Connection Options¶

In this dialog, you can configure the following parameters of the connection between the Design Studio and Virtual DataPort.

Connection options¶

Options related to the execution of queries

• Query timeout (milliseconds): maximum time the Design Studio will wait for a query to finish. If zero, it will wait indefinitely until the sentence ends.

• Chunk Timeout (milliseconds): maximum time that Virtual DataPort will wait before returning a new block to the Design Studio. When this time is surpassed, the Server sends the current block even if it does not contain the number of results specified in the Chunk Size parameter.

  Note

  If Chunk size and Chunk timeout are zero, the Server returns all the results in a single block. If both values are different from 0, the Server returns a chunk whenever one of these conditions happen:

  • The chunk is filled (Chunk size)

  • Or, after a certain time of not sending any chunk to the client (Chunk timeout).

• Chunk size (rows): The results obtained by executing a sentence can be divided into blocks (chunks), so the Virtual DataPort Server does not have to wait until a sentence ends, to send the processed tuples to the Design Studio.

  This parameter establishes the maximum number of results that a block can contain.

  When the Server obtains enough results to complete a block, it sends this block to the client and continues processing the next results.

Other connection options

• Maximum number of active connections: maximum number of active connections opened by the Design Studio, per session.

  When a user logs in, Design Studio creates a pool of connections with Virtual DataPort, on behalf of this user. Maximum number of active connections is the maximum number of connections of each one of these pools. When a user does something that requires executing a command in Virtual DataPort (e.g. create view, publish a web service, etc), Design Studio obtains a connection from the pool of this user, executes the command for this action and returns the connection to the pool.

  There is one pool per session, not per user. That is, if the same user logs in from two separate browsers, Design Studio will open two pools of connections for this user.

  The VQL Shell is not affected by this option because it does not obtain the connection from the pool; each tab of the VQL Shell has its own connection that remains open until the user closes the VQL Shell, the user logs out or the user’s session expires.

  Default value: 20. This value is adequate for any scenario.

• Maximum waiting time to obtain a connection: maximum time in milliseconds the Design Studio will wait for a connection before showing an error. If you enter “-1”, the Design Studio will wait indefinitely.

• Use WAN optimized communications: if selected, the communications with the server will be optimized for high latency networks. May reduce performance if used in LAN environments.

• Use only SSL communications: if selected, the communication with the server will be forced to be secured. If SSL is disabled on the Virtual DataPort server, the communication will fail.

• Use the header User-agent of the user’s browser: if it is on, the Design Studio transmits the user-agent header of the client’s browser to the Virtual DataPort server. If you want that Design Studio always uses the same user agent in the connections it opens to Virtual DataPort, switch off this option and enter a value in Custom user agent.

• Connect only to allowed Virtual DataPort Server hostnames: if it is on, Design Studio only allow users to connect to the Virtual DataPort servers list of Allowed Virtual DataPort Server hostnames.

• Allowed Virtual DataPort Server hostnames: if you enable this, you limit the hostnames Design Studio is allowed to connect to. The URLs must follow the format hostname[:port] (the port is optional). For example: denodo-server-1.acme.com, denodo-server-2.acme.com:9999, denodo-server-3.acme.com:9999, etc. Otherwise, Design Studio can open a connection to any Virtual DataPort the user enters in the login page.

  When you enable this feature, the login page of Design Studio will have a drop-down that lists the hostnames you enter here so they do not have to remember the hostnames they want to connect to.

Kerberos Settings¶

In this wizard you enable Single Sign On (SSO) on the Design Studio using Kerberos authentication when you access the Design Studio of a Denodo Platform installation.

Kerberos settings¶

1. Select Use Kerberos to enable Kerberos.

2. In the box Server Principal, enter the “Service Principal Name” (SPN) used to create the keytab file. That is, the SPN with the Fully Qualified Domain Name (FQDN) of the computer in which the Design Studio is running. For example, “HTTP/denodo-prod.subnet1.contoso.com@CONTOSO.COM”.

   If you are going to access Design Studio through a load balancer, the SPN must be the FQDN of the domain name registered in the load balancer.

3. In the field Keytab file, drag and drop the keytab file over the specified area or click it to open a file explorer to select the file. If a key tab file was previously uploaded, it will be shown and you could use the trash icon to delete it.

4. Leave the Kerberos configuration file box empty unless the host where this Design Studio runs does not belong to a Kerberos realm (e.g., a Windows Active Directory domain). If this host does not belong to a Kerberos realm, do one of the following:

   a. Drag and drop the krb5.conf or krb5.ini file with the Kerberos settings over the specified area or click it to open a file explorer to select the file. If a configuration file was previously uploaded, it will be shown and you could use the trash icon to delete it. b. Or follow the steps described in the appendix Enabling Kerberos Authentication Without Joining a Kerberos Realm.

