Note: Cogent DataHub software v11 contain new features that may not be supported by your target operating system. Please see our Installation Notes for more details.

Installing DataHub software v11 on a system running an earlier version

When you install DataHub software v11 on a system running v7, v8, v9 or v10 the installer will ask you to uninstall the earlier version.  DataHub software v11 will be installed and will use the existing configuration files from the earlier installation.

When you install DataHub software v11 on a systems running OPC DataHub software v6.4, you will be asked if you want to copy the configuration from the earlier version, but it will not replace the earlier version. You can run OPC DataHub software v6.4 and Cogent DataHub software on the same system, though there may be conflicts that require you to modify your configuration.

If you want to make a backup of your current DataHub configuration, you can do that by copying the contents of the DataHub configuration directory. The location of this directory will depend on which operating system you are running. See this link to documentation for more details.

See below for more information about copying your local WebView pages and media to DataHub software v9/v10/v11.

OpenSSL breaking change:

DataHub v11 uses OpenSSL 3.3, a change from previous versions that use OpenSSL 1.1. OpenSSL 3 requires certificates to have stronger keys than in previous versions, so when DataHub v11 is acting as an SSL client it will reject connections to servers using weak certificates.

This is a breaking change. If you are using tunnelling, MQTT or web server functions in a DataHub application, you may need to re-generate the certificates for any DataHub installation being upgraded to v11 from an earlier version. If you intend to connect DataHub v11 to older versions, you may also need to upgrade the SSL certificates on the older versions.

The sample certificate, datahub.pem, that is installed with the DataHub installation has been changed in v11 to use a stronger key. This certificate is used for testing. It is not valid – it is self-signed, possibly expired and issued to an invalid DNS name. If you are using the test certificate in an older version of DataHub, you can copy datahub.pem from a v11 installation to the earlier DataHub installation to enable the connection.

If you have generated your own server certificates then you may not be affected by this change. Most certificate generators default to an acceptable key length and hashing algorithm. If your generated certificate is weak, you will need to generate a new one.

If the DataHub v11 tunneller rejects a certificate because its key is weak, you will see a message similar to this in the DataHub event log:

[2024-06-25 05:47:06.977] I: [TCP to TUN000 into domain]:
SSL Certificate failure: 66: depth 0: EE certificate key too weak: 
/C=CA/ST=Ontario/L=Georgetown/O=Cogent Real-Time Systems Inc.
/OU=Developers/CN=developers.cogentrts.com/[email protected]

Look for the failure message, “EE certificate key too weak”.

If you cannot upgrade the certificate on a server for some reason, you can modify the configuration in the client to accept invalid certificates:

• In the DataHub Tunnel/Mirror Slave SSL configuration, un-check the options “Reject invalid certificates” and “Reject host name mismatch”.
• In the DataHub MQTT Client Authentication configuration, check the option “Accept invalid certificates”.

OPC UA connections are not affected by this change.

For MQTT:

In DataHub V10, the MQTT broker would always send all QoS 0 retained messages in response to a subscription, regardless of the broker setting, “Maximum per-client message queue length”. In DataHub V11, the MQTT broker respects the queue length setting. This may result in unexpected loss of retained topic information when the client initially connects. To restore the behaviour of V10, set the DataHub broker’s “Maximum per-client message queue length” to zero, indicating no queue length limit. In that case, DataHub V11 will use its own smart queue management based on the recipient’s data ingestion rate. The default queue length in DataHub V11 is now zero.

Tunnelling between DHv11 and DH v10, DHv9, DHv8, DHv7 or DHv6.4

You can tunnel between DataHub software v11 and v10, v9, v8, v7, and v6.4. When tunneling between v11 and v6.4 you may run into a known issue with licensing that appears when the network of DataHub connections is not a simple star configuration.

You can tunnel using WebSocket between v11, v10, v9, v8, and v7, but you can only tunnel between v11 and v6.4 using a non-SSL connection.

You can tunnel through a proxy between v11 and v10, v9, v8 or v7 as long as v9/v10/v11 is the client initiating the connection.

There is one known issue relating to tunnelling in DataHub software v9/v10/v11.  Although binary tunnel connections between v9/v10/v11 and v9/v10/v11 will succeed, binary tunnel connections between v9/v10/v11 and earlier versions will fail. They may appear to succeed but no data values are delivered. The DataHub Event Log may contain error messages depending on the direction of the connection. This is made necessary by a change in the timestamp representation from 32 to 64 bits. Text connections (non-binary) are compatible between v11 and earlier versions.

Moving WebView pages and media to DataHub software v11

When you upgrade to from v9 to v10/v11, the DataHub installer will attempt to copy your old WebView pages to a new folder in order to make them visible in WebView v11.  If you would like to do this manually, below are the steps involved.

User-generated content is now stored in the DataHub configuration folder, not the Program Files folder.

Default Configuration Folder

The default DataHub configuration folder is:
C:Users<Windows Login>AppDataRoamingCogent DataHub

where <Windows Login> is the user name you used to log in to Windows. You can change the configuration folder using the -H command-line option on DataHub icon, or by setting it through the DataHub Service Manager application.

Personal Files

Assuming you log in to WebView as the admin user, your personal WebView v8 pages can be found here:
C:Program Files (x86)CogentCogent DataHubPluginWebServerhtmlSilverlightPagesUsersadmin

These pages need to be copied into the following location for use with WebView v9/v10:
<Configuration Folder>WebContentContentOrganizationsLocalUsersadminPages

Similarly, any personal images you added to WebView v8 will now be found in:
C:Program Files (x86)CogentCogent DataHubPluginWebServerhtmlSilverlightImages

These images need to be copied into the following location for use with WebView v9/v10:
<Configuration Folder>WebContentContentOrganizationsLocalUsersadminImages

You must do the same for Media and Script files.

Public Files

If you have created publicly accessible pages, images, etc. then you will find the v8 files in:
C:Program Files (x86)CogentCogent DataHubPluginWebServerhtmlSilverlightPages

These need to be copied to:
<Configuration Folder>WebContentContentOrganizationsLocalPages

Images, media files, and scripts need to be similarly copied.

Custom Controls

If you have created custom WebView controls, they will only work in Silverlight. You need to recompile these controls separately for Desktop WebView. Controls and ControlAssemblies are now differentiated between Silverlight and WPF versions. For examples, if you have created a custom control DLL called MyCustomControl.dll, you would install it in DataHub software v8 in:
C:Program Files (x86)CogentCogent DataHubPluginWebServerhtmlSilverlightControlAssembliesCompanyMyCustomControl.dll

In DataHub software v9/v10/v11, you can install it in one of two locations:
C:Program FilesCogentCogent DataHubPluginWebServerhtmlContentCommonControlAssembliesCompanySilverlightMyCustomControl.dll

Or
<Configuration Folder>WebContentContentOrganizationsLocalControlAssembliesCompanySilverlightMyCustomControl.dll

You must similarly distinguish XAML and XML files for your custom controls if they are different between Silverlight and WPF versions.

If you need assistance moving your custom controls, please contact Skkynet’s technical support team at [email protected].