Appion

h1. Troubleshooting the Web Server:

h4. Run the web server troubleshooter

A web server troubleshooting tool is available at http://YOUR_HOST/myamiweb/test/checkwebserver.php.

You can browse to this page from the Appion and Leginon Tools home page (http://YOUR_HOST/myamiweb) by clicking on [test Dataset] and then [Troubleshoot].

This page will automatically confirm that your configuration file and PHP installation and settings are correct and point you to the appropriate documentation to correct any issues.

h4. Firewall settings 

You may need to configure your firewall to allow incoming HTTP (port 80) and MySQL (port 3306) traffic:

<pre>

$ system-config-securitylevel

</pre>

h4. Security-enhanced linux 

"Security-enhanced linux (SELinux)":http://en.wikipedia.org/wiki/Security-Enhanced_Linux  may be preventing your files from loading. To fix this run the following command:

<pre>

$ sudo /usr/bin/chcon -R -t httpd_sys_content_t /var/www/html/

</pre>

see "this website":http://docs.fedoraproject.org/selinux-apache-fc3/sn-simple-setup.html  for more details on SELinux

h4. Slow image loading

If you find that you have many users viewing images, and the images are taking too long to load, there are several ways to address this.

# [[leginon:Alternative reduxd installation on file server]]

# [[leginon:Using imcache to cache mrc images as jpeg images of the default size on myamiweb]]

h4. Seg fault errors messages in Apache log: Web server does not inform user when login credentials are incorrect

If you try to run a job directly from the web gui, and the job fails without providing a message, check to see if it could be due to bad credentials. Test a username or password that you know are incorrect. If you do not receive a clear error message in the GUI, try the following fix.

Install latest version of http://pecl.php.net/package/ssh2:

<pre>

wget http://pecl.php.net/get/ssh2-0.12.tgz

tar -xzvf ssh2-0.12.tgz 

cd ssh2-0.12

yum install automake make php-devel libtool openssl-devel gcc++ gcc

phpize

yum install gcc php-devel php-pear libssh2 libssh2-devel

./configure 

make

make test

cp modules/ssh2.so   /usr/lib64/php/modules/

service httpd restart

</pre>

There were @Segmentation fault@ messages in the apache error log and I narrowed it down to "Cluster->authenticatedConnection()":https://emg.nysbc.org/projects/appion/repository/entry/trunk/myamiweb/processing/inc/cluster.inc#L293

It seems that the fix for "PHP :: Bug #63192":https://bugs.php.net/bug.php?id=63192 was needed to fix this bug.