TODAY web servers become more and more

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1 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL Web server performance analysis Sebastian Dabkiewicz [email protected] Abstract Web servers become more and more important for company s which core business is on the internet. Several web server software is available and is used. In this report a comparison is made between the Apache web server and the Nginx web server. During the tests with static and dynamic files the differences between both can be seen. Nginx performed very good using static files, while Apache performed much better using dynamic files. So for every specific task is a web server available. Index Terms Apache httpd, Nginx, Web server, performance 1 INTRODUCTION TODAY web servers become more and more important for company s especially if their core business is web related, like a online-shop or a online-service. The web server marked is a marked with a lot of competition. There are many open- and closed source web servers available. In the Netcraft statistics[7] the top four web servers the statistic share about 92,5 % of the whole web server marked as seen in figure 1. some marked share from Apache because of the good performance on static files. It is also used for load balancing. At the 21th February 2012 the Apache httpd webserver was updated by version [3]. The fists big update since four years. The new Apache httpd version should increase his performance. So the event driven multi-processing module (MPM) is not longer experimental and the memory usage should be reduced. In this report a comparisation will be made betwee Apache and Nginx Research questions How compares the Apache httpd web server against Nginx ? - How is the performance using static pages? - How is the performance using dynamic pages? - What is the server load? In chapter 2 a global situation of the environment and the used software if given. Fig. 1. Netcraft March 2012 Web Server Survey Two of the top four web servers are open-source software, namely Apache[2] and Nginx[12]. Nginx picked the in the last years Chapter 3 describes the methods which are used to determine the network bandwidth and the maximal possible connection which the server can handle. The chapter 4 describes the thest which are conducted.

2 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL In chapter 5 the results of the test will be discussed. Thereafter a conclusion is given in chapter 6. Finally in chapter 7 there will be some suggestions made for future research. 2 ENVIRONMENT To conduction the performance of the web servers I used two 3 server in lab, two for web server and one for testing 2.1 web server For this project two different web servers will be used, Apache and Nginx These two are the most used open-source web servers at the moment Apache2 Apache 2 is the most used web server in the world. Apache can be used with different worker modules, the main three are: Prefork, Worker and Event. Every worker has his own characteristics. Below a short description of the working of each worker from the Apache httpd cumentation Prefork: The prefork[9] Multi-Processing Module (MPM) implements a non-threaded, preforking web server. Each server process may answer incoming requests, and a parent process manages the size of the server pool. It is appropriate for sites that need to avoid threading for compatibility with non-threadsafe libraries. It is also the best MPM for isolating each request, so that a problem with a single request will not affect any other Worker: The worker[10] Multi-Processing Module (MPM) implements a hybrid multi-process multi-threaded server. By using threads to serve requests, it is able to serve a large number of requests with fewer system resources than a process-based server. However, it retains much of the stability of a process-based server by keeping multiple processes available, each with many threads Event: The event[4] Multi-Processing Module (MPM) is designed to allow more requests to be served simultaneously by passing off some processing work to supporting threads, freeing up the main threads to work on new requests. It is based on the worker MPM, which implements a hybrid multi-process multi-threaded server. Run-time configuration directives are identical to those provided by worker Nginx Nginx is a web server which was written for the Russian search engine Rambler. Because of the good configuration possibilities and performance also other sites started using the Nginx web server. Like Apache it is possible to configure the server in different ways. Nginx comes with workers Worker: Multiple workers are possible in Nginx, the standard value is one. Depending on the number of CPU s and CPU cores a value can be chosen. When in ubt, setting it to the number of available CPU cores would be a good start. [11] 2.2 Server Every server gets a Debian Squeeze 64-bit installation with standard tools and a SSH-server for remote login Server configuration For a good performance of web servers some changes to the Linux kernel default sysctl settings sysctl[6] have to be. According to a paper named Performance Scalability of a Multi-Core Web Server[13] I changed the values of the server. The changes can be found in appendix C.

