FrankenPHP worker mode does not utilize all CPU

[supriyo-biswas]

What happened?

I'm facing an issue with FrankenPHP version FrankenPHP v1.9.1 PHP 8.4.12 Caddy v2.10.2 h1:g/gTYjGMD0dec+UgMw8SnfmJ3I9+M2TdvoRL/Ovu6U8= where the CPU will not be fully utilized. For example, when I conduct a load test, the CPU usage will hover around 30% and the response time keeps increasing, and the application can only do about ~150 RPS of requests.

In my older setup consisting of Caddy + PHP-FPM, I can make ~600 QPS.

This is my FrankenPHP configuration:

{
	servers {
		log_credentials
	}

	frankenphp {
		max_wait_time 30s

		php_ini error_log /dev/stderr
		php_ini opcache.validate_timestamps false

		worker {
			file /app/public/index.php
			max_consecutive_failures 3
		}
	}
}

http://:8000 {
	root * /app/public

	php_server {
		try_files {path} index.php
		root /app/public
	}

	header {
		X-Content-Type-Options "nosniff"
		X-XSS-Protection "1; mode=block"
		-Server
		-X-Powered-By
	}

	log {
		output file /var/log/access.log {
			roll_size 10MiB
			roll_uncompressed
			roll_keep 3
		}
		format filter {
			resp_headers delete
		}
	}
}

I also tried increasing the worker count like this:

worker {
   num 32
}

Is there something I should change in the above configuration so that it can handle more requests?

Build Type

Docker (Debian Trixie)

