最近由于在mac上配置了php_debug后，经常遇到Too many open files..
当发生这个错误后，重启一下php-fpm就能临时解决，但是过一段时间又会出现这个问题。
首先理解一下出现这个错误的原因
too many open files(打开的文件过多)是Linux系统中常见的错误，从字面意思上看就是说程序打开的文件数过多，不过这里的files不单是文件的意思，也包括打开的通讯链接(比如socket)，正在监听的端口等等，所以有时候也可以叫做句柄(handle)，这个错误通常也可以叫做句柄数超出系统限制。
引起的原因就是进程在某个时刻打开了超过系统限制的文件数量以及通讯链接数，通过命令ulimit -a可以查看当前系统设置的最大句柄数是多少：
Last login: Fri Jun 28 11:21:18 on ttys001
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ulimit -awenqidongdeMBP:~ wenqidong$ ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
file size (blocks, -f) unlimited
max locked memory (kbytes, -l) unlimited
max memory size (kbytes, -m) unlimited
open files (-n) 256
pipe size (512 bytes, -p) 1
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 1418
virtual memory (kbytes, -v) unlimited
wenqidongdeMBP:~ wenqidong$ 这里可以看到 open files是 256 ;
现在找出php-fpm的进程
ps -ef | grep php-fpm显示有4个进程ID
wenqidongdeMBP:log wenqidong$ ps -ef | grep php-fpm
501 35602 1 0 5:47下午 ?? 0:00.72 php-fpm
501 35603 35602 0 5:47下午 ?? 0:04.63 php-fpm
501 35604 35602 0 5:47下午 ?? 0:05.81 php-fpm
501 35618 35602 0 5:47下午 ?? 0:05.47 php-fpm
501 37485 37420 0 11:43上午 ttys001 0:00.00 grep php-fpm接着再看一下每个进程ID打开文件的情况
使用命令lsof -p 进程id可以查看单个进程所有打开的文件详情，使用命令lsof -p 进程id | wc -l可以统计进程打开了多少文件：
wenqidongdeMBP:log wenqidong$ lsof -p 35604 | wc -l
292
wenqidongdeMBP:log wenqidong$ lsof -p 35603 | wc -l
290
wenqidongdeMBP:log wenqidong$ lsof -p 35602 | wc -l
46
wenqidongdeMBP:log wenqidong$ lsof -p 35618 | wc -l
291可以看到四个进程，其中有3个已经超过设定值 256了 。看一下第一个进程主要是打开发哪些文件:
wenqidongdeMBP:log wenqidong$ lsof -p 35604
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
php-fpm 35604 wenqidong cwd DIR 1,5 288 4319917140 /Users/wenqidong/log
php-fpm 35604 wenqidong txt REG 1,5 12324224 4317891463 /usr/local/Cellar/php@7.1/7.1.23/sbin/php-fpm
php-fpm 35604 wenqidong txt REG 1,5 1871160 4324689703 /usr/local/Cellar/openssl/1.0.2r/lib/libcrypto.1.0.0.dylib
php-fpm 35604 wenqidong txt REG 1,5 377416 4324689719 /usr/local/Cellar/openssl/1.0.2r/lib/libssl.1.0.0.dylib
php-fpm 35604 wenqidong txt REG 1,5 86408 4317895710 /usr/local/Cellar/libzip/1.5.1/lib/libzip.5.0.dylib
php-fpm 35604 wenqidong txt REG 1,5 21344 4317860737 /usr/local/Cellar/libmemcached/1.0.18_2/lib/libmemcachedutil.2.dylib
php-fpm 35604 wenqidong txt REG 1,5 466696 4317867063 /usr/local/Cellar/aspell/0.60.6.1_1/lib/libaspell.15.dylib
php-fpm 35604 wenqidong txt REG 1,5 8320 4317867062 /usr/local/Cellar/aspell/0.60.6.1_1/lib/libpspell.15.dylib
php-fpm 35604 wenqidong txt REG 1,5 21024 4328486783 /Library/Preferences/Logging/.plist-cache.4T8M7S65
php-fpm 35604 wenqidong txt REG 1,5 247244 4319476119 /usr/local/Cellar/libpq/11.1/lib/libpq.5.11.dylib
php-fpm 35604 wenqidong txt REG 1,5 365056 4317869946 /usr/local/Cellar/freetds/1.00.104/lib/libsybdb.5.dylib
php-fpm 35604 wenqidong txt REG 1,5 186368 4317889344 /usr/local/Cellar/mcrypt/2.6.8/lib/libmcrypt.4.4.8.dylib
php-fpm 35604 wenqidong txt REG 1,5 35772 4317867478 /usr/local/Cellar/libtool/2.4.6_1/lib/libltdl.7.dylib
php-fpm 35604 wenqidong txt REG 1,5 252820 4317889787 /usr/local/Cellar/openldap/2.4.46/lib/libldap-2.4.2.10.9.dylib
php-fpm 35604 wenqidong txt REG 1,5 52272 4317889793 /usr/local/Cellar/openldap/2.4.46/lib/liblber-2.4.2.10.9.dylib
php-fpm 35604 wenqidong txt REG 1,5 1052984 4317874398 /usr/local/Cellar/libiconv/1.15/lib/libiconv.2.dylib
php-fpm 35604 wenqidong txt REG 1,5 418480 4317874180 /usr/local/Cellar/gmp/6.1.2_2/lib/libgmp.10.dylib
