1

Good morning,

I am trying to start up Apache HTTPD 2.4.23 on my Centos 5.11 (Linux version 2.6.18-371.6.1.el5 ([email protected]) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-54)) server. I manually configured it with the following options:

  • With apr 1.5.2
  • With apr-utils 1.5.4
  • With pcre 8.37

My HTTPD.conf file looks like this:

{#
# This is the main Apache HTTP server configuration file.  It contains the
# configuration directives that give the server its instructions.
# See <URL:http://httpd.apache.org/docs/2.4/> for detailed information.
# In particular, see
# <URL:http://httpd.apache.org/docs/2.4/mod/directives.html>
# for a discussion of each configuration directive.
#
# Do NOT simply read the instructions in here without understanding
# what they do.  They're here only as hints or reminders.  If you are unsure
# consult the online docs. You have been warned.
#
# Configuration and logfile names: If the filenames you specify for many
# of the server's control files begin with "/" (or "drive:/" for Win32), the
# server will use that explicit path.  If the filenames do *not* begin
# with "/", the value of ServerRoot is prepended -- so "logs/access_log"
# with ServerRoot set to "/usr/local/apache2" will be interpreted by the
# server as "/usr/local/apache2/logs/access_log", whereas "/logs/access_log"
# will be interpreted as '/logs/access_log'.

#
# ServerRoot: The top of the directory tree under which the server's
# configuration, error, and log files are kept.
#
# Do not add a slash at the end of the directory path.  If you point
# ServerRoot at a non-local disk, be sure to specify a local disk on the
# Mutex directive, if file-based mutexes are used.  If you wish to share the
# same ServerRoot for multiple httpd daemons, you will need to change at
# least PidFile.
#
ServerRoot "/opt/apache"

#
# Mutex: Allows you to set the mutex mechanism and mutex file directory
# for individual mutexes, or change the global defaults
#
# Uncomment and change the directory if mutexes are file-based and the default
# mutex file directory is not on a local disk or is not appropriate for some
# other reason.
#
# Mutex default:logs

#
# Listen: Allows you to bind Apache to specific IP addresses and/or
# ports, instead of the default. See also the <VirtualHost>
# directive.
#
# Change this to Listen on specific IP addresses as shown below to
# prevent Apache from glomming onto all bound IP addresses.
#
#Listen 12.34.56.78:80
Listen 8080

