I have some process of php-fpm always growing.
Showing the memory used (with ps command) shows this.
I have tried two things:
1) strace, but there's tons and tons of information. It's a Symfony framework and I see tons of files being accessed or opened, but no clue at all. Neverending log ... each 1 or 2 or 3 seconds, it shows 2000 lines of trace suddenly.
I see this:
fstat(7, {st_mode=S_IFREG|0644, st_size=1029, ...}) = 0
fstat(7, {st_mode=S_IFREG|0644, st_size=1029, ...}) = 0
fstat(7, {st_mode=S_IFREG|0644, st_size=1029, ...}) = 0
mmap(NULL, 1029, PROT_READ, MAP_SHARED, 7, 0) = 0x7f88da53d000
munmap(0x7f88da53d000, 1029) = 0
close(7) = 0
chdir("/") = 0
clock_gettime(CLOCK_MONOTONIC, {21720, 148391054}) = 0
times({tms_utime=6933, tms_stime=7614, tms_cutime=0, tms_cstime=0}) = 1720128933
close(11) = 0
setitimer(ITIMER_PROF, {it_interval={0, 0}, it_value={0, 0}}, NULL) = 0
umask(022) = 0
sendto(12, "\1\0\0\0\1", 5, MSG_DONTWAIT, NULL, 0) = 5
close(12) = 0
fcntl(6, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=0}) = 0
munmap(0x7f88ba000000, 2097152) = 0
setitimer(ITIMER_PROF, {it_interval={0, 0}, it_value={0, 0}}, NULL) = 0
clock_gettime(CLOCK_MONOTONIC, {21720, 149294252}) = 0
accept(0,
then it stops for 1-5 seconds, and the it shows 2000 lines of a lot of lstat files of the framework... houndreds of blocks like this one (this is ONE as example, but all blocks are different
lstat("/var/www/vhosts/mywebsite.com/vendor/composer/../symfony/swiftmailer-bundle/DependencyInjection/SmtpTransportConfigurator.php", {st_mode=S_IFREG|0644, st_size=1029, ...}) = 0
lstat("/var/www/vhosts/mywebsite.com/vendor/composer/../symfony/swiftmailer-bundle/DependencyInjection", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www/vhosts/mywebsite.com/vendor/composer/../symfony/swiftmailer-bundle", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www/vhosts/mywebsite.com/vendor/composer/../symfony", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www/vhosts/mywebsite.com/vendor/composer", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www/vhosts/mywebsite.com/vendor", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www/vhosts/mywebsite.com", {st_mode=S_IFDIR|0775, st_size=4096, ...}) = 0
lstat("/var/www/vhosts/mywebsite.com", {st_mode=S_IFDIR|0710, st_size=4096, ...}) = 0
lstat("/var/www/vhosts", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
2) lsof but I can't get information of what script is, or why.