php-fpm 35604 wenqidong txt REG 1,5 50172 4316294820 /usr/local/Cellar/gettext/0.19.8.1/lib/libintl.8.dylib
php-fpm 35604 wenqidong txt REG 1,5 177300 4327727898 /usr/local/Cellar/libpng/1.6.37/lib/libpng16.16.dylib
php-fpm 35604 wenqidong txt REG 1,5 211376 4317874275 /usr/local/Cellar/jpeg/9c/lib/libjpeg.9.dylib
php-fpm 35604 wenqidong txt REG 1,5 391080 4327730306 /usr/local/Cellar/webp/1.0.2/lib/libwebp.7.dylib
php-fpm 35604 wenqidong txt REG 1,5 605540 4327728087 /usr/local/Cellar/freetype/2.10.0/lib/libfreetype.6.dylib
php-fpm 35604 wenqidong txt REG 1,5 2534440 4316030936 /usr/local/Cellar/icu4c/62.1/lib/libicui18n.62.1.dylib
php-fpm 35604 wenqidong txt REG 1,5 1552904 4316030955 /usr/local/Cellar/icu4c/62.1/lib/libicuuc.62.1.dylib
php-fpm 35604 wenqidong txt REG 1,5 26841184 4316030962 /usr/local/Cellar/icu4c/62.1/lib/libicudata.62.1.dylib
php-fpm 35604 wenqidong txt REG 1,5 60840 4316030951 /usr/local/Cellar/icu4c/62.1/lib/libicuio.62.1.dylib
php-fpm 35604 wenqidong txt REG 1,5 373876 4317867695 /usr/local/Cellar/unixodbc/2.3.7/lib/libodbc.2.dylib
php-fpm 35604 wenqidong txt REG 1,5 282788 4320679594 /usr/local/lib/php/pecl/20160303/xdebug.so
php-fpm 35604 wenqidong txt REG 1,5 318992 4317891470 /usr/local/Cellar/php@7.1/7.1.23/lib/php/20160303/opcache.so
php-fpm 35604 wenqidong txt REG 1,5 1558496 4324460045 /usr/local/lib/php/pecl/20160303/swoole.so
php-fpm 35604 wenqidong txt REG 1,5 558048 4319499935 /usr/local/Cellar/brotli/1.0.7/lib/libbrotlienc.1.0.7.dylib
php-fpm 35604 wenqidong txt REG 1,5 80932 4317896198 /usr/local/Cellar/zlib/1.2.11/lib/libz.1.2.11.dylib
php-fpm 35604 wenqidong txt REG 1,5 135712 4319499932 /usr/local/Cellar/brotli/1.0.7/lib/libbrotlicommon.1.0.7.dylib
php-fpm 35604 wenqidong txt REG 1,5 105296 4317957996 /usr/local/lib/php/pecl/20160303/memcached.so
php-fpm 35604 wenqidong txt REG 1,5 174320 4317860735 /usr/local/Cellar/libmemcached/1.0.18_2/lib/libmemcached.11.dylib
php-fpm 35604 wenqidong txt REG 1,5 444412 4317963414 /usr/local/lib/php/pecl/20160303/redis.so
php-fpm 35604 wenqidong txt REG 1,5 973824 4325410994 /usr/lib/dyld
php-fpm 35604 wenqidong 0u CHR 3,2 0t16121 311 /dev/null
php-fpm 35604 wenqidong 1u CHR 3,2 0t16121 311 /dev/null
php-fpm 35604 wenqidong 2u CHR 3,2 0t16121 311 /dev/null
php-fpm 35604 wenqidong 3u REG 1,5 0 4329100708 /private/tmp/.ZendSem.dcK8t4
php-fpm 35604 wenqidong 5w REG 1,5 81054 4329084751 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php
php-fpm 35604 wenqidong 6u IPv4 0xc4c9d0d2760506b1 0t0 TCP localhost:cslistener (LISTEN)
php-fpm 35604 wenqidong 7w REG 1,5 349924 4329100717 /Users/wenqidong/log/xdebug/trace.3130015676.35604.xt
php-fpm 35604 wenqidong 8w REG 1,5 62076 4329100730 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.009a55
php-fpm 35604 wenqidong 9w REG 1,5 253848 4329100732 /Users/wenqidong/log/xdebug/trace.3130015676.35604.027687.xt
php-fpm 35604 wenqidong 10w REG 1,5 121711 4329100745 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.031571
php-fpm 35604 wenqidong 11w REG 1,5 828 4329100722 /Users/wenqidong/log/xdebug/trace.1573365040.35604.xt
php-fpm 35604 wenqidong 12 NPOLICY
php-fpm 35604 wenqidong 13u unix 0xc4c9d0d27255d569 0t0 ->0xc4c9d0d27255c5c9
php-fpm 35604 wenqidong 14w REG 1,5 577126 4329100746 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0dfb13.xt
php-fpm 35604 wenqidong 15w REG 1,5 79743 4329100762 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0c055a
php-fpm 35604 wenqidong 16w REG 1,5 344300 4329100763 /Users/wenqidong/log/xdebug/trace.3130015676.35604.080774.xt
