Quick Start for HVR - SQL Server

Last updated on Sep 23, 2020

Contents

This quick start guide helps you to get started with HVR for replicating data between SQL Server databases.

To proceed with this replication you must have basic understanding about HVR's architecture and terminologies like Hub, Location, Channel, Location Groups, Actions etc.

The example here demonstrates how to replicate tables from one SQL Server database (source location) to another SQL Server database (target location).

In real-life scenarios, the source location(s) and the target location(s) reside on different machines and the HVR hub can reside on source or target or a separate machine. However, in this example, for simplicity we have the source, target, and HVR hub on the same machine

Before proceeding with this example ensure that the requirements for using HVR with SQL Server are met.

For information about access privileges and advanced configuration changes required for performing replication using SQL Server, see Requirements for SQL Server.

Create Test Databases and Tables

Generally when getting started with HVR a source schema with tables and data already exists. If so then this step can be skipped.

This Quickstart uses two empty tables named dm01_product and dm01_order. In an existing SQL server database, create a test schema and create the tables using the following commands.

Make sure the database is setup for log-based capture as described in Grants for log-based capture.

In SQL Server Management Studio, create database testdb1. Next, create the test tables:

C:\> cd %HVR_HOME%\demo\hvr_demo01\base\sqlserver
C:\> osql -U hvr -P hvr -d testdb1 < hvr_demo01.cre
C:\> osql -U hvr -P hvr -d testdb1 < hvr_demo01.mod

For the target, create two test databases, each containing two empty tables named dm01_product and dm01_order.

In SQL Server Management Studio, create databases testdb2 and testdb3. You can either create the tables using HVRs scripts or let HVR create them during initial loading (HVR Refresh with Create Absent Tables).

Create the test tables using HVRs script:

 C:\> cd %HVR_HOME%\demo\hvr_demo01\base\sqlserver
 C:\> osql -U hvr -P hvr -d testdb2 < hvr_demo01.cre
 C:\> osql -U hvr -P hvr -d testdb2 < hvr_demo01.mod
 C:\> osql -U hvr -P hvr -d testdb3 < hvr_demo01.cre
 C:\> osql -U hvr -P hvr -d testdb3 < hvr_demo01.mod

Create the Hub Database

This section describes how to create a hub database. The hub database is a repository database that HVR uses to control its replication activities. It contains HVR catalog tables that hold all specifications of replication such as the names of the replicated databases, the replication direction and the list of tables to be replicated. For more information about HVR hub server and database, see section Hub Server in System Requirements.

HVR supports the creation of a hub database on certain databases (location classes) only. For the list of supported location classes, see section Hub Database in Capabilities.

For this demonstration, the hub database (e.g. hvrhub) is created in SQL Server.

Create the hub database using the SQL Server Management Studio. Alternatively, use the following SQL statement:

create database hvrhub

Download and Install HVR

An HVR distribution is available for download at https://www.hvr-software.com/account/. To request a trial version, visit https://www.hvr-software.com/free-trial/.

Install HVR on a hub machine. For details on installing HVR, see the respective operating system sections:

The HVR distribution requires a license key in order for the software to operate. Please see the HVR licensing page for more details on how to install the HVR license.

After the installation, you can control HVR using the HVR graphical user interface (HVR GUI).

  • If the hub machine is Windows, then HVR GUI can be executed directly on the hub machine. 
    • To control HVR remotely from your PC, connect to the hub machine using Windows Remote Desktop Connection and launch HVR GUI on the hub machine.
  • If the hub machine is Linux, then HVR GUI can be executed directly on the hub machine. However, an application like X Server or VNC viewer must be installed to run HVR GUI directly on Linux. 
    • To control HVR remotely from your PC, install HVR on the PC (with Windows or macOS) and configure the HVR Remote Listener on the hub machine.
  • If the hub machine is Unix, then HVR GUI should typically be run remotely from a PC to control HVR installed on the hub machine. To do this, install HVR on the PC (with Windows or macOS) and configure the HVR Remote Listener on the hub machine. 

The HVR Remote Listener allows you to connect HVR GUI available on your PC to the remote HVR hub machine. For more information about connecting to remote HVR installation, see Configuring Remote Installation of HVR on Unix or Linux and Configuring Remote Installation of HVR on Windows.

Launch HVR GUI

This section describes how to launch HVR GUI on various operating systems.
  • On Windows and macOS, double-click the HVR shortcut icon available on the desktop or execute command hvrgui in the CLI.
  • On Linux, double-click the hvrgui file available in the HVR_extracted_path/bin directory or execute command hvrgui in the CLI.

    Linux requires applications like X server or VNC viewer to execute HVR GUI.

  • On Unix, HVR GUI is not supported. So, HVR GUI should be run on a remote PC (with Windows, Linux, or macOS) to control HVR installed on the Unix machine.


Register Hub

This section describes how to connect HVR GUI to the hub database.

When HVR GUI is launched for the first time, the Register Hub dialog is displayed automatically. The Register Hub dialog can also be accessed from the main menu File ▶ Register Hub.

Skip steps 1 to 4, if HVR GUI is executed directly on the hub machine or if HVR hub is connected to a remote SQL Server database without using the SQL Server protocol. For more information about connecting HVR hub with remote SQL Server database, see section Connecting HVR Hub to a Remote SQL Server Database in Requirements for SQL Server.

  1. Click Connect to HVR on remote machine.

    To connect HVR GUI on a PC to a remote HVR hub machine, the HVR Remote Listener must be configured and running on the HVR hub machine.