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
php-fpm 25690 www_plesk cwd DIR 202,1 4096 2 /
php-fpm 25690 www_plesk rtd DIR 202,1 4096 2 /
php-fpm 25690 www_plesk txt REG 202,1 4821232 1537261 /opt/plesk/php/7.2/sbin/php-fpm
php-fpm 25690 www_plesk DEL REG 0,5 1406882 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406876 /dev/zero
php-fpm 25690 www_plesk mem REG 202,1 27000 1985 /lib/x86_64-linux-gnu/libnss_dns-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 26258 24695 /usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache
php-fpm 25690 www_plesk DEL REG 0,5 1406861 /dev/zero
php-fpm 25690 www_plesk mem REG 202,1 47600 1991 /lib/x86_64-linux-gnu/libnss_files-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 47648 1995 /lib/x86_64-linux-gnu/libnss_nis-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 93128 1968 /lib/x86_64-linux-gnu/libnsl-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 35688 1983 /lib/x86_64-linux-gnu/libnss_compat-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 134624 1328699 /opt/plesk/php/7.2/lib/php/modules/zip.so
php-fpm 25690 www_plesk mem REG 202,1 247952 50760 /usr/lib/x86_64-linux-gnu/libxslt.so.1.1.28
php-fpm 25690 www_plesk mem REG 202,1 83816 50761 /usr/lib/x86_64-linux-gnu/libexslt.so.0.8.17
php-fpm 25690 www_plesk mem REG 202,1 31752 1328672 /opt/plesk/php/7.2/lib/php/modules/xsl.so
php-fpm 25690 www_plesk mem REG 202,1 47816 1328671 /opt/plesk/php/7.2/lib/php/modules/xmlwriter.so
php-fpm 25690 www_plesk mem REG 202,1 81096 1328675 /opt/plesk/php/7.2/lib/php/modules/xmlrpc.so
php-fpm 25690 www_plesk mem REG 202,1 31528 1328674 /opt/plesk/php/7.2/lib/php/modules/xmlreader.so
php-fpm 25690 www_plesk mem REG 202,1 383544 53078 /usr/lib/libtidy-0.99.so.0.0.0
php-fpm 25690 www_plesk mem REG 202,1 52360 1328682 /opt/plesk/php/7.2/lib/php/modules/tidy.so
php-fpm 25690 www_plesk mem REG 202,1 14792 1328666 /opt/plesk/php/7.2/lib/php/modules/sysvshm.so
php-fpm 25690 www_plesk mem REG 202,1 10600 1328667 /opt/plesk/php/7.2/lib/php/modules/sysvsem.so
php-fpm 25690 www_plesk mem REG 202,1 14888 1328669 /opt/plesk/php/7.2/lib/php/modules/sysvmsg.so
php-fpm 25690 www_plesk mem REG 202,1 998080 1328679 /opt/plesk/php/7.2/lib/php/modules/sqlite3.so
php-fpm 25690 www_plesk mem REG 202,1 303432 1328693 /opt/plesk/php/7.2/lib/php/modules/soap.so
php-fpm 25690 www_plesk mem REG 202,1 695312 51937 /usr/lib/x86_64-linux-gnu/libaspell.so.15.2.0
php-fpm 25690 www_plesk mem REG 202,1 23080 1328670 /opt/plesk/php/7.2/lib/php/modules/pspell.so
php-fpm 25690 www_plesk mem REG 202,1 35816 1328668 /opt/plesk/php/7.2/lib/php/modules/posix.so
php-fpm 25690 www_plesk mem REG 202,1 270512 1328697 /opt/plesk/php/7.2/lib/php/modules/phar.so
php-fpm 25690 www_plesk mem REG 202,1 139048 1328680 /opt/plesk/php/7.2/lib/php/modules/pgsql.so
php-fpm 25690 www_plesk mem REG 202,1 27896 1328677 /opt/plesk/php/7.2/lib/php/modules/pdo_sqlite.so