php-fpm 35604 wenqidong 17w REG 1,5 81125 4329100781 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.015da7
php-fpm 35604 wenqidong 18w REG 1,5 828 4329100753 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0c058a.xt
php-fpm 35604 wenqidong 19w REG 1,5 349940 4329100782 /Users/wenqidong/log/xdebug/trace.3130015676.35604.09bd38.xt
php-fpm 35604 wenqidong 20w REG 1,5 121578 4329100797 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0b76ed
php-fpm 35604 wenqidong 21w REG 1,5 828 4329100772 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0a4b13.xt
php-fpm 35604 wenqidong 22w REG 1,5 577126 4329100798 /Users/wenqidong/log/xdebug/trace.3130015676.35604.075790.xt
php-fpm 35604 wenqidong 23w REG 1,5 100853 4329100817 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0532f6
php-fpm 35604 wenqidong 24w REG 1,5 828 4329100783 /Users/wenqidong/log/xdebug/trace.1573365040.35604.09d5a3.xt
php-fpm 35604 wenqidong 25w REG 1,5 460091 4329100818 /Users/wenqidong/log/xdebug/trace.3130015676.35604.046009.xt
php-fpm 35604 wenqidong 26w REG 1,5 112764 4329100898 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.021fb3
php-fpm 35604 wenqidong 27w REG 1,5 828 4329100803 /Users/wenqidong/log/xdebug/trace.1573365040.35604.08c199.xt
php-fpm 35604 wenqidong 28w REG 1,5 528724 4329100899 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0090e9.xt
php-fpm 35604 wenqidong 29w REG 1,5 101627 4329100959 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.00361d
php-fpm 35604 wenqidong 30w REG 1,5 828 4329100819 /Users/wenqidong/log/xdebug/trace.1573365040.35604.036be2.xt
php-fpm 35604 wenqidong 31w REG 1,5 464438 4329100960 /Users/wenqidong/log/xdebug/trace.3130015676.35604.017861.xt
php-fpm 35604 wenqidong 32w REG 1,5 101754 4329100991 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.00ad44
php-fpm 35604 wenqidong 33w REG 1,5 828 4329100900 /Users/wenqidong/log/xdebug/trace.1573365040.35604.05a9e6.xt
php-fpm 35604 wenqidong 34w REG 1,5 464438 4329100992 /Users/wenqidong/log/xdebug/trace.3130015676.35604.03f2e4.xt
php-fpm 35604 wenqidong 35w REG 1,5 101620 4329101017 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.02752c
php-fpm 35604 wenqidong 36w REG 1,5 828 4329100961 /Users/wenqidong/log/xdebug/trace.1573365040.35604.022ab6.xt
php-fpm 35604 wenqidong 37w REG 1,5 464438 4329101018 /Users/wenqidong/log/xdebug/trace.3130015676.35604.00f433.xt
php-fpm 35604 wenqidong 38w REG 1,5 79754 4329101025 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.062e1e
php-fpm 35604 wenqidong 39w REG 1,5 828 4329100993 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0b73dc.xt
php-fpm 35604 wenqidong 40w REG 1,5 344300 4329101026 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0c601d.xt
php-fpm 35604 wenqidong 41w REG 1,5 89439 4329101047 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0c7a45
php-fpm 35604 wenqidong 42w REG 1,5 828 4329101019 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0b7772.xt
php-fpm 35604 wenqidong 43w REG 1,5 394710 4329101048 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0a433b.xt
php-fpm 35604 wenqidong 44w REG 1,5 126704 4329101069 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0a76d9
php-fpm 35604 wenqidong 45w REG 1,5 828 4329101035 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0c08d9.xt
php-fpm 35604 wenqidong 46w REG 1,5 610170 4329101070 /Users/wenqidong/log/xdebug/trace.3130015676.35604.08c949.xt
