ehttpd

Multithreaded HTTP server written in assembler (32-bit GAS)

Features:

• Multithreading!
• No runtime libraries dependency - just pure GNU Assembly (GAS) and syscalls.
• Binary is only 23K
• GET / HEAD requests (icluding basic headers, like Content-Length)
• Validates requests and returns some error codes (400, 404, 405, 500, 505)
• Low memory usage (~240 VIRT, ~12 RES on average)
• High performance (tested with up to 255 concurrent users, 7k requests / second)
• No memory leaks.
• Tested on Fedora 31 and Ubuntu 18.04

Build:

All resulting files are stored in bin/

Just httpd binary:

• make

httpd + copy static content for tests:

• make all

make all + debug messages and debug symbols:

• make debug

clean:

• make clean

Usage:

• Copy ehttpd binary to location where you store your web content.
• Run ehttpd
• index.html is server by default (i.e. for request URI '/')
• Server runs on port 7555 (so open localhost:7555)
• Make sure port 7555 is allowed in firewall if you wish to actualy share the content.

Tests:

Run ehttp server first with static content present.

Basic tests checking various errors and responses:

• test/run_test.pl

Simple stress test (call some requests from test content repeatedly)

• test/run_stress_test.pl

Performance:

• I made some tests with siege tool (https://www.joedog.org/siege-home/).
• As a content I used openconnect documentation (on my machine it was in /usr/share/doc/openconnect/)
• List of URLs is available in test/siege_open_connect_uri.txt (during tests they were called at random)
• I tested for 10 minutes and 255 concurrent users.

Command:

siege -c255 -t10m -i -f test/siege_open_connect_uri.txt

Results:

• Transactions: 4349789 hits
• Availability: 100.00 %
• Elapsed time: 599.77 secs
• Data transferred: 27067.95 MB
• Response time: 0.03 secs
• Transaction rate: 7252.43 trans/sec
• Throughput: 45.13 MB/sec
• Concurrency: 234.27
• Successful transactions: 4349812
• Failed transactions: 0
• Longest transaction: 16.03
• Shortest transaction: 0.00

Adjustment tips:

To improve performance for specific content, one can:

• Change blksize used for reading files (SEND_FILE_ARG_BLKSIZE argument of send_file_content call in io_helpers.s). This function is called from request.s and by default equals blksize from stat syscall.
• Change socket backlog(BACKLOG_SIZE in ehttpd.s), by default its 8.