php-fpm 25690 www_plesk mem REG 202,1 194544 9381 /usr/lib/x86_64-linux-gnu/libpq.so.5.8
php-fpm 25690 www_plesk mem REG 202,1 44600 1328681 /opt/plesk/php/7.2/lib/php/modules/pdo_pgsql.so
php-fpm 25690 www_plesk mem REG 202,1 27768 1328687 /opt/plesk/php/7.2/lib/php/modules/pdo_odbc.so
php-fpm 25690 www_plesk mem REG 202,1 31672 1328684 /opt/plesk/php/7.2/lib/php/modules/pdo_mysql.so
php-fpm 25690 www_plesk mem REG 202,1 110168 1328678 /opt/plesk/php/7.2/lib/php/modules/pdo.so
php-fpm 25690 www_plesk mem REG 202,1 427552 51744 /usr/lib/x86_64-linux-gnu/libodbc.so.2.0.0
php-fpm 25690 www_plesk mem REG 202,1 68680 1328686 /opt/plesk/php/7.2/lib/php/modules/odbc.so
php-fpm 25690 www_plesk mem REG 202,1 134296 1328683 /opt/plesk/php/7.2/lib/php/modules/mysqli.so
php-fpm 25690 www_plesk mem REG 202,1 1674464 1328665 /opt/plesk/php/7.2/lib/php/modules/mbstring.so
php-fpm 25690 www_plesk mem REG 202,1 72872 1328691 /opt/plesk/php/7.2/lib/php/modules/ldap.so
php-fpm 25690 www_plesk mem REG 202,1 43624 1328700 /opt/plesk/php/7.2/lib/php/modules/json.so
php-fpm 25690 www_plesk mem REG 202,1 55304 25752 /usr/lib/x86_64-linux-gnu/libicuio.so.55.1
php-fpm 25690 www_plesk mem REG 202,1 2496856 25754 /usr/lib/x86_64-linux-gnu/libicui18n.so.55.1
php-fpm 25690 www_plesk mem REG 202,1 482160 1328692 /opt/plesk/php/7.2/lib/php/modules/intl.so
php-fpm 25690 www_plesk mem REG 202,1 117288 2603 /lib/x86_64-linux-gnu/libaudit.so.1.0.0
php-fpm 25690 www_plesk mem REG 202,1 55904 21215 /lib/x86_64-linux-gnu/libpam.so.0.83.1
php-fpm 25690 www_plesk mem REG 202,1 1100216 50574 /usr/lib/libc-client.so.2007e.0
php-fpm 25690 www_plesk mem REG 202,1 89480 1328695 /opt/plesk/php/7.2/lib/php/modules/imap.so
php-fpm 25690 www_plesk mem REG 202,1 166032 1979 /lib/x86_64-linux-gnu/libexpat.so.1.6.0
php-fpm 25690 www_plesk mem REG 202,1 39272 50718 /usr/lib/x86_64-linux-gnu/libltdl.so.7.3.1
php-fpm 25690 www_plesk mem REG 202,1 73640 25834 /usr/lib/x86_64-linux-gnu/libXext.so.6.4.0
php-fpm 25690 www_plesk mem REG 202,1 273832 51273 /usr/lib/x86_64-linux-gnu/libfontconfig.so.1.9.0
php-fpm 25690 www_plesk mem REG 202,1 2087104 51314 /usr/lib/x86_64-linux-gnu/libfftw3.so.3.4.4
php-fpm 25690 www_plesk mem REG 202,1 96504 51337 /usr/lib/x86_64-linux-gnu/liblqr-1.so.0.3.2
php-fpm 25690 www_plesk mem REG 202,1 353392 51331 /usr/lib/x86_64-linux-gnu/liblcms2.so.2.0.6
php-fpm 25690 www_plesk mem REG 202,1 138448 51307 /usr/lib/x86_64-linux-gnu/libgomp.so.1.0.0
php-fpm 25690 www_plesk mem REG 202,1 2707304 9717 /usr/lib/x86_64-linux-gnu/libMagickCore-6.Q16.so.2.0.0
php-fpm 25690 www_plesk mem REG 202,1 1200744 6527 /usr/lib/x86_64-linux-gnu/libMagickWand-6.Q16.so.2.0.0
php-fpm 25690 www_plesk mem REG 202,1 426816 1328701 /opt/plesk/php/7.2/lib/php/modules/imagick.so
php-fpm 25690 www_plesk mem REG 202,1 22640 25828 /usr/lib/x86_64-linux-gnu/libXdmcp.so.6.0.0
php-fpm 25690 www_plesk mem REG 202,1 14456 25826 /usr/lib/x86_64-linux-gnu/libXau.so.6.0.0
php-fpm 25690 www_plesk mem REG 202,1 137728 25830 /usr/lib/x86_64-linux-gnu/libxcb.so.1.1.0
