1Introduction 2============ 3 4LiteSpeed SAPI module is a dedicated interface for PHP integration with 5LiteSpeed Web Server. LiteSpeed SAPI has similar architecture to the 6FastCGI SAPI with there major enhancements: better performance, dynamic 7spawning and PHP configuration modification through web server 8configuration and .htaccess files. 9 10Our simple benchmark test ("hello world") shows that PHP with 11LiteSpeed SAPI has 30% better performance over PHP with FastCGI SAPI, 12which is nearly twice the performance that Apache mod_php can deliver. 13 14A major drawback of FastCGI PHP comparing to Apache mod_php is lacking 15the flexibilities in PHP configurations. PHP configurations cannot be 16changed at runtime via configuration files like .htaccess files or web 17server's virtual host configuration. In shared hosting environment, 18each hosting account will has its own "open_basedir" overridden in 19server configuration to enhance server security when mod_php is used. 20usually, FastCGI PHP is not an option in shared hosting environment 21due to lacking of this flexibility. LiteSpeed SAPI is carefully designed 22to address this issue. PHP configurations can be modified the same way 23as that in mod_php with the same configuration directives. 24 25PHP with LiteSpeed SAPI is highly recommended over FastCGI PHP for 26PHP scripting with LiteSpeed web server. 27 28 29Building PHP with LiteSpeed SAPI 30================================ 31 32You need to add "--with-litespeed" to the configure command to build 33PHP with LiteSpeed SAPI, all other SAPI related configure options 34should be removed. 35 36For example: 37 ./configure --with-litespeed 38 make 39 40You should find an executable called 'php' under sapi/litespeed/ 41directory after the compilation succeeds. Copy it to 42'lsws/fcgi-bin/lsphp' or wherever you prefer, if LiteSpeed web server 43has been configured to run PHP with LiteSpeed SAPI already, you just 44need to overwrite the old executable with this one and you are all 45set. 46 47Start PHP from command line 48=========================== 49 50Usually, lsphp is managed by LiteSpeed web server in a single server 51installation. lsphp can be used in clustered environment with one 52LiteSpeed web server at the front, load balancing lsphp processes 53running on multiple backend servers. In such environment, lsphp can be 54start manually from command with option "-b <socket_address>", socket 55address can be IPv4, IPv6 or Unix Domain Socket address. 56for example: 57 58 ./lsphp -b [::]:3000 59 60have lsphp bind to port 3000 on all IPv4 and IPv6 address, 61 62 ./lsphp -b *:3000 63 64have lsphp bind to port 300 on all IPv4 address. 65 66 ./lsphp -b 192.168.0.2:3000 67 68have lsphp bind to address 192.168.0.2:3000. 69 70 ./lsphp -b /tmp/lsphp_manual.sock 71 72have lsphp accept request on Unix domain socket "/tmp/lsphp_manual.sock" 73 74 75Using LiteSpeed PHP with LiteSpeed Web Server 76============================================= 77 78Detailed information about how to configure LiteSpeed web server with 79PHP support is available from our website, at: 80 81https://www.litespeedtech.com/docs/webserver 82 83Usually, PHP support has been configured out of box, you don't need to 84change it unless you want to change PHP interface from FastCGI to 85LiteSpeed SAPI or vice versa. 86 87Brief instructions are as follow: 88 891) Login to web administration interface, go to 'Server'->'Ext App' tab, 90 add an external application of type "LSAPI app", "Command" should be 91 set to a shell command that executes the PHP binary you just built. 92 "Instances" should be set to "1". Add "LSAPI_CHILDREN" environment 93 variable to match the value of "Max Connections". More tunable 94 environment variable described below can be added. 95 962) Go to 'Server'->'Script Handler' tab, add a script handler 97 configuration: set 'suffix' to 'php', 'Handler Type' to 'LiteSpeed 98 API', 'Handler Name' should be the name of external application 99 just defined. 100 101 1023) Click 'Apply Changes' link on the top left of the page, then click 103 'graceful restart'. Now PHP is running with LiteSpeed SAPI. 104 105Tunings 106------- 107 108There are a few environment variables that can be tweaked to control the 109behavior of LSAPI application. 