Adding Data Instances

A data instance contains an element for every single database defined in the grid. An element stores a portion of the data of a single database. The data may be distributed among a number of elements equal to the number of data instances defined in the grid.

Perform the following tasks to create data instances in a grid:

Note:

Remember that the operations described in the following topics only modify the latest version of the model and do not become part of the operational grid until those changes are applied. See Applying the Changes Made to the Model.

Create a Host for a Data Instance

As with a host associated with a management instance, for every system you intend to use to store a portion of the data of a database, you must manually add the system as a host model object. Likewise, you must provide the communication parameters (fully qualified domain or IP address) of the system. Although, each host can have more than one data instance, it is recommended that you only configure one data instance per host.

To create a data instance, you need to associate the host with a data space group. All data space groups must be associated with the same number of data instances. If you follow the recommendation of one data instance per host, all data space groups must be associated with the same number of hosts.

As mentioned in Adding the Standby Management Instance, the ttGridAdmin hostCreate command creates a host in the grid. You can associate the host with a data space group at host creation or later.

Create a host for a data instance and associate it with data space group 1. Ensure that you identify the fully qualified domain name or IP address of the host.

% ttGridAdmin hostCreate -internalAddress int-host3 -externalAddress ext-host3.example.com -dataSpaceGroup 1
Host host3 created in Model

Note:

If you do not specify a name for the host, TimesTen Scaleout sets the OS host name of the remote system as the name of the new host.

Figure 4-5 shows a graphical representation of the model of the grid1 grid after creating the host3 host.

Figure 4-5 The Model After Adding a Host for a Data Instance

Description of "Figure 4-5 The Model After Adding a Host for a Data Instance"

For more information on the ttGridAdmin hostCreate command, see Create a Host (hostCreate) in Oracle TimesTen In-Memory Database Reference.

Create the Installation for the Data Instance

Every host must have an installation associated with it. A host can either have its own copy of the installation files or share an installation with one or more hosts through network-attached storage. For shared installations, an installation model object with the location of the shared installation files must be associated with the host. See Copying an Installation on Linux/UNIX in Oracle TimesTen In-Memory Database Installation, Migration, and Upgrade Guide.

The ttGridAdmin installationCreate command creates an installation in the grid and associates it with a host.

Create an installation in a directory of your choice in the host3 host, for example, the /grid directory.

% ttGridAdmin installationCreate host3 -location /grid
Installation installation1 on Host host3 created in Model

Note:

If you do not specify a name for the installation, TimesTen Scaleout sets installation1 as the name of the installation. Any subsequent installation associated with the same host requires that you provide a name for it.
If the management instance running the command has only one installation associated with it and the source for the installation files is not specified in the -source option of the ttGridAdmin installationCreate command, TimesTen Scaleout copies the installation files from the installation associated with the management instance running the command.

Figure 4-6 shows a graphical representation of the model of the grid1 grid after creating the installation1 installation in the host3 host.

Figure 4-6 The Model After Adding an Installation for the Data Instance

Description of "Figure 4-6 The Model After Adding an Installation for the Data Instance"

For more information on the ttGridAdmin installationCreate command, see Create an Installation (installationCreate) in Oracle TimesTen In-Memory Database Reference.

Create the Data Instance

The ttGridAdmin instanceCreate command creates an instance in the grid and associates it with a host and installation.

Create a data instance in the location of your choice in the host3 host, for example, the /grid directory.

% ttGridAdmin instanceCreate host3 -location /grid
Instance instance1 on Host host3 created in Model

Note:

If you do not specify a name for the instance, TimesTen Scaleout sets instance1 as the name of the instance. Any subsequent instances associated with the same host requires that you provide a name for it.
Because the host3 host only has the installation1 installation associated with it, the installation1 installation is associated with the instance1 data instance by default and there is no need to specify the -installation option.
TimesTen Scaleout defines an instance as a data instance by default. Use the -type management option of the ttGridAdmin instanceCreate command to create a management instance.
TimesTen Scaleout creates a subdirectory with the instance name in the specified location. TimesTen Scaleout allocates all instance files in this subdirectory. For example, the instance files of the instance1 data instance are allocated in the /grid/instance1 directory of the host3 host.
TimesTen Scaleout sets the default values for the TCP/IP port numbers of the instance daemon and server (6624 and 6625, respectively) if you do not specify a value for the port numbers. Use the -daemonPort or -csPort options of the ttGridAdmin instanceCreate utility to set different values for the port numbers.

Figure 4-7 shows a graphical representation of the model of the grid1 grid after creating a data instance.

Figure 4-7 The Model After Adding a Data Instance

Description of "Figure 4-7 The Model After Adding a Data Instance"

For more information on the ttGridAdmin instanceCreate command, see Create an Instance (instanceCreate) in Oracle TimesTen In-Memory Database Reference.

Create Data Instances by Duplicating the Configuration of an Existing Host

As mentioned in Adding the Standby Management Instance, you can create an instance (management or data) by duplicating the configuration of an existing host, including its associated installations and instances with the -like and -cascade options of the ttGridAdmin hostCreate command.

The -like option identifies the host to be duplicated and associates the new host with the same data space group. You can override the data space group associated with the new host by providing different parameters in the -dataSpaceGroup option.
The -cascade option duplicates the configuration of the installations and data instances associated with the specified host.

Create five data instances based on the same attributes defined for the host3 host and its associated installation and data instance. Also, associate two hosts with data space group 2 and two hosts with data space 3, instead of data space group 1. Ensure that you identify the fully qualified domain name of the new hosts.

% ttGridAdmin hostCreate -internalAddress int-host4 -externalAddress ext-host4.example.com -like host3 -cascade -dataSpaceGroup 2
Host host4 created in Model
Installation installation1 created in Model
Instance instance1 created in Model

% ttGridAdmin hostCreate -internalAddress int-host5 -externalAddress ext-host5.example.com -like host3 -cascade -dataSpaceGroup 3
Host host5 created in Model
Installation installation1 created in Model
Instance instance1 created in Model

% ttGridAdmin hostCreate -internalAddress int-host6 -externalAddress ext-host6.example.com -like host3 -cascade 
Host host6 created in Model
Installation installation1 created in Model
Instance instance1 created in Model

% ttGridAdmin hostCreate -internalAddress int-host7 -externalAddress ext-host7.example.com -like host4 -cascade
Host host7 created in Model
Installation installation1 created in Model
Instance instance1 created in Model

% ttGridAdmin hostCreate -internalAddress int-host8 -externalAddress ext-host8.example.com -like host5 -cascade
Host host8 created in Model
Installation installation1 created in Model
Instance instance1 created in Model

Note:

If you do not specify a name for the host, TimesTen Scaleout sets the OS hostname of the remote system as the name of the new host.
Any additional option you define in the ttGridAdmin hostCreate command will overwrite the attributes inherited from the existing host in the new host, as shown with the addition of the -dataSpaceGroup parameter in the command that creates the host4 and host5 hosts.
Notice that the ttGridAdmin hostCreate commands that create the host7 and host8 hosts use the host4 and host5 hosts, respectively, as reference in the -like option.

Figure 4-8 shows a graphical representation of the model of the grid1 grid after duplicating the host3 host as the host4, host5, host6, host7, and host8 hosts and their associated installations and instances.

Figure 4-8 The Model After Duplicating an Existing Host

Description of "Figure 4-8 The Model After Duplicating an Existing Host"

For more information on the ttGridAdmin hostCreate command, see Create a Host (hostCreate) in Oracle TimesTen In-Memory Database Reference.