Worker Mode

Yes

Operating System

GNU/Linux

CPU Architecture

x86_64

PHP configuration

PHP Version 8.4.12
System	Linux 8a0bde0c86fe 6.8.0-71-generic #71-Ubuntu SMP PREEMPT_DYNAMIC Tue Jul 22 16:52:38 UTC 2025 x86_64
Build Date	Aug 28 2025 18:15:48
Build System	Linux - Docker
Build Provider	https://github.com/docker-library/php
Configure Command	'./configure' '--build=x86_64-linux-gnu' '--with-config-file-path=/usr/local/etc/php' '--with-config-file-scan-dir=/usr/local/etc/php/conf.d' '--enable-option-checking=fatal' '--with-mhash' '--with-pic' '--enable-mbstring' '--enable-mysqlnd' '--with-password-argon2' '--with-sodium=shared' '--with-pdo-sqlite=/usr' '--with-sqlite3=/usr' '--with-curl' '--with-iconv' '--with-openssl' '--with-readline' '--with-zlib' '--enable-phpdbg' '--enable-phpdbg-readline' '--with-pear' '--with-libdir=lib/x86_64-linux-gnu' '--enable-embed' '--enable-zts' '--disable-zend-signals' 'build_alias=x86_64-linux-gnu' 'PHP_UNAME=Linux - Docker' 'PHP_BUILD_PROVIDER=https://github.com/docker-library/php'
Server API	FrankenPHP
Virtual Directory Support	enabled
Configuration File (php.ini) Path	/usr/local/etc/php
Loaded Configuration File	(none)
Scan this dir for additional .ini files	/usr/local/etc/php/conf.d
Additional .ini files parsed	/usr/local/etc/php/conf.d/docker-php-ext-gd.ini, /usr/local/etc/php/conf.d/docker-php-ext-gmp.ini, /usr/local/etc/php/conf.d/docker-php-ext-intl.ini, /usr/local/etc/php/conf.d/docker-php-ext-opcache.ini, /usr/local/etc/php/conf.d/docker-php-ext-pcntl.ini, /usr/local/etc/php/conf.d/docker-php-ext-pdo_pgsql.ini, /usr/local/etc/php/conf.d/docker-php-ext-sodium.ini, /usr/local/etc/php/conf.d/docker-php-ext-zip.ini
PHP API	20240924
PHP Extension	20240924
Zend Extension	420240924
Zend Extension Build	API420240924,TS
PHP Extension Build	API20240924,TS
PHP Integer Size	64 bits
Debug Build	no
Thread Safety	enabled
Thread API	POSIX Threads
Zend Signal Handling	disabled
Zend Memory Manager	enabled
Zend Multibyte Support	provided by mbstring
Zend Max Execution Timers	enabled
IPv6 Support	enabled
DTrace Support	disabled
Registered PHP Streams	https, ftps, compress.zlib, php, file, glob, data, http, ftp, phar, zip
Registered Stream Socket Transports	tcp, udp, unix, udg, ssl, tls, tlsv1.0, tlsv1.1, tlsv1.2, tlsv1.3
Registered Stream Filters	zlib.*, convert.iconv.*, string.rot13, string.toupper, string.tolower, convert.*, consumed, dechunk
Zend logoThis program makes use of the Zend Scripting Language Engine:
Zend Engine v4.4.12, Copyright (c) Zend Technologies with Zend OPcache v8.4.12, Copyright (c), by Zend Technologies
Configuration
Core
PHP Version	8.4.12
Directive	Local Value	Master Value
allow_url_fopen	On	On
allow_url_include	Off	Off
arg_separator.input	&	&
arg_separator.output	&	&
auto_append_file	no value	no value
auto_globals_jit	On	On
auto_prepend_file	no value	no value
browscap	no value	no value
default_charset	UTF-8	UTF-8
default_mimetype	text/html	text/html
disable_classes	no value	no value
disable_functions	no value	no value
display_errors	On	On
display_startup_errors	On	On
doc_root	no value	no value
docref_ext	no value	no value
docref_root	no value	no value
enable_dl	On	On
enable_post_data_reading	On	On
error_append_string	no value	no value
error_log	/dev/stderr	/dev/stderr
error_log_mode	0644	0644
error_prepend_string	no value	no value
error_reporting	no value	no value
expose_php	On	On
extension_dir	/usr/local/lib/php/extensions/no-debug-zts-20240924	/usr/local/lib/php/extensions/no-debug-zts-20240924
fiber.stack_size	no value	no value
file_uploads	On	On
hard_timeout	2	2
highlight.comment	#FF8000	#FF8000
highlight.default	#0000BB	#0000BB
highlight.html	#000000	#000000
highlight.keyword	#007700	#007700
highlight.string	#DD0000	#DD0000
