今天是个好日子。在将高负载后端 php 服务器迁移到新服务器后，我遇到了问题。 （ 投入的 ） 。为此我开始比较 ubuntu 16 和 20（18 相同）。
我购买了 2 个类似的 m5.large aws 实例并简单地检查：
简单的脚本strace -c php -r " exit(1);"
这给了我
ubuntu@ip-172-31-40-209:~$ sudo uname -srm
Linux 5.4.0-1009-aws x86_64
ubuntu@ip-172-31-40-209:~$ sudo php --version
PHP 7.3.17-1+ubuntu20.04.1+deb.sury.org+1 (cli) (built: Apr 28 2020 14:49:03) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.17, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.3.17-1+ubuntu20.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies
ubuntu@ip-172-31-40-209:~$ sudo sysctl -a | grep vm.nr_hugepages
vm.nr_hugepages = 0
vm.nr_hugepages_mempolicy = 0
ubuntu@ip-172-31-40-209:~$ cat /sys/kernel/mm/transparent_hugepage/enabled
always [madvise] never
ubuntu@ip-172-31-40-209:~$ cat /sys/kernel/mm/transparent_hugepage/defrag
always defer defer+madvise [madvise] never
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
31.94 0.002967 18 157 munmap
27.64 0.002567 4 549 1 mmap
12.12 0.001126 6 173 mprotect
9.32 0.000866 4 182 5 openat
4.86 0.000451 3 135 1 read
4.35 0.000404 2 182 close
3.63 0.000337 1 181 fstat
1.48 0.000137 6 20 futex
1.02 0.000095 3 26 brk
0.74 0.000069 69 1 poll
0.60 0.000056 0 85 rt_sigaction
0.54 0.000050 4 11 fcntl
0.36 0.000033 8 4 write
0.25 0.000023 11 2 writev
0.18 0.000017 2 8 getpid
0.17 0.000016 4 4 uname
0.12 0.000011 11 1 sysinfo
0.12 0.000011 3 3 getrandom
0.11 0.000010 10 1 connect
0.10 0.000009 0 40 1 stat
0.06 0.000006 6 1 unlink
0.06 0.000006 6 1 fchmod
0.05 0.000005 2 2 socket
0.04 0.000004 2 2 gettid
0.03 0.000003 1 2 rt_sigprocmask
0.03 0.000003 1 3 2 access
0.02 0.000002 2 1 getegid
0.01 0.000001 1 1 getuid
0.01 0.000001 1 1 getgid
0.01 0.000001 1 1 geteuid
0.01 0.000001 1 1 getppid
0.00 0.000000 0 8 3 lstat
0.00 0.000000 0 43 3 lseek
0.00 0.000000 0 39 39 ioctl
0.00 0.000000 0 8 pread64
0.00 0.000000 0 1 execve
0.00 0.000000 0 1 getcwd
0.00 0.000000 0 2 readlink
0.00 0.000000 0 3 getrusage
0.00 0.000000 0 2 1 arch_prctl
0.00 0.000000 0 2 getdents64
0.00 0.000000 0 1 set_tid_address
0.00 0.000000 0 1 set_robust_list
0.00 0.000000 0 2 prlimit64
------ ----------- ----------- --------- --------- ----------------
100.00 0.009288 1894 56 total
https://gist.github.com/futureisrise/46cc3d0bb55e612038fb7a95bc5efbfa完整的 strace 调用。
相同的脚本在 ubuntu 16 上运行。
ubuntu@ip-172-31-44-252:~$ sudo uname -srm
Linux 4.4.0-1105-aws x86_64
ubuntu@ip-172-31-44-252:~$ sudo php -v
PHP 7.3.17-1+ubuntu16.04.1+deb.sury.org+1 (cli) (built: Apr 19 2020 07:44:05) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.17, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.3.17-1+ubuntu16.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies
ubuntu@ip-172-31-44-252:~$sudo sysctl -a | grep vm.nr_hugepages
sysctl: reading key "net.ipv6.conf.all.stable_secret"
sysctl: reading key "net.ipv6.conf.default.stable_secret"
sysctl: reading key "net.ipv6.conf.ens5.stable_secret"
sysctl: reading key "net.ipv6.conf.lo.stable_secret"
vm.nr_hugepages = 0
vm.nr_hugepages_mempolicy = 0
ubuntu@ip-172-31-44-252:~$ cat /sys/kernel/mm/transparent_hugepage/enabled
always [madvise] never
ubuntu@ip-172-31-44-252:~$ cat /sys/kernel/mm/transparent_hugepage/defrag
[always] madvise never
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
0.00 0.000000 0 46 read
0.00 0.000000 0 69 3 open
0.00 0.000000 0 69 close
0.00 0.000000 0 20 stat
0.00 0.000000 0 73 fstat
0.00 0.000000 0 8 3 lstat
0.00 0.000000 0 24 3 lseek
0.00 0.000000 0 130 mmap
0.00 0.000000 0 81 mprotect
0.00 0.000000 0 52 munmap
0.00 0.000000 0 12 brk
0.00 0.000000 0 80 rt_sigaction
0.00 0.000000 0 2 rt_sigprocmask
0.00 0.000000 0 20 20 ioctl
0.00 0.000000 0 24 23 access
0.00 0.000000 0 1 execve
0.00 0.000000 0 2 getdents
0.00 0.000000 0 1 getcwd
0.00 0.000000 0 2 readlink
0.00 0.000000 0 2 getrlimit
0.00 0.000000 0 1 sysinfo
0.00 0.000000 0 1 arch_prctl
0.00 0.000000 0 19 futex
0.00 0.000000 0 1 set_tid_address
0.00 0.000000 0 1 clock_getres
0.00 0.000000 0 1 set_robust_list
0.00 0.000000 0 2 getrandom
------ ----------- ----------- --------- --------- ----------------
100.00 0.000000 744 52 total
详细信息在这里https://gist.github.com/futureisrise/de0a54d28e794c4d9bff714a1cbd21e1
正如我们所看到的，ubuntu 16 速度快了很多倍。还通过 blackfire io、newrelic 等进行了测试。当出现 DDOS 攻击时 - 服务器 CPU 负载非常高。
为了让这个测试清楚 - 刚刚安装
add-apt-repository ppa:ondrej/php
apt update
apt install strace php7.3 php7.3-cli