php-fpm 25690 www_plesk mem REG 202,1 1285552 25832 /usr/lib/x86_64-linux-gnu/libX11.so.6.3.0
php-fpm 25690 www_plesk mem REG 202,1 694800 25840 /usr/lib/x86_64-linux-gnu/libfreetype.so.6.12.1
php-fpm 25690 www_plesk mem REG 202,1 363264 51325 /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2
php-fpm 25690 www_plesk mem REG 202,1 149904 2138 /lib/x86_64-linux-gnu/libpng12.so.0.54.0
php-fpm 25690 www_plesk mem REG 202,1 72520 51670 /usr/lib/x86_64-linux-gnu/libXpm.so.4.11.0
php-fpm 25690 www_plesk mem REG 202,1 389088 1328694 /opt/plesk/php/7.2/lib/php/modules/gd.so
php-fpm 25690 www_plesk mem REG 202,1 5045800 1328698 /opt/plesk/php/7.2/lib/php/modules/fileinfo.so
php-fpm 25690 www_plesk mem REG 202,1 1115136 2154 /lib/x86_64-linux-gnu/libglib-2.0.so.0.4800.2
php-fpm 25690 www_plesk mem REG 202,1 14656 25804 /usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0.4800.2
php-fpm 25690 www_plesk mem REG 202,1 46944 52829 /usr/lib/x86_64-linux-gnu/libenchant.so.1.6.0
php-fpm 25690 www_plesk mem REG 202,1 23904 1328688 /opt/plesk/php/7.2/lib/php/modules/enchant.so
php-fpm 25690 www_plesk mem REG 202,1 172216 1328673 /opt/plesk/php/7.2/lib/php/modules/dom.so
php-fpm 25690 www_plesk mem REG 202,1 1756696 24914 /usr/lib/x86_64-linux-gnu/libdb-5.3.so
php-fpm 25690 www_plesk mem REG 202,1 52776 1328690 /opt/plesk/php/7.2/lib/php/modules/dba.so
php-fpm 25690 www_plesk mem REG 202,1 39224 1997 /lib/x86_64-linux-gnu/libcrypt-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 870240 25802 /usr/lib/x86_64-linux-gnu/libsqlite3.so.0.8.6
php-fpm 25690 www_plesk mem REG 202,1 304072 25885 /usr/lib/x86_64-linux-gnu/libhx509.so.5.0.0
php-fpm 25690 www_plesk mem REG 202,1 60928 25881 /usr/lib/x86_64-linux-gnu/libheimbase.so.1.0.0
php-fpm 25690 www_plesk mem REG 202,1 166128 25883 /usr/lib/x86_64-linux-gnu/libwind.so.0.0.0
php-fpm 25690 www_plesk mem REG 202,1 31104 25780 /usr/lib/x86_64-linux-gnu/libffi.so.6.0.4
php-fpm 25690 www_plesk mem REG 202,1 89904 25873 /usr/lib/x86_64-linux-gnu/libroken.so.18.1.0
php-fpm 25690 www_plesk mem REG 202,1 204168 25878 /usr/lib/x86_64-linux-gnu/libhcrypto.so.4.1.0
php-fpm 25690 www_plesk mem REG 202,1 661872 25875 /usr/lib/x86_64-linux-gnu/libasn1.so.8.0.0
php-fpm 25690 www_plesk mem REG 202,1 560808 25887 /usr/lib/x86_64-linux-gnu/libkrb5.so.26.0.0
php-fpm 25690 www_plesk mem REG 202,1 35920 25889 /usr/lib/x86_64-linux-gnu/libheimntlm.so.0.1.0
php-fpm 25690 www_plesk mem REG 202,1 14256 2172 /lib/x86_64-linux-gnu/libkeyutils.so.1.5
php-fpm 25690 www_plesk mem REG 202,1 76192 25740 /usr/lib/x86_64-linux-gnu/libtasn1.so.6.5.1
php-fpm 25690 www_plesk mem REG 202,1 408472 25738 /usr/lib/x86_64-linux-gnu/libp11-kit.so.0.1.0
php-fpm 25690 www_plesk mem REG 202,1 264256 25891 /usr/lib/x86_64-linux-gnu/libgssapi.so.3.0.0
php-fpm 25690 www_plesk mem REG 202,1 109296 25916 /usr/lib/x86_64-linux-gnu/libsasl2.so.2.0.25
php-fpm 25690 www_plesk mem REG 202,1 43664 25861 /usr/lib/x86_64-linux-gnu/libkrb5support.so.0.1