html_errors	On	On
ignore_repeated_errors	Off	Off
ignore_repeated_source	Off	Off
ignore_user_abort	On	Off
implicit_flush	Off	Off
include_path	.:/usr/local/lib/php	.:/usr/local/lib/php
input_encoding	no value	no value
internal_encoding	no value	no value
log_errors	Off	Off
mail.add_x_header	Off	Off
mail.force_extra_parameters	no value	no value
mail.log	no value	no value
mail.mixed_lf_and_crlf	Off	Off
max_execution_time	30	30
max_file_uploads	20	20
max_input_nesting_level	64	64
max_input_time	-1	-1
max_input_vars	1000	1000
max_multipart_body_parts	-1	-1
memory_limit	128M	128M
open_basedir	no value	no value
output_buffering	0	0
output_encoding	no value	no value
output_handler	no value	no value
post_max_size	8M	8M
precision	14	14
realpath_cache_size	4096K	4096K
realpath_cache_ttl	120	120
register_argc_argv	On	On
report_memleaks	On	On
report_zend_debug	Off	Off
request_order	no value	no value
sendmail_from	no value	no value
sendmail_path	/usr/sbin/sendmail -t -i	/usr/sbin/sendmail -t -i
serialize_precision	-1	-1
short_open_tag	On	On
SMTP	localhost	localhost
smtp_port	25	25
sys_temp_dir	no value	no value
syslog.facility	LOG_USER	LOG_USER
syslog.filter	no-ctrl	no-ctrl
syslog.ident	php	php
unserialize_callback_func	no value	no value
upload_max_filesize	2M	2M
upload_tmp_dir	no value	no value
user_dir	no value	no value
user_ini.cache_ttl	300	300
user_ini.filename	.user.ini	.user.ini
variables_order	EGPCS	EGPCS
xmlrpc_error_number	0	0
xmlrpc_errors	Off	Off
zend.assertions	1	1
zend.detect_unicode	On	On
zend.enable_gc	On	On
zend.exception_ignore_args	Off	Off
zend.exception_string_param_max_len	15	15
zend.max_allowed_stack_size	0	0
zend.multibyte	Off	Off
zend.reserved_stack_size	0	0
zend.script_encoding	no value	no value
ctype
ctype functions	enabled
curl
cURL support	enabled
cURL Information	8.14.1
Age	11
Features
AsynchDNS	Yes
CharConv	No
Debug	No
GSS-Negotiate	No
IDN	Yes
IPv6	Yes
krb4	No
Largefile	Yes
libz	Yes
NTLM	Yes
NTLMWB	No
SPNEGO	Yes
SSL	Yes
SSPI	No
TLS-SRP	Yes
HTTP2	Yes
GSSAPI	Yes
KERBEROS5	Yes
UNIX_SOCKETS	Yes
PSL	Yes
HTTPS_PROXY	Yes
MULTI_SSL	No
BROTLI	Yes
ALTSVC	Yes
HTTP3	Yes
UNICODE	No
ZSTD	Yes
HSTS	Yes
GSASL	No
Protocols	dict, file, ftp, ftps, gopher, gophers, http, https, imap, imaps, ldap, ldaps, mqtt, pop3, pop3s, rtmp, rtmpe, rtmps, rtmpt, rtmpte, rtmpts, rtsp, scp, sftp, smb, smbs, smtp, smtps, telnet, tftp, ws, wss
Host	x86_64-pc-linux-gnu
SSL Version	OpenSSL/3.5.1
ZLib Version	1.3.1
libSSH Version	libssh2/1.11.1
Directive	Local Value	Master Value
curl.cainfo	no value	no value
date
date/time support	enabled
timelib version	2022.12
"Olson" Timezone Database Version	2025.2
Timezone Database	internal
Default timezone	UTC
Directive	Local Value	Master Value
date.default_latitude	31.7667	31.7667
date.default_longitude	35.2333	35.2333
date.sunrise_zenith	90.833333	90.833333
date.sunset_zenith	90.833333	90.833333
date.timezone	UTC	UTC
dom
DOM/XML	enabled
DOM/XML API Version	20031129
libxml Version	2.9.14
HTML Support	enabled
XPath Support	enabled
XPointer Support	enabled
Schema Support	enabled
RelaxNG Support	enabled
fileinfo
fileinfo support	enabled
libmagic	545
filter
Input Validation and Filtering	enabled
Directive	Local Value	Master Value
filter.default	unsafe_raw	unsafe_raw
filter.default_flags	no value	no value
frankenphp
Version	v1.9.1
gd
GD Support	enabled
GD Version	bundled (2.1.0 compatible)
GIF Read Support	enabled
GIF Create Support	enabled
PNG Support	enabled
libPNG Version	1.6.48
WBMP Support	enabled
XBM Support	enabled
BMP Support	enabled
TGA Read Support	enabled
Directive	Local Value	Master Value
gd.jpeg_ignore_warning	On	On
gmp
gmp support	enabled
GMP version	6.3.0
hash
hash support	enabled
