For few days I noticed following error message when trying to reload apache. * apache2 has detected an error in your setup: apache2: Syntax error on line 111 of /etc/apache2/httpd.conf: Cannot load modules/mod_lbmethod_byrequests.so into server: /usr/lib64/apache2/modules/mod_lbmethod_byrequests.so: undefined symbol: ap_proxy_balancer_get_best_worker Some logs in web server stopped working due to that error. Recompiling apache did not resolve it. Any idea what could have go wrong? emerge --info Portage 2.3.43 (python 3.5.5-final-0, default/linux/amd64/17.0, gcc-7.3.0, glibc-2.27-r5, 4.14.23 x86_64) ================================================================= System uname: Linux-4.14.23-x86_64-Intel-R-_Core-TM-_i3-4130_CPU_@_3.40GHz-with-gentoo-2.6 Timestamp of repository gentoo: Tue, 24 Jul 2018 15:45:01 +0000 Head commit of repository gentoo: 3ac48d9469a8ae37109abae96588c9ce2ee5dc7c sh bash 4.4_p23 ld GNU ld (Gentoo 2.30 p3) 2.30.0 distcc 3.2rc1 x86_64-pc-linux-gnu [disabled] app-shells/bash: 4.4_p23::gentoo dev-java/java-config: 2.2.0-r4::gentoo dev-lang/perl: 5.26.2::gentoo dev-lang/python: 2.7.15::gentoo, 3.5.5-r1::gentoo, 3.6.6::gentoo dev-util/cmake: 3.12.0::gentoo dev-util/pkgconfig: 0.29.2::gentoo sys-apps/baselayout: 2.6::gentoo sys-apps/openrc: 0.38.1::gentoo sys-apps/sandbox: 2.13::gentoo sys-devel/autoconf: 2.69-r4::gentoo sys-devel/automake: 1.15.1-r2::gentoo, 1.16.1-r1::gentoo sys-devel/binutils: 2.30-r3::gentoo sys-devel/gcc: 7.3.0-r3::gentoo sys-devel/gcc-config: 1.9.1::gentoo sys-devel/libtool: 2.4.6-r5::gentoo sys-devel/make: 4.2.1-r3::gentoo sys-kernel/linux-headers: 4.17::gentoo (virtual/os-headers) sys-libs/glibc: 2.27-r5::gentoo Repositories: gentoo location: /mnt/4tb/portage sync-type: rsync sync-uri: rsync://rsync.europe.gentoo.org/gentoo-portage priority: -1000 sync-rsync-verify-jobs: 1 sync-rsync-verify-max-age: 24 sync-rsync-extra-opts: sync-rsync-verify-metamanifest: no sft location: /var/lib/layman/sft masters: gentoo priority: 0 dotnet location: /var/lib/layman/dotnet masters: gentoo priority: 1 jm-overlay location: /var/lib/layman/jm-overlay masters: dotnet gentoo priority: 2 haskell location: /var/lib/layman/haskell masters: gentoo priority: 3 bigvo location: /usr/local/portage masters: gentoo priority: 4 gentoo-osm location: /usr/local/geo masters: gentoo priority: 5 hackport location: /usr/local/hackport masters: gentoo priority: 6 ACCEPT_KEYWORDS="amd64 ~amd64 ~x86" ACCEPT_LICENSE="*" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=native -O2 -pipe -fgcse-sm -fgcse-las -fgcse-after-reload -ftree-vectorize" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /opt/proxhttpsproxy/config.ini /usr/share/gnupg/qualified.txt /var/bind /var/lib/unifi/data/system.properties" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-march=native -O2 -pipe -fgcse-sm -fgcse-las -fgcse-after-reload -ftree-vectorize -fabi-version=0" DISTDIR="/mnt/4tb/distfiles" ENV_UNSET="DBUS_SESSION_BUS_ADDRESS DISPLAY PERL5LIB PERL5OPT PERLPREFIX PERL_CORE PERL_MB_OPT PERL_MM_OPT XAUTHORITY XDG_CACHE_HOME XDG_CONFIG_HOME XDG_DATA_HOME XDG_RUNTIME_DIR" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync metadata-transfer multilib-strict news nodoc noinfo noman parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="http://127.0.0.1/ http://gentoo.prz.rzeszow.pl ftp://gentoo.imj.fr/pub/gentoo/ http://mirror.netcologne.de/gentoo/" LANG="pl_PL.utf8" LC_ALL="pl_PL.UTF-8" LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -Wl,--as-needed -Wl,--relax -Wl,--sort-common" LINGUAS="pl" MAKEOPTS="-j5" PKGDIR="/mnt/4tb/distfiles/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --exclude=/.git" PORTAGE_TMPDIR="/tmp/" USE="acpi alsa amd64 auth berkdb bzip2 cairo caps cdda cddb cdr cli corefonts crypt css custom-cflags custom-optimization cxx dbus dri dvb dvd dvdr enca firmware-loader fontconfig fortran2003 fuse gdal gdbm geoip geos gif gmp gphoto2 hdf5 iconv icu imap irda ithreads jemalloc jpeg jpeg2k lapack lcd libass libnotify libtirpc libv4l linguas_pl lirc llvm lm_sensors logrotate lz4 lzma lzo mixer mmx mmxext modules mpeg multilib ncurses network nls nptl ocr openmp openssl optimisememory pam pch pcre pgo png postfix postgres proj readline remote remote-access samba sasl scanner seccomp sendmail sensord snmp spamassassin sqlite sse sse2 sse3 sse4_1 sse4_2 ssl ssse3 stream svg symlink system-jsoncpp system-sqlite tcpd thread threads tiff truetype tv udev unicode usb v4l v4l2 vaapi vhosts xmltv zlib zstd" ABI_X86="64 32" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias authn_dbd dbd http2 ident imagemap lbmethod_byrequests lbmethod_bytraffic slotmem_shm proxy_balancer proxy" CALLIGRA_FEATURES="karbon plan sheets stage words" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="aes avx avx2 fma3 mmx mmxext popcnt sse sse2 sse3 sse4_1 sse4_2 ssse3" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="evdev keyboard mouse" KERNEL="linux" L10N="pl" LCD_DEVICES="bayrad cfontz cfontz633 imon imonlcd glk hd44780 lb216 lcdm001 mtxorb ncurses text picolcd" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LIRC_DEVICES="devinput" LLVM_TARGETS="AMDGPU BPF X86" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-6 php7-0" POSTGRES_TARGETS="postgres9_6" PYTHON_SINGLE_TARGET="python3_5" PYTHON_TARGETS="python2_7 python3_5 python3_6" RUBY_TARGETS="ruby20" SANE_BACKENDS="gt68xx plustek" USERLAND="GNU" VIDEO_CARDS="intel i965" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CC, CPPFLAGS, CTARGET, CXX, EMERGE_DEFAULT_OPTS, INSTALL_MASK, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS
Please post the output of emerge --info www-servers/apache to this bug.
