In cPanel environment the hosting (system) user ‘username’ has database creation privilege for any database that starts with username_ prefix. You can verify it by running ‘SHOW GRANTS for username@localhost;’ in mysql client:

GRANT ALL PRIVILEGES ON `username\_%`.* TO 'username'@'localhost'

This username can thus be used to create/drop databases dynamically from Java/JSP code. To execute DDL (Data Definition Language) commands (CREATE, DROP) you will need to call executeUpdate() instead of most commonly used executeQuery() that returns ResultSet. executeUpdate() returns integer – 0 in case we run DROP and 1 when we run CREATE.

int result = statement.executeUpdate("CREATE DATABASE username_databasename");

You need to update username and password variables in the example code. Also do not forget to put mysql-connector-java.X.X.X-bin.jar in your WEB-INF/lib or application server-wide lib directory.

Specifying database name in connection used to create and drop databases is optional. In case of MySQL you can of course use everlasting ‘mysql’ database and in PostgreSQL use ‘template1′ database.

In a bare system (e.g. dedicated or VPS without a control panel) you would normally use ‘root’ user to create/drop databases unless you created another user and assigned him correct privileges.

connection = DriverManager.getConnection("jdbc:mysql://localhost/", "root", "rootpassword");

Note that databases created dynamically will not be shown in cPanel’s database list.

Here goes the full code of create_drop_database.jsp for your reference:

<%@page import="java.sql.*" %>
<%

// database to be created/dropped
String database = null;
// your cPanel username and password here - the user has right to create/drop databases
String username = "username";
String password = "secret";

String url = "jdbc:mysql://localhost/";
Connection connection = null;
Statement statement = null;
ResultSet rset = null;
boolean databaseListChanged = false;
int result = -1;

try { 
    Class.forName("com.mysql.jdbc.Driver").newInstance(); 
} catch(ClassNotFoundException e) { 
    out.println("Class not found: "+ e.getMessage());
    return;
}

try {

    connection = DriverManager.getConnection(url, username, password); 
    statement = connection.createStatement();

    out.println("<b>List of databases accessible by user " + username + ":</b><br/>");
    rset = statement.executeQuery("SHOW DATABASES");
    while (rset.next())   {
        out.println(rset.getString(1) + "<br/>");
    }
    rset.close();
    out.println("<hr>");

    if (request.getParameter("database") != null) {
        database = (String)request.getParameter("database");
        if (request.getParameter("Create") != null &&
            request.getParameter("Create").equals("Create")) {
            result = statement.executeUpdate("CREATE DATABASE " +  database);
            out.println("result of 'CREATE DATABASE '" + database + " is " + result);
            databaseListChanged = true;
        } else if (request.getParameter("Drop") != null &&
            request.getParameter("Drop").equals("Drop")) {
            result = statement.executeUpdate("DROP DATABASE " +  database);
            out.println("result of 'DROP DATABASE '" + database + " is " + result);
            databaseListChanged = true;
        }
    }

    statement.close();
    connection.close();
    if (databaseListChanged) { response.sendRedirect(request.getRequestURL().toString() + "?result=" + result); }
    if (request.getParameter("result") != null) { 
        out.println("result of last CREATE or DROP database is " + request.getParameter("result") + "<br/>");
    }
%>

<form action="create_drop_database.jsp" method="post"><table>
<tr><td align="left">Database name to create or drop: <input type="text" name="database" size="20"></td></tr>
<tr><td align="left"><input type="submit" name="Create" value="Create">
<input type="submit" name="Drop" value="Drop">
<input type="reset" name="Reset" value="Reset"></td></tr>
</table></form>

<%

} catch (SQLException e) {
    out.println(e.getMessage());
} finally {
    try {
        if(connection != null) connection.close();
    } catch(SQLException e) {}
}

%>

And here are 2 screenshots of its output:
1) after deleting database (result is 0)
2) after creating database (result is 1)

Creating and deleting databases on the fly is rarely used as this process is a bit costly IO-wise. If you initially decided for using this method you may need to rethink your needs as probably your goal can be achieved without using create/drop.