Hashing Engines	md2 md4 md5 sha1 sha224 sha256 sha384 sha512/224 sha512/256 sha512 sha3-224 sha3-256 sha3-384 sha3-512 ripemd128 ripemd160 ripemd256 ripemd320 whirlpool tiger128,3 tiger160,3 tiger192,3 tiger128,4 tiger160,4 tiger192,4 snefru snefru256 gost gost-crypto adler32 crc32 crc32b crc32c fnv132 fnv1a32 fnv164 fnv1a64 joaat murmur3a murmur3c murmur3f xxh32 xxh64 xxh3 xxh128 haval128,3 haval160,3 haval192,3 haval224,3 haval256,3 haval128,4 haval160,4 haval192,4 haval224,4 haval256,4 haval128,5 haval160,5 haval192,5 haval224,5 haval256,5
MHASH support	Enabled
MHASH API Version	Emulated Support
iconv
iconv support	enabled
iconv implementation	glibc
iconv library version	2.41
Directive	Local Value	Master Value
iconv.input_encoding	no value	no value
iconv.internal_encoding	no value	no value
iconv.output_encoding	no value	no value
intl
Internationalization support	enabled
ICU version	76.1
ICU Data version	76.1
ICU TZData version	2024b
ICU Unicode version	16.0
Directive	Local Value	Master Value
intl.default_locale	en	no value
intl.error_level	0	0
intl.use_exceptions	Off	Off
json
json support	enabled
libxml
libXML support	active
libXML Compiled Version	2.9.14
libXML Loaded Version	20914
libXML streams	enabled
mbstring
Multibyte Support	enabled
Multibyte string engine	libmbfl
HTTP input encoding translation	disabled
libmbfl version	1.3.2
mbstring extension makes use of "streamable kanji code filter and converter", which is distributed under the GNU Lesser General Public License version 2.1.
Multibyte (japanese) regex support	enabled
Multibyte regex (oniguruma) version	6.9.9
Directive	Local Value	Master Value
mbstring.detect_order	no value	no value
mbstring.encoding_translation	Off	Off
mbstring.http_input	no value	no value
mbstring.http_output	no value	no value
mbstring.http_output_conv_mimetypes	^(text/|application/xhtml\+xml)	^(text/|application/xhtml\+xml)
mbstring.internal_encoding	no value	no value
mbstring.language	neutral	neutral
mbstring.regex_retry_limit	1000000	1000000
mbstring.regex_stack_limit	100000	100000
mbstring.strict_detection	Off	Off
mbstring.substitute_character	no value	no value
mysqlnd
mysqlnd	enabled
Version	mysqlnd 8.4.12
Compression	supported
core SSL	supported
extended SSL	supported
Command buffer size	4096
Read buffer size	32768
Read timeout	86400
Collecting statistics	Yes
Collecting memory statistics	No
Tracing	n/a
Loaded plugins	mysqlnd,debug_trace,auth_plugin_mysql_native_password,auth_plugin_mysql_clear_password,auth_plugin_caching_sha2_password,auth_plugin_sha256_password
API Extensions	no value
openssl
OpenSSL support	enabled
OpenSSL Library Version	OpenSSL 3.5.1 1 Jul 2025
OpenSSL Header Version	OpenSSL 3.5.1 1 Jul 2025
Openssl default config	/usr/lib/ssl/openssl.cnf
Directive	Local Value	Master Value
openssl.cafile	no value	no value
openssl.capath	no value	no value
pcntl
pcntl support	enabled
pcre
PCRE (Perl Compatible Regular Expressions) Support	enabled
PCRE Library Version	10.44 2024-06-07
PCRE Unicode Version	15.0.0
PCRE JIT Support	enabled
PCRE JIT Target	x86 64bit (little endian + unaligned)
Directive	Local Value	Master Value
pcre.backtrack_limit	1000000	1000000
pcre.jit	On	On
pcre.recursion_limit	100000	100000
PDO
PDO support	enabled
PDO drivers	sqlite, pgsql
pdo_pgsql
PDO Driver for PostgreSQL	enabled
PostgreSQL(libpq) Version	17.5
pdo_sqlite
PDO Driver for SQLite 3.x	enabled
SQLite Library	3.46.1
Phar
Phar: PHP Archive support	enabled
Phar API version	1.1.1
Phar-based phar archives	enabled
Tar-based phar archives	enabled
ZIP-based phar archives	enabled
gzip compression	enabled
bzip2 compression	disabled (install ext/bz2)
Native OpenSSL support	enabled
Phar based on pear/PHP_Archive, original concept by Davey Shafik.
Phar fully realized by Gregory Beaver and Marcus Boerger.
Portions of tar implementation Copyright (c) 2003-2009 Tim Kientzle.