#
# Dynamic Shared Object (DSO) Support
#
# To be able to use the functionality of a module which was built as a DSO you
# have to place corresponding `LoadModule' lines at this location so the
# directives contained in it are actually available _before_ they are used.
# Statically compiled modules (those listed by `httpd -l') do not need
# to be loaded here.
#
# Example:
# LoadModule foo_module modules/mod_foo.so
#
LoadModule authn_file_module modules/mod_authn_file.so
#LoadModule authn_dbm_module modules/mod_authn_dbm.so
#LoadModule authn_anon_module modules/mod_authn_anon.so
#LoadModule authn_dbd_module modules/mod_authn_dbd.so
#LoadModule authn_socache_module modules/mod_authn_socache.so
LoadModule authn_core_module modules/mod_authn_core.so
LoadModule authz_host_module modules/mod_authz_host.so
LoadModule authz_groupfile_module modules/mod_authz_groupfile.so
LoadModule authz_user_module modules/mod_authz_user.so
#LoadModule authz_dbm_module modules/mod_authz_dbm.so
#LoadModule authz_owner_module modules/mod_authz_owner.so
#LoadModule authz_dbd_module modules/mod_authz_dbd.so
LoadModule authz_core_module modules/mod_authz_core.so
LoadModule access_compat_module modules/mod_access_compat.so
LoadModule auth_basic_module modules/mod_auth_basic.so
#LoadModule auth_form_module modules/mod_auth_form.so
#LoadModule auth_digest_module modules/mod_auth_digest.so
#LoadModule allowmethods_module modules/mod_allowmethods.so
#LoadModule file_cache_module modules/mod_file_cache.so
#LoadModule cache_module modules/mod_cache.so
#LoadModule cache_disk_module modules/mod_cache_disk.so
#LoadModule cache_socache_module modules/mod_cache_socache.so
#LoadModule socache_shmcb_module modules/mod_socache_shmcb.so
#LoadModule socache_dbm_module modules/mod_socache_dbm.so
#LoadModule socache_memcache_module modules/mod_socache_memcache.so
#LoadModule watchdog_module modules/mod_watchdog.so
#LoadModule macro_module modules/mod_macro.so
#LoadModule dbd_module modules/mod_dbd.so
#LoadModule dumpio_module modules/mod_dumpio.so
#LoadModule buffer_module modules/mod_buffer.so
#LoadModule ratelimit_module modules/mod_ratelimit.so
LoadModule reqtimeout_module modules/mod_reqtimeout.so
#LoadModule ext_filter_module modules/mod_ext_filter.so
#LoadModule request_module modules/mod_request.so
#LoadModule include_module modules/mod_include.so
LoadModule filter_module modules/mod_filter.so
#LoadModule substitute_module modules/mod_substitute.so
#LoadModule sed_module modules/mod_sed.so
LoadModule mime_module modules/mod_mime.so
LoadModule log_config_module modules/mod_log_config.so
#LoadModule log_debug_module modules/mod_log_debug.so
#LoadModule logio_module modules/mod_logio.so
LoadModule env_module modules/mod_env.so
#LoadModule expires_module modules/mod_expires.so
LoadModule headers_module modules/mod_headers.so
#LoadModule unique_id_module modules/mod_unique_id.so
LoadModule setenvif_module modules/mod_setenvif.so
LoadModule version_module modules/mod_version.so
#LoadModule remoteip_module modules/mod_remoteip.so
LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_connect_module modules/mod_proxy_connect.so
LoadModule proxy_ftp_module modules/mod_proxy_ftp.so
LoadModule proxy_http_module modules/mod_proxy_http.so
LoadModule proxy_fcgi_module modules/mod_proxy_fcgi.so
#LoadModule proxy_scgi_module modules/mod_proxy_scgi.so
LoadModule proxy_wstunnel_module modules/mod_proxy_wstunnel.so
LoadModule proxy_ajp_module modules/mod_proxy_ajp.so
LoadModule proxy_balancer_module modules/mod_proxy_balancer.so
#LoadModule proxy_express_module modules/mod_proxy_express.so
#LoadModule proxy_hcheck_module modules/mod_proxy_hcheck.so
#LoadModule session_module modules/mod_session.so
#LoadModule session_cookie_module modules/mod_session_cookie.so
#LoadModule session_dbd_module modules/mod_session_dbd.so
#LoadModule slotmem_shm_module modules/mod_slotmem_shm.so
#LoadModule lbmethod_byrequests_module modules/mod_lbmethod_byrequests.so
#LoadModule lbmethod_bytraffic_module modules/mod_lbmethod_bytraffic.so
#LoadModule lbmethod_bybusyness_module modules/mod_lbmethod_bybusyness.so
#LoadModule lbmethod_heartbeat_module modules/mod_lbmethod_heartbeat.so
LoadModule unixd_module modules/mod_unixd.so
#LoadModule dav_module modules/mod_dav.so
LoadModule status_module modules/mod_status.so
LoadModule autoindex_module modules/mod_autoindex.so
#LoadModule info_module modules/mod_info.so
#LoadModule cgid_module modules/mod_cgid.so
#LoadModule dav_fs_module modules/mod_dav_fs.so
#LoadModule vhost_alias_module modules/mod_vhost_alias.so
#LoadModule negotiation_module modules/mod_negotiation.so
LoadModule dir_module modules/mod_dir.so
#LoadModule actions_module modules/mod_actions.so
#LoadModule speling_module modules/mod_speling.so
#LoadModule userdir_module modules/mod_userdir.so
LoadModule alias_module modules/mod_alias.so
LoadModule rewrite_module modules/mod_rewrite.so
LoadModule jk_module modules/mod_jk.so

<IfModule unixd_module>
#
# If you wish httpd to run as a different user or group, you must run
# httpd as root initially and it will switch.
#
# User/Group: The name (or #number) of the user/group to run httpd as.
# It is usually good practice to create a dedicated user and group for
# running httpd, as with most system services.
#
User daemon
Group daemon