3 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL MEASURING To be able to expect results it is necessary to measure things like network bandwidth and the maximum of connections which the server should be able to handle resulting on the available bandwidth. 3.1 Iperf Iperf[5] is a tool to measure the network bandwidth. Measuring the network bandwidth is important to get accurate results. For example one can have a 1 Gbps network and a 1 Gbps network switch. So one can assume to be able to transfer data at 1 Gbps, but due different quality of the used hardware inside the switch the speed real speed could be slower. Also other users on the same switch can influence the speed. Therefore I conduct my testing in the evening hours so that the actual chance to be the only one who is using the network in the lab intensely. Using the Iperf tool resulted in an network bandwidth of 941 Mbps. 3.2 Maximum number of connections After the network speed is measured one can calculate the maximal connections which could be made to the web server based on the file size. The formula is: hit/s = bandwithmbps 106 bit/1s filesizebytes 8bits/1byte Using this formula for a 900 Mbps network and a file size of 150 bytes gives the following example: hits/s = 900s 106 bit/1s 150 8bits/1byte 3.3 Apache Benchmarking tool The Apache HTTP server benchmarking tool (ab)[1] is be used to test the performance of an web server. 4 TEST To conduct the test static and dynamic files are used. This to see the difference with only serving a page and serving a page which is parsed at the server. 4.1 Static Files As static file I use a small HTML-file with a size of 91 bytes and furthermore a image file with a file size of 55 Kilobytes. 4.2 Dynamic File For the dynamic part, I used PHP[8], although PHP is not really a dynamic language, the file is be parsed at the server and then send to the client, which makes it a bit dynamic. The used files can be found in appendix E. Each file is tested at different request and concurrency levels as seen in figure 2. Fig. 2. Testing parameters To test this files a script is written to automate this, running the script took about 4 hours per server. The script can be found in appendix D. 5 RESULTS After conducting the test a lot of data is gained. Because the test is performed at different request levels, which gave almost the same result, I only discuss the results with a request level of requests. 5.1 Static files HTML-file The HTML-file has a file size of 91 bytes, applying the formula chapter 3 one get the following result: hits/s = 941 Mbps 106 bit/1s 91 bytes 8 bits/ 1 byte As seen in in figure 3 and table 1, apache performed better then one Nginx worker 7212 requests per second against 7367 requests per second with Apache 2 event. But when increasing the workers in Nginx (figure 4), it reaches 7742 requests per second with 4 workers, which is 500 requests per second more than Apache can handle.

4 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL Here can be seen that the network is the bottleneck, and only hits can be expected, which is almost be reached during the test. All web servers reached about 2000 requests per second. Fig. 3. Results of the HTML test Worker 1 Prefork Event Worker TABLE 1 HTML-File Fig. 5. Results of the image test Worker 1 Prefork Event Worker TABLE 3 Image File Fig. 4. Results of the HTML test for Nginx The result of the image test using different workers in Nginx can be found below in figure 6. Worker 1 Worker 2 Worker 3 Worker TABLE 2 HTML-File Nginx Fig. 6. Results of the image test Image-file The image file has a file size of bytes, applying the formula from chapter 3 one get the following result: hits/s = 941 Mbps 106 bit/1s bytes 8 bits/ 1 byte 5.2 Dynamic file Hello World The result of the hello worki-file has a file size of 11 bytes, applying the formula from 3 one get the following result:

5 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL Worker 1 Worker 2 Worker 3 Worker TABLE 4 Image File-Nginx hits/s = 941 Mbps 106 bit/1s 11 bytes 8 bits/ 1 byte As seen the maximum hits per second are about 10.5 million. As seen in figure 7 and table 5 this number is not reached. Looking at figure 7 and table 5 one can see that the Apache web server performs much better than the Nginx server requests per second with Nginx vs request per seconds with the event mpm from Apache. Fig. 8. Results of the hello world test Nginx Worker 1 Worker 2 Worker 3 Worker TABLE 6 Hello World Nginx Fig. 7. Results of the hello world test Worker 1 Prefork Event Worker TABLE 5 Hello World Apache. Nginx could handle about 500 requests per seconds more then Apache. The image test didn t give any surprise, because the large file size the network was the bottleneck, and every server reaches about 2000 request per second. The CPU of the servers where almost idle during the test. So for a site with much large files and much visitors an network connection with more bandwidth is needed or an multi server environment where the load is spread between different servers. Using dynamic files one sees that Apache works much better than Nginx, even with more workers enabled request per second is a lot, when assuming that a browser handles about 10 requests per main. The CPU load was at both server around 30 % during the PHP hello test. Even with using more workers in Nginx, the maximum reqests wich are processed is 3501 request per seconds with 4 workers. Which is 1600 request per seconds less then the Apache 2 worker server. 6 CONCLUSION As can seen in the result section Nginx performs very well on static files comparing to 7 FUTURE WORK For a project the setup of the web servers will satisfy. But it would be desirable to have a setup with a real site, which produces an actual real load, so that the differences between both web servers better could be measured.

6 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL APPENDIX A APACHE CONFIG A.1 httpd.conf ServerRoot "/usr/local/apache2" Listen 80 LoadModule authn_file_module modules/mod_authn_file.so LoadModule authn_core_module modules/mod_authn_core.so LoadModule authz_host_module modules/mod_authz_host.so LoadModule authz_groupfile_module modules/mod_authz_groupfile.so LoadModule authz_user_module modules/mod_authz_user.so LoadModule authz_core_module modules/mod_authz_core.so LoadModule access_compat_module modules/mod_access_compat.so LoadModule auth_basic_module modules/mod_auth_basic.so LoadModule reqtimeout_module modules/mod_reqtimeout.so LoadModule filter_module modules/mod_filter.so LoadModule mime_module modules/mod_mime.so LoadModule log_config_module modules/mod_log_config.so LoadModule env_module modules/mod_env.so LoadModule headers_module modules/mod_headers.so LoadModule setenvif_module modules/mod_setenvif.so LoadModule version_module modules/mod_version.so LoadModule unixd_module modules/mod_unixd.so LoadModule status_module modules/mod_status.so LoadModule autoindex_module modules/mod_autoindex.so LoadModule dir_module modules/mod_dir.so LoadModule alias_module modules/mod_alias.so LoadModule php5_module modules/libphp5.so AddHandler php5-script.php AddType text/html.php <IfModule unixd_module> User daemon Group daemon # Main server configuration # ServerAdmin [email protected] <Directory /> AllowOverride none Require all denied </Directory>

7 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL DocumentRoot "/usr/local/apache2/htcs" <Directory "/usr/local/apache2/htcs"> Options Indexes FollowSymLinks AllowOverride None Require all granted </Directory> <IfModule dir_module> DirectoryIndex index.html <Files ".ht*"> Require all denied </Files> ErrorLog "logs/error_log" LogLevel warn <IfModule log_config_module> LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined LogFormat "%h %l %u %t \"%r\" %>s %b" common <IfModule logio_module> # You need to enable mod_logio.c to use %I and %O LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedio CustomLog "logs/access_log" common <IfModule alias_module> ScriptAlias /cgi-bin/ "/usr/local/apache2/cgi-bin/" <Directory "/usr/local/apache2/cgi-bin"> AllowOverride None Options None Require all granted </Directory> <IfModule mime_module>

8 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL TypesConfig conf/mime.types AddType application/x-compress.z AddType application/x-gzip.gz.tgz # Supplemental configuration # textless IfModule proxy_html_module > Include conf/extra/proxy-html.conf <IfModule ssl_module> SSLRanmSeed startup builtin SSLRanmSeed connect builtin