Directive	Local Value	Master Value
phar.cache_list	no value	no value
phar.readonly	On	On
phar.require_hash	On	On
posix
POSIX support	enabled
random
Version	8.4.12
readline
Readline Support	enabled
Readline library	8.2
Directive	Local Value	Master Value
cli.pager	no value	no value
cli.prompt	\b \>	\b \>
Reflection
Reflection	enabled
session
Session Support	enabled
Registered save handlers	files user
Registered serializer handlers	php_serialize php php_binary
Directive	Local Value	Master Value
session.auto_start	Off	Off
session.cache_expire	0	180
session.cache_limiter	no value	nocache
session.cookie_domain	no value	no value
session.cookie_httponly	On	Off
session.cookie_lifetime	0	0
session.cookie_path	/	/
session.cookie_samesite	lax	no value
session.cookie_secure	Off	Off
session.gc_divisor	100	100
session.gc_maxlifetime	28800	1440
session.gc_probability	1	1
session.lazy_write	On	On
session.name	sessionid	PHPSESSID
session.referer_check	no value	no value
session.save_handler	user	files
session.save_path	no value	no value
session.serialize_handler	php	php
session.sid_bits_per_character	4	4
session.sid_length	32	32
session.upload_progress.cleanup	On	On
session.upload_progress.enabled	On	On
session.upload_progress.freq	1%	1%
session.upload_progress.min_freq	1	1
session.upload_progress.name	PHP_SESSION_UPLOAD_PROGRESS	PHP_SESSION_UPLOAD_PROGRESS
session.upload_progress.prefix	upload_progress_	upload_progress_
session.use_cookies	On	On
session.use_only_cookies	On	On
session.use_strict_mode	On	Off
session.use_trans_sid	Off	Off
SimpleXML
SimpleXML support	enabled
Schema support	enabled
sodium
sodium support	enabled
libsodium headers version	1.0.18
libsodium library version	1.0.18
SPL
SPL support	enabled
Interfaces	OuterIterator, RecursiveIterator, SeekableIterator, SplObserver, SplSubject
Classes	AppendIterator, ArrayIterator, ArrayObject, BadFunctionCallException, BadMethodCallException, CachingIterator, CallbackFilterIterator, DirectoryIterator, DomainException, EmptyIterator, FilesystemIterator, FilterIterator, GlobIterator, InfiniteIterator, InvalidArgumentException, IteratorIterator, LengthException, LimitIterator, LogicException, MultipleIterator, NoRewindIterator, OutOfBoundsException, OutOfRangeException, OverflowException, ParentIterator, RangeException, RecursiveArrayIterator, RecursiveCachingIterator, RecursiveCallbackFilterIterator, RecursiveDirectoryIterator, RecursiveFilterIterator, RecursiveIteratorIterator, RecursiveRegexIterator, RecursiveTreeIterator, RegexIterator, RuntimeException, SplDoublyLinkedList, SplFileInfo, SplFileObject, SplFixedArray, SplHeap, SplMinHeap, SplMaxHeap, SplObjectStorage, SplPriorityQueue, SplQueue, SplStack, SplTempFileObject, UnderflowException, UnexpectedValueException
sqlite3
SQLite3 support	enabled
SQLite Library	3.46.1
Directive	Local Value	Master Value
sqlite3.defensive	On	On
sqlite3.extension_dir	no value	no value
standard
Dynamic Library Support	enabled
Path to sendmail	/usr/sbin/sendmail -t -i
Directive	Local Value	Master Value
assert.active	On	On
assert.bail	Off	Off
assert.callback	no value	no value
assert.exception	On	On
assert.warning	On	On
auto_detect_line_endings	Off	Off
default_socket_timeout	60	60
from	no value	no value
session.trans_sid_hosts	no value	no value
session.trans_sid_tags	a=href,area=href,frame=src,form=	a=href,area=href,frame=src,form=
unserialize_max_depth	4096	4096
url_rewriter.hosts	no value	no value
url_rewriter.tags	form=	form=
user_agent	no value	no value
tokenizer
Tokenizer Support	enabled
xml
XML Support	active
XML Namespace Support	active
libxml2 Version	2.9.14
xmlreader
XMLReader	enabled
xmlwriter
XMLWriter	enabled
Zend OPcache
Opcode Caching	Up and Running
Optimization	Enabled
SHM Cache	Enabled
