litespeed-quic/EXAMPLES.txt
2018-04-02 15:17:56 -04:00

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# Copyright (c) 2017 - 2018 LiteSpeed Technologies Inc. See LICENSE.
LSQUIC Examples
===============
test/http_client.c demonstrates how to use HTTP features of QUIC.
Usage Examples
--------------
Fetch Google's home page:
./http_client -H www.google.com -s 74.125.22.106:443 -p /
or even
./http_client -H www.google.co.uk -s 2a00:1450:4009:80c::2003:443 -p /
In the example above, -H specifies the domain; it is also used as the value
of SNI paramater in the handshake.
POST a file to calculate its CRC32 checksum:
./http_client -H www.litespeedtech.com -s 127.0.0.1:443 \
-p /cgi-bin/crc32.cgi -P file-256M -M POST
HTTP/1.1 200 OK
content-type: text/plain
date: Fri, 09 Jun 2017 08:40:45 GMT
server: LiteSpeed
alt-svc: quic=":443"; v="35,37"
CRC32: 2A0E7DBB
This is a good way to check that the payload gets to the other side
correctly. The CGI script is:
#!/usr/bin/perl
use String::CRC32;
printf "Content-type: text/plain\r\n\r\nCRC32: %X\n", crc32(*STDIN)
On the command line, I do
alias crc32="perl -MString::CRC32 -e'printf qq(%X\n), crc32(<>)'"
To submit several requests concurrently, one can use -n and -r options:
./http_client -H www.litespeedtech.com -s 127.0.0.1:443 \
-p /cgi-bin/crc32.cgi -P file-256M -M POST -n 3 -r 10
This will open three parallel connections which will make ten POST
requests together.
To perform load testing, it is good to mix sending and receiving data:
for i in {1..100}; do
./http_client $COMMON_OPTS -p /cgi-bin/crc32.cgi -P file-256M \
-M POST >out-post.$i &
./http_client $COMMON_OPTS -p /docs/file-256M >out-get.$i &
sleep 1
done
If you don't want to create a hundred 256-megabyte out-get.* files, use -K
flag to discard output.
Control QUIC Settings via -o Flag
---------------------------------
Most of the settings in struct lsquic_engine_settings can be controlled
via -o flag. With exception of es_versions, which is a bit mask, other
es_* options can be mapped to corresponding -o value via s/^es_//:
es_cfcw => -o cwcf=12345
es_max_streams_in => -o max_streams_in=123
And so on.
The code to set options via -o flag lives in set_engine_option(). It is good
to update this function at the same time as member fields are added to struct
lsquic_engine_settings.
Control LSQUIC Behavior via Environment Variables
-------------------------------------------------
LSQUIC_PACER_INTERTICK
Number of microsecods to use as constant intertick time in lieu of the
pacer's dynamic intertick time approximation.
Only available in debug builds.
LSQUIC_CUBIC_SAMPLING_RATE
Number of microseconds between times CWND is logged at info level.
Only available in debug builds.
Control Network-Related Stuff
-----------------------------
-D Set `do not fragment' flag on outgoing UDP packets.
-z BYTES Maximum size of outgoing UDP packets. The default is 1370
bytes for IPv4 socket and 1350 bytes for IPv6 socket.
-S opt=val Socket options. Supported options:
sndbuf=12345 # Sets SO_SNDBUF
rcvbuf=12345 # Sets SO_RCVBUF
More Compilation Options
------------------------
-DFULL_CONN_STATS=1
Track some statistics about full connection -- packets in, sent, delayed,
stream payload per packet size ratio, and some others -- and print them
at NOTICE level when connection is destroyed.
This is useful when performing network testing and especially analyzing
the effects of changing send buffer size (see -S sndbuf= in the previous
section).
-DLSQUIC_PACKINTS_SANITY_CHECK=1
Turn on sanity checking for packet interval code. The packet interval
code, shared by both send and receive history modules, contained a bug
which prompted me to add a checking function.
-DLSQUIC_SEND_STATS=0
Turn off statistics collection performed by the send controller: number
of packets sent, resent, and delayed.
-DLSQUIC_LOWEST_LOG_LEVEL=LSQ_LOG_WARN
If you want to go even faster: compile out some log levels entirely.
-DLSQUIC_EXTRA_CHECKS=1
Add relatively expensive run-time sanity checks