5. We recommend selecting the check box Activate Kerberos debug mode the first time you set up Kerberos in case you run into any issues. Once Kerberos is working, disable this.

   When this option is enabled, check the appendix How to Debug Kerberos in Web Applications of the Installation Guide to learn how to see the debug information.

After saving the Kerberos configuration, restart the Design Studio to have these changes take effect. The next time the users access the Design Studio, they will not need to provide their user name and password, because the browser will send the Kerberos credentials of their system. In order for this to work, they need to access using the full qualified URL (FQDN) configured in step 2. For example, https://denodo-prod.subnet1.contoso.com:9443/denodo-design-studio/.

Authentication dialog with Single Sign-On¶

The users can provide the URI of the Virtual DataPort server adding the uri parameter to the URL. If they do it, the Design Studio will try to authenticate them against that server without showing authentication page. For example: https://denodo-prod.subnet1.contoso.com:9443/denodo-design-studio/?uri=//localhost:9999/admin#/

Informative Message¶

You can add an informative message that will be displayed to all users when they log in to the Design Studio. The message can be used to display a welcome message, inform users when the service is expected to be down for maintenance, legal disclaimers, etc.

Sample informative message¶

To customize the message you can use the editor with the tools available. If you feel more comfortable working with HTML, click to see and edit the HTML. Click Ok to save the changes.

Application Settings¶

In this dialog you can configure several settings of Design Studio.

• Enable community resources: enable or disable the suggestions that Design Studio displays when the users click the help button .

  The suggestions could include documentation, expert trails, KB documents, videos, tutorials, test drives, free trials, training courses, certification exams or blog posts.

  To be able to show these suggestions, when a user logs in to Design Studio, the browser sends a request to an API of “community.denodo.com” to obtain the names and links to these community resources.

  This is enabled by default.

• Enable browser storage: Design Studio stores in the users’ browser several settings, for the convenience of the user. Among others:

  • The content of the VQL Shell, including the Execution logs so users can see their own queries the next time they log in.

  • The tabs that we opened the last time the user logged in.

  • VQL panel of elements in Design Studio: store in the users’ browser the options selected by the user the last time the user opened this panel.

  • Dialogs “Import”, “Export” and “Export Database” of the menu “File”: remember the latest selected options.

  This feature uses the local storage of the browser of each user so this feature will not work for users that log in to Design Studio using a private window of the browser.

  This is enabled by default. Design Studio stores these settings every minute.

• Maximum number of rows displayed: Design Studio limits the number of rows that the VQL Shell and the Query panel display because if it displayed all the results of the queries, the browser of the user could crash. For example, if the user executed a query that returns one million rows, the browser would not be able to display that.

  Default value: 1,000 rows.

  Note

  This setting does not affect Execute and Download, which can obtain all the rows.

• Disable “Execute and download” feature: with this feature, the Execute and Download option will be disabled on the VQL Shells and the Query panel for all users.

  The feature “Execute and download” is enabled by default.

• Maximum number of rows returned by the “Execute and download” feature: with this feature, you can set a limit on the amount of rows the “Execute and Download” option will retrieve.

  Default value: 500,000 rows.

• Disable “Copy displayed results to clipboard” feature: with this feature, the Copy displayed results to clipboard option will be disabled on the VQL Shells and the Query panel for all users.

  This is disabled by default. That is, by default user can use Copy displayed results to clipboard.

Disable the Preferences Page of Design Studio¶

The administrator can disable the preferences page of Design Studio. The benefit of disabling this is that only users with access to the computer where Design Studio runs can change the settings. However, it is also more cumbersome because the administrator will have to modify manually the configuration file of Design Studio (i.e. <DENODO_HOME>/conf/design-studio/DesignStudioBackend.properties) and restart Design Studio when changing any of the properties of this file.

To disable the preferences page of Design Studio, follow these steps:

1. Open the file <DENODO_HOME>/conf/design-studio/DesignStudioBackend.properties and add this:

   weblogin.enabled=false
   

2. Stop Design Studio.

   To stop it, you can execute the script <DENODO_HOME>/bin/designstudio_shutdown or with the Control Center.

3. Wait a few seconds and try to access Design Studio. You should get the error 404. The page you requested was not found. This is to verify that the service is actually stopped.

4. Start Design Studio.

   To start it, you can execute the script <DENODO_HOME>/bin/designstudio_startup or with the Control Center.

After this, if users go to the preferences page (“/denodo-design-studio/#/web-local-login”), Design Studio will redirect them to the standard login page.

To restore the access to the preferences page, set the value of weblogin.enabled to true or remove the property.