As fastcgi subprocesses do not start separate shells, they do not read shell resource scripts (e.g. .bashrc) from your home directory. They use environment variables of parent process instead and evidently your expected java related variables will not be there.
You will need to define needed variables in your php script for example:

echo 'test without shell (variables defined in php)';
$JAVA_HOME = "/opt/jdk1.6.0_43";
$PATH = "$JAVA_HOME/bin:".getenv('PATH');
putenv("JAVA_HOME=$JAVA_HOME");
putenv("PATH=$PATH");
$r=`echo $JAVA_HOME; which java; java -version 2>&1`;
echo "<pre>$r</pre>";

Another solution is to call bash explicitly in shell_exec (or with backticks) as interactive shell and then it will read in your .bashrc defined variables like JAVA_HOME, JAVA_OPTS and PATH:

echo 'test with interactive shell (variables in ~/.bashrc)';
$r=`bash -ic 'echo \$JAVA_HOME; which java; java -version 2>&1'`;
echo "<pre>$r</pre>";
echo 'another variant of above';
exec("bash -ic 'echo \$JAVA_HOME; which java; java -version 2>&1'", &$myOutput, &$result);
echo "<pre>".join("<br/>",$myOutput)."<br/>result = ".$result."</pre>";

Note: java messages go to stderr so it must be redirected to stdin to be catched by shell_exec and printed by the php script thus the 2>&1 redirection.

The same way you may define CLASSPATH variable so that your jars are found by java process. Use full paths for other input/output files provided in java command line (for example a file with data to be processed or a file where results will be stored).

On a shared hosting server you have limited JVM related resources like heap and PermGen memory so you should also set correct JAVA_OPTS if you are not using the ‘bash interactive’ method.

Yet another approach to get Java and its parameters visible by PHP is to source a file (commonly known as envvars in case of Apache) that sets or modifies environment variables when Apache is started but this solution only makes sense on a VPS or dedciated server as it makes global changes affecting all PHP subprocesses.

And last but not least there is php-java bridge project that you may also use for executing Java code from PHP – it provides better integration between the languages.
See more in How to run PHP applications in Tomcat 7 with PHP-Java bridge?

SEVERE: Error loading WebappClassLoader     
  delegate: false                                                 
  repositories:                           
    /WEB-INF/classes/                                             
----------> Parent Classloader:
org.apache.catalina.loader.StandardClassLoader@16fd0b7                    
 javax.faces.webapp.FacesServlet                           
java.lang.ClassNotFoundException: javax.faces.webapp.FacesServlet

Most possible cause is that JSF libraries are missing. These could have been included in your local development environment calsspath in a way but have not been bundled into the final WAR file. You should check locally why this happened and correct it for the future.

But for now, to recover from this error simply download latest JSF 2.1 or JSF 1.2 libraries (jars) from http://www.oracle.com/technetwork/java/javaee/download-139288.html or directly from http://javaserverfaces.java.net/download.html

In case of JSF 2.1 you get single jar (for example javax.faces-2.1.17.jar) to put into Tomcat’s lib or your application’s WEB-INF/lib directory.

In case of JSF 1.2 you get zip archive (for example mojarra-1.2_14-binary.zip) so unpack it and get jsf-api.jar and jsf-impl.jar from lib directory inside the archive. Have the jars located in Tomcat’s lib or your application’s WEB-INF/lib directory or your application server’s classpath whatever suits you best.

Do not forget to restart your application server and optionally check its logs to confirm the error is gone and no other error messages are present.

In this tutorial we have x509 PEM OpenSSL certifcate used in Apache2 and related private key. Now we want to use them directly in Tomcat by importing them into Java keystore. This situation differs from the case when you generate key using keytool.

What we have:
a) key – www_yourdomain_com.key
b) certificate – www_yourdomain_com.crt
c) intermediate cetificates bundle – www_yourdomain_com_intermediate.crt

JDK6 keytool allows for quite easy import procedure. It was more complicated with previous JDK version. Let’s go.

1) We build intermediate keystore in PKCS12 format using the key and certificate (including intermediate certifciates).

