Skip to main content
Outside service Partner
Hitachi Vantara Knowledge

Monitoring and managing replication


The Replication page in the Tenant Management Console shows information about replication of the current tenant when both of these conditions are true:

The tenant is eligible for and currently selected for replication.

The HCP system is configured to show this information.

If the tenant is eligible for but not currently selected for replication, the page shows a replication status of Not Replicating.

You can use the statistics and graphs on the Replication page to monitor replication progress. You can also use the page to select and deselect namespaces to be replicated along with the tenant.

To display the Replication page, in the top-level menu of the Tenant Management Console, select Services Replication.

RoleWebHelp.png

Roles: To view the Replication page, you need the monitor or administrator role. To select and deselect namespaces for replication, you need the administrator role.

For an introduction to replication, see Replication.

© 2015, 2019 Hitachi Vantara Corporation. All rights reserved.

Tenant-level view of replication


At the tenant level, the Replication page shows:

Only on an HCP system that’s sending data for the tenant to other systems, the approximate number of objects and parts of multipart objects currently waiting to be replicated in all namespaces owned by the tenant.

Only on an HCP system that’s sending data for the tenant to other systems, the approximate amount of data currently waiting to be replicated in all namespaces owned by the tenant, in bytes.

On an HCP system that’s sending data for the tenant to other systems or receiving data for the tenant from other systems, the current rate of replication activity, expressed as operations per second and as bytes per second. An operation is the replication of a single item, such as the creation of a new object, a metadata change, or a namespace configuration change.

These rates are the sums of the corresponding rates for the tenant's namespaces.

A list of the namespaces selected for replication with the tenant. For each namespace, the list shows a progress bar that measures the up-to-date-as-of time for replication of that namespace, along with this time as a numeric value. The length of the progress bar represents 30 days, with the right end representing the current time.

The up-to-date-as-of time is the difference between:

oThe time before which objects, object parts, metadata changes, and configuration changes are guaranteed to have been sent to other systems or received from other systems

oThe current time

© 2015, 2019 Hitachi Vantara Corporation. All rights reserved.

Managing the namespace list


By default, the namespace list on the Replication page includes all the namespaces that are selected for replication. The namespaces are listed 20 at a time in ascending order by namespace name.

You can page through, sort, and filter the list of namespaces. The Replication page indicates which namespaces are shown out of the total number of namespaces in the current list.

Paging

You can change the number of namespaces shown at a time on the Replication page. To do this, in the Items per page field, select the number of namespaces you want. The options are 10, 20, and 50.

To page forward or backward through the namespace list, click on the next ( TenantForward.png ) or back ( TenantBack.png ) control, respectively.

To jump to a specific page in the namespace list:

1.In the Page field, type the page number you want.

2.Press Enter.

Sorting

You can sort the namespace list in ascending or descending order by namespace name. To sort the list, click on the Name column heading. Each time you click on the column heading, the sort order switches between ascending and descending.

Filtering

You can filter the namespace list by namespace name or tag. The filtered list includes only those namespaces with a name or tag, as applicable, that begins with or is the same as a specified text string.

To filter the namespace list:

1.In the field above the Name column, select Name to filter by name or Tag to filter by tag.

2.In the next field, type the text string you want to use as a filter. This string can be up to 64 characters long, can contain any valid UTF-8 characters except commas (,), and is not case sensitive. White space is allowed.

3.Click on the find control ( FindControl.png ).

To redisplay the entire list of namespaces after filtering it, click on the clear filter control ( ClearFilterControl.png ).

© 2015, 2019 Hitachi Vantara Corporation. All rights reserved.

Namespace-level view of replication


To view more detailed information about the replication of an individual namespace listed on the Replication page, click on the namespace name. The panel that opens shows:

The date and time before which objects, parts of multipart objects, metadata changes, and configuration changes for the namespace are guaranteed to have been sent to other systems or received from other systems

A graph of the history of the up-to-date-as-of time for replication of the namespace

A graph of the history of the data transmission rate for replication of the namespace

A graph of the history of the operation rate for replication of the namespace

On an HCP system that’s sending data for the tenant to other systems, the panel also shows this information for the namespace:

The approximate number of objects and parts of multipart objects currently waiting to be replicated

The approximate amount of data currently waiting to be replicated

© 2015, 2019 Hitachi Vantara Corporation. All rights reserved.

Up-to-date-as-of time


The Up to date as of section in the namespace replication panel contains a graph that shows the history of the up-to-date-as-of time for replication of the namespace. The section heading shows the current up-to-date-as-of time. If the graph is not currently visible, click on Up to date as of to display it.

The x‑axis in this graph marks the passage of time. It shows 30 days (or fewer if replication has been occurring for less than 30 days). The y-axis marks the up-to-date-as-of time in days, hours, or minutes. As the up-to-date-as-of time varies, the measurement unit for the y-axis grows or shrinks as needed (for example, from days to hours to minutes). The lower the up-to-date-as-of time, the closer replication is to being synchronized with current namespace activity.

© 2015, 2019 Hitachi Vantara Corporation. All rights reserved.

Data transmission rate


The Transfer Rate section in the namespace replication panel contains a graph that shows the history of the rate of replication data transmissions for the namespace per second. The section heading shows the current data transmission rate. If the graph is not currently visible, click on Transfer Rate to display it.

The x‑axis in this graph marks the passage of time. It shows 30 days (or fewer if replication or recovery has been occurring for less than 30 days). The y-axis marks the data transmission rate in KB, MB, or GB. As the transmission rate varies, the measurement unit for the y-axis grows or shrinks as needed (for example, from KB to MB to GB).

© 2015, 2019 Hitachi Vantara Corporation. All rights reserved.

Operation rate


The Operations per Second section in the namespace replication panel contains a graph that shows the history of the rate of replication operations for the namespace per second. The section heading shows the current operation rate. If the graph is not currently visible, click on Operations per Second to display it.

The x‑axis in this graph marks the passage of time. It shows 30 days (or fewer if replication or recovery has been occurring for less than 30 days). The y-axis marks the operation rate in tens, hundreds, or thousands. As the operation rate varies, the measurement unit on the y-axis grows or shrinks as needed (for example, from tens to hundreds to thousands).

© 2015, 2019 Hitachi Vantara Corporation. All rights reserved.

Selecting or deselecting namespaces for replication


On the Replication page, at any time, you can change which namespaces are replicated with the tenant and, if allowed by the tenant configuration, specify whether those namespaces allow erasure coding. If you disable replication for a namespace that was already being replicated, replication of that namespace stops. If you subsequently enable replication for that namespace again, replication of the namespace starts again from where it stopped.

When you reenable replication of a namespace that has already been replicated, all operations that occurred in that namespace while replication was not happening, including object deletions, are replicated to the other system. During this replication, conflicts can occur between changes made on different systems while the namespace was not being replicated. For information on how HCP resolves these conflicts, see Replication collision handling.

If you disable replication for a namespace that has already been replicated and then delete the namespace on one or more systems, the namespace deletions are not replicated. If you then reenable replication for that namespace and the namespace still exists on one or more systems, the namespace is replicated back to the systems where you deleted it.

TipWebHelp.png

Tip: You can also enable or disable replication for a namespace and specify whether the namespace allows erasure coding on the namespace Replication panel. For more information on doing this, see Changing replication options.

NoteWebHelp.png

Notes: 

Depending on the current status of replication, if the tenant is being replicated, you may not be able to disable replication for namespaces that are being replicated.

Allowing erasure coding for a namespace that has shredding enabled as the default for new objects can significantly increase the load on all systems in the replication topology. For information on shredding, see Default shred setting.

ImportantWebHelp.png

Important: Disabling replication for a namespace that has already been replicated may cause object data in that namespace to become inaccessible on one or more systems in the replication topology.

To change the replication and erasure coding options for namespaces, on the Replication page:

1.Click on Namespace Selection for Replication.

The Namespace Replication Selection section lists all the tenant's namespaces. For each namespace, the section shows whether the namespace is cloud optimized.

The Namespace Replication Selection section has a column in which you can select or deselect namespaces for replication. If you can specify whether namespaces allow erasure coding, this section also has a column in which you can allow or disallow erasure coding for namespaces.

2.In the Namespace Replication Selection section:

oTo enable or disable replication for a namespace, select or deselect the namespace in the Replication column.

To enable or disable replication for all namespaces at the same time, select or deselect the Replication column heading.

When you deselect Replication for a namespace, Allow Erasure Coding is automatically deselected for that namespace.

oTo allow or disallow erasure coding for a namespace, select or deselect the namespace in the Allow Erasure Coding column. This option is available only for cloud-optimized namespaces.

To allow or disallow erasure coding for all cloud-optimized namespaces at the same time, select or deselect the Replication column heading.

When you select Allow Erasure Coding for a namespace, Replication is automatically selected for that namespace.

The Allow Erasure Coding column is present only if you're allowed to choose whether namespaces allow erasure coding.

3.Click on Update Namespaces.

© 2015, 2019 Hitachi Vantara Corporation. All rights reserved.