File Cache	Disabled
JIT	Disabled
Startup	OK
Shared memory model	mmap
Cache hits	274
Cache misses	342
Used memory	13776936
Free memory	120440792
Wasted memory	0
Interned Strings Used memory	3615400
Interned Strings Free memory	4773208
Cached scripts	244
Cached keys	477
Max keys	16229
OOM restarts	0
Hash keys restarts	0
Manual restarts	0
Start time	2025-09-08T07:57:46+0000
Last restart time	none
Last force restart time	none
Directive	Local Value	Master Value
opcache.blacklist_filename	no value	no value
opcache.dups_fix	Off	Off
opcache.enable	On	On
opcache.enable_cli	Off	Off
opcache.enable_file_override	Off	Off
opcache.error_log	no value	no value
opcache.file_cache	no value	no value
opcache.file_cache_consistency_checks	On	On
opcache.file_cache_only	Off	Off
opcache.file_update_protection	2	2
opcache.force_restart_timeout	180	180
opcache.huge_code_pages	Off	Off
opcache.interned_strings_buffer	8	8
opcache.jit	disable	disable
opcache.jit_bisect_limit	0	0
opcache.jit_blacklist_root_trace	16	16
opcache.jit_blacklist_side_trace	8	8
opcache.jit_buffer_size	64M	64M
opcache.jit_debug	0	0
opcache.jit_hot_func	127	127
opcache.jit_hot_loop	64	64
opcache.jit_hot_return	8	8
opcache.jit_hot_side_exit	8	8
opcache.jit_max_exit_counters	8192	8192
opcache.jit_max_loop_unrolls	8	8
opcache.jit_max_polymorphic_calls	2	2
opcache.jit_max_recursive_calls	2	2
opcache.jit_max_recursive_returns	2	2
opcache.jit_max_root_traces	1024	1024
opcache.jit_max_side_traces	128	128
opcache.jit_max_trace_length	1024	1024
opcache.jit_prof_threshold	0.005	0.005
opcache.lockfile_path	/tmp	/tmp
opcache.log_verbosity_level	1	1
opcache.max_accelerated_files	10000	10000
opcache.max_file_size	0	0
opcache.max_wasted_percentage	5	5
opcache.memory_consumption	128	128
opcache.opt_debug_level	0	0
opcache.optimization_level	0x7FFEBFFF	0x7FFEBFFF
opcache.preferred_memory_model	no value	no value
opcache.preload	no value	no value
opcache.preload_user	no value	no value
opcache.protect_memory	Off	Off
opcache.record_warnings	Off	Off
opcache.restrict_api	no value	no value
opcache.revalidate_freq	2	2
opcache.revalidate_path	Off	Off
opcache.save_comments	On	On
opcache.use_cwd	On	On
opcache.validate_permission	Off	Off
opcache.validate_root	Off	Off
opcache.validate_timestamps	Off	Off
zip
Zip	enabled
Zip version	1.22.6
Libzip version	1.11.3
BZIP2 compression	Yes
XZ compression	Yes
ZSTD compression	Yes
AES-128 encryption	Yes
AES-192 encryption	Yes
AES-256 encryption	Yes
zlib
ZLib Support	enabled
Stream Wrapper	compress.zlib://
Stream Filter	zlib.inflate, zlib.deflate
Compiled Version	1.3.1
Linked Version	1.3.1
Directive	Local Value	Master Value
zlib.output_compression	Off	Off
zlib.output_compression_level	-1	-1
zlib.output_handler	no value	no value
Additional Modules
Module Name
Environment
Variable	Value
HOSTNAME	8a0bde0c86fe
PHP_INI_DIR	/usr/local/etc/php
HOME	/root
GODEBUG	cgocheck=0
PHP_LDFLAGS	-Wl,-O1 -pie
PHP_CFLAGS	-fstack-protector-strong -fpic -fpie -O2 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
PHP_VERSION	8.4.12
GPG_KEYS	AFD8691FDAEDF03BDF6E460563F15A9B715376CA 9D7F99A0CB8F05C8A6958D6256A97AF7600A39A6 0616E93D95AF471243E26761770426E17EBBB3DD
PHP_CPPFLAGS	-fstack-protector-strong -fpic -fpie -O2 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
PHP_ASC_URL	https://www.php.net/distributions/php-8.4.12.tar.xz.asc
PHP_URL	https://www.php.net/distributions/php-8.4.12.tar.xz
PATH	/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
XDG_CONFIG_HOME	/config
XDG_DATA_HOME	/data
PHPIZE_DEPS	autoconf dpkg-dev file g++ gcc libc-dev make pkg-config re2c
PWD	/app
PHP_SHA256	c1b7978cbb5054eed6c749bde4444afc16a3f2268101fb70a7d5d9b1083b12ad
LINES	50
COLUMNS	80
SHELL_VERBOSITY	0
PHP Variables
Variable	Value
$_COOKIE['sessionid']	a829554456b04c3acf7913639f6d919b
