CSWeb Server Optimization Quick Reference

Applies to: IIS + PHP FastCGI + MySQL on Windows Server (WAMP) and Apache + PHP-FPM + MySQL on Linux (LAMP)

This is a quick reference for systems administrators.

MySQL (my.ini)

Setting	Recommended Value	Note
`innodb_buffer_pool_size`	50% of total RAM	Most impactful single setting — keeps working data in memory
`innodb_buffer_pool_instances`	`8`	Reduces contention under concurrent load
`innodb_log_buffer_size`	`64M`	Sized for one second of peak write traffic
`innodb_log_file_size`	6% of buffer pool size	e.g. 16G pool → 1G log file. Reduces log rotation frequency without excessive recovery time
`innodb_flush_log_at_trx_commit`	`2`	Flushes to OS cache per commit, to disk per second — appropriate for field data workloads
`max_connections`	`500`	Set above expected peak concurrent connections
`thread_cache_size`	`100`	Reduces thread creation overhead during connection spikes
`back_log`	`250`	Absorbs short connection queue bursts
`slow_query_log`	`1`	Keep enabled as safety net
`long_query_time`	`10`	Only logs catastrophic queries — no overhead under normal operation

Storage: SSD for the MySQL data directory is strongly recommended for large-scale deployments. HDD performance degrades significantly under high concurrent write load.

PHP (php.ini)

OPcache

Setting	Value
`zend_extension`	`php_opcache.dll` (Windows) / `opcache.so` (Linux — usually auto-loaded)
`opcache.enable`	`1`
`opcache.memory_consumption`	`256`
`opcache.interned_strings_buffer`	`16`
`opcache.max_accelerated_files`	`20000`
`opcache.validate_timestamps`	`0` — OPcache must be manually reset after deployments
`opcache.revalidate_freq`	`0`
`opcache.enable_file_override`	`1`
`opcache.cache_id`	`csweb_cache` — required on Windows/IIS for shared cache across worker processes

APCu

Setting	Value
`extension`	`php_apcu.dll` — obtain from pecl.php.net
`apc.enabled`	`1`
`apc.shm_size`	`32M`
`apc.ttl`	`0` — static reference data; cache clears on IIS restart
`apc.enable_cli`	`0`
`apc.serializer`	`php`

Windows: APCu is not bundled with PHP. Download the NTS x64 DLL matching your PHP version from pecl.php.net and place it in your PHP ext directory.

Linux: Install via sudo apt install php[version]-apcu or sudo pecl install apcu.

After any code deployment: run opcache_reset() or restart the PHP process to clear stale cached bytecode.

IIS (WAMP)

FastCGI Settings

IIS Manager → FastCGI Settings → Edit PHP entry

Setting	Default	Recommended
`maxInstances`	4	`50` — set below MySQL `max_connections`
`instanceMaxRequests`	200	`10000`
`activityTimeout`	30s	`60s`
`requestTimeout`	90s	`120s`
`PHP_FCGI_MAX_REQUESTS` (env var)	500	`10000` — must match `instanceMaxRequests`

Application Pool Settings

IIS Manager → Application Pools → [pool] → Advanced Settings

Setting	Default	Recommended
Idle Time-out	20 min	`0` (disabled)
Regular Time Interval recycling	1740 min	`0` (disabled) or schedule off-peak
Maximum Worker Processes	1	`1` — do not increase; APCu is not shared across worker processes

Apache (LAMP)

PHP-FPM Pool (`/etc/php/[version]/fpm/pool.d/www.conf`)

PHP-FPM manages the pool of PHP worker processes on Linux. The equivalent of IIS maxInstances is controlled by the pm (process manager) mode and its associated settings.

Setting	Default	Recommended
`pm`	`dynamic`	`dynamic` — leave as-is
`pm.max_children`	5	`50` — maximum PHP worker processes; set below MySQL `max_connections`
`pm.start_servers`	2	`10` — processes spawned on startup
`pm.min_spare_servers`	1	`5` — minimum idle processes kept ready
`pm.max_spare_servers`	3	`20` — maximum idle processes kept ready
`pm.max_requests`	500	`10000` — requests per worker before recycling; reduces process churn
`request_terminate_timeout`	0	`120s` — terminates hung workers; align with PHP `max_execution_time`

After changes: restart PHP-FPM with sudo systemctl restart php[version]-fpm

Apache Settings (`/etc/apache2/apache2.conf` or `/etc/httpd/conf/httpd.conf`)

Setting	Default	Recommended
`KeepAlive`	On	`On` — allows connection reuse across multiple requests
`KeepAliveTimeout`	5s	`5s` — leave as-is for REST API workloads
`MaxKeepAliveRequests`	100	`500` — increase for high-volume sync workloads

MPM Worker / Event settings (/etc/apache2/mods-enabled/mpm_event.conf):

Setting	Default	Recommended
`MaxRequestWorkers`	150	`400` — maximum simultaneous connections
`ThreadsPerChild`	25	`25` — leave as-is
`ServerLimit`	16	`16` — leave as-is

Note: Apache with PHP-FPM should use mpm_event or mpm_worker, not mpm_prefork. Prefork is incompatible with PHP-FPM and significantly less efficient under concurrent load. Confirm with: apache2ctl -V | grep MPM

Response Compression (`mod_deflate`)

# Add to apache2.conf or a .conf file in conf-available/
<IfModule mod_deflate.c>
AddOutputFilterByType DEFLATE application/json
AddOutputFilterByType DEFLATE application/json; charset=utf-8
</IfModule>

Enable the module with: sudo a2enmod deflate && sudo systemctl restart apache2

Restart Reference

WAMP (IIS + Windows)

Change Made	Action Required
`php.ini` changes	Restart Application Pool
OPcache / APCu settings	Restart Application Pool
New PHP extension added	Restart Application Pool
FastCGI settings	`iisreset`
`my.ini` MySQL changes	Restart MySQL Service

LAMP (Apache + Linux)

Change Made	Action Required
`php.ini` changes	`sudo systemctl restart php[version]-fpm`
OPcache / APCu settings	`sudo systemctl restart php[version]-fpm`
PHP-FPM pool changes	`sudo systemctl restart php[version]-fpm`
Apache config changes	`sudo systemctl restart apache2`
`my.cnf` MySQL changes	`sudo systemctl restart mysql`

Post-Change Validation

PHP — confirm via phpinfo():

OPcache section present → Opcode Caching: Enabled
cache_id shows csweb_cache
APCu section present and enabled

MySQL — confirm settings took effect by running in MySQL client:

SHOW VARIABLES LIKE 'innodb_buffer_pool_size';
SHOW VARIABLES LIKE 'innodb_log_file_size';
SHOW VARIABLES LIKE 'innodb_flush_log_at_trx_commit';
SHOW VARIABLES LIKE 'max_connections';

Verify each value matches what was set in my.ini. If a value still shows the old default, MySQL did not pick up the config change — confirm the correct my.ini path is being used and restart the MySQL service.

See also: CSWeb Best Practices