Swoole sending check_worker_exit_status() log - php

Question

I have a problem while using laravel with swoole on php 8.1.Some requests finished with HTTP 408 sometimes. Then when I looked at the log file, I saw the following error.
[2022-07-29 08:59:52 $28.0] WARNING Server::check_worker_exit_status(): worker(pid=49, id=4) abnormal exit, status=0, signal=9
then I watched all the processes with "strace" command. I saw the worker killed by manager process. Logs are bellow:
ps -aux
www 54 0.0 0.9 473088 39424 ? Sl 12:40 0:00 swoole_http_server: master process
www 65 0.0 0.5 401440 21036 ? S 12:40 0:00 swoole_http_server: manager process
www 1608 0.2 1.3 427668 52384 ? S 13:19 0:00 swoole_http_server: worker process
strace.log:
54 13:27:40.909415 kill(1608, 0) = 0
54 13:27:40.909598 kill(1608, SIGKILL) = 0
1608 13:27:40.943992 +++ killed by SIGKILL +++
65 13:27:40.944275 --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=1608, si_uid=1111, si_status=SIGKILL, si_utime=3840, si_stime=1000} ---
65 13:27:40.944400 rt_sigreturn({mask=[]}) = 1608
I tryed a lot of things but not fixed this problem. How can i deal it?
php -v:
PHP 8.1.8 (cli) (built: Jul 11 2022 08:30:39) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.1.8, Copyright (c) Zend Technologies
with Zend OPcache v8.1.8, Copyright (c), by Zend Technologies
php --ri swoole
swoole
Swoole => enabled
Author => Swoole Team <team#swoole.com>
Version => 4.8.10
Built => Jul 6 2022 13:14:29
coroutine => enabled with boost asm context
epoll => enabled
eventfd => enabled
signalfd => enabled
cpu_affinity => enabled
spinlock => enabled
rwlock => enabled
sockets => enabled
openssl => OpenSSL 3.0.2 15 Mar 2022
dtls => enabled
http2 => enabled
json => enabled
curl-native => enabled
pcre => enabled
mutex_timedlock => enabled
pthread_barrier => enabled
futex => enabled
mysqlnd => enabled
async_redis => enabled
Directive => Local Value => Master Value
swoole.enable_coroutine => On => On
swoole.enable_library => On => On
swoole.enable_preemptive_scheduler => Off => Off
swoole.display_errors => On => On
swoole.use_shortname => On => On
swoole.unixsock_buffer_size => 8388608 => 8388608
php artisan --version
Laravel Framework 9.21.3
uname -a
Linux 9968d896fe6c 5.15.0-41-generic #44-Ubuntu SMP Wed Jun 22 14:20:53 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
gcc -v
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 11.2.0-19ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-11-gBFGDP/gcc-11-11.2.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-gBFGDP/gcc-11-11.2.0/debian/tmp-gcn/usr --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.2.0 (Ubuntu 11.2.0-19ubuntu1)