# cat www_yourdomain_com.crt www_yourdomain_com_intermediate.crt > www_yourdomain_com_all.crt
# openssl pkcs12 -export -in www_yourdomain_com_all.crt -inkey www_yourdomain_com.key \
    -passout pass:changeit > keystore.p12

2) We then convert this store into a Java key store:

# keytool -importkeystore -srckeystore keystore.p12 -srcstoretype PKCS12 \
    -srcstorepass changeit -deststorepass changeit -destkeypass changeit \ 
    -destkeystore keystore -alias 1 -destalias tomcat

3) Now we modify HTTPS connector in Tomcat’s conf/server.xml to read:

<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
    maxThreads="150" scheme="https" secure="true"
    keystoreFile="${catalina.base}/keystore" keystorePass="changeit"
    keyAlias="tomcat" clientAuth="false" sslProtocol="TLS" />

Notes:
- A (might be temporary) password is needed for destination store and key to avoid a null reference exception at import step
- We use ‘alias 1′ for keytool to correcty find our certificate/key in keystore.p12
- Choose your own destination password
- You may import CA/intermediate certificates separately later instead of doing it in one bundle with website certificate like in above example (start with CA cert and go down)

If you are using APR (Apache Portable Runtime) to increase performance then you do not use keystore format. Instead you use the original certificates and key in PEM format (OpenSSL).

<Connector port="8443" scheme="https" secure="true" SSLEnabled="true"
    SSLCertificateFile="${catalina.base}/www_yourdomain_com.crt"
    SSLCertificateKeyFile="${catalina.base}/www_yourdomain_com.key"
    SSLPassword="" 
    SSLCertificateChainFile="${catalina.base}/www_yourdomain_com_intermedaite.crt"
    keyAlias="tomcat" SSLProtocol="TLSv1"/>

References: How to use SSL certificates with Java, Tomcat and cPanel?

Usually, MySQL global parameter wait_timeout is set to 28800 (i.e. 8 hours). If your page is not accessed for more than 8 hours (e.g. in the night) MySQL will close the connection on its side. If your database connection config (in Java app) is not prepared for such case your page may display error message and also the error will be logged. For example:

org.hibernate.SessionException: Session is closed!
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure           
The last packet successfully received from the server was 22,761 milliseconds ago.  The last packet sent successfully to the server was 9 milliseconds ago.
java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.

Usually the connection will be also dropped on your application side and a new one created so subsequent queries may work. But what if we want to be sure our site visitors will not ever see the error? We need to enable idle connection testing.

How to configure database connection parameters in your code to test connection before use? Here goes an example for Hibernate. C3P0 project – an extension of JDBC – will help us to achieve it.

You can verify MySQL wait_timeout in your environment with:

mysql> show global variables like 'wait_timeout';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wait_timeout  | 28800 | 
+---------------+-------+

To correct the issue in a generic application that uses hibernate-core 3.3.1.GA perform the following 3 steps:

1) Download hibernate-c3p0-3.3.1.GA.jar and c3p0-0.9.1.jar into Tomcat’s lib or application’s WEB-INF/lib

2) In generic WEB-INF/classes/hibernate.cfg.xml add 3 new properties:

// tell hibernate to use C3P0
<property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property> 

// If this is a number greater than 0, C3P0 will test all idle, pooled but unchecked-out connections, every this number of seconds
// Set this to something below your MySQL wait_timeout
<property name="c3p0.idle_test_period">14400</property> 

// a query used to test connections
<property name="c3p0.preferredTestQuery">select 1;</property>

Here is full hibernate.cfg.xml from our application.

3) Restart the Tomcat and enjoy!

Other settings that should also be set in hibernate config file (parameter names differ from these used in c3p0.properties) are listed here. Note, that if you do not set them in hibernate config file – hibernate defaults for these paramters will override c3p0.properties counterparts.

Next planned article will handle the same issue with DBCP.

References:
http://www.mchange.com/projects/c3p0/index.html
http://community.jboss.org/wiki/HowToConfigureTheC3P0ConnectionPool

In this copy and paste tutorial we assume that your server IP is 10.1.1.1 and the domain name you are setting DNS zone for is yourdomain.com. Let’s begin with installing required packages and making named to start at boot time.

yum -y install bind-chroot bind bind-utils
chkconfig named on

You may have different bind version so replace 9.3.6 with your version accordingly and copy example configuration files.

cp /usr/share/doc/bind-9.3.6/sample/etc/* /var/named/chroot/etc

Optionally, you may delete view “internal” from /var/named/chroot/etc/named.conf

perl -i.bak -ne 'local $/; $f = <>; $f =~ s/view "internal".*?^key ddns_key/key ddns_key/ms; print $f' /var/named/chroot/etc/named.conf

In view “external” replace “my.external.zone” with your domain name “yourdomain.com”. This will also update zone file name.

sed -i 's/my.external.zone/yourdomain.com/g' /var/named/chroot/etc/named.conf

With below command generate and the paste the key into “key ddns_key” secret field.

