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Hitachi Vantara Knowledge

Link overview

To monitor the status of and activity on a replication link, you use the link status Overview panel in the HCP System Management Console. To display this panel:

  1. In the list of links on the replication Links page, click the link you want to monitor.
  2. On the replication link details page, click Status.
  3. In the link Status panel, click the Overview tab.

If the replication link is part of one or more active, retiring, or retired erasure coding topologies, the top part of the link status Overview panel lists the topologies that include that link.

The Sending and Receiving sections in the link status Overview panel show the current status of activity on the link:

  • For an active/active link, a section labeled Sending shows the status of send activity on the local system. A section labeled Receiving shows the status of send activity on the remote system.
  • For an outbound active/passive link during replication and an inbound active/passive link during data recovery, a section labeled Sending shows the status of send activity on the local system.
  • For an outbound active/passive link during data recovery and an inbound active/passive link during replication, a section labeled Receiving shows the status of send activity on the remote system.

The Sending and Receiving sections show:

  • Data pending

    The approximate amount of data currently waiting to be sent to the other system, in bytes. This is the sum of the amounts of data waiting to be sent in each HCP namespace being replicated on the link. This value does not include data in the default namespace.

    Information about pending data is not available in the Receiving section on a replica during replication or on a primary system during data recovery.

  • Objects pending

    The approximate number of objects and parts of multipart objects currently waiting to be sent to the other system. This is the sum of the numbers of objects and object parts waiting to be sent in each HCP namespace being replicated on the link. This number does not include objects in the default namespace.

    The number of objects pending does not include parts of in-progress multipart uploads. Those parts are not replicated until the applicable multipart upload has been completed.

    Information about pending objects and object parts is not available in the section on a replica during replication or on a primary system during data recovery.

  • Up to date as of

    The amount of time that is the difference between:

    • The date and time before which configuration changes and changes to namespace content are guaranteed to have been sent to the other system
    • The current date and time

If the Replication Verification service is running or has ever run, a Verifying section appears below the Receiving section. The Verifying section shows:

  • Last Pass Completed

    The date and time at which the Replication Verification service finished its last run.

  • Status

    The current status of the Replication Verification service. Possible values are:

    • Enabled

      The Replication Verification service is either running or set to run the next time the Replication service runs.

    • Disabled

      The Replication Verification service is not running and is not set to run.

  • Issues Found

    Either None or the current total number of nonreplicating objects and object parts in all the namespaces owned by the tenants on the link. If nonreplicating objects or object parts exist, View appears next to Issues Found. To see a list of the tenants with namespaces that contain nonreplicating objects or object parts, click View. The list shows the total number of nonreplicating objects and ojbect parts for each tenant.

    If you have administrative access to a listed tenant, you can click the tenant name in the list to open the Tenant Management Console for that tenant. In the Tenant Management Console, you can see which namespaces have nonreplicating objects and object parts. For each of those namespaces, you can view a list of the nonreplicating objects and object parts in the namespace.

The link status Overview panel also contains:

  • A graph showing the history of the rate of data transmissions on the link
  • A graph showing the history of the rate of operations on the link
  • For active/active links and outbound active/passive links, one or two pie charts showing the amount of used and free storage space on the remote system

The statistics for replication links are updated every ten minutes. To see updated statistics, redisplay the Links page.

Data transmission rate

The Transfer Rate graph in the link status Overview panel for a replication link shows the history of the rate of data transmissions on the link per second. For an active/active link, this is the rate of data transmission from the local system to the remote system. For an active/passive link, this is the rate of data transmission during replication or recovery, whichever is happening at the time. In any case, the data transmission rate is cumulative for all the HCP tenants and default-tenant directories on the link.

If the Transfer Rate graph is not currently visible, click Transfer Rate to display it.

The x‑axis in the Transfer Rate graph marks the passage of time. The axis shows 30 days (or fewer if the replication link was created less than 30 days ago). 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).

The graph heading displays the current data transmission rate. Factors that affect this rate include the amount of other traffic on the network, the current load on both systems involved in the link, and whether data is being compressed or encrypted. Also, larger objects and object parts have higher rates of throughput.

Operation rate

The Operations per Second graph in the link status Overview panel for a replication link shows the history of the rate of operations on the link per second. An operation is the replication of any of these:

  • An object, object part, directory, symbolic link, metadata change, or object deletion
  • An HCP tenant or HCP namespace or the modification or deletion of an HCP tenant or HCP namespace
  • For HCP tenants only, the creation, modification, or deletion of a user account
  • The creation, modification, or deletion of a retention class
  • The creation, modification, or deletion of a content class
  • A tenant log message

For an active/active link, the Operations per Second graph shows the operation rate for replication from the local system to the remote system. For an active/passive link, the graph shows the operation rate during replication or recovery, whichever is happening at the time. In any case, the operation rate is cumulative for all the tenants being replicated or recovered on the link.

If the Operations per Second graph is not currently visible, click Operations per Second to display it.

The x‑axis in the Operations per Second graph marks the passage of time. The axis shows 30 days (or fewer if the replication link was created less than 30 days ago). 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).

The graph heading displays the current rate of replication operations. Factors that affect the operation rate are the same as those that affect the data transmission rate.

Remote storage space

The Remote Total Primary Storage pie chart in the link status Overview panel for an active/active link or an outbound active/passive link during replication shows the amounts of free and used space in primary storage for the other system involved in the link. Each amount is also shown as a number of bytes.

In a SAIN system with spindown storage, the storage being measured in this chart includes both primary running storage and primary spindown storage. In this case, a second pie chart to the right, labeled Remote Primary Running Storage, shows the amounts of free and used space in only primary running storage.

The two systems involved in a replication link do not necessarily have the same storage capacity or storage tiering strategies. If a system receiving replicated data starts to run low on free space in primary running storage, you need to evaluate whether to take action on that system to address the issue (for example, by increasing the primary running storage capacity or by tiering more data to other types of storage).

When primary running storage in the remote system for a replication link is almost full, the Overview page in the HCP System Management Console for the local system displays an alert. When the storage is full, the Console displays a different alert, and HCP automatically suspends replication on the link.

 

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