I have often been hearing queries from customers, that, they already have several instances of Informix running in their organization and they would like to evaluate the Flexible Grid feature that eases their administration efforts and provides them the luxury of performing DDL and DML operations from a single node.
This short technical snippet is intended for users who are willing to take the advantages offered by the Informix Flexible Grid feature. And this content can also be referred by users who already have Informix Cluster setup or have Replication topology in place and would now like to evaluate the use of Informix Flexible Grid.
To start with, the basic requirement to create a Grid is to have Informix servers to be participating in ER activity, before they are pulled into the Grid as Grid servers. The technical content offers step by step snap shot to help users define a Informix server as an ER server and then start working on creating a Grid and Regions within the Grid, based on the needs and requirements.
Requirement 1: List out the Informix servers that are scheduled to be defined as ER server and then shall be further participating in the Grid
Requirement 2: To define a server or set of servers as ER server(s), the user needs to manually update the SQLHOSTS file to add a GROUP entry and the SQLHOSTS entry for all the servers that are participating.
To illustrate, in the following example, I shall be considering the Informix servers ‘clp’, ‘prot4’ and ‘special_1’ to be defined as ER servers. So, in this regard, the SQLHOSTS file for all the three servers mentioned above, looks as follows:
Here, g_prot4, g_special_1, g_clp are the names of the GROUP and i=100, i=200 & i=300 stand for unique identifiers.
In short, all the SQLHOSTS file will have the same entries, i.e each SQLHOSTS file will have entries for the other two servers as well.
Requirement 3: The Informix servers those are shortlisted to be defined as ER servers should have connection entries in OpenAdmin Tool.
Step by Step process to define ER Server using OpenAdmin Tool
Step 1: Log on to OpenAdmin Tool
Step 2: Navigate to Replication à ER Domain page, as available on the left hand side menu, to add a Informix server or set of Informix servers to participate in the ER activity
Step 3: The user is prompted with the message to define the Informix server as an ER server. Press YES and continue.
Step 4: The user will be now asked to work through the ER Wizard to define the Informix server as an ER server.
Step 5: In the first step, the wizard prompts the user to choose the server that shall be defined as an ER server.
Choose a server and click on ‘NEXT’
Step 6: In the second step of the wizard, the user needs to choose to create a new ER domain and can prefer to have the node as ‘Root Node’, as shown below. If the server is the first node in the domain, then it shall be the Root Node, however, if the user adds it to an existing ER domain, then, the user can choose it to be either NonRoot Node or Leaf Node.
Step 7: In the third step of the wizard, the user is prompted to specify the SBSPACE ( for ER row data ) and DBSPACE ( ER Catalog information ). If the Informix server doesn’t have those entries already, then the user can create them, in this step.
Click NEXT to continue.
Step 8: In the fourth step of the wizard, which is the final one, the user is allowed to review the settings. Click on NEXT to define a new ER Server.
Step 9: The user should see the conclusion message “ Congratulations! The new ER server was defined successfully.
Repeat the steps from Step 2, to define further set of Informix servers, which are shortlisted to be part of the Flexible Grid.
Note: Defining an Informix server as an ER server doesn’t enable the replication or start the replication. It only means that the server(s) / node(s) are ready to be replication enabled.