php-fpm 35604 wenqidong 47w REG 1,5 88675 4329101078 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.084535
php-fpm 35604 wenqidong 48w REG 1,5 828 4329101050 /Users/wenqidong/log/xdebug/trace.1573365040.35604.028edb.xt
php-fpm 35604 wenqidong 49w REG 1,5 395268 4329101080 /Users/wenqidong/log/xdebug/trace.3130015676.35604.01feb5.xt
php-fpm 35604 wenqidong 50w REG 1,5 126658 4329101102 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0ca6fc
php-fpm 35604 wenqidong 51w REG 1,5 828 4329101071 /Users/wenqidong/log/xdebug/trace.1573365040.35604.062b53.xt
php-fpm 35604 wenqidong 52w REG 1,5 610170 4329101103 /Users/wenqidong/log/xdebug/trace.3130015676.35604.090c42.xt
php-fpm 35604 wenqidong 53w REG 1,5 101622 4329101117 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.046668
php-fpm 35604 wenqidong 54w REG 1,5 828 4329101082 /Users/wenqidong/log/xdebug/trace.1573365040.35604.014fee.xt
php-fpm 35604 wenqidong 55w REG 1,5 464438 4329101118 /Users/wenqidong/log/xdebug/trace.3130015676.35604.04fd90.xt
php-fpm 35604 wenqidong 56w REG 1,5 121580 4329101135 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0482c9
php-fpm 35604 wenqidong 57w REG 1,5 828 4329101104 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0af4df.xt
php-fpm 35604 wenqidong 58w REG 1,5 577126 4329101136 /Users/wenqidong/log/xdebug/trace.3130015676.35604.047997.xt
php-fpm 35604 wenqidong 59w REG 1,5 105233 4329101169 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.037139
php-fpm 35604 wenqidong 60w REG 1,5 828 4329101119 /Users/wenqidong/log/xdebug/trace.1573365040.35604.075286.xt
php-fpm 35604 wenqidong 61w REG 1,5 489953 4329101170 /Users/wenqidong/log/xdebug/trace.3130015676.35604.089e08.xt
php-fpm 35604 wenqidong 62w REG 1,5 115971 4329102383 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.060355
php-fpm 35604 wenqidong 63w REG 1,5 828 4329101141 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0e29c7.xt
php-fpm 35604 wenqidong 64w REG 1,5 532042 4329102384 /Users/wenqidong/log/xdebug/trace.3130015676.35604.093e51.xt
php-fpm 35604 wenqidong 65w REG 1,5 87819 4329102422 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.034565
php-fpm 35604 wenqidong 66w REG 1,5 828 4329101171 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0566e4.xt
php-fpm 35604 wenqidong 67w REG 1,5 381977 4329102423 /Users/wenqidong/log/xdebug/trace.3130015676.35604.057662.xt
php-fpm 35604 wenqidong 68w REG 1,5 121861 4329102543 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0c8f7a
php-fpm 35604 wenqidong 69w REG 1,5 828 4329102388 /Users/wenqidong/log/xdebug/trace.1573365040.35604.018053.xt
php-fpm 35604 wenqidong 70w REG 1,5 578466 4329102544 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0bf3cf.xt
php-fpm 35604 wenqidong 71w REG 1,5 115921 4329102592 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.081a66
php-fpm 35604 wenqidong 72w REG 1,5 828 4329102424 /Users/wenqidong/log/xdebug/trace.1573365040.35604.01e63c.xt
php-fpm 35604 wenqidong 73w REG 1,5 532042 4329102593 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0799fa.xt
php-fpm 35604 wenqidong 74w REG 1,5 146613 4329102609 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0c4c16
php-fpm 35604 wenqidong 75w REG 1,5 828 4329102547 /Users/wenqidong/log/xdebug/trace.1573365040.35604.05ab7b.xt
php-fpm 35604 wenqidong 76w REG 1,5 731448 4329102610 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0c4464.xt
php-fpm 35604 wenqidong 77w REG 1,5 80954 4329102628 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.05e212
php-fpm 35604 wenqidong 78w REG 1,5 828 4329102597 /Users/wenqidong/log/xdebug/trace.1573365040.35604.081c43.xt
php-fpm 35604 wenqidong 79w REG 1,5 349924 4329102629 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0a185b.xt
php-fpm 35604 wenqidong 80w REG 1,5 121899 4329102680 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0bc68c
php-fpm 35604 wenqidong 81w REG 1,5 828 4329102611 /Users/wenqidong/log/xdebug/trace.1573365040.35604.03f757.xt
php-fpm 35604 wenqidong 82w REG 1,5 578466 4329102681 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0aaff5.xt
php-fpm 35604 wenqidong 83w REG 1,5 100892 4329107762 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.08c2b1
php-fpm 35604 wenqidong 84w REG 1,5 828 4329102631 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0b4035.xt
php-fpm 35604 wenqidong 85w REG 1,5 460091 4329107763 /Users/wenqidong/log/xdebug/trace.3130015676.35604.04f909.xt
php-fpm 35604 wenqidong 86w REG 1,5 100896 4329107786 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.075a4b
php-fpm 35604 wenqidong 87w REG 1,5 828 4329102684 /Users/wenqidong/log/xdebug/trace.1573365040.35604.01fcdf.xt
php-fpm 35604 wenqidong 88w REG 1,5 460091 4329107787 /Users/wenqidong/log/xdebug/trace.3130015676.35604.074ebf.xt
php-fpm 35604 wenqidong 89w REG 1,5 132439 4329107943 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.07d1cc
php-fpm 35604 wenqidong 90w REG 1,5 828 4329107764 /Users/wenqidong/log/xdebug/trace.1573365040.35604.03b6db.xt
php-fpm 35604 wenqidong 91w REG 1,5 643289 4329107944 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0c46f4.xt
php-fpm 35604 wenqidong 92w REG 1,5 100996 4329108165 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.05fe26
php-fpm 35604 wenqidong 93w REG 1,5 828 4329107788 /Users/wenqidong/log/xdebug/trace.1573365040.35604.00b0ea.xt
php-fpm 35604 wenqidong 94w REG 1,5 460091 4329108166 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0b44a1.xt
php-fpm 35604 wenqidong 95w REG 1,5 100906 4329108188 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.03ba9b
php-fpm 35604 wenqidong 96w REG 1,5 828 4329107951 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0ef85e.xt
php-fpm 35604 wenqidong 97w REG 1,5 460091 4329108189 /Users/wenqidong/log/xdebug/trace.3130015676.35604.047b4a.xt
php-fpm 35604 wenqidong 98w REG 1,5 100844 4329108312 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0a18af
php-fpm 35604 wenqidong 99w REG 1,5 828 4329108167 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0f3266.xt
php-fpm 35604 wenqidong 100w REG 1,5 460091 4329108313 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0c04ba.xt
php-fpm 35604 wenqidong 101w REG 1,5 100866 4329108329 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0838fc
php-fpm 35604 wenqidong 102w REG 1,5 828 4329108190 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0dce4a.xt
php-fpm 35604 wenqidong 103w REG 1,5 460091 4329108330 /Users/wenqidong/log/xdebug/trace.3130015676.35604.09395c.xt
php-fpm 35604 wenqidong 104w REG 1,5 100873 4329108344 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.098027
php-fpm 35604 wenqidong 105w REG 1,5 828 4329108314 /Users/wenqidong/log/xdebug/trace.1573365040.35604.008a9f.xt
php-fpm 35604 wenqidong 106w REG 1,5 460091 4329108345 /Users/wenqidong/log/xdebug/trace.3130015676.35604.044c57.xt
php-fpm 35604 wenqidong 107w REG 1,5 100910 4329108357 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0add5d
php-fpm 35604 wenqidong 108w REG 1,5 828 4329108331 /Users/wenqidong/log/xdebug/trace.1573365040.35604.04a11f.xt
php-fpm 35604 wenqidong 109w REG 1,5 460091 4329108358 /Users/wenqidong/log/xdebug/trace.3130015676.35604.07461b.xt
php-fpm 35604 wenqidong 110w REG 1,5 100854 4329108374 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.09fcef
php-fpm 35604 wenqidong 111w REG 1,5 828 4329108346 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0e07c6.xt
php-fpm 35604 wenqidong 112w REG 1,5 460091 4329108375 /Users/wenqidong/log/xdebug/trace.3130015676.35604.070656.xt
php-fpm 35604 wenqidong 113w REG 1,5 100932 4329108387 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.084410
php-fpm 35604 wenqidong 114w REG 1,5 828 4329108359 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0ed412.xt
php-fpm 35604 wenqidong 115w REG 1,5 460091 4329108388 /Users/wenqidong/log/xdebug/trace.3130015676.35604.039722.xt
php-fpm 35604 wenqidong 116w REG 1,5 100874 4329108399 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0196ba
php-fpm 35604 wenqidong 117w REG 1,5 828 4329108376 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0bc5a2.xt
php-fpm 35604 wenqidong 118w REG 1,5 460091 4329108400 /Users/wenqidong/log/xdebug/trace.3130015676.35604.095928.xt
php-fpm 35604 wenqidong 119w REG 1,5 100859 4329108412 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.036434
php-fpm 35604 wenqidong 120w REG 1,5 828 4329108389 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0d5d1f.xt
php-fpm 35604 wenqidong 121w REG 1,5 460091 4329108413 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0335e5.xt
php-fpm 35604 wenqidong 122w REG 1,5 100862 4329108488 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0e1c9c
php-fpm 35604 wenqidong 123w REG 1,5 828 4329108401 /Users/wenqidong/log/xdebug/trace.1573365040.35604.013602.xt
php-fpm 35604 wenqidong 124w REG 1,5 460091 4329108489 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0ea9f5.xt
php-fpm 35604 wenqidong 125w REG 1,5 100840 4329108522 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0f237a
php-fpm 35604 wenqidong 126w REG 1,5 828 4329108415 /Users/wenqidong/log/xdebug/trace.1573365040.35604.084333.xt
php-fpm 35604 wenqidong 127w REG 1,5 460091 4329108523 /Users/wenqidong/log/xdebug/trace.3130015676.35604.064d85.xt
php-fpm 35604 wenqidong 128w REG 1,5 100905 4329108534 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.07ad4d
php-fpm 35604 wenqidong 129w REG 1,5 828 4329108490 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0ef618.xt
php-fpm 35604 wenqidong 130w REG 1,5 460091 4329108535 /Users/wenqidong/log/xdebug/trace.3130015676.35604.02324a.xt
php-fpm 35604 wenqidong 131w REG 1,5 100872 4329108546 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.040be8
php-fpm 35604 wenqidong 132w REG 1,5 828 4329108524 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0f3d8d.xt
php-fpm 35604 wenqidong 133w REG 1,5 460091 4329108547 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0258a2.xt
php-fpm 35604 wenqidong 134w REG 1,5 100874 4329108561 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.02acb7
php-fpm 35604 wenqidong 135w REG 1,5 828 4329108536 /Users/wenqidong/log/xdebug/trace.1573365040.35604.08f6e1.xt
php-fpm 35604 wenqidong 136w REG 1,5 460091 4329108562 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0b667d.xt
php-fpm 35604 wenqidong 137w REG 1,5 100916 4329108578 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.03d7f8
php-fpm 35604 wenqidong 138w REG 1,5 828 4329108548
.....
/Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.01070d
php-fpm 35604 wenqidong 241w REG 1,5 828 4329140988 /Users/wenqidong/log/xdebug/trace.1573365040.35604.063ce5.xt
php-fpm 35604 wenqidong 242w REG 1,5 460091 4329141378 /Users/wenqidong/log/xdebug/trace.3130015676.35604.0db669.xt
php-fpm 35604 wenqidong 243w REG 1,5 100871 4329141391 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.026a15
php-fpm 35604 wenqidong 244w REG 1,5 828 4329141367 /Users/wenqidong/log/xdebug/trace.1573365040.35604.0078ea.xt
php-fpm 35604 wenqidong 245w REG 1,5 460091 4329141392 /Users/wenqidong/log/xdebug/trace.3130015676.35604.061d30.xt
php-fpm 35604 wenqidong 246w REG 1,5 100872 4329141403 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0d0301
php-fpm 35604 wenqidong 247w REG 1,5 828 4329141379 /Users/wenqidong/log/xdebug/trace.1573365040.35604.076667.xt
php-fpm 35604 wenqidong 248w REG 1,5 460091 4329141404 /Users/wenqidong/log/xdebug/trace.3130015676.35604.006948.xt
php-fpm 35604 wenqidong 249w REG 1,5 100852 4329141414 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.0999e2
php-fpm 35604 wenqidong 250w REG 1,5 828 4329141393 /Users/wenqidong/log/xdebug/trace.1573365040.35604.00dd52.xt
php-fpm 35604 wenqidong 251w REG 1,5 460091 4329141415 /Users/wenqidong/log/xdebug/trace.3130015676.35604.044df6.xt
php-fpm 35604 wenqidong 252w REG 1,5 59348 4329141422 /Users/wenqidong/log/xdebug/profiler/cachegrind.out._Users_wenqidong_cdinfo_showdoc_server_index_php.02a653
php-fpm 35604 wenqidong 253w REG 1,5 828 4329141405 /Users/wenqidong/log/xdebug/trace.1573365040.35604.06adfb.xt
php-fpm 35604 wenqidong 254w REG 1,5 248908 4329141423 /Users/wenqidong/log/xdebug/trace.3130015676.35604.03e523.xt
wenqidongdeMBP:log wenqidong$
可以看出 大部分的文件都是 xdebug/trade.相关的，看来这个问题确实跟最近启动的调试功能有关。
如果文件数过多使用lsof -p 进程id命令无法完全查看的话，可以使用lsof -p 进程id > openfiles.log将执行结果内容输出到日志文件中查看。
解决方法
- 增大允许打开的文件数——命令方式
ulimit -n 2048这样就可以把当前用户的最大允许打开文件数量设置为2048了，但这种设置方法在重启后会还原为默认值。 这个命令执行后，还需要重启一下php-fpm才会生效。
ulimit -n命令非root用户只能设置到4096。
想要设置到8192需要sudo权限或者root用户。
- 增大允许打开的文件数——修改系统配置文件
vim /etc/security/limits.conf
#在最后加入
* soft nofile 4096
* hard nofile 4096 或者只加入
* - nofile 8192最前的 * 表示所有用户，可根据需要设置某一用户，例如
roy soft nofile 8192
roy hard nofile 8192 注意"nofile"项有两个可能的限制措施。
就是项下的hard和soft。
要使修改过得最大打开文件数生效，必须对这两种限制进行设定。 如果使用"-"字符设定, 则hard和soft设定会同时被设定。
- 检查程序问题
1）打开的这些文件是不是都是必要的？
2）定位到打开这些文件的代码
3）是否程序操作了文件写入，但是没有进行正常关闭
4）是否程序进行了通讯，但是没有正常关闭(也就是没有超时结束的机制)如果程序中存在这些问题的话，无论系统句柄数设置的多么大，随着时间的推移，也一定会占用完。