Setting up and managing content replication

You can automatically replicate folders and content between repositories using replication jobs. These jobs are controlled by the replication service, which finds content that needs to be replicated and then calls the transfer service to carry out the replication. Replication suits an environment where you are running multiple, separate instances of Alfresco Community Edition and then replicating a subset of the content between these servers.

Content replication is designed to assist geographically distributed deployments where performance may be affected by network latency or bandwidth limitations.

Fast access by serving content from local servers
High availability - removes the single point of failure

For network administrators replication provides:

Reduced network overhead

By default, replicated content is read-only on the target repository. This ensures the integrity of the content is not compromised by uncontrolled updates. An option is provided in the Alfresco Share user interface for users to navigate to the content's source repository to make any updates.

The replication service controls content replication between different repositories. The replication service is responsible for persisting replication jobs that specify what is to be replicated, to where, and when. In addition, it monitors the status of currently executing replication jobs and enables replications to be canceled.

The replication service finds the nodes that need to be transferred, and then it delegates the transfer of content to the transfer service.

Replication jobs are managed in the Alfresco Share Admin Tools.

Note: You can't run simultaneous replication jobs. If you send two replication jobs to a target repository at the same time, the first job received by the repository runs without issue. The second job attempts to run but fails with an error.

Configuring content replication

You can configure Alfresco Community Edition to replicate content between source and target repositories.

Shut down the server on the source and target repositories.
In the source repository, open the alfresco-global.properties file and make the following updates:
Set the replication.enabled property to true:
```
replication.enabled=true
```
Note: If this line is not present in the alfresco-global.properties file or the value is set to false, you will not be able to run any replication jobs. You might see this error message in Share:
Save the file.
In the target repository, open the alfresco-global.properties file and make the following updates:
1. Set the transferservice.receiver.enabled property to true:
```
transferservice.receiver.enabled=true
```
Save the file.
Restart both source and target repositories.
Create a transfer target, as specified in Creating a new transfer target for content replication [5].

Creating a new transfer target for content replication

The transfer service stores files that control and monitor the operation of the transfer service in the Transfers space in the Data Dictionary.

The Transfer Target Groups space contains the transfer target definitions that specify where transfers go to. There is a group level below the folder which is used to classify different sets of transfer targets. This folder contains a group called Default Group.

You can add transfer targets by creating new transfer folders.

In the source repository, create a new folder in Company Home > Data Dictionary > Transfers > Transfer Target Groups > Default Group.
1. In the New Folder window specify a name, for example, Replica. You can add a title, and description of the new folder