php-fpm 25690 www_plesk mem REG 202,1 14648 1960 /lib/x86_64-linux-gnu/libcom_err.so.2.1
php-fpm 25690 www_plesk mem REG 202,1 186872 25865 /usr/lib/x86_64-linux-gnu/libk5crypto.so.3.1
php-fpm 25690 www_plesk mem REG 202,1 860392 25867 /usr/lib/x86_64-linux-gnu/libkrb5.so.3.3
php-fpm 25690 www_plesk mem REG 202,1 219336 25734 /usr/lib/x86_64-linux-gnu/libnettle.so.6.2
php-fpm 25690 www_plesk mem REG 202,1 207640 25732 /usr/lib/x86_64-linux-gnu/libhogweed.so.4.2
php-fpm 25690 www_plesk mem REG 202,1 1239440 25744 /usr/lib/x86_64-linux-gnu/libgnutls.so.30.6.2
php-fpm 25690 www_plesk mem REG 202,1 322928 10117 /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2.10.5
php-fpm 25690 www_plesk mem REG 202,1 59640 10118 /usr/lib/x86_64-linux-gnu/liblber-2.4.so.2.10.5
php-fpm 25690 www_plesk mem REG 202,1 301376 25869 /usr/lib/x86_64-linux-gnu/libgssapi_krb5.so.2.2
php-fpm 25690 www_plesk mem REG 202,1 113584 25923 /usr/lib/x86_64-linux-gnu/librtmp.so.1
php-fpm 25690 www_plesk mem REG 202,1 207208 25736 /usr/lib/x86_64-linux-gnu/libidn.so.11.6.15
php-fpm 25690 www_plesk mem REG 202,1 452992 10557 /usr/lib/x86_64-linux-gnu/libcurl.so.4.4.0
php-fpm 25690 www_plesk mem REG 202,1 89256 1287184 /opt/plesk/php/7.2/lib/php/modules/curl.so
php-fpm 25690 www_plesk mem REG 202,1 35344 1328676 /opt/plesk/php/7.2/lib/php/modules/bcmath.so
php-fpm 25690 www_plesk mem REG 202,1 256760 1328685 /opt/plesk/php/7.2/lib/php/modules/mysqlnd.so
php-fpm 25690 www_plesk mem REG 202,1 15185280 2826090 /opt/dynatrace/oneagent/agent/lib64/liboneagentphp.so
php-fpm 25690 www_plesk mem REG 202,1 4816792 2826084 /opt/dynatrace/oneagent/agent/lib64/liboneagentloader.so
php-fpm 25690 www_plesk mem REG 202,1 438752 1328689 /opt/plesk/php/7.2/lib/php/modules/opcache.so
php-fpm 25690 www_plesk mem REG 202,1 1385896 1283865 /opt/plesk/php/7.2/lib/php/modules/ioncube_loader_lin_7.2.so
php-fpm 25690 www_plesk DEL REG 0,5 1406862 /dev/zero
php-fpm 25690 www_plesk mem REG 202,1 1668976 28956 /usr/lib/locale/locale-archive
php-fpm 25690 www_plesk mem REG 202,1 89696 1965 /lib/x86_64-linux-gnu/libgcc_s.so.1
php-fpm 25690 www_plesk mem REG 202,1 1566440 51083 /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21
php-fpm 25690 www_plesk mem REG 202,1 25913104 25753 /usr/lib/x86_64-linux-gnu/libicudata.so.55.1
php-fpm 25690 www_plesk mem REG 202,1 80496 2002 /lib/x86_64-linux-gnu/libgpg-error.so.0.17.0
php-fpm 25690 www_plesk mem REG 202,1 456632 2066 /lib/x86_64-linux-gnu/libpcre.so.3.13.2
php-fpm 25690 www_plesk mem REG 202,1 1636360 25757 /usr/lib/x86_64-linux-gnu/libicuuc.so.55.1
php-fpm 25690 www_plesk mem REG 202,1 919168 1001 /lib/x86_64-linux-gnu/libgcrypt.so.20.0.5
php-fpm 25690 www_plesk mem REG 202,1 137400 2004 /lib/x86_64-linux-gnu/liblzma.so.5.0.0
php-fpm 25690 www_plesk mem REG 202,1 130224 2073 /lib/x86_64-linux-gnu/libselinux.so.1
php-fpm 25690 www_plesk mem REG 202,1 18624 2107 /lib/x86_64-linux-gnu/libattr.so.1.1.0
