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Manage S3 Oplog Storage

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  • Considerations
  • Prerequisites
  • Procedures

Throughout the lifecycle of a backup, MongoDB Agent tails the oplog of each replica set and sends new oplog entries to Ops Manager. The Agent sends the oplog entries in compressed bundles of approximately 10 MB in size called oplog slices. These oplog slices are stored in one or more MongoDB databases called oplog stores. Every Ops Manager deployment needs at least one oplog store.

When you enable backups, Ops Manager prompts you to create your first oplog store. This can be a local oplog store or an S3-compatible oplog store. Once you create the first oplog store, you manage it separately from your snapshot stores. You can create additional oplog stores.

This tutorial covers creating additional S3-compatible oplog stores to store oplog entries. Like any MongoDB instance, an S3-compatible oplog store can exist on any host running MongoDB and S3-compatible storage bucket (without subfolders) that the Ops Manager application can access.

Ops Manager must be the only manager on the S3-compatible storage bucket that you use for snapshots. You also need to configure the S3-compatible storage bucket to avoid using features that Ops Manager does not support.

When configuring the S3-compatible storage bucket:

  • Do not create subfolders in the S3-compatible storage buckets that you use with Ops Manager. Ops Manager only supports using entire S3-compatible storage buckets.

  • Disable AWS S3-compatible storage bucket versioning. Versioning is not supported in Ops Manager for the S3-compatible storage buckets used for snapshots.

  • Do not create AWS S3-compatible storage lifecycle rules. Lifecycle rules that expire or transition current versions of Ops Manager snapshot objects to archives results in incomplete snapshots that you can't use to restore the configuration.

After you create an S3-compatible oplog store, you cannot move it to another S3-compatible storage bucket. If you need to use a different S3-compatible storage bucket to host your S3-compatible oplog store, you must create a new S3-compatible oplog store in the same S3-compatible storage bucket. The S3-compatible storage snapshot bucket must be different than the oplog S3-compatible storage bucket.

MongoDB supports endpoints for:

IBM and Dell EMC support a subset of the full AWS S3-compatible storage API.

You can use other S3-compatible storage-compatible endpoints. Ops Manager attempts to validate these endpoints when you save the S3-compatible oplog store setup. If validation passes, Ops Manager saves the configuration. If validation fails, Ops Manager displays an error and doesn't save the configuration.

  1. Make sure you have an IAM user on AWS.

  2. Create your own AWS access keys for your IAM user. This allows you to create S3-compatible storage buckets and store oplog files in them. MongoDB does not create or issue AWS access keys.

  3. Create your own S3 bucket to store your S3-compatible oplog stores.

    Note

    The IAM user for which you created the AWS access keys must own the AWS S3-compatible storage bucket.

  1. Create an Access Key and Secret Key using IBM credential tools.

  2. Create your own S3-compatible storage-compatible bucket.

  1. Create an Access Key and Secret Key from your ECS User ID.

  2. Create your own S3-compatible storage-compatible bucket.

Other S3-compatible storage-compatible endpoints can be used. Ops Manager attempts to validate these endpoints when you save the configuration. If validation passes, the configuration, Ops Manager saves it. If validation fails, Ops Manager displays an error and doesn't save the configuration.

The format of the Username and Password depend upon the authentication mechanism. Select one of the following tabs:

1
  1. Click the Admin link.

  2. Click the Backup tab.

  3. (Optional) If you have not previously set the head directory, set it in the Head Directory box.

  4. Click the Oplog Storage page.

2
3
Field
Necessity
Contents
Name
Required
Enter the label for the S3-compatible oplog store.
S3 Bucket Name
Required
Enter the name of the S3-compatible storage bucket where you want to host the the S3-compatible oplog store.
Region Override
Conditional

Type the region where your S3-compatible storage bucket resides.

Use this field only if your S3-compatible storage-compatible store's S3 Endpoint doesn't support region scoping. Don't provide a value for this field with AWS S3-compatible storage buckets.

S3 Endpoint
Required

Enter the URL for this AWS S3-compatible storage or S3-compatible storage-compatible bucket.

What URL you write depends upon:

  1. Your S3 Bucket Name and

  2. If you checked Path Style Access.

Example

You created an S3-compatible storage bucket called mybucket on AWS in the US East region.

Path Style Access
Checked
Not Checked
S3 Endpoint
s3.us-east-2.amazonaws.com
mybucket.s3.us-east-2.amazonaws.com
Requests to Bucket
https://s3.us-east-2.amazonaws.com/mybucket
https://mybucket.s3.us-east-2.amazonaws.com
S3 Max Connections
Required
Enter a positive integer indicating the maximum number of connections to this AWS S3-compatible storage or S3-compatible storage-compatible bucket.
Path Style Access
Optional

Select if you want your AWS S3-compatible storage or S3-compatible storage-compatible bucket to use a path-style URL endpoint (s3.amazonaws.com/<bucket>) instead of a virtual-host-style URL endpoint (<bucket>.s3.amazonaws.com).