9 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL APPENDIX B NGINX CONFIG B.1 nginx.conf user nginx; worker_processes 4; worker_rlimit_nofile 65535; error_log /var/log/nginx/error.log warn; pid /var/run/nginx.pid; events { # worker_connections 1024; worker_connections 16384; use epoll; } http { include /etc/nginx/mime.types; default_type application/octet-stream; log_format main $remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" "$http_x_forwarded_for" ; access_log /var/log/nginx/access.log main; sendfile on; #tcp_nopush on; keepalive_timeout 90; #gzip on; include /etc/nginx/conf.d/*.conf; } B.2 default.conf server { listen 80; server_name localhost; #charset koi8-r; #access_log /var/log/nginx/log/host.access.log main;

10 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL location / { root /usr/share/nginx/html; index index.html index.htm index.php; } #error_page 404 /404.html; # redirect server error pages to the static page /50x.html # error_page /50x.html; location = /50x.html { root /usr/share/nginx/html; } # proxy the PHP scripts to Apache listening on :80 # #location \.php$ { # proxy_pass #} # pass the PHP scripts to FastCGI server listening on :9000 # location \.php$ { include /etc/nginx/fastcgi_params; fastcgi_pass :9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME /usr/share/nginx/html$fastcgi_script_name; } # deny access to.htaccess files, if Apache s cument root # concurs with nginx s one # #location /\.ht { # deny all; #} }

11 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL APPENDIX C SERVER CONFIG fs.file-max = net.core.netdev_max_backlog = net.core.optmem_max = net.core.rmem_default = net.core.rmem_max = net.core.somaxconn = net.core.wmem_default = net.core.wmem_max = net.ipv4.conf.all.rp_filter = 1 net.ipv4.conf.default.rp_filter = 1 net.ipv4.ip_local_port_range = net.ipv4.tcp_congestion_control = bic net.ipv4.tcp_ecn = 0 net.ipv4.tcp_max_syn_backlog = net.ipv4.tcp_max_tw_buckets = net.ipv4.tcp_mem = net.ipv4.tcp_rmem = net.ipv4.tcp_sack = 1 net.ipv4.tcp_syncookies = 0 net.ipv4.tcp_timestamps = 1 net.ipv4.tcp_wmem = net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_tw_recycle = 1

12 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL APPENDIX D AB SCRIPT #!/bin/bash for i in for j in echo "ab -n $i -c $j -k ab -n $i -c $j >> apache/index-$j-$i.txt for a in for b in echo "ab -n $a -c $b -k ab -n $a -c $b >> apache/uitzicht-$b-$a.txt for c in for d in echo "ab -n $c -c $d -k ab -n $c -c $d >> nignx2/hello-$d-$c.txt for e in for f in echo "ab -n $e -c $f -k ab -n $e -c $f >> apache/indexphp-$f-$e.txt

13 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL APPENDIX E TEST FILES E.1 index.html <html> <head> <title>server X </head> <body> <h1>server X </body> </html> E.2 uizicht.jpg Fig. 9. file: uitzicht.jpg, source: Sebastian Dabkiewicz E.3 index.php <?php phpinfo();?> E.4 hello.php <?php echo "Hello World";?>

14 WEB SERVER PERFORMANCE ANALYSIS, LIA PROJECT, 2ND APRIL REFERENCES [1] ab - apache http server benchmarking tool. Website. available at on 01st April [2] Apache httpd. Website. available at on 01st April [3] Apache httpd Website. available at on 01st April [4] Event mpm. Website. available at on 01st April [5] Iperf. Website. available at on 01st April [6] Linux Kernel. Linux IP Sysctl Documentation. available at txt; on 01st April [7] Netcraft. Website. available at on 01st April [8] Php. Website. available at on 01st April [9] Prefork mpm. Website. available at on 01st April [10] Worker mpm. Website. available at on 01st April [11] Worker processes. Website. available at core\ module.html\#worker\ processes; on 01st April [12] Nginx. Website. available at on 01st April [13] Bryan Veal and Annie Foong. Performance Scalability of a Multi-Core Web Server, November 2007.