How to Migrate an Application

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How to Migrate an Application

As an operator, you can migrate an application instance from one grid to another. Migration is the process of moving an application from one grid to another. Migration requires a source grid and a target grid, unlike import and export, which require only one grid at any given point.

You migrate an application for the following reasons:

Lack of resources on an existing grid
Decommission or maintenance of an existing grid
Back-up of your data and application configuration
Moving an application from a staging to production environment, or vice versa

You can either migrate an application from a remote grid or a URL to an existing grid, or from an existing grid to a remote grid.

Notes:

Verify if you need to do any of the following migration before migrating an application:
- Catalog migrate
- Class migrate
Migration is not backward compatible. Therefore, verify all appliances that are used in the application exist on the destination grid. If yes, continue; if no, migrate appliances.
This scenario assumes all appliances that are used in the source grid also exist in the target grid.

Important! Stop the application before you start the migration process.

How to Migrate an Application

To migrate an application, perform the following steps:

Set up trust between grids
Determine if you are migrating to or from, and if migrating from, a grid or URL.
Choose among the following tasks:

Set up trust between Grids

Establish a two-way trust between the target and the source grids before you migrate an application, so that the grids trust each other implicitly.

Follow these steps:

Log in to the source grid, click the grid shell, and execute the grid info –v command
The command retrieves the value of the grid public SSH key.
Copy the value of the grid public SSH Key.
Note: Verify the key is on a single line with no blank space.
Log in to the target grid and execute a command similar to the following to create a user:
```
user create targetgrid@yourcompany.net pwd=somepwd sshkey="sshkey"
```
Note: The SSH parameter of this grid is the public SSH key retrieved in Step # 1.
Execute a command similar to the following to provide app_developer access to the new user on the target grid ACL:
```
grid modify_acl local:user:targetgrid@yourcompany.net=app_developer
```
The app_developer access allows the new user to migrate an application.
Execute a command similar to the following to provide configure access to the new user on the target grid ACL of the applications that you want to migrate:
```
app modify_acl myapp local:user:targetgrid@yourcompany.net=configure
```
To migrate an application from a remote grid or URL, go to the source grid, select the Applications tab, and click the Migrate From icon.
To migrate an application to a remote grid, go to the source grid, select the Applications tab, and click the Migrate To icon.

Note: To initiate the migration process, you can also right click and select Migrate From or Migrate To.
(Optional) Remove the newly created user from the remote grid if you do not need to migrate any more applications.

Migrate from a Remote Grid

As an operator, you can migrate an application from a remote grid to an existing grid.

Follow these steps:

Go to the Applications tab and click the Migrate From icon.
The Migrate wizard appears.
Complete the following tabs:

General

Includes general information to migrate an application. The tab contains the following fields:

Remote Grid

Specifies the DNS name or IP address of the remote grid from which you migrate the application (for example, mygrid.ca.net).

Remote Application Name

Specifies the name of the application that you want to migrate.

New Application Name

(Optional) Specifies a new name for the migrated application.

Note: Migrate from Grid option is similar to executing the application migrate command from the grid shell.

Configure Interfaces

Includes parameter for connection to external interfaces. The tab contains the following fields:

Name

Specifies the interface name.

To edit this field, click the cell.

Network

Specifies the network resource. For example, VLAN 3029.

To select a network, click the cell and open the drop-down list. Alternatively, you can select the blank from the drop-down list and can enter an IP address as typed text.

IP Address

Specifies the IP address for the interface.

To select an IP address, click the cell and open the drop-down list.

Limit: 256 IP addresses.

Note: If a selected network has more than 256 IP addresses, this field becomes a text field. Use Info tooltip to display the available ranges of IP addresses for the selected network. You can view the available ranges of the IP addresses in the dashboard.

Info

Displays information about the selected interface, such as the prefix, gateway, and name servers.

Configuration Properties

Allows you to set values for application properties, which lets you modify an instance of the application. Property values are useful for configuring location-specific parameters, such as IP addresses, and for configuring tuning parameters, such as cache sizes.

Note: Property values explicitly configured for this application are in bold. Mandatory property values that have not yet been configured are highlighted in red.

For information about the property, its type, and allowed values, click Info. To restore the default value of a property, click Restore. Click Reset All to reset property values to their defaults.

Finalizing

Allows you to select the following options:

Do not compress volumes when migrating application

Disables compression when transferring volumes for the application.

Note: This option speeds up the operation if the application contains large volumes.

Skip cleanup upon failure or completion

Skips cleanup of the imported application in case of failure or completion.
Click OK.
The Migrating dialog of the wizard displays the overall progress for the application import operation.

Note: You can configure the application using the Application Configuration after the migration completes.

Migrate from URL

As an Operator, you can migrate an application from a URL.

Follow these steps:

Go to the Applications tab, click the Migrate From icon, and complete the following fields:

URL

Specifies URL of the application archive directory. Must be in the form: http://path.

Application Name

Specifies the name of the imported application.

User Name

(Optional) Specifies the user name to access to the HTTP server.

Password

(Optional) Specifies the password to access to the HTTP server.

Note: The Import from URL option is similar to executing the application import command from the Grid Shell and specifying a URL for the exchange directory.
Click OK.
The Migrating dialog of the wizard displays the overall progress for the application import operation.

Note: You can configure the application using the Application Configuration after the migration completes.

Migrate to a Remote Grid

You can migrate your application to a remote grid to upgrade the existing grid. You may also periodically migrate a production application to a separate test grid for maintenance upgrade verification.

Follow these steps:

Go to the Applications tab, click the Migrate To icon, and complete the following tabs:

General

Includes general information to migrate an application. The tab contains the following fields:

Remote Grid

Specifies the DNS name or IP address of the remote grid to which you move the application (for example, mygrid.ca.net).

New Application Name

(Optional) New name for the migrated application. If you do not specify a new name, the application name will remain the same.

Configure Interfaces

Includes parameter for connection to external interfaces. The tab contains the following fields:

Name

Specifies the interface name.

To edit this field, click the cell.

Network

Specifies the network resource. For example, VLAN 3029.

To select a network, click the cell and open the drop-down list. Alternatively, you can select the blank from the drop-down list and can enter an IP address as typed text.

IP Address

Specifies the IP address for the interface.

To select an IP address, click the cell and open the drop-down list.

Limit: 256 IP addresses.

Note: If a selected network has more than 256 IP addresses, this field becomes a text field. Use Info tooltip to display the available ranges of IP addresses for the selected network. You can view the available ranges of the IP addresses in the dashboard.

Info

Displays information about the selected interface, such as the prefix, gateway, and name servers.

Configuration Properties

Allows you to set values for properties of the application, which lets you modify an instance of the application. Property values are useful for configuring location-specific parameters, such as IP addresses, and for configuring tuning parameters, such as cache sizes.

Note: Property values explicitly configured for this application are in bold. Mandatory property values that have not yet been configured are highlighted in red.

For information about the property, its type, and allowed values, click Info. To restore the default value of a property, click Restore. Click Reset All to reset property values to their defaults.

Finalizing

Allows you to select the following options:

Do not compress volumes when migrating application

Disables compression when transferring volumes for the application.

Note: This option speeds up the operation if the application contains large volumes.

Skip cleanup upon failure or completion

Skips cleanup of the imported application in case of failure or completion.
Click OK.
The Migrating dialog of the wizard displays the overall progress for the application import operation.

Note: You can configure the application using the Application Configuration after the migration completes.

Catalog and Class Migrate

catalog migrate

Migrate a catalog from or to a remote grid.

Syntax

cat migrate <remote_grid> <cat> [.name=<new name>][.store=<store>] [<option>]*

Options

<cat>

Name of catalog to migrate. It may a global or application local catalog.

.name=<new name>

New name for the migrated catalog. It may be a global or application local catalog.

.store=<store>

Specifies the volume store where volumes are created. May be set to one of the following values:

local - store volumes on local server storage

san - store volumes on a SAN

--export

Migrate the catalog to the remote grid. This requires bi-directional trust between the two grids.

--import

Migrate the catalog from the remote grid.

--nocompress

Do not compress volumes when migrating the catalog.

--nocleanup

Skip cleanup upon failure or completion (troubleshooting).

--debug

Show debug information during migration (troubleshooting)

--preserve_acl

Preserve the global catalog ACL if it is present.

--preserve_local_acl

Preserve local principals in the global catalog ACL.

--preserve_global_acl

Preserve global principals in the global catalog ACL.

Examples

cat migrate myoldgrid.3tera.net /mycat

Migrate a global catalog from a remote grid to the local grid.

cat migrate myoldgrid.3tera.net /mycat .name=/mynewcat

Migrate a global catalog from a remote grid and rename it in the process.

cat migrate mynewgrid.3tera.net myapp/local .name=/newlocal

Migrate an application local catalog from a remote grid as a global catalog on the local grid.

Notes

The catalog MUST NOT exist on the destination grid.
If neither the --export or -import options are specified, the catalog is migrated FROM the remote grid.
SSH agent and agent forwarding must be enabled on the client machine for the remote grid access to work.
--nocompress option is useful when migrating catalogs that have very large volumes.
By default global catalog ACL's are not preserved during migration.

class migrate

Migrate a class from/to a remote grid.

Syntax

class migrate <remote_grid> <class> [ .name=<new name>] [.store=<store>] [<option>]*

Arguments

<remote_grid>

Name of remote grid

<class>

Name of the class to migrate. The class may be in a global or local catalog or may be a singleton.

.name=<new name>

New name for the migrated class. The name may refer to a global or local catalog or may refer to a singleton.

.store=<store>

Specifies the volume store where volumes are created. May be set to one of the following values:

local - store volumes on local server storage

san - store volumes on a SAN

Note: the .store option is not available on AppLogic® for System z.

--export

Migrate the class TO the remote grid.

--import

Migrate the class FROM the remote grid.

--nocompress

Do not compress class volumes during migration.

--nocleanup

skip cleanup upon failure or completion (troubleshooting)

--debug

show debug information during migration (troubleshooting)

Examples

class migrate myoldgrid.3tera.net /mycat:myclass

migrate catalog class to the current grid.

class migrate myoldgrid.3tera.net /mycat:myclass .name=myapp:myclass

migrate catalog class to the current grid as an application singleton.

class migrate mynewgrid.3tera.net /myapp/local:myclass .name=/mycat:myclass --export

migrate local catalog class to the remote grid as a global catalog class.

Notes:

The class MUST NOT exist on the destination grid.
If neither the --export or --import options are specified, the class is migrated FROM the remote grid.
SSH agent and agent forwarding must be enabled on the client machine for the remote grid access to work.
The --nocompress option is useful when migrating classes that have very large volumes.