SECRET=`/usr/sbin/dns-keygen`; sed -i "s/secret .*$/secret \"$SECRET\";/" /var/named/chroot/etc/named.conf

Copy the other template files into your chrooted /var/named.

cp -r /usr/share/doc/bind-9.3.6/sample/var/named/* /var/named/chroot/var/named

And now create zone file for yourdomain.com assuming you will be using your own nameservers ns1/ns2.yourdomain.com with the server’s public IP. Don’t forget to update MYDOMAIN, MYIP.

MYDOMAIN=yourdomain.com; MYIP=10.1.1.1; SERIAL=`date +%s`
echo -e "\$TTL 14400
@       86400   IN      SOA     ns1.$MYDOMAIN. root.$MYDOMAIN. (
        \t$SERIAL    ; serial, timestamp
        \t86400        ; refresh, seconds
        \t7200        ; retry, seconds
        \t3600000        ; expire, seconds
        \t86400 )        ; minimum, seconds

$MYDOMAIN. 86400 IN NS ns1.$MYDOMAIN.
$MYDOMAIN. 86400 IN NS ns2.$MYDOMAIN.

$MYDOMAIN. IN A $MYIP

localhost.$MYDOMAIN. IN A 127.0.0.1

$MYDOMAIN. IN MX 0 $MYDOMAIN.

mail IN CNAME $MYDOMAIN.
www IN CNAME $MYDOMAIN.
ftp IN A $MYIP
$MYDOMAIN. IN TXT \"v=spf1 a mx -all\"" > /var/named/chroot/var/named/yourdomain.com.db

Clear the environment variables we used and start named.

unset SECRET MYDOMAIN MYIP SERIAL
service named start

Finally, you may test if the nameserver responds with correct information by querying it from another host and asking for all records of your domain (zone transfer):

u7:~$ host -t IXFR yourdomain.com 10.1.1.1
Using domain server:
Name: 10.1.1.1
Address: 10.1.1.1#53

yourdomain.com has SOA record ns1.yourdomain.com. root.yourdomain.com. 1352893256 86400 7200 3600000 86400
yourdomain.com descriptive text "v=spf1 a mx -all"
yourdomain.com mail is handled by 0 yourdomain.com.
yourdomain.com name server ns1.yourdomain.com.
yourdomain.com name server ns2.yourdomain.com.
yourdomain.com has address 10.1.1.1
ftp.yourdomain.com has address 10.1.1.1
localhost.yourdomain.com has address 127.0.0.1
mail.yourdomain.com is an alias for yourdomain.com.
www.yourdomain.com is an alias for yourdomain.com.
yourdomain.com has SOA record ns1.yourdomain.com. root.yourdomain.com. 1352893256 86400 7200 3600000 86400

Now register your nameservers in your domain registrar control panel. For example:
ns1.yourdomain.com 10.1.1.1
ns2.yourdomain.com 10.1.1.1
and you are all set.

In such case you may change registrar to a better one (transfer out  your domain) or register your own nameservers (ns1.yourdomain.com ns2.yourdomain.com) using your VPS IP (or IPs) in their control panel. Then you can run your own nameserver software on the VPS. Commonly used DNS software includes BIND, tinydns, PowerDNS.

For basic use like serving all queries related to a domain or a set of domains from single IP, Centos users can do below steps when logged in as ‘root’.

1. Install dnsmasq and backup its config file.

yum install dnsmasq
cp /etc/dnsmasq.conf /etc/dnsmasq.conf.bak

2. Disable a few features to lower resource usage.

sed -i -e 's/^#no-resolv/no-resolv/' -e 's/^#no-poll/no-poll/' -e 's/^#no-host/no-host/' /etc/dnsmasq.conf

3. In the below command replace yourdomain.com with your domain name and 10.10.10.10 with your VPS IP address.

sed -i 's/^#address=/doubleclick.net/127.0.0.1/address=\/yourdomain.com\/10.10.10.10/' /etc/dnsmasq.conf

4. Optionally you can verify the changes you made.

diff -Nu /etc/dnsmasq.conf /etc/dnsmasq.conf.bak

5. Start dnsmasq and make it start at boot time.

service dnsmasq start
chkconfig dnsmasq on

Now, if you run a DNS query for your domain or a host/subdomain you should receive your VPS IP. For example from your PC ping www.yourdomain.com and 10.10.10.10 (your VPS IP) should reply.