php-fpm 25690 www_plesk mem REG 202,1 138696 1970 /lib/x86_64-linux-gnu/libpthread-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 1868984 1971 /lib/x86_64-linux-gnu/libc-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 2361856 21565 /lib/x86_64-linux-gnu/libcrypto.so.1.0.0
php-fpm 25690 www_plesk mem REG 202,1 428384 21561 /lib/x86_64-linux-gnu/libssl.so.1.0.0
php-fpm 25690 www_plesk mem REG 202,1 1809656 25949 /usr/lib/x86_64-linux-gnu/libxml2.so.2.9.3
php-fpm 25690 www_plesk mem REG 202,1 31232 1987 /lib/x86_64-linux-gnu/libacl.so.1.1.0
php-fpm 25690 www_plesk mem REG 202,1 14608 1973 /lib/x86_64-linux-gnu/libdl-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 1088952 1967 /lib/x86_64-linux-gnu/libm-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 31712 1996 /lib/x86_64-linux-gnu/librt-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 104864 2120 /lib/x86_64-linux-gnu/libz.so.1.2.8
php-fpm 25690 www_plesk mem REG 202,1 66800 2111 /lib/x86_64-linux-gnu/libbz2.so.1.0.4
php-fpm 25690 www_plesk mem REG 202,1 522664 25784 /usr/lib/x86_64-linux-gnu/libgmp.so.10.3.0
php-fpm 25690 www_plesk mem REG 202,1 101200 1975 /lib/x86_64-linux-gnu/libresolv-2.23.so
php-fpm 25690 www_plesk mem REG 202,1 548432 747 /lib/x86_64-linux-gnu/liboneagentproc.so
php-fpm 25690 www_plesk mem REG 202,1 162632 1969 /lib/x86_64-linux-gnu/ld-2.23.so
php-fpm 25690 www_plesk DEL REG 0,5 1406870 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406867 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406866 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406865 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406864 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406863 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406846 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406845 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406844 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406843 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406842 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406841 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406840 /dev/zero
php-fpm 25690 www_plesk DEL REG 0,5 1406839 /dev/zero
php-fpm 25690 www_plesk mem REG 202,1 536520 2093 /lib/x86_64-linux-gnu/libsystemd.so.0.14.0
php-fpm 25690 www_plesk 0u unix 0xffff8803a285a000 0t0 1406893 /var/www/vhosts/system/mywebsite.com/php-fpm.sock type=STREAM
php-fpm 25690 www_plesk 1w FIFO 0,10 0t0 1407453 pipe
php-fpm 25690 www_plesk 2w FIFO 0,10 0t0 1407454 pipe
php-fpm 25690 www_plesk 3r CHR 1,9 0t0 11 /dev/urandom
php-fpm 25690 www_plesk 4w CHR 1,8 0t0 10 /dev/random
php-fpm 25690 www_plesk 6u REG 202,1 0 513276 /tmp/.ZendSem.1t93Xa (deleted)
php-fpm 25690 www_plesk 8r CHR 1,9 0t0 11 /dev/urandom
php-fpm 25690 www_plesk 9w FIFO 0,10 0t0 1406869 pipe
php-fpm 25690 www_plesk 11u unix 0xffff8803a2bf8800 0t0 1418861 type=STREAM
Any other chance to get real information of the script running ?