here is missing part ================================================================= Package Settings ================================================================= www-servers/apache-2.4.34-r1::gentoo was built with the following: USE="gdbm ssl suexec suexec-caps threads -debug -doc -ldap -libressl (-selinux) -static -suexec-syslog" ABI_X86="(64)" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_core authn_dbd authn_dbm authn_file authz_core authz_dbm authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock dbd deflate dir env expires ext_filter file_cache filter headers http2 ident imagemap include info lbmethod_byrequests lbmethod_bytraffic log_config logio mime mime_magic negotiation proxy proxy_balancer rewrite setenvif slotmem_shm socache_shmcb speling status unique_id unixd userdir usertrack vhost_alias -access_compat -asis -auth_digest -authz_dbd -brotli -cache_disk -cache_socache -cern_meta -charset_lite -dumpio -lbmethod_bybusyness -lbmethod_heartbeat -log_forensic -macro -md -proxy_ajp -proxy_connect -proxy_fcgi -proxy_ftp -proxy_html -proxy_http -proxy_scgi -proxy_wstunnel -ratelimit -remoteip -reqtimeout -substitute -version -watchdog -xml2enc" APACHE2_MPMS="-event -prefork -worker" LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -Wl,--as-needed -Wl,--relax -Wl,--sort-common -Wl,--no-as-needed"
The problem is that mod_proxy is loaded AFTER modules which depend on it attempt to load. Not sure why the order suddenly matters, but change your httpd.conf to: <IfDefine INFO> LoadModule info_module modules/mod_info.so </IfDefine> LoadModule log_config_module modules/mod_log_config.so LoadModule logio_module modules/mod_logio.so LoadModule macro_module modules/mod_macro.so LoadModule mime_module modules/mod_mime.so LoadModule mime_magic_module modules/mod_mime_magic.so LoadModule negotiation_module modules/mod_negotiation.so <IfDefine PROXY> LoadModule proxy_module modules/mod_proxy.so LoadModule lbmethod_bybusyness_module modules/mod_lbmethod_bybusyness.so LoadModule lbmethod_byrequests_module modules/mod_lbmethod_byrequests.so LoadModule lbmethod_bytraffic_module modules/mod_lbmethod_bytraffic.so LoadModule lbmethod_heartbeat_module modules/mod_lbmethod_heartbeat.so </IfDefine>
@Josh G Yes that indeed has worked with exception that in my case I did not use all those modules, but idea behind it worked. </IfDefine> LoadModule log_config_module modules/mod_log_config.so LoadModule logio_module modules/mod_logio.so LoadModule mime_module modules/mod_mime.so LoadModule mime_magic_module modules/mod_mime_magic.so LoadModule negotiation_module modules/mod_negotiation.so <IfDefine PROXY> LoadModule proxy_module modules/mod_proxy.so LoadModule lbmethod_byrequests_module modules/mod_lbmethod_byrequests.so LoadModule lbmethod_bytraffic_module modules/mod_lbmethod_bytraffic.so </IfDefine> Looking at the "genlop -t apache" output I see that apache was just updated to version 2.4.34 which in changelog has bunch of mod_proxy* related fixes. Could be that somewhere there now is implemented more strict checking at the module load, but that is just my guess.
I'm confirming this bug. I solved it by loading "proxy_module modules/mod_proxy.so" before "lbmethod_bytraffic_module modules/mod_lbmethod_bytraffic.so" as mentionned by Josh in comment #3 www-servers/apache-2.4.34-r1:2::gentoo USE="gdbm ssl suexec suexec-caps threads -debug -doc -ldap -libressl (-selinux) -static -suexec-syslog" APACHE2_MODULES="access_compat actions alias auth_basic authn_alias authn_anon authn_core authn_dbm authn_file authz_core authz_dbm authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir env expires ext_filter file_cache filter headers http2 include info lbmethod_bytraffic log_config logio mime mime_magic negotiation proxy proxy_balancer proxy_http ratelimit rewrite setenvif slotmem_shm socache_shmcb speling status unique_id unixd userdir usertrack vhost_alias -asis -auth_digest -authn_dbd -authz_dbd -brotli -cache_disk -cache_socache -cern_meta -charset_lite -dbd -dumpio -ident -imagemap -lbmethod_bybusyness -lbmethod_byrequests -lbmethod_heartbeat -log_forensic -macro -md -proxy_ajp -proxy_connect -proxy_fcgi -proxy_ftp -proxy_html -proxy_scgi -proxy_wstunnel -remoteip -reqtimeout -substitute -version -watchdog -xml2enc" APACHE2_MPMS="worker -event -prefork"
