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Cloud Storage Gateway:Configure express synchronization

Last Updated:Aug 29, 2024

The express synchronization feature of Cloud Storage Gateway (CSG) allows you to efficiently synchronize changes in an Object Storage Service (OSS) bucket to all local clients that are connected to the bucket by using a file gateway.

Prerequisites

Background information

When you configure the express synchronization feature, you can add one or more shares that are connected to the same OSS bucket to an express synchronization group. All data changes in the bucket are simultaneously synchronized to the CSG agents that are mapped to the shares in the express synchronization group. You do not need to separately synchronize data changes from the bucket. This improves the efficiency and accuracy of data synchronization.

Express synchronization must be used together with MNS. If you enable express synchronization, you are charged for using MNS. For more information about MNS billing, see Billing.

Create a synchronization group

Important

If you do not specify a version ID when you delete an object from a versioned bucket, the DeleteObject or DeleteObjects event notification is not triggered. This is because a request to delete an object from a versioned bucket without a version ID specified does not delete any object version. Instead, the current version of the object is made a previous version and a delete marker is added as the current version of the object. As a result, CSG detects no deletion operation on the object.

To enable express synchronization, you must create a synchronization group and add shares to the group.

  1. Log on to the CSG console.

  2. In the upper-left corner of the console, select the region where the file gateway resides.

  3. In the left-side navigation pane, click Express Sync.

  4. In the upper-right corner of the Sync Groups page, click Create.

  5. In the Basic Information step of the Create Sync Group wizard, configure the parameters described in the following table and click Next.

    Parameter

    Description

    Sync Group Name

    Enter the name of the synchronization group.

    Note

    The synchronization group name must be 1 to 128 characters in length, and can contain letters, digits, periods (.), underscores (_), and hyphens (-). It must start with a letter.

    OSS Region

    Specify the region where the OSS bucket resides.

    Bucket Name

    Select the name of the OSS bucket. You can select only one OSS bucket for an express synchronization group. All data changes in the bucket are synchronized to the CSG agents that are mapped to the shares in the group.

    Note

    If no share is connected to the OSS bucket, no OSS bucket is available in the drop-down list. In this case, you must create a share in the file gateway to map your CSG agent to the OSS bucket. For more information, see Manage shares.

    Bucket Subdirectory

    Select a specific subdirectory of the bucket from which you want to synchronize data.

  6. In the Sync Group Settings step of the Create Sync Group wizard, select the intended shares from the Available Shares section and click the > icon. The shares are displayed in the Selected Shares section. Click Next.

    To remove a share from the selected shares, select the share in the Selected Shares section and click the < icon.

    Note

    After you add an NFS share to a synchronization group, you can specify the noac parameter when you mount the share to a local directory on the CSG agent. This allows you to view the synchronization result at the earliest opportunity. For more information, see the example in Access an NFS share.

  7. In the Confirmation step of the Create Sync Group wizard, confirm information about the synchronization group. If nothing goes wrong, click OK.

Manage a synchronization group

After you create a synchronization group, all data changes in the OSS bucket are automatically synchronized to the CSG agents that are mapped to the shares in the synchronization group. You can perform the following operations to manage a synchronization group:

  • View the details of a synchronization group

    On the Sync Groups page, click the synchronization group name in the Sync Group Name column or click Details in the Actions column.

    In the Sync Group Details dialog box, you can view the details of the synchronization group. You can also click the icon to view the details in a list, or click the icon to view the details on a map. The Sync Group Details dialog box shows the basic information of the synchronization group and the shares in the group. You can also view the following information from the list.

    Item

    Description

    Message Topic Name

    The name of the MNS topic that is used by the synchronization group.

    Shared Status

    The status of the share in the synchronization group. The share can be in one of the following states:

    • Full Data Sync Awaiting: indicates that the share is waiting for the initial full synchronization.

    • Full Data Sync in Progress: indicates that the share is being used for the full synchronization.

    • Sync Normal: indicates that the share is being used to synchronize data as expected.

    • Express Sync Disabled: indicates that the express synchronization feature is disabled for the share.

    • Message Queue Inaccessible: indicates that the queue that corresponds to the share cannot be accessed.

    • Message Topic Inaccessible: indicates that the topic that corresponds to the share cannot be accessed.

    • Message Queue and Topic Inaccessible: indicates that the queue and topic that correspond to the share cannot be accessed.

    Message Queue Name

    The name of the MNS queue that is used by the synchronization group.

  • Add a share to or remove a share from a synchronization group

    Find the synchronization group and click Settings in the Actions column. In the Set Sync Group dialog box, add a share to or remove a share from the synchronization group. To add or remove a share, follow the instructions in Step 6 in the Create a synchronization group section.

  • Delete a synchronization group

    To delete a synchronization group, find the synchronization group on the Sync Groups page and click Delete in the Actions column. In the message that appears, click OK.