110 111* LSAPI_CHILDREN or PHP_LSAPI_CHILDREN (default: 0) 112 113There are two ways to let PHP handle multiple requests concurrently, 114Server Managed Mode and Self Managed Mode. In Server Managed Mode, 115LiteSpeed web server dynamically spawn/stop PHP processes, in this mode 116"Instances" should match "Max Connections" configuration for PHP 117external application. To start PHP in Self Managed Mode, "Instances" 118should be set to "1", while "LSAPI_CHILDREN" environment variable should 119be set to match the value of "Max Connections" and >1. Web Server will 120start one PHP process, this process will start/stop children PHP processes 121dynamically based on on demand. If "LSAPI_CHILDREN" <=1, PHP will be 122started in server managed mode. 123 124Self Managed Mode is preferred because all PHP processes can share one 125shared memory block for the opcode cache. 126 127Usually, there is no need to set value of LSAPI_CHILDREN over 100 in 128most server environment. 129 130 131* LSAPI_AVOID_FORK (default: 0) 132 133LSAPI_AVOID_FORK specifies the policy of the internal process manager in 134"Self Managed Mode". When set to 0, the internal process manager will stop 135and start children process on demand to save system resource. This is 136preferred in a shared hosting environment. When set to 1, the internal 137process manager will try to avoid freqently stopping and starting children 138process. This might be preferred in a dedicate hosting environment. 139 140 141* LSAPI_EXTRA_CHILDREN (default: 1/3 of LSAPI_CHILDREN or 0) 142 143LSAPI_EXTRA_CHILDREN controls the maximum number of extra children processes 144can be started when some or all existing children processes are in 145malfunctioning state. Total number of children processes will be reduced to 146LSAPI_CHILDREN level as soon as service is back to normal. 147When LSAPI_AVOID_FORK is set to 0, the default value is 1/3 of 148LSAPI_CHIDLREN, When LSAPI_AVOID_FORK is set to 1, the default value is 0. 149 150 151* LSAPI_MAX_REQS or PHP_LSAPI_MAX_REQUESTS (default value: 10000) 152 153This controls how many requests each child process will handle before 154it exits automatically. Several PHP functions have been identified 155having memory leaks. This parameter can help reducing memory usage 156of leaky PHP functions. 157 158 159* LSAPI_MAX_IDLE (default value: 300 seconds) 160 161In Self Managed Mode, LSAPI_MAX_IDLE controls how long a idle child 162process will wait for a new request before it exits. This option help 163releasing system resources taken by idle processes. 164 165 166* LSAPI_MAX_IDLE_CHILDREN 167 (default value: 1/3 of LSAPI_CHILDREN or LSAPI_CHILDREN) 168 169In Self Managed Mode, LSAI_MAX_IDLE_CHILDREN controls how many idle 170children processes are allowed. Excessive idle children processes 171will be killed by the parent process immediately. 172When LSAPI_AVOID_FORK is set to 0, the default value is 1/3 of 173LSAPI_CHIDLREN, When LSAPI_AVOID_FORK is set to 1, the default value 174is LSAPI_CHILDREN. 175 176 177* LSAPI_MAX_PROCESS_TIME (default value: 300 seconds) 178 179In Self Managed Mode, LSAPI_MAX_PROCESS_TIME controls the maximum 180processing time allowed when processing a request. If a child process 181can not finish processing of a request in the given time period, it 182will be killed by the parent process. This option can help getting rid 183of dead or runaway child process. 184 185 186* LSAPI_PGRP_MAX_IDLE (default value: FOREVER ) 187 188In Self Managed Mode, LSAPI_PGRP_MAX_IDLE controls how long the parent 189process will wait before exiting when there is no child process. 190This option help releasing system resources taken by an idle parent 191process. 192 193 194* LSAPI_PPID_NO_CHECK 195 196By default a LSAPI application check the existence of its parent process 197and exits automatically if the parent process died. This is to reduce 198orphan process when web server is restarted. However, it is desirable 199to disable this feature, such as when a LSAPI process was started 200manually from command line. LSAPI_PPID_NO_CHECK should be set when 201you want to disable the checking of existence of parent process. 202When PHP started by "-b" option, it is disabled automatically. 203 204 205Compatibility with Apache mod_php 206================================= 207 208LSAPI PHP supports PHP configuration overridden via web server configuration 209as well as .htaccess. 210Since 4.0 release "apache_response_headers" function is supported. 211 212 213 214Contact 215======= 216 217For support questions, please post to our free support forum, at: 218 219https://www.litespeedtech.com/support/forum/ 220 221For bug report, please send bug report to bug [at] litespeedtech.com. 222