  2. Enter the name or IP-address of the hub machine in the Node field (e.g. myserver).
  3. Enter the port number (defined in the HVR Remote Listener of the hub machine) in the Port field (e.g. 4343).
  4. Enter the Login (e.g. myserveradmin) and Password for the hub machine. By default, this is the operating system login credentials of the hub machine.
  5. Select SQL Server in the Class pane.
  6. Specify Database Connection details. For more information about the Database Connection fields, see section Location Connection.
    1. Enter the HVR hub database name in the Database field. For example, hvrhub.
    2. Enter the SQL Server user name in the User field. This username is used to connect HVR to the SQL Server database. For example, hvr.
    3. Enter the password for the SQL Server user in the Password field.
  7. Click Connect.

  8. Click OK in the prompt dialog asking to create catalog tables in the hub database. HVR displays this prompt when connecting to a hub database for the first time.

Upon successful connection to the hub database, the navigation tree pane displays the hub machine and the hub database. Location ConfigurationChannel Definitions, and Scheduler are displayed under the hub database.

Create SQL Server Locations

Next create three locations (one for each test database) using right-click on Location Configuration ▶ New Location.

In this example there is no need to check Connect to HVR on remote machine because testdb1 is on the same machine as the hub.

Ignore the Group Membership tab for now.

Make locations for testdb2 and testdb3 too.

Now define a channel using Channel Definitions ▶ New Channel.

Create Location Groups

The channel needs two location groups. Under the new channel, right-click Location Groups ▶ New Group. Enter a group name (for instance CENTRAL).

Add location db1 as a member of this group by checking the box for db1.

Then create a second location group, called DECENTRAL that has members db2 and db3.

The new channel also needs a list of tables to replicate. This can be done as follows: right-click Tables ▶ Table Explore.

  • Choose the first of the three locations ▶ Connect.
  • In the Table Explore window, click on both tables and click Add.
  • In new dialog HVR Table Name click OK.
  • Close the Table Explore window.
  • Perform table select again on one of the other locations and confirm that all tables to be replicated have value Same in column Match.

Define Actions

The new channel needs two actions to indicate the direction of replication.
  • Right-click group CENTRAL ▶ New Action ▶ Capture.
  • Right-click Group DECENTRAL ▶ New Action ▶ Integrate. Check /OnErrorSaveFailed, this affects how replication errors are handled.

Note that the Actions pane only displays actions related to the objects selected in the left-hand pane. So click channel hvr_demo01 to see both actions.

Enable Replication with HVR Initialize

Now that the channel definition is complete, create the runtime replication system.
  1. Right-click channel hvr_demo01 ▶ HVR Initialize
  2. Choose Create or Replace Objects and click HVR Initialize.

From the moment that HVR Initialize is done, all changes to database sourcedb will be captured by HVR when its capture job looks inside the logging.

HVR initialize also creates three replication jobs, which can be seen under the Scheduler node in the GUI.

Start Scheduling of Replication Jobs

Start the Scheduler on the hub machine by clicking in the HVR GUI on the Scheduler node of the hub database.

Next, instruct the HVR Scheduler to trigger the replication jobs.

The replication jobs inside the Scheduler each execute a script under $HVR_CONFIG/job/hvrhub/hvr_demo01 that has the same name as the job. So job hvr_demo01–cap–db1 detects changes on database testdb1 and stores these as transactions files on the hub machine. The other two jobs (hvr_demo01–integ–db2 and hvr_demo01–integ–db3) pick up these transaction files and perform inserts, updates and deletes on the two target databases.

Test Replication

To test replication, make a change in testdb1:
 SQL> insert into dm01_product values (1, 19.99, 'DVD');

In the HVR log file you can see the output of the jobs by clicking on View Log. This log file can be found in *%HVR_CONFIG%\log*hubdb\hvr_demo01–cap–db1.

The job output looks like this:

 C:\> notepad %HVR_CONFIG%\log\hvrhub\hvr.out
  
 hvr_demo01-cap-db1: Capture cycle 1.
 hvr_demo01-cap-db1: Selected 1 row from 'dm01_product__c0' (201 wide).
 hvr_demo01-cap-db1: Routed 212 bytes (compression=42.7%) from 'db1' into \
 2 locations.
 hvr_demo01-cap-db1: Finished. (elapsed=1.20s)
 hvr_demo01-integ-db2: Integrate cycle 1 for 1 transaction file (212 bytes).
 hvr_demo01-integ-db2: Integrated 1 change from 'dm01_product' (1 ins).
 hvr_demo01-integ-db2: Integrate used 1 transaction and took 0.017 seconds.
 hvr_demo01-integ-db2: Finished. (elapsed=0.14s)
 hvr_demo01-integ-db3: Integrate cycle 1 for 1 transaction file (212 bytes).
 hvr_demo01-integ-db3: Integrated 1 change from 'dm01_product' (1 ins).
 hvr_demo01-integ-db3: Integrate used 1 transaction and took 0.02 seconds.
 hvr_demo01-integ-db3: Finished. (elapsed=0.15s)

This indicates that the jobs replicated the original change to testdb2 and testdb3. A query on testdb2 confirms this:

 SQL> select * from dm01_product;

prod_id

prod_price

prod_descrip

1

19.99

DVD

HVR Compare and Refresh

HVR Compare checks whether two locations have identical rows, and HVR Refresh copies the content of one location to the second location. In the HVR GUI, right-click on a channel and select HVR Compare (or HVR Refresh). Choose source and target locations.

The outcome of the comparison is displayed below;