To review the S3-compatible storage bucket URL conventions, see the AWS S3 documentation

Server Side Encryption
Optional
Select to enable server-side encryption. Clear to disable server-side encryption.
S3 Authorization Mode
Required

Select the method used to authorize access to the S3-compatible storage bucket specified in S3 Bucket Name.

Keys
Ops Manager uses AWS Access Key and AWS Secret Key to authorize access to your S3-compatible storage bucket.
IAM Role
Ops Manager uses an AWS IAM role to authorize access to your S3-compatible storage bucket. AWS Access Key and AWS Secret Key fields are ignored. To learn more, see the AWS documentation
Keys with Custom CA Bundle
Conditional

Click Choose file to add a custom Certificate Authority chain. This chain can validate against a self-signed certificate on the S3-compatible storage bucket.

Ops Manager displays this field when you set S3 Authorization Mode to Keys.

AWS Access Key
Conditional

Enter your AWS Access Key ID.

Ops Manager displays this field when you set S3 Authorization Mode to Keys.

AWS Secret Key
Conditional

Enter your AWS Secret Access Key.

Ops Manager displays this field when you set S3 Authorization Mode to Keys.

Datastore Type
Required
Select Standalone, Replica Set or Sharded Cluster. This MongoDB database stores the metadata for the blockstore.
MongoDB Host List
Conditional

Enter a comma-separated list of mongod instances (for a Replica Set) or mongos instances (for a Sharded Cluster) in the <hostname:port> format that comprise the blockstore metadata database.

Example

host1.example.com:27017,host2.example.com:27017,host2.example.com:27018

Ops Manager displays this field when you set Datastore Type to Replica Set or Sharded Cluster.

Important

Ops Manager uses this metadata store as a sync store. Make sure to provision this store with sufficient storage space.

MongoDB Hostname
Conditional

Enter the hostname of the S3-compatible oplog store metadata database.

Ops Manager displays this field when you set Datastore Type to Standalone.

Important

Ops Manager uses this metadata store as a sync store. Make sure to provision this store with sufficient storage space.

MongoDB Port
Conditional

Enter the port number of the S3-compatible oplog store metadata database.

Ops Manager displays this field when you set Datastore Type to Standalone.

Username
Optional

If you set this value:

Password
Optional

If you set this value:

Warning

If you did not use the credentialstool to encrypt this password, it is stored as plaintext in the database.

Connection Options
Optional

Enter any additional configuration file options for the MongoDB instance.

This field supports unescaped values only.

For proper syntax, see Connection String URI Format in the MongoDB manual.

Encrypted Credentials
Optional
Select if the credentials for the database were encrypted using the credentialstool. The credentials include the Username, Password, AWS Access Key ID and AWS Secret Key.
Use TLS/SSL
Optional

Select if the S3-compatible oplog store metadata database only accepts connection encrypted using TLS.

Beyond this checkbox, to connect this S3-compatible oplog store using TLS, you must enable TLS on the S3 oplog store database.

New Assignment Enabled
Optional
Select if you want to enable this S3-compatible oplog store after creating it. This is selected by default so the S3-compatible oplog store can be assigned backup jobs. If you clear this checkbox, the S3-compatible oplog store is created but you cannot assign backups to this S3-compatible oplog store.
4

Ops Manager lists oplog stores in a table on the Oplog Storage page. Each row contains the settings for each local and S3-compatible oplog store.

1
  1. Click the Admin link.

  2. Click the Backup tab.

  3. (Optional) If you have not previously set the head directory, set it in the Head Directory box.

  4. Click the Oplog Storage page.

2
3

In the MongoDB Connection column, update any values that need to be changed in the following fields:

Field
Necessity
Contents
S3 Bucket Name
Required
Enter the name of the S3-compatible storage bucket where you want to host the the S3-compatible oplog store.
Region Override
Conditional

Type the region where your S3-compatible storage bucket resides.

Use this field only if your S3-compatible storage-compatible store's S3 Endpoint doesn't support region scoping. Don't provide a value for this field with AWS S3-compatible storage buckets.

S3 Endpoint
Required

Enter the URL for this AWS S3-compatible storage or S3-compatible storage-compatible bucket.

What URL you write depends upon:

  1. Your S3 Bucket Name and

  2. If you checked Path Style Access.

Example

You created an S3-compatible storage bucket called mybucket on AWS in the US East region.

Path Style Access
Checked
Not Checked
S3 Endpoint
s3.us-east-2.amazonaws.com
mybucket.s3.us-east-2.amazonaws.com
Requests to Bucket
https://s3.us-east-2.amazonaws.com/mybucket
https://mybucket.s3.us-east-2.amazonaws.com
S3 Max Connections
Required
Enter a positive integer indicating the maximum number of connections to this AWS S3-compatible storage or S3-compatible storage-compatible bucket.
Path Style Access
Optional

Click if you want your AWS S3-compatible storage or S3-compatible storage-compatible bucket to use a path-style URL endpoint (s3.amazonaws.com/<bucket>) instead of a virtual-host-style URL endpoint (<bucket>.s3.amazonaws.com).

To review the S3-compatible storage bucket URL conventions, see the AWS S3 documentation

Server Side Encryption
Optional
Click to enable server-side encryption. Clear to disable server-side encryption.
S3 Authorization Mode
Required

Select the method used to authorize access to the S3-compatible storage bucket specified in S3 Bucket Name.

Keys
Ops Manager uses AWS Access Key and AWS Secret Key to authorize access to your S3-compatible storage bucket.
IAM Role
Ops Manager uses an AWS IAM role to authorize access to your S3-compatible storage bucket. AWS Access Key and AWS Secret Key fields are ignored. To learn more, see the AWS documentation
Keys with Custom CA Bundle
Conditional

Click Choose file to add a custom Certificate Authority chain. This chain can validate against a self-signed certificate on the S3-compatible storage bucket.

Ops Manager displays this field when you set S3 Authorization Mode to Keys.

AWS Access Key
Conditional

Enter your AWS Access Key ID.

Ops Manager displays this field when you set S3 Authorization Mode to Keys.

AWS Secret Key
Conditional

Enter your AWS Secret Access Key.

Ops Manager displays this field when you set S3 Authorization Mode to Keys.

Note

Ops Manager doesn't display the existing Secret Access Key.

<hostname>:<port>
Required

Enter in one or more hosts that comprise the S3-compatible storage Snapshot Store metadata database in the <hostname:port> format.

Important

S3 Oplog Hosting Concerns

  • Ops Manager uses this metadata store as a sync store. Make sure to provision this store with sufficient storage space.

  • If you change these hosts, the S3-compatible oplog store they host must have the same data as the original S3-compatible oplog store. Changing the host to a new S3-compatible oplog store results in data loss.

  • If the S3-compatible oplog store metadata database is a Replica Set or Sharded Cluster, type a comma-separated list of mongod instances (for a Replica Set) or mongos instances (for a Sharded Cluster).

    Example

    host1.example.com:27017,host2.example.com:27017,host2.example.com:27018

  • If the S3-compatible oplog store metadata database is a standalone MongoDB instance, type the hostname:port of the instance.

MongoDB Auth Username
Optional

If you set this value:

MongoDB Auth Password
Optional

If you set this value:

Warning

If you did not use the credentialstool to encrypt this password, it is stored as plaintext in the database.

Note

Ops Manager doesn't display the existing MongoDB Auth Password.

Encrypted Credentials
Optional
Select if the credentials for the database were encrypted using the credentialstool. The credentials include the Username, Password, AWS Access Key ID and AWS Secret Key.
Use TLS/SSL
Optional

Select if the S3-compatible oplog store database only accepts connection encrypted using TLS.

Beyond this checkbox, to connect this S3-compatible oplog store using TLS, you must enable TLS on the S3 oplog store database.

Connection Options
Optional

Enter any additional configuration file options for the MongoDB instance. This field supports unescaped values only.

To review the proper syntax, see Connection String URI Format in the MongoDB manual.

Assignment Labels
Optional
Enter a comma-separated list of labels to assign the S3-compatible oplog stores to specific projects.
Write Concern
Required

Select your preferred Write Concern:

Default
Deployment Type
Default Write Concern
Standalone
Journaled
Replica sets or sharded clusters
W2
Journaled
A primary or standalone MongoDB instance acknowledged the write and wrote that write to their on-disk journals.
Acknowledged
A primary or standalone acknowledged the write.
W2
More than one of the cluster members acknowledged the write.
Majority
A majority of the replica set members acknowledged the write.
4

To enable this S3-compatible oplog store, select Assignment Enabled.

This is selected by default so the S3-compatible oplog store can be assigned backup jobs. If you clear this checkbox, Ops Manager creates the S3-compatible oplog store but you cannot assign backups to it.

5
6

If you change any connection string values or the Write Concern, restart all the Ops Manager instances including those running Backup Daemons.

Warning

Modifying the connection string values or the Write Concern for an existing S3-compatible oplog store requires you to restart all Ops Manager components, including those only running the Backup Daemon to apply those changes. Connection parameters include:

  • <hostname>:<port>

  • MongoDB Auth Username

  • MongoDB Auth Password

  • Encrypted Credentials

  • Use TLS/SSL

  • Connection Options

  • Write Concern

If you change to another S3-compatible oplog store host, Ops Manager doesn't copy the data on the existing S3-compatible oplog store to the other S3-compatible oplog store.

Tip

See also:

To learn more about the MongoDB connection string URI, see Connection String URI Format in the MongoDB Manual.

1
  1. Click the Admin link.

  2. Click the Backup tab.

  3. (Optional) If you have not previously set the head directory, set it in the Head Directory box.

  4. Click the Oplog Storage page.

2

Click Delete <oplogstore> beneath the name of the S3-compatible oplog store you want to delete.

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