$_COOKIE['locale']	en
$_SERVER['COLUMNS']	80
$_SERVER['PHP_CFLAGS']	-fstack-protector-strong -fpic -fpie -O2 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
$_SERVER['XDG_DATA_HOME']	/data
$_SERVER['HOSTNAME']	8a0bde0c86fe
$_SERVER['PHP_INI_DIR']	/usr/local/etc/php
$_SERVER['PHP_LDFLAGS']	-Wl,-O1 -pie
$_SERVER['PHP_CPPFLAGS']	-fstack-protector-strong -fpic -fpie -O2 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
$_SERVER['PHP_URL']	https://www.php.net/distributions/php-8.4.12.tar.xz
$_SERVER['XDG_CONFIG_HOME']	/config
$_SERVER['SHELL_VERBOSITY']	0
$_SERVER['HOME']	/root
$_SERVER['GPG_KEYS']	AFD8691FDAEDF03BDF6E460563F15A9B715376CA 9D7F99A0CB8F05C8A6958D6256A97AF7600A39A6 0616E93D95AF471243E26761770426E17EBBB3DD
$_SERVER['PHP_ASC_URL']	https://www.php.net/distributions/php-8.4.12.tar.xz.asc
$_SERVER['LINES']	50
$_SERVER['GODEBUG']	cgocheck=0
$_SERVER['PHP_VERSION']	8.4.12
$_SERVER['PATH']	/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
$_SERVER['PHPIZE_DEPS']	autoconf dpkg-dev file g++ gcc libc-dev make pkg-config re2c
$_SERVER['PWD']	/app
$_SERVER['PHP_SHA256']	c1b7978cbb5054eed6c749bde4444afc16a3f2268101fb70a7d5d9b1083b12ad
$_SERVER['REMOTE_ADDR']	213.202.223.72
$_SERVER['REMOTE_HOST']	213.202.223.72
$_SERVER['REMOTE_PORT']	55732
$_SERVER['DOCUMENT_ROOT']	/app/public
$_SERVER['PATH_INFO']	no value
$_SERVER['PHP_SELF']	/index.php
$_SERVER['DOCUMENT_URI']	/index.php
$_SERVER['SCRIPT_FILENAME']	/app/public/index.php
$_SERVER['SCRIPT_NAME']	/index.php
$_SERVER['HTTPS']	no value
$_SERVER['SSL_PROTOCOL']	no value
$_SERVER['SSL_CIPHER']	no value
$_SERVER['REQUEST_SCHEME']	http
$_SERVER['SERVER_NAME']	91.99.211.138
$_SERVER['SERVER_PORT']	8000
$_SERVER['CONTENT_LENGTH']	no value
$_SERVER['GATEWAY_INTERFACE']	CGI/1.1
$_SERVER['SERVER_PROTOCOL']	HTTP/1.1
$_SERVER['SERVER_SOFTWARE']	FrankenPHP
$_SERVER['HTTP_HOST']	91.99.211.138:8000
$_SERVER['AUTH_TYPE']	no value
$_SERVER['REMOTE_IDENT']	no value
$_SERVER['REQUEST_URI']	/
$_SERVER['CONTENT_TYPE']	no value
$_SERVER['QUERY_STRING']	no value
$_SERVER['REQUEST_METHOD']	GET
$_SERVER['HTTP_ACCEPT_LANGUAGE']	en-US,en;q=0.9
$_SERVER['HTTP_COOKIE']	sessionid=a829554456b04c3acf7913639f6d919b; locale=en
$_SERVER['HTTP_CACHE_CONTROL']	max-age=0
$_SERVER['HTTP_UPGRADE_INSECURE_REQUESTS']	1
$_SERVER['HTTP_ACCEPT_ENCODING']	gzip, deflate
$_SERVER['HTTP_CONNECTION']	keep-alive
$_SERVER['HTTP_USER_AGENT']	Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36
$_SERVER['HTTP_ACCEPT']	text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7
$_SERVER['REQUEST_TIME_FLOAT']	1757318297.6583
$_SERVER['REQUEST_TIME']	1757318297
$_SERVER['argv']	
Array
(
)
$_SERVER['argc']	0
$_ENV['LINES']	50
$_ENV['GODEBUG']	cgocheck=0
$_ENV['PHP_VERSION']	8.4.12
$_ENV['PATH']	/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
$_ENV['PHPIZE_DEPS']	autoconf dpkg-dev file g++ gcc libc-dev make pkg-config re2c
$_ENV['PWD']	/app
$_ENV['PHP_SHA256']	c1b7978cbb5054eed6c749bde4444afc16a3f2268101fb70a7d5d9b1083b12ad
$_ENV['COLUMNS']	80
$_ENV['PHP_CFLAGS']	-fstack-protector-strong -fpic -fpie -O2 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
$_ENV['XDG_DATA_HOME']	/data
$_ENV['HOSTNAME']	8a0bde0c86fe
$_ENV['PHP_INI_DIR']	/usr/local/etc/php
$_ENV['PHP_LDFLAGS']	-Wl,-O1 -pie
$_ENV['PHP_CPPFLAGS']	-fstack-protector-strong -fpic -fpie -O2 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
$_ENV['PHP_URL']	https://www.php.net/distributions/php-8.4.12.tar.xz
$_ENV['XDG_CONFIG_HOME']	/config
$_ENV['SHELL_VERBOSITY']	0
$_ENV['HOME']	/root
$_ENV['GPG_KEYS']	AFD8691FDAEDF03BDF6E460563F15A9B715376CA 9D7F99A0CB8F05C8A6958D6256A97AF7600A39A6 0616E93D95AF471243E26761770426E17EBBB3DD
$_ENV['PHP_ASC_URL']	https://www.php.net/distributions/php-8.4.12.tar.xz.asc

