使用apache启动Passenger时，出现以下错误：
[ 2014-09-29 08:35:08.7694 18178/7f4ed722d700 apache2/Hooks.cpp:1303 ]: Initializing Phusion Passenger...
[ 2014-09-29 08:35:08.7806 18179/7fc2336a7720 agents/Base.cpp:1591 ]: Random seed: 1411994108
[ 2014-09-29 08:35:08.7807 18179/7fc2336a7720 agents/Watchdog/Main.cpp:698 ]: Starting Watchdog...
[ 2014-09-29 08:35:08.7809 18179/7fc2336a7720 agents/Watchdog/Main.cpp:538 ]: Options: { 'analytics_log_user' => 'nobody', 'default_group' => 'puppet', 'default_python' => 'python', 'default_ruby' => '/usr/bin/ruby', 'default_user' => 'puppet', 'log_level' => '3', 'max_pool_size' => '6', 'passenger_root' => '/usr/lib/ruby/gems/1.8/gems/passenger-4.0.52', 'passenger_version' => '4.0.52', 'pool_idle_time' => '300', 'prestart_urls' => 'aHR0cHM6Ly9kZXYtcHVwcGV0Y2EuYm55bWVsbG9uLm5ldC91c3Ivc2hhcmUvcHVwcGV0L3JhY2svcHVwcGV0bWFzdGVyZC9wdWJsaWMA', 'temp_dir' => '/var/log/httpd', 'union_station_gateway_address' => 'gateway.unionstationapp.com', 'union_station_gateway_port' => '443', 'user_switching' => 'true', 'web_server_passenger_version' => '4.0.52', 'web_server_pid' => '18178', 'web_server_type' => 'apache', 'web_server_worker_gid' => '2', 'web_server_worker_uid' => '2' }
[ 2014-09-29 08:35:08.8074 18182/7ff9c2f6b720 agents/Base.cpp:1591 ]: Random seed: 1411994108
[ 2014-09-29 08:35:08.8076 18182/7ff9c2f6b720 agents/HelperAgent/Main.cpp:643 ]: Starting PassengerHelperAgent...
[ 2014-09-29 08:35:08.8156 18182/7ff9c2f6b720 agents/HelperAgent/Main.cpp:650 ]: PassengerHelperAgent online, listening at unix:/var/log/httpd/passenger.1.0.18178/generation-0/request
[ 2014-09-29 08:35:08.8308 18187/7f4b9962c7e0 agents/Base.cpp:1591 ]: Random seed: 1411994108
[ 2014-09-29 08:35:08.8312 18187/7f4b9962c7e0 agents/LoggingAgent/Main.cpp:333 ]: Starting PassengerLoggingAgent...
**[Mon Sep 29 08:35:09.859284 2014] [passenger:error] [pid 18178:tid 139976593561344] *** Passenger could not be initialized because of this error: Unable to start the Phusion Passenger watchdog because it encountered the following error during startup: **Unable to start the Phusion Passenger logging agent: it seems to have been killed with signal SIGKILL during startup****
我可以在这个位置找到PassengerLoggingAgent：
./usr/lib/ruby/gems/1.8/gems/passenger-4.0.52/buildout/agents/PassengerLoggingAgent
我对Passenger 进行了Gem 安装，构建运行良好。
环境：RHEL 6.4 乘客版本：4.0.52 Apache：2.4.2
httpd.conf:
LoadModule passenger_module /usr/lib/ruby/gems/1.8/gems/passenger-4.0.52/buildout/apache2/mod_passenger.so
<IfModule mod_passenger.c>
PassengerRoot /usr/lib/ruby/gems/1.8/gems/passenger-4.0.52
PassengerDefaultRuby /usr/bin/ruby
PassengerLogLevel 3
PassengerUser puppet
PassengerGroup puppet
PassengerDefaultUser puppet
PassengerDefaultGroup puppet
PassengerFriendlyErrorPages on
PassengerTempDir /var/log/httpd
PassengerSpawnMethod direct
PassengerStartTimeout 500
PassengerPreStart https://myserver.com/usr/share/puppet/rack/puppetmasterd/public
</IfModule>
conf.d
PassengerMaxPoolSize 12
# Recycle master processes after they service 1000 requests
PassengerMaxRequests 1000
# Stop processes if they sit idle for 10 minutes
PassengerPoolIdleTime 600
Listen 8140
<VirtualHost *:8140>
# Make Apache hand off HTTP requests to Puppet earlier, at the cost of
# interfering with mod_proxy, mod_rewrite, etc. See note below.
PassengerHighPerformance On
ServerName myserver.com
SSLEngine On
# Only allow high security cryptography. Alter if needed for compatibility.
SSLProtocol ALL -SSLv2 -SSLv3
SSLCipherSuite EDH+CAMELLIA:EDH+aRSA:EECDH+aRSA+AESGCM:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH:+CAMELLIA256:+AES256:+CAMELLIA128:+AES128:+SSLv3:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!DSS:!RC4:!SEED:!IDEA:!ECDSA:kEDH:CAMELLIA256-SHA:AES256-SHA:CAMELLIA128-SHA:AES128-SHA
SSLHonorCipherOrder on
SSLCertificateFile /var/lib/puppet/ssl/certs/myserver.com.pem
SSLCertificateKeyFile /var/lib/puppet/ssl/private_keys/myserver.com.pem
SSLCertificateChainFile /var/lib/puppet/ssl/ca/ca_crt.pem
SSLCACertificateFile /var/lib/puppet/ssl/ca/ca_crt.pem
SSLCARevocationFile /var/lib/puppet/ssl/ca/ca_crl.pem
SSLCARevocationCheck chain
SSLVerifyClient optional
SSLVerifyDepth 1
SSLOptions +StdEnvVars +ExportCertData
# Apache 2.4 introduces the SSLCARevocationCheck directive and sets it to none
# which effectively disables CRL checking. If you are using Apache 2.4+ you must
# specify 'SSLCARevocationCheck chain' to actually use the CRL.
# These request headers are used to pass the client certificate
# authentication information on to the puppet master process
RequestHeader set X-SSL-Subject %{SSL_CLIENT_S_DN}e
RequestHeader set X-Client-DN %{SSL_CLIENT_S_DN}e
RequestHeader set X-Client-Verify %{SSL_CLIENT_VERIFY}e
DocumentRoot /usr/share/puppet/rack/puppetmasterd/public
PassengerAppRoot /usr/share/puppet/rack/puppetmasterd
<Directory /usr/share/puppet/rack/puppetmasterd/>
Options None
AllowOverride all
# Apply the right behavior depending on Apache version.
<IfVersion < 2.4>
Order allow,deny
Allow from all
</IfVersion>
<IfVersion >= 2.4>
Require all granted
</IfVersion>
Options -MultiViews
</Directory>
<Directory /usr/share/puppet/rack/puppetmasterd/public >
Options None
AllowOverride all
# Apply the right behavior depending on Apache version.
<IfVersion < 2.4>
Order allow,deny
Allow from all
</IfVersion>
<IfVersion >= 2.4>
Require all granted
</IfVersion>
Options -MultiViews
</Directory>
ErrorLog /var/log/httpd/myserver.com_ssl_error.log
CustomLog /var/log/httpd/myserver.com_ssl_access.log combined
</VirtualHost>有人可以帮忙解决这个问题吗？