</IfModule>

# 'Main' server configuration
#
# The directives in this section set up the values used by the 'main'
# server, which responds to any requests that aren't handled by a
# <VirtualHost> definition.  These values also provide defaults for
# any <VirtualHost> containers you may define later in the file.
#
# All of these directives may appear inside <VirtualHost> containers,
# in which case these default settings will be overridden for the
# virtual host being defined.
#

#
# ServerAdmin: Your address, where problems with the server should be
# e-mailed.  This address appears on some server-generated pages, such
# as error documents.  e.g. [email protected]
#
ServerAdmin [email protected]

#
# ServerName gives the name and port that the server uses to identify itself.
# This can often be determined automatically, but we recommend you specify
# it explicitly to prevent problems during startup.
#
# If your host doesn't have a registered DNS name, enter its IP address here.
#
#ServerName www.example.com:80

#
# Deny access to the entirety of your server's filesystem. You must
# explicitly permit access to web content directories in other
# <Directory> blocks below.
#
<Directory />
    Options FollowSymLinks
    AllowOverride None
    Order deny,allow
    Allow from all
</Directory>

#
# Note that from this point forward you must specifically allow
# particular features to be enabled - so if something's not working as
# you might expect, make sure that you have specifically enabled it
# below.
#

#
# DocumentRoot: The directory out of which you will serve your
# documents. By default, all requests are taken from this directory, but
# symbolic links and aliases may be used to point to other locations.
#
DocumentRoot "/opt/apache//htdocs"
<Directory "/opt/apache//htdocs">
    #
    # Possible values for the Options directive are "None", "All",
    # or any combination of:
    #   Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
    #
    # Note that "MultiViews" must be named *explicitly* --- "Options All"
    # doesn't give it to you.
    #
    # The Options directive is both complicated and important.  Please see
    # http://httpd.apache.org/docs/2.4/mod/core.html#options
    # for more information.
    #
    Options Indexes FollowSymLinks

    #
    # AllowOverride controls what directives may be placed in .htaccess files.
    # It can be "All", "None", or any combination of the keywords:
    #   AllowOverride FileInfo AuthConfig Limit
    #
    AllowOverride None

    #
    # Controls who can get stuff from this server.
    #
    Order allow,deny
    Allow from all
</Directory>

#
# DirectoryIndex: sets the file that Apache will serve if a directory
# is requested.
#
<IfModule dir_module>
    DirectoryIndex index.html
</IfModule>

#
# The following lines prevent .htaccess and .htpasswd files from being
# viewed by Web clients.
#
<Files ".ht*">
    Order allow,deny
    Deny from all
    Satisfy All
</Files>

#
# ErrorLog: The location of the error log file.
# If you do not specify an ErrorLog directive within a <VirtualHost>
# container, error messages relating to that virtual host will be
# logged here.  If you *do* define an error logfile for a <VirtualHost>
# container, that host's errors will be logged there and not here.
#
ErrorLog "logs/error_log"

#
# LogLevel: Control the number of messages logged to the error_log.
# Possible values include: debug, info, notice, warn, error, crit,
# alert, emerg.
#
LogLevel debug

<IfModule log_config_module>
    #
    # The following directives define some format nicknames for use with
    # a CustomLog directive (see below).
    #
    LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
    LogFormat "%h %l %u %t \"%r\" %>s %b" common

    <IfModule logio_module>
      # You need to enable mod_logio.c to use %I and %O
      LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedio
    </IfModule>

    #
    # The location and format of the access logfile (Common Logfile Format).
    # If you do not define any access logfiles within a <VirtualHost>
    # container, they will be logged here.  Contrariwise, if you *do*
    # define per-<VirtualHost> access logfiles, transactions will be
    # logged therein and *not* in this file.
    #
    CustomLog "logs/access_log" common

    #
    # If you prefer a logfile with access, agent, and referer information
    # (Combined Logfile Format) you can use the following directive.
    #
    #CustomLog "logs/access_log" combined
</IfModule>