Of course dnsmasq is more powerful than above. You may also use /etc/hosts to define records for selected hosts or enable mail (MX) lines in /etc/dnsmasq.conf to name a few. Dnsmasq.conf contains verbose comments for you to read first.

Note: I do not like the mess created by tinydns anyway you may also try this DNS server due to its low resource usage.

Default logger in Tomcat 6 and 7 is java.util.logging logger. Previously Log4J was used. See an example how increased logging verbosity helps solving an issue. When deploying fresh Grails application all error messages we initially got were:

INFO: Deploying web application archive /home/grailswebapp/appservers/apache-tomcat-7.0.30/webapps/grailswebapp.war
Configuring Spring Security Core ...
... finished configuring Spring Security Core
Oct 12, 2012 4:00:37 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart
Oct 12, 2012 4:00:37 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [/tixomatic] startup failed due to previous errors

Quite unclear information, not leading straight to a reason and solution. Let’s now stop the Tomcat and put logging.properties file into application’s WEB-INF/classes with the following content:

org.apache.catalina.core.ContainerBase.[Catalina].level = INFO
org.apache.catalina.core.ContainerBase.[Catalina].handlers = java.util.logging.ConsoleHandler

Clear catalina.out and start Tomcat. Now we get (scroll right to see ‘Access denied for user’ message):

INFO: Deploying web application archive /home/grailswebapp/appservers/apache-tomcat-7.0.30/webapps/grailswebapp.war
Oct 12, 2012 4:13:37 PM org.apache.catalina.core.ApplicationContext log
INFO: No Spring WebApplicationInitializer types detected on classpath
Oct 12, 2012 4:13:38 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring root WebApplicationContext
Configuring Spring Security Core ...
... finished configuring Spring Security Core
Oct 12, 2012 4:13:42 PM org.apache.catalina.core.StandardContext listenerStart
SEVERE: Exception sending context initialized event to listener instance of class org.codehaus.groovy.grails.web.context.GrailsContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManagerPostProcessor': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Cannot resolve reference to bean 'hibernateProperties' while setting bean property 'hibernateProperties'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateProperties': Cannot resolve reference to bean 'dialectDetector' while setting bean property 'properties' with key [hibernate.dialect]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dialectDetector': Invocation of init method failed; nested exception is org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Access denied for user 'grailswebapp_dbuser1'@'server.company.net' (using password: YES))
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527)
    at org.codehaus.groovy.grails.commons.spring.ReloadAwareAutowireCapableBeanFactory.doCreateBean(ReloadAwareAutowireCapableBeanFactory.java:126)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.context.support.AbstractApplicationContext.registerBeanPostProcessors(AbstractApplicationContext.java:707)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:449)
    at org.codehaus.groovy.grails.commons.spring.DefaultRuntimeSpringConfiguration.getApplicationContext(DefaultRuntimeSpringConfiguration.java:153)
    at org.codehaus.groovy.grails.commons.spring.GrailsRuntimeConfigurator.configure(GrailsRuntimeConfigurator.java:170)
    at org.codehaus.groovy.grails.commons.spring.GrailsRuntimeConfigurator.configure(GrailsRuntimeConfigurator.java:127)
    at org.codehaus.groovy.grails.web.context.GrailsConfigUtils.configureWebApplicationContext(GrailsConfigUtils.java:121)
    at org.codehaus.groovy.grails.web.context.GrailsContextLoader.initWebApplicationContext(GrailsContextLoader.java:104)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:111)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4791)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5285)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:618)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:963)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1600)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)

and a few more related exceptions ending with

Oct 12, 2012 4:13:42 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart
Oct 12, 2012 4:13:42 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [/tixomatic] startup failed due to previous errors

It means somewhere in the code the database host was referenced with a host name different from localhost while only localhost access is granted or SQL credentials are wrong. Just checking these 2 items made problem solved and logging.properties was removed to avoid excessive logging.

Similar issue where increased verbosity helped with quick resolution was

org.apache.catalina.core.StandardContext start SEVERE: Error listenerStart
org.apache.catalina.core.StandardContext start SEVERE: Context [/grailswebapp] startup failed due to previous errors

In this case it was a ClassNotFoundException and problem has been solved after adding required class or jar.

Yet another example of unclear error message when JDK6 was used for application compiled with JDK7:

INFO: Deploying web application archive /home/tomcat/apache-tomcat-7.0.32/webapps/ROOT.war
Oct 13, 2012 8:03:33 AM org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart
Oct 13, 2012 8:03:33 AM org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [] startup failed due to previous errors

And after enabling verbose logging we know where we are (wrong JDK version used):

INFO: Deploying web application archive /home/tomcat/apache-tomcat-7.0.32/webapps/ROOT.war
Oct 13, 2012 8:05:19 AM org.apache.catalina.core.StandardContext listenerStart
SEVERE: Error configuring application listener of class website.web.MainAggregation
java.lang.UnsupportedClassVersionError: website/web/MainAggregation : Unsupported major.minor version 51.0 (unable to load class website.web.MainAggregation)

Refer Tomcat 7 documentation for more on logging.

If your key-based connection works fine (refer ‘Steps to connect with Putty using key based authentication’ article) lets start Putty again and create SSH tunnel needed to remotely connect to PostgreSQL database.

1. Load my_conection seesion but do not open it.
2. Goto Connection > SSH > Tunnels in left side Putty area.
3. Find ‘Add new forwarded port’ secton and:
a) in ‘Source port’ enter an arbitrary local port for example 5433 (it can be also 5432 if no PostgreSQL server is using it locally).
b) in ‘Destination’ enter destiantion hostname and port for example: 127.0.0.1:5432
Click Add.

4. Go to Session and save my_connection
5. Download PgAdminIII (in this tutorial version 1.16.0 was used – you can use any other client the same way). PostgreSQL server will see the connection as coming from 127.0.0.1 and will accept it when correct database credentials are given.

6. Start pgAdminIII > File > Add Server and fill in connection details

Click Ok and you should be connected. When in Windows you can see your tunnel listening and established connection by listing open ports and connections with ‘netstat -an’ in command line.

For SSH access from Windows we recommend PuTTY and PuTTYgen from http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

1. Login to cPanel and go to Security > SSH/Shell Access to generate SSH key pair for use with a standalone SSH client like Putty.

2. Click Manage SSH Keys > Genarate a New Key. You should use a password to protect the key. You will be asked the password each time you use the key.

This will create kay pair (id_dsa, id_dsa.pub) in /home/USERNAME/.ssh
In 11.32.4 version of cPanel there seems to be a problem with generating key size different than 1024.

3. In Public key section click ‘Manage Authorization’ and ‘Authorize’

This will create authorized_keys and authorized_keys2 file in your /home/USERNAME/.ssh
In each of these files your public key string is included.

4. In Private key section click ‘View/Download’ beside the key (id_dsa) and then under ‘Private SSH Key id_dsa conversion to ppk format:’ enter the password you set in step #2 and click Convert to get the key in format suitable for Putty and download the key (id_dsa.ppk or id_rsa.ppk) to your PC.

Note: Before leaving this cPanel page check first if the downloaded key is the same as the one displayed in cPanel. You may just check last line starting with ‘Private-MAC:’.

5. Run putty.exe and in Putty:

a) Enter your hosting server hostname (consult ‘New Hosting Account Created’ email if in doubt)
b) Set correct SSH port (consult ‘New Hosting Account Created’ email if in doubt)

Enter connection label e.g. ‘my_connection’ and click Save. ‘my_connection’ will appear added below ‘Default Settings’.

c) Click SSH > Auth in the left menu and choose ‘Private key file for authentication’. Use path to your id_dsa.ppk or id_rsa.ppk here.

In the example the file was read from “C:\” path.

d) Click Connection > Data in the left menu and set ‘Auto-login username’ to your username.

e) Click Session in the top of left menu, make sure ‘my_connection’ is highlighted and save.
f) Double click the session name. You should be prompted for password from step #2 and subsequently logged in.

In another article we will show how to use this encrypted connection to have PgAdminIII or any other PostgreSQL client tunnelled to the PostgreSQL server.