Management servers

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The management server is a system that has IBM® Copy Services Manager installed. The management server provides a central point of control for managing data replication.

You can create a high-availability environment by setting up a standby management server. A standby management server is a second instance of Copy Services Manager that runs on a different physical system, but is continuously synchronized with the primary (or active) Copy Services Manager server. The active management server issues commands and processes events, while the standby management server records the changes to the active server. As a result, the standby management server contains identical data to the active management server and can take over and run the environment without any loss of data. If the active management server fails, you can issue the Takeover command to make the standby management server take over.

Connecting the active management server to the standby management server

Ensure that the active management server is connected to the standby management server. This connection creates the management server relationship that begins the synchronization process. Each management server can be in only one management server relationship.

The files that are synced to the standby management server are database updates, properties, csv files, basic registry, and ldap registry. After basic and ldap registries are synced to the standby server, you no longer need to setup basic and ldap users on the standby server. All user authentication and authorization configurations are sent to the standby server.

Note: If the active or standby is a z/OS server, no files or users are synced, and you need to configure user management.

Important: After the active server and standby server reaches a synchronized state, it is recommended to login to the standby server to ensure that the authentication configuration is synced successfully.

Problems might occur during the synchronization process. For example, the management server relationship might become disconnected for a number of reasons, including a connectivity problem or a problem with the alternative server.

Before synchronizing the standby server, Copy Services Manager takes a backup of the standby server. If the standby server is synchronized and an issue occurs, the standby server can be restored by using the backup zip file. If a problem occurs during the synchronization process, the alternative server database is restored to its original state before the synchronization process began. Issue the Reconnect command to restore synchronization.

Automatic reconnection for active and standby servers after disconnection

When the active and standby servers are disconnected, leaving them in a Disconnected Consistent state, the active server automatically attempts to reconnect to the standby and resynchronize the servers.

Regardless of the cause of disconnection (server reboot or network outage), once the active server is running, and determines that a standby was previously defined and was consistent at the time of the disconnection, a reconnection with will automatically occur.

By default, the active server attempts to reconnect to the standby every minute for up to ten times. If the servers fail to automatically reconnect after ten attempts, a manual reconnection is required. To modify the default number of attempts, contact support.

When an automatic reconnection occurs, the standby server creates an autobackup prior to resynchronizing with the active server. This autobackup can be used if the active server becomes corrupted and the resynchronization corrupts the standby as well.

If a takeover is initiated on the standby server, it becomes an active server, and on during the next reconnection attempt, the original active server recognizes that a takeover was initiated and stops attempting to reconnect to the former standby.

Completing a takeover on the standby management server

After issuing a takeover on the standby server, it's important to avoid having two active management servers. If there are two active management servers and a condition occurs on the storage systems, both management servers respond to the same conditions, which might lead to unexpected behavior. In addition, both servers may attempt to run scheduled tasks.

Starting with the 6.3.12 release, the original active server will attempt to reconnect to the standby server. If the original active server determines that a takeover was completed on the standby, the original active server will immediate go into a disconnected Standby Server mode. This will help avoid the case where both servers are active and management scheduled tasks or events.

Important: If the active server does not automatically go into a Standby Mode after performing the takeover, shut down the active server to prevent the two servers from managing the same set of pairs.

The original active will remain in a standby mode after a takeover, until it is officially synchronized as a standby server OR a Takeover command is issued to the original active.

Important: To make the original active server an active server again, without making it a standby, issue the Takeover command. Please note that this may result in two active servers. Shut down the original standby or immediately make it a Standby server again to avoid any issues with two active servers.

Viewing the status of the management servers

You can view the status of the active and standby management severs from the Management Servers page in the Copy Services Manager graphical user interface (GUI). If you are logged on to the active management server, the icons on this panel show the status of the standby management server. If you are logged on to the standby management server, the icons on this panel show the status of the active management server.

When the status is Synchronized, the standby management server contains the same data that the active management server contains. Any update to the active management server database is replicated to the standby server database.

Setting exceptions for ephemeral port numbers

For management servers that use an Internet Protocol version 4 (IPv4) connection, the port that is shown on the Management Servers page of the Copy Services Manager GUI is the listener port. This port is set when Copy Services Manager is installed.

However, when the management server initiates a connection to standby server, the management server uses an ephemeral port.

An ephemeral port is a temporary port number that is assigned for the duration the connection. When the connection terminates, the ephemeral port is available for reuse. When the management server reconnects to the standby server, a new ephemeral port number is assigned.

If you are using a firewall, you must create exceptions that enable the management server to connect to the standby server by using outbound ephemeral ports.

Information specific to management servers in z/OS environments

If the standby management server is not in the active server z/OS® sysplex, the standby server is not able to communicate with the storage systems by using a z/OS connection. Therefore, another connection must be made by using a TCP/IP connection.

Copy Services Manager Basic Edition does not support active and standby management servers. If you are using this product, the menu item Management Servers is not available.