<IfModule alias_module>
    #
    # Redirect: Allows you to tell clients about documents that used to
    # exist in your server's namespace, but do not anymore. The client
    # will make a new request for the document at its new location.
    # Example:
    # Redirect permanent /foo http://www.example.com/bar

    #
    # Alias: Maps web paths into filesystem paths and is used to
    # access content that does not live under the DocumentRoot.
    # Example:
    # Alias /webpath /full/filesystem/path
    #
    # If you include a trailing / on /webpath then the server will
    # require it to be present in the URL.  You will also likely
    # need to provide a <Directory> section to allow access to
    # the filesystem path.

    #
    # ScriptAlias: This controls which directories contain server scripts.
    # ScriptAliases are essentially the same as Aliases, except that
    # documents in the target directory are treated as applications and
    # run by the server when requested rather than as documents sent to the
    # client.  The same rules about trailing "/" apply to ScriptAlias
    # directives as to Alias.
    #
    ScriptAlias /cgi-bin/ "/opt/apache//cgi-bin/"

</IfModule>

<IfModule cgid_module>
    #
    # ScriptSock: On threaded servers, designate the path to the UNIX
    # socket used to communicate with the CGI daemon of mod_cgid.
    #
    #Scriptsock cgisock
</IfModule>

#
# "/opt/apache//cgi-bin" should be changed to whatever your ScriptAliased
# CGI directory exists, if you have that configured.
#
<Directory "/opt/apache//cgi-bin">
    AllowOverride None
    Options None
    Order allow,deny
    Allow from all
</Directory>

<IfModule mime_module>
    #
    # TypesConfig points to the file containing the list of mappings from
    # filename extension to MIME-type.
    #
    TypesConfig conf/mime.types

    #
    # AddType allows you to add to or override the MIME configuration
    # file specified in TypesConfig for specific file types.
    #
    #AddType application/x-gzip .tgz
    #
    # AddEncoding allows you to have certain browsers uncompress
    # information on the fly. Note: Not all browsers support this.
    #
    #AddEncoding x-compress .Z
    #AddEncoding x-gzip .gz .tgz
    #
    # If the AddEncoding directives above are commented-out, then you
    # probably should define those extensions to indicate media types:
    #
    AddType application/x-compress .Z
    AddType application/x-gzip .gz .tgz

    #
    # AddHandler allows you to map certain file extensions to "handlers":
    # actions unrelated to filetype. These can be either built into the server
    # or added with the Action directive (see below)
    #
    # To use CGI scripts outside of ScriptAliased directories:
    # (You will also need to add "ExecCGI" to the "Options" directive.)
    #
    #AddHandler cgi-script .cgi

    # For type maps (negotiated resources):
    #AddHandler type-map var

    #
    # Filters allow you to process content before it is sent to the client.
    #
    # To parse .shtml files for server-side includes (SSI):
    # (You will also need to add "Includes" to the "Options" directive.)
    #
    #AddType text/html .shtml
    #AddOutputFilter INCLUDES .shtml
</IfModule>

#
# The mod_mime_magic module allows the server to use various hints from the
# contents of the file itself to determine its type.  The MIMEMagicFile
# directive tells the module where the hint definitions are located.
#
#MIMEMagicFile conf/magic

#
# Customizable error responses come in three flavors:
# 1) plain text 2) local redirects 3) external redirects
#
# Some examples:
#ErrorDocument 500 "The server made a boo boo."
#ErrorDocument 404 /missing.html
#ErrorDocument 404 "/cgi-bin/missing_handler.pl"
#ErrorDocument 402 http://www.example.com/subscription_info.html
#

#
# MaxRanges: Maximum number of Ranges in a request before
# returning the entire resource, or one of the special
# values 'default', 'none' or 'unlimited'.
# Default setting is to accept 200 Ranges.
#MaxRanges unlimited

#
# EnableMMAP and EnableSendfile: On systems that support it,
# memory-mapping or the sendfile syscall may be used to deliver
# files.  This usually improves server performance, but must
# be turned off when serving from networked-mounted
# filesystems or if support for these functions is otherwise
# broken on your system.
# Defaults: EnableMMAP On, EnableSendfile Off
#
#EnableMMAP off
#EnableSendfile on

# Supplemental configuration
#
# The configuration files in the conf/extra/ directory can be
# included to add extra features or to modify the default configuration of
# the server, or you may simply copy their contents here and change as
# necessary.