More info:
part of the top
top - 21:13:22 up 6:11, 2 users, load average: 0.84, 0.92, 0.89
Tasks: 206 total, 1 running, 205 sleeping, 0 stopped, 0 zombie
%Cpu(s): 15.5 us, 5.4 sy, 0.0 ni, 78.8 id, 0.1 wa, 0.0 hi, 0.2 si, 0.2 st
KiB Mem : 16431376 total, 8608756 free, 2660328 used, 5162292 buff/cache
KiB Swap: 1048572 total, 1048572 free, 0 used. 13156496 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
9573 www_p+ 20 0 631700 99808 54084 S 30.9 0.6 0:01.86 php-fpm
9645 www_p+ 20 0 603164 50004 27864 S 11.6 0.3 0:00.35 php
26995 www_p+ 20 0 773664 231460 43620 S 6.6 1.4 2:06.97 php-fpm
25685 www_p+ 20 0 778512 238372 43632 S 3.7 1.5 2:57.93 php-fpm
25688 www_p+ 20 0 793032 251636 42408 S 3.7 1.5 2:16.99 php-fpm
25940 www_p+ 20 0 789220 250440 45004 S 3.7 1.5 2:14.46 php-fpm
25690 www_p+ 20 0 861668 251364 47144 S 2.3 1.5 2:27.00 php-fpm
25831 www_p+ 20 0 862860 251556 46112 S 2.3 1.5 2:20.00 php-fpm
output of a strace of one of them (php-fpm) with -c attribute (10 seconds):
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
63.17 0.018411 0 409063 700 lstat
27.45 0.008000 727 11 accept
2.45 0.000713 0 20071 fstat
2.00 0.000584 0 6582 mmap
1.45 0.000424 0 6905 close
1.21 0.000353 0 6872 open
1.04 0.000304 0 6588 munmap
0.38 0.000110 0 3065 clock_gettime
0.15 0.000043 0 247 lseek
0.15 0.000043 1 33 sendto
0.14 0.000041 0 912 read
0.09 0.000027 0 1214 gettimeofday
0.09 0.000026 3 9 brk
0.08 0.000022 0 383 31 stat
0.08 0.000022 0 706 288 access
0.07 0.000020 0 55 fcntl
0.00 0.000000 0 32 write
0.00 0.000000 0 384 poll
0.00 0.000000 0 88 rt_sigaction
0.00 0.000000 0 11 rt_sigprocmask
0.00 0.000000 0 22 ioctl
0.00 0.000000 0 6 madvise
0.00 0.000000 0 44 setitimer
0.00 0.000000 0 21 socket
0.00 0.000000 0 21 11 connect
0.00 0.000000 0 375 recvfrom
0.00 0.000000 0 11 shutdown
0.00 0.000000 0 22 setsockopt
0.00 0.000000 0 11 getsockopt
0.00 0.000000 0 11 getcwd
0.00 0.000000 0 22 chdir
0.00 0.000000 0 350 350 readlink
0.00 0.000000 0 33 umask
0.00 0.000000 0 22 times
0.00 0.000000 0 1 restart_syscall
0.00 0.000000 0 10 sendmmsg
------ ----------- ----------- --------- --------- ----------------
100.00 0.029143 464213 1380 total
Notes:
Your primary problem of memory usage is something that you're going to have to attach a debugger or profiler to diagnose and is most likely a memory leak inside the application itself rather than anything inherent to PHP. As a stopgap measure you could configure FPM to recycle its workers more frequently to release the accumulated memory.
http://php.net/manual/en/install.fpm.configuration.php#pm.max-requests
The secondary problem that you have is your composer autoloader is still traversing the filesystem on every load, which seems to be why you have such a huge number of lstat calls. This has no effect on your memory usage, but it's a lot of needless IO that can be avoided very simply: