Search

Cross-Platform Edition

Version 24.2.9039

Cross-Platform Edition

The Cross-Platform edition of CData Arc includes an embedded Eclipse Jetty web server so that you can run Arc without any external server configuration. In addition, the installation includes a WAR file that can be deployed to any Java servlet container like Apache Tomcat, Eclipse Jetty, or IBM WebSphere.

The embedded Jetty server requires that JDK 11 or later is installed on the machine. Deploying to an external Java servlet container requires Servlet 3.0 (Jetty 8+, Tomcat 7+, WebSphere 8+, and so on).

Note: No matter how you choose to deploy Arc, the files and folders in AppDirectory must be readable and writable by the user who runs the application. The service installer that is included with the Java Edition setup uses cdataarc as this user.

If the application was run previously as a different user and you want to restore the necessary permissions for an cdataarc user to run the application, you should use a command similar to this example:

sudo chown -R cdataarc:cdataarc /opt/arc

Windows

In Windows, Arc is installed as a service by default. To access the application, you must first ensure that the service is running. Once the service is running, you can access the Arc admin console by opening a web browser and entering http://localhost:8080/ in the URL field.

You can also run the application without the service through a java command. CData recommends using the service, but this method can be useful for certain configurations.

Starting and Stopping the Service

You can start and stop the service in any of the following ways:

Start Menu Shortcuts

The Arc installer creates start menu shortcuts that allow you to easily use the application. To access these shortcuts, open the Start menu and expand the CData Arc folder. These shortcuts are available:

  • Launch CData Arc Admin Console: Opens a web browser window in your default web browser to the admin console URL, http://localhost:8080/. If the service is not running, the web browser returns an error.

  • Start CData Arc: Starts the Arc service. By default, this service runs when Windows starts so you do not need to run this command every time you run the application.

  • Stop CData Arc: Stops the Arc service. This action is necessary when you upgrade Arc.

Services Management Console

To open the Services Management Console, open the start menu and type services. Select the Services application that appears.

Scroll down to the service called CData Arc. If that service is running, the Status column says Running. Right-click the service to access options to Start, Stop, and Restart it.

Command Prompt

Advanced users can use a Windows command prompt to issue commands manually to the service. Open a command prompt and change the directory to the installation folder (by default, C:\Program Files\CData\CData Arc).

Note: You can also use a Microsoft PowerShell window to issue these commands, but the syntax is slightly different. Modify the commands accordingly if you use PowerShell.

To start the Arc service, issue this command:

arc.exe -start

Use the following commands to restart or stop the service:

arc.exe --restart --ServiceName "CData Arc"
arc.exe --stop --ServiceName "CData Arc"

Launching Without the Service

To run Arc without starting the service, open a command prompt in the installation folder. Issue the following command to start the application:

java -jar arc.jar

Linux

After you install Arc to a location of your choice, you can run Arc as a service or run the application manually. CData recommends using a service if you use Arc for critical applications.

Running Arc as a Service

Running Arc as a service enables the application to run independently from any user process and to restart automatically upon rebooting. This is the preferred method critical applications.

CData recommends creating a daemon to manage the Arc application on Linux. A script that is included in the installation package can do this automatically. You can also create the daemon manually if necessary.

The safest way to configure the Arc daemon is to run the script that is included in the installation package, provided that the system uses the systemd daemon manager:

bash ./service.sh

This script creates a daemon called arc.service. You can then use systemctl to manage the daemon:

systemctl enable arc
systemctl start arc

Running the Standalone Application

To start Arc without creating a service, use the terminal to open the arc.jar file in the installation directory with a configuration file argument, as shown here:

java -jar arc.jar

Configuring the Embedded Jetty Server

Arc comes pre-configured to work immediately in any environment. However, you can customize the way you access the data that is exposed in Arc by generating the arc.properties file in the Arc installation directory (for Windows, this is C:\Program Files\CData\CData Arc by default).

Generating the arc.properties File

Before you can make any customizations to the embedded Jetty server, you must create the arc.properties file. Run the following command in the installation directory where arc.jar is located:

java -jar arc.jar -GenerateProperties

This creates the arc.properties file in the installation directory. The file contains parameters that you can modify to change the port or to enable TLS/SSL.

Note: Once you have generated this file, upgrades to Arc do not overwrite it.

Changing the Port

To change the port on which the embedded server listens:

  1. Locate the arc.properties file in InstallationDirectory and open it in a text editor.

  2. Locate the following line where the port is set:

    cdata.http.port=8080

  3. Change this value to the port number that you want.

Enabling TLS/SSL

To enable TLS/SSL connections (HTTPS), you also need to modify the arc.properties file in InstallationDirectory, as follows:

  1. Set the cdata.tls.keyStoreType setting to the type of keystore to use. Valid values include jks, pkcs12, and jceks.

  2. Set the cdata.tls.keyStorePath setting to the path of the keystore to use. Note that ${cdata.home} might be used to refer to InstallationDirectory.

  3. Set the cdata.tls.keyStorePassword setting to the password for the keystore.

  4. Set the cdata.tls.port setting to the port that should be used to host the server.

  5. (Optional) Set the cdata.http.port setting to an empty string to disable plaintext connections.

The final result should look like this:

;; HTTP
cdata.http.port=

;; TLS
cdata.tls.port=8443
cdata.tls.keyStoreType=PKCS12
cdata.tls.keyStorePath=${cdata.home}/mycertificate.pfx
cdata.tls.keyStorePassword=mypassword

Note: If you obtain an external private key for configuration in Arc, be sure to change the owner of the certificate to the service account that is used to host Arc (cdataarc:cdataarc).

Generating a Jetty XML File

In most deployments, the arc.properties file provides the full range of necessary configuration options for the embedded Jetty server. However, if you require a more complex deployment, you can generate a Jetty XML file that serves as a starting point for further modifications. To generate this file, run the following command in the Arc installation directory where arc.jar is located:

java -jar arc.jar -GenerateXML

When the command completes, the arc.xml configuration file appears in the webapp folder. As long as it remains in that folder, it is used to start the application.

Starting and Stopping the Server

If you use the service.sh script to set up an Arc service, see Running as a Service. Otherwise, the Running In-Process section is applicable.

Running In-Process

Start the embedded Jetty server by executing the arc.jar file that is extracted from the application download during setup. You can use standard Java syntax, as shown below, to execute this file and start the server:

java -jar arc.jar

To stop the server, pass the -stop parameter to this command:

java -jar arc.jar -stop

Running as a Service

You can manipulate the Arc service by using standard system service commands, referencing arc as the name of the service.

To start the service, submit this command:

systemctl start arc

To stop the service, submit this command:

systemctl stop arc

To restart the service, submit this command:

systemctl restart arc

Configuration in Tomcat

Deploy the WAR File

You have two options for deploying a WAR file to Tomcat.

  • Copy the WAR file into the webapps folder.

  • Deploy the WAR file from within the management console in Tomcat. The Apache Tomcat documentation covers this method in more detail. See the documentation for your version of Tomcat.

It is possible that the WAR file might exceed the default maximum size that is allowed for file uploads in Tomcat. To overcome errors during deployment, you can edit the web.xml file of the manager application to allow larger files. Depending on your Tomcat configuration, this file might reside in /usr/share/tomcat7-admin/manager/WEB-INF or in another similar directory. In this file, you can change the size, in bytes, of the maximum allowed file size. For example, to allow deployment of a 200-MB WAR file, edit the following values to change the maximum allowed file size:

<multipart-config>
     <!-- 200-MB max -->
  <max-file-size>209715200</max-file-size>
  <max-request-size>209715200</max-request-size>
  <file-size-threshold>0</file-size-threshold>
</multipart-config>

Configure the Java Authentication and Service (JAAS)

To enable Arc to manage users dynamically within the application, you must configure the JAAS as described in the following subsections.

Create the Login Module

Create a JAAS configuration file with the name jaas.config in this folder: $CATALINA_BASE/conf/.

Include the following content in jaas.config to use standard authentication:

Arc {
  arc.LoginModule required;
};

If you want to use LDAP or Windows Active Directory to authenticate users, add this content instead:

Arc {
  com.sun.security.auth.module.LdapLoginModule REQUIRED
    userProvider="ldaps://ab1cdef234.wfsaas.net:636/CN=Users,DC=example,DC=com"
    authIdentity="{USERNAME}@example.com"
    userFilter="(&(|(samAccountName={USERNAME})(userPrincipalName={USERNAME})(cn={USERNAME}))(objectClass=user))"
    useSSL=false;
  arcesb.LoginModule optional;
};

In this example, you should modify the values for the userProvider, authIdentity, and userFilter attributes to suit your environment.

Create (or Modify) the JAASRealm Module

Create a context for Arc by creating (or modifying, if it is present) the configuration XML file that is located here:

$CATALINA_BASE/conf/Catalina/localhost/arc.xml

Note: Depending on how Tomcat is configured, this path might be slightly different. In this example, Catalina refers to the engine name, and localhost is the host name that is defined in server.xml.

Define a &lt;Context&gt; block and add a &lt;Realm&gt; element as shown below:

<Context>
  <Realm className="org.apache.catalina.realm.JAASRealm" appName="Arc"
    userClassNames="arc.SimplePrincipal"
    roleClassNames="arc.GroupPrincipal" />
</Context>

Then, update the &lt;Host&gt; element in the server.xml configuration file for the Tomcat server by setting the copyXML attribute to true, as shown below:

<Host name="localhost" appBase="webapps" unpackWARS="true" autoDeploy="true" copyXML="true">
  ...
</Host>

Note: If an application-specific context is present in server.xml, it takes precedence over arc.xml. For example:

<Context path="arc">
   ...
</Context>

CData recommends that you relocate any application context overrides, such as APP_DIRECTORY or APP_DB, to arc.xml where JAASRealm is defined.

Make the Login Module Visible

The Java virtual machine (JVM) must be directed to the login module (jaas.config) for the configuration to be visible. Set the java.security.auth.login.config system property on the JVM to the path of the jaas.config file. To do so, append the following line to the $CATALINA_BASE/conf/catalina.properties file:

java.security.auth.login.config=${catalina.base}/conf/jaas.config

Configure Data Directory Permissions

Give the user of the process that runs the Java servlet container Read/Write access to the data directory in the appropriate location, as follows:

  • Windows: C:\ProgramData\CData\Arc\

  • Linux: ~/cdata/arc

Restart the Tomcat server for the changes to take effect. You can now log in to the application.

Configuration in WebSphere

Configure the WebSphere Class Loader

For WebSphere to load the application resources correctly, you must follow these steps:

  1. In WebSphere, navigate to Application > Application Types > WebSphere enterprise applications.

  2. Select Arc.

  3. Select Class loading and update detection.

  4. Choose Classes loaded with local class loader first (parent last).

  5. Choose Single class loader for application.

  6. Click OK. Then click Save.

Configure the Java Authentication and Service (JAAS)

The following process is required to configure the JAAS and to enable Arc to manage users dynamically in the WebSphere Application Server:

  1. Deploy Arc:

    1. Enable application security (navigate to Security > Global security > Enable application security).

    2. Add the custom login module to the system login, as follows:

      1. Navigate to Security > Global security > Java Authentication and Authorization Service > System logins > WEB_INBOUND. Click New to add a new entry named arc.LoginModule. Note that the arc.LoginModule must appear before com.ibm.ws.security.server.lm.ltpaLoginModule.

      2. Select the Use login module proxy check box.

      3. Select OPTIONAL under Authentication strategy.

      4. Add isWebSphere under Custom properties and set it to true.

  2. Create groups:

    1. Navigate to Users and Groups > Manage Groups > Create.

    2. Create cdata_admin, cdata_standard, and cdata_support groups.

  3. Map groups to roles:

    1. Navigate to Applications > Application Types > WebSphere enterprise applications > arc_war > Security role to user/group mapping.

    2. Map the cdata_admin group to the cdata_admin role.

    3. Map the cdata_standard group to the cdata_standard role.

    4. Map the cdata_support group to the cdata_support role.

    5. Map All Authenticated in Application’s Realm to the cdata_user role.

  4. Set the com.ibm.ws.webcontainer.AllowQueryParamWithNoEqual property to true:

    1. Navigate to Server > Server Types > Web Sphere Application Servers and select the server on which Arc is hosted.

    2. Select Container Settings > Web Container Settings > Web Container.

    3. Select Additional Properties > Custom Properties.

    4. Add this new property: com.ibm.ws.webcontainer.AllowQueryParamWithNoEqual

    5. Set the value to true.

  5. Restart WebSphere.

Configure Data Directory Permissions

Give the user of the process that runs the Java servlet container Read/Write access to the data directory:

  • Windows: C:\ProgramData\CData\Arc\

  • Linux: ~/cdata/arc

Restart the WebSphere server for the changes to take effect. You can now log into the application.

Configuration in Jetty

Although Arc comes with an embedded Jetty web server, you can also use the application with an external Jetty setup.

Deploy the WAR File

Copy the WAR file into Jetty’s webapps folder.

Configure the Java Authentication and Service (JAAS)

To configure the JAAS and to enable Arc to manage application users, you must perform the steps that are described in the following subsections.

Add the JAAS Module

Submit the following command to install the JAAS module:

java -jar {JETTY_HOME}/start.jar --add-to-start=jaas

Create the Login Module

Create a login configuration file with the name login.config in this folder: {JETTY_BASE}/etc/login.conf

Place the following content in the login.config file:

Arc {
    arc.LoginModule required debug=true;
};

Update the Security Handler

The Security Handler configuration is in the arc.xml configuration file. Modify the securityHandler block as follows:

<Set name="securityHandler">
  <New class="org.eclipse.jetty.security.ConstraintSecurityHandler">
   <Set name="loginService">
     <New class="org.eclipse.jetty.jaas.JAASLoginService">
          <!-- This name is the same as **login-config > realm-name** in web.xml.  -->
       <Set name="name">ArcRealm</Set>
          <!-- LoginModuleName must match the name of your LoginModule, as declared in your login-module configuration file. -->
       <Set name="loginModuleName">Arc</Set>
       <!-- Set the principal class name for the custom role. -->
       <Set name="roleClassNames">
           <Array type="java.lang.String">
             <Item>arc.GroupPrincipal</Item>
           </Array>
         </Set>
     </New>
   </Set>
  </New>
</Set>

Configure Data Directory Permissions

Give the user of the process that runs the Java servlet container Read/Write access to the data directory:

  • Windows: C:\ProgramData\CData\Arc\

  • Linux: ~/cdata/arc

Restart the Jetty server for the changes to take effect. You can now log into the application.

User Management

Upon initial startup, Arc prompts you for the creation of a user with username and password credentials. After the first user is created, you can add, delete, and manage users on the Users tab of the Settings page in the application.

When you deploy Arc to an external Java servlet (that is, when you are not using the embedded server that is included with the application), JAAS configuration is required in order to allow Arc to manage users. The previous sections detail the process of JAAS configuration for each specific external servlet.

Find and Configure the Application Directory

The Arc ApplicationDirectory folder contains all the data that is used by the application: configuration data, application data, logging data, certificates, and so on. The default location of ApplicationDirectory depends on whether Arc is hosted via the embedded web server or via an external Java servlet container.

For the embedded web server, ApplicationDirectory is the same as InstallationDirectory. By default, that location is the following:

/opt/arc

When Arc is hosted in an external Java servlet container, ApplicationDirectory is relative to the home directory of the user who is running the server:

~/arc

In this path, ‘~’ resolves to the home directory of the user who is running the server that hosts the application.

You can configure the ApplicationDirectory folder, which is useful in a variety of scenarios:

  • clustering multiple instances of Arc

  • using a shared network drive for application data

  • embedding Arc within other systems that access the same folders

Changing ApplicationDirectory moves the application’s data files. However, it does not move other application resources like EXE files, JAR files, and so on. These resources are held in the InstallationDirectory folder, which might be the same as ApplicationDirectory, but the location of those resources does not change if ApplicationDirectory is changed.

Embedded Java Server

When you use the Cross-Platform Edition with the embedded Jetty server, by default the ApplicationDirectory is the InstallationDirectory. To modify this, generate the arc.properties file. Open the file in a text editor, then set the cdata.app.directory setting to the path of the desired directory. The following example demonstrates what this might look like when you set the data directory to a shared folder on a mounted drive:

cdata.app.directory=/mnt/shared/arc

If Arc can locate the cdata.app.directory path and it has the appropriate permissions to read and write at that path, it creates the data folder in the specified directory.

External Java Server

When you use the Cross-Platform Edition with an external Java servlet (any server other than the Jetty server that is included with the application), the details of configuring the application data directory depend upon the specific servlet that is used. Using the syntax that is appropriate for the specific servlet, the AppDirectory environment variable must be set to the path of the directory that you want.

If Arc can locate the AppDirectory path and it has the appropriate permissions to read and write at that path, it creates the data folder in the specified directory.

Configure the Application Database

The Arc application database stores several tables of application data, including the following:

  • Transaction Log: metadata for each transaction that is processed by the application
  • Application Log: application-level errors and events
  • Access Log: requests to the application’s web endpoint
  • Audit Log: user-made changes to the Arc configuration

By default, Arc uses a Derby database that resides in ApplicationDirectory as the application database. However, you can configure the application to use an enterprise database like SQL Server, PostgreSQL, or MySQL.

Embedded Java Server

When you use the Cross-Platform Edition with the embedded Jetty server, the default application database is a Derby database in the ApplicationDirectory. To modify this, generate the arc.properties file. Open the file in a text editor, then set the cdata.app.db setting to a Java Database Connectivity (JDBC) connection string that contains the appropriate connection parameters for the database that you want. The following examples illustrate this setting for the MySQl, PostgreSQL, and SQl databases:

MySQL

cdata.app.db=jdbc:cdata:mysql:server=localhost;port=3306;database=mysql;user=MyUserName;password=MyPassword

PostgreSQL

cdata.app.db=jdbc:cdata:postgresql:server=localhost;port=5432;database=postgresql;user=MyUserName;password=MyPassword

SQL Server

cdata.app.db=jdbc:cdata:sql:server=localhost;database=sqlserver;user=MyUserName;password=MyPassword

If Arc can establish a connection successfully with the cdata.app.db connection string, it uses that database as the application database.

Note: To reduce the possibility of deadlocks when using SQL Server as your application database, CData recommends that you ensure that READ_COMMITTED_SNAPSHOT is enabled.

Generating an Encrypted Database Connection String

Arc provides the ability to generate an encrypted connection string for your application database connection. You can use this encrypted connection string to specify the application database without storing your login credentials in plain text in the Arc configuration files. To generate an encrypted connection string, issue the following command in the installation directory where arc.jar is located, substituting your connection information for the example string in quotation marks:

java -jar arc.jar -EncryptConnectionString "jdbc:cdata:mysql:Server=serverName;Port=1234;Database=databaseName;User=userName;Password=passwordSample"

After you issue the command, the command window prints the encrypted string. For example:

ENCRYPTEDA:5TWyjE0U4GBEVNkd51SqbMXaBwVGqj5uyMfTHt48y/F5l3sDPZynNnPMb/ppXzuFTzFPywA1/SSKUgLy9nAuvA7RAdZj7WsKI1xAgDMmEFNQ68/lHjFYZpS10sIaoUloyZVDkj4uLHTZ0SaMD5PPUA==

You can then use this encrypted string in place of the plain text value for cdata.app.db as shown above.

External Java Server

When you use the Cross-Platform Edition with an external Java servlet (any server other than the Jetty server that is included with the application), the details for configuring the application database depend upon the specific servlet that is used. Using the syntax that is appropriate for the specific servlet, choose one of the following approaches when you configure the server:

  • Define a JNDI data source to include the connection properties for the target database.

  • Set the APP_DB environment variable to a JDBC connection string.

If Arc can use the JDNI data source or the APP_DB connection string to arc to a database, it uses that database as the application database.

Login Lockouts

Arc automatically locks out users who enter incorrect passwords too many times in order to prevent brute-force attacks. By default, a user who enters six incorrect passwords within five minutes is locked out for thirty minutes.

You can modify the lockout settings by editing the XML configuration file that governs the web-server behavior. These three settings are relevant to lockouts:

  • LockoutFailedAttempts: the number of incorrect passwords that trigger a lockout. Set LockoutFailedAttempts to 0 to disable lockouts.

  • LockoutMinutes: the duration of the lockout. The default duration is thirty minutes.

  • LockoutTimeCheckPeriod: the period after which the number of failed attempts is reset to 0. The default period is five minutes.

Embedded Jetty Server

You can modify lockout settings by generating the arc.properties file and adding a comma-separated list of name:value pairs to initParameters, as shown below:

cdata.initParameters=LockoutFailedAttempts:0

Tomcat

The syntax for editing the lockout settings the Tomcat arc.xml file is the following:

<Context>
  <Parameter name="LockoutFailedAttempts" value="0" />
</Context>

Common Issues and Solutions

This section lists common issues that you can encounter when you deploy Arc in a Java environment. The recommended solution for each issue is included. For additional help, contact CData Technical Support at [email protected].

Issue

Arc fails to start, or it starts by using an AppDirectory other than what is expected

This error might indicate that Arc does not have the permissions that are required to access ApplicationDirectory. (ApplicationDirectory is a folder that stores critical information regarding the configuration of jobs, connections, transformations, and so on.) One possible cause for this error is running Arc as a local user before you set it up as a service. In this case, it is possible that certain resources created by the application were created under the local user. As a result, those resources are not available when you run Arc as a service.

In a Linux operating environment, the easiest way to ensure that the service account (or any other account that you want to use to run Arc) can access ApplicationDirectory is to use the chown command. For example, if ApplicationDirectory is in the default Linux location and Arc should run under the service account, the following command should resolve the error:

sudo chown -R cdataarc:cdataarc /opt/arc