# Server-pool management (MPM specific)
#Include conf/extra/httpd-mpm.conf

# Multi-language error messages
#Include conf/extra/httpd-multilang-errordoc.conf

# Fancy directory listings
#Include conf/extra/httpd-autoindex.conf

# Language settings
#Include conf/extra/httpd-languages.conf

# User home directories
#Include conf/extra/httpd-userdir.conf

# Real-time info on requests and configuration
#Include conf/extra/httpd-info.conf

# Virtual hosts
#Include conf/extra/httpd-vhosts.conf

# Local access to the Apache HTTP Server Manual
#Include conf/extra/httpd-manual.conf

# Distributed authoring and versioning (WebDAV)
#Include conf/extra/httpd-dav.conf

# Various default settings
#Include conf/extra/httpd-default.conf

# Configure mod_proxy_html to understand HTML4/XHTML1
<IfModule proxy_html_module>
Include conf/extra/proxy-html.conf
</IfModule>

# Secure (SSL/TLS) connections
#Include conf/extra/httpd-ssl.conf
#
# Note: The following must must be present to support
#       starting without SSL on platforms with no /dev/random equivalent
#       but a statically compiled-in mod_ssl.
#
<IfModule ssl_module>
SSLRandomSeed startup builtin
SSLRandomSeed connect builtin
</IfModule>

Include conf/mod_jk.conf
Include conf/VirtualHost.conf
}

Now, the problem I am having. I start apache by going to the bin folder and running./apachectl start. However, the first thing that happens is, I get an error:

[root@cs-uktest2 bin]# ./apachectl start
httpd: Syntax error on line 116 of /opt/apache/conf/httpd.conf: Cannot load modules/mod_proxy.so into server: /opt/apache/modules/mod_proxy.so: undefined symbol: apr_global_mutex_lockfile

So, I comment out the mod_proxy module in HTTPD.conf, and all it does is tell me the same error for the next module, until I get to mod_rewrite.so. Now, I have this switched on in VirtualHost.conf, which looks like this:

[root@cs-uktest2 conf]# cat VirtualHost.conf
<VirtualHost 172.17.100.42:8080>
Servername 172.17.100.42
ServerAlias 172.17.100.42
DocumentRoot "/opt/apache/htdocs"
ErrorLog logs/172.17.100.42-error.log
CustomLog logs/172.17.100.42.log common
RewriteEngine On
JkMount /jkstatus/ stat
JkMount /manager* lb

</VirtualHost>

so I cant very well disable it. When I do disable it, I just get an exception when it tries to load VirtualHost.

Oh, for clarity, I am using apache as a load balancer for two other application servers. Therefore I have also installed tomcat connectors, but I configured this post-installation with apxs.

If anyone has any idea why I am getting this undefined symbol: apr_global_mutex_lockfile issue then I would be very grateful to hear from you! I have done substantial googling and plenty of people talking about problems loading Mod_ssl.so and getting this error, but I am not using mod_ssl.so!

Its worth confirming that mod_proxy.so DOES exist in my modules directory, and mod_proxy.h is in the 'include' folder too. Perhaps that is the problem?

I have reconfigured apr, apr-utils, pcre and apache several times to see if it solves it. It doesnt.

Thanks in advance

2 Answers 2

0

In case anyone comes across this issue in future, here is what I did to resolve the problem.

1) I realised I didnt actually need mod_proxy to run my load balancer, mod_jk was sufficient. Therefore I commented out all mod_proxy modules.

2) When I ran 'ldd /opt/apache/bin/httpd' I could see that HTTPD was looking in the wrong place for apr-utils. It was actually trying to pull them from /usr/lib64, rather than /usr/apr-util, where I had installed it. so I tried to entirely remove apache and apr-util, and recompile them both, but this didnt solve the issue either.