Relevant log output

[nickchomey]

what is your application like? is it doing a lot of database queries or disk i/o? external http requests? What is the RAM like during the load test - does it max out?

If you run caddy + php-fpm right now, does it get 600 rps? If not, perhaps something changed in the app.

[supriyo-biswas]

@nickchomey the current version of the app can do 600 RPS under PHP-FPM, and the setups are comparable (same system spec, same RAM etc).

It is a pretty “normal” application that stores sessions in Redis and writes some entries to the database. Although in my load test, the database is never touched as it doesn’t save anything, and network latency can be eliminated as a source since I run all components (DB, Redis etc) on the same server for this load test.

[withinboredom]

Usually when we see this, it is due to something taking a global lock during a request, thus resulting in a single request being able to performed at a time. I noticed you have the SHM Cache feature turned on, which does take a global lock, but that shouldn't be an issue once all your PHP files have been compiled.

I was really hoping php/php-src#16565 would have been merged into 8.5, so we could fix a lot of this stuff by only taking a full lock when we need to actually write to the data structure, and a shared lock when reading.

Anyway, this might be a regression somewhere where we are unnecessarily taking a global lock on each request. Or it could be an extension doing the same. You mention using Redis, is there any other extension you're using during your tests?

[AlliBalliBaba]

Are you using some kind of framework, how many CPU cores are you using? Is it the same if you disable access logs?

150 RPS seems kinda low if you are just doing stress testing, would need some more information about the application itself.

[supriyo-biswas]

@withinboredom

Anyway, this might be a regression somewhere where we are unnecessarily taking a global lock on each request. Or it could be an extension doing the same. You mention using Redis, is there any other extension you're using during your tests?

My Dockerfile containing the list of all modules used is as follows; the caddyfile being used is the one above.

FROM dunglas/frankenphp:1-php8.4
RUN apt-get update && apt-get install -y \
    libpq-dev \
    libicu-dev \
    libzip-dev \
    libgmp-dev \
    libpng-dev \
    libjpeg-dev \
    && docker-php-ext-install \
    pdo_pgsql \
    intl \
    zip \
    pcntl \
    gmp \
    gd \
    && apt-get remove -y \
    libpq-dev \
    libicu-dev \
    libzip-dev \
    libgmp-dev \
    libpng-dev \
    libjpeg-dev \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /app

COPY . .
RUN mkdir -p data && ln -s /tmp data/cache

EXPOSE 80
CMD ["usr/local/bin/frankenphp", "run", "--config", "/app/Caddyfile"]

@AlliBalliBaba

Are you using some kind of framework, how many CPU cores are you using? Is it the same if you disable access logs?

The application is something custom written on top of Symfony's HTTPFoundation, but the code is nothing special. Are there specific suggestions I could look at, like somehow being able to profile the code to know where the time is being spent? Is there a guide I could use?

[AlliBalliBaba]

Yes you can use Xdebug to create a CPU profile and flamegraph. There are some guides out there like this one, but in worker mode you have to manually call xdebug_start_trace and xdebug_stop_trace at the beginning and end of the request.

I also suspect you are running into some locking behavior and based on your installed extensions it might be some kind of file based locking. Are you maybe using native or file based sessions? (since there does not seem to be redis installed)

Increasing the amount of threads usually only helps if you are doing slow IO (which you aren't if everything is local)

If you are able to give a small reproducer in code of an endpoint that becomes slow that might also help greatly.

[AlliBalliBaba]

If it's a custom worker mode implementation, it might also help sharing the worker setup code

[supriyo-biswas]

Sorry for the noise, apparently the issue was a network throttling issue by my ISP where traffic to non-80/443 ports were being throttled, and the FrankenPHP setup was exposed outside of these ports.

Moving to a different network, I found FrankenPHP being able to do ~1400 RPS.
Thank you.