use SCTP rather than TCP (FreeBSD and Linux)
-u, --udp
use UDP rather than TCP
-b, --bandwidth n[KM]
set target bandwidth to n bits/sec (default 1 Mbit/sec for UDP, unlimited for TCP). If there are multiple streams (-P flag), the bandwidth limit is applied separately to each stream. You can also
add a ’/’ and a number to the bandwidth specifier. This is called "burst mode". It will send the given number of packets without pausing, even if that temporarily exceeds the specified bandwidth
limit. Setting the target bandwidth to 0 will disable bandwidth limits (particularly useful for UDP tests).
-t, --time n
time in seconds to transmit for (default 10 secs)
-n, --bytes n[KM]
number of bytes to transmit (instead of -t)
-k, --blockcount n[KM]
number of blocks (packets) to transmit (instead of -t or -n)
-l, --length n[KM]
length of buffer to read or write (default 128 KB for TCP, 8KB for UDP)
--cport port
bind data streams to a specific client port (for TCP and UDP only, default is to use an ephemeral port)
-P, --parallel n
number of parallel client streams to run
-R, --reverse
run in reverse mode (server sends, client receives)
-w, --window n[KM]
window size / socket buffer size (this gets sent to the server and used on that side too)
-M, --set-mss n
set TCP/SCTP maximum segment size (MTU - 40 bytes)
-N, --no-delay
set TCP/SCTP no delay, disabling Nagle’s Algorithm
-4, --version4
only use IPv4
-6, --version6
only use IPv6
-S, --tos n
set the IP ’type of service’
-L, --flowlabel n
set the IPv6 flow label (currently only supported on Linux)
-X, --xbind name
Bind SCTP associations to a specific subset of links using sctp_bindx(3). The --B flag will be ignored if this flag is specified. Normally SCTP will include the protocol addresses of all active
links on the local host when setting up an association. Specifying at least one --X name will disable this behaviour. This flag must be specified for each link to be included in the association, and
is supported for both iperf servers and clients (the latter are supported by passing the first --X argument to bind(2)). Hostnames are accepted as arguments and are resolved using getaddrinfo(3).
If the --4 or --6 flags are specified, names which do not resolve to addresses within the specified protocol family will be ignored.
--nstreams n
Set number of SCTP streams.
-Z, --zerocopy
Use a "zero copy" method of sending data, such as sendfile(2), instead of the usual write(2).
-O, --omit n
Omit the first n seconds of the test, to skip past the TCP slow-start period.
-T, --title str
Prefix every output line with this string.
-C, --congestion algo
Set the congestion control algorithm (Linux and FreeBSD only). An older --linux-congestion synonym for this flag is accepted but is deprecated.
--get-server-output
Get the output from the server. The output format is determined by the server (in particular, if the server was invoked with the --json flag, the output will be in JSON format, otherwise it will be
in human-readable format). If the client is run with --json, the server output is included in a JSON object; otherwise it is appended at the bottom of the human-readable output.
AUTHORS
A list of the contributors to iperf3 can be found within the documentation located at http://software.es.net/iperf/dev.html#authors.
SEE ALSO
libiperf(3), http://software.es.net/iperf
ESnet October 2015 IPERF(1)