Eventually what I did was to compile apache on another server I had, and copy across /opt/apache/bin/httpd to the original server. That solved the issue!

I admit, there is probably a much simpler way of redirecting where httpd looks for apr-util, but I couldn't find that answer. So this is very much 'the long way round' answer, but ultimately the problem is that httpd is looking at the wrong file locations for apr-util.

Thanks

0

@Nathan

  1. I had similar kind of issue and was able to fix them by adding symbolic link to my new apr directory.

  2. GOTCHA: Make sure if you or system admin does a system/kernel patch the symbolic link gets overridden again and the problem will re-manifest. I don't know how to avoid them.

My Error Message and solution:

./apachectl -M
httpd: Syntax error on line 69 of /usr/local/apache-httpd-2.4.25/conf/httpd.conf: 
Cannot load modules/mod_ssl.so into server: /usr/local/apache-httpd-2.4.25/modules/mod_ssl.so: undefined symbol: apr_global_mutex_lockfile

[httpd@vlb-usr/localdev bin]$ ldd httpd
        linux-vdso.so.1 =>  (0x00007fffef5fd000)
        libpcre.so.1 => /usr/local/dependencies/pcre-8.38/lib/libpcre.so.1 (0x00002b234a983000)
        libaprutil-1.so.0 => /usr/local/dependencies/apr-util-1.5.4/lib/libaprutil-1.so.0 (0x00002b234aba0000)
        libexpat.so.0 => /lib64/libexpat.so.0 (0x0000003c5da00000)
        libapr-1.so.0 => /usr/lib64/libapr-1.so.0 (0x00002b234adda000) ++++++
        libuuid.so.1 => /lib64/libuuid.so.1 (0x0000003c59a00000)
        librt.so.1 => /lib64/librt.so.1 (0x0000003c5a600000)
        libcrypt.so.1 => /lib64/libcrypt.so.1 (0x0000003c6bc00000)
        libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003c5a200000)
        libdl.so.2 => /lib64/libdl.so.2 (0x0000003c59e00000)
        libc.so.6 => /lib64/libc.so.6 (0x0000003c59200000)
        /lib64/ld-linux-x86-64.so.2 (0x0000003c58e00000)

++++++ Issue is in here - But when I build Apache from source I did assign them properly..

//Apache configure command
./configure --prefix=/usr/local/apache-httpd-2.4.25 \
    --with-pcre=/usr/local/dependencies/pcre-8.38 \
    --with-apr=/usr/local/dependencies/apr-1.5.2 \
    --with-apr-util=/usr/local/dependencies/apr-util-1.5.4 \
    --enable-so \
    --enable-module=ssl \
    --enable-ssl=shared \
    --with-ssl=/usr/local/ssl-1.0.2k


//Before changes
[root@vlb-usr/localdev lib64]# ls -l libapr*
lrwxrwxrwx 1 root root     17 Mar 20 00:12 libapr-1.so.0 -> libapr-1.so.0.2.7
-rwxr-xr-x 1 root root 165144 May 20  2011 libapr-1.so.0.2.7
lrwxrwxrwx 1 root root     21 Mar 20 00:12 libaprutil-1.so.0 -> libaprutil-1.so.0.2.7
-rwxr-xr-x 1 root root 108136 Dec  2  2010 libaprutil-1.so.0.2.7

//Solution
cd /usr/lib64
unlink libapr-1.so.0
ln -s /usr/local/dependencies/apr-1.5.2/lib/libapr-1.so.0 libapr-1.so.0

//After changes

[root@vlb-usr/localdev lib64]# ls -l libapr*
lrwxrwxrwx 1 root root     48 Mar 20 01:37 libapr-1.so.0 -> /usr/local/dependencies/apr-1.5.2/lib/libapr-1.so.0
-rwxr-xr-x 1 root root 165144 May 20  2011 libapr-1.so.0.2.7
lrwxrwxrwx 1 root root     21 Mar 20 00:12 libaprutil-1.so.0 -> libaprutil-1.so.0.2.7
-rwxr-xr-x 1 root root 108136 Dec  2  2010 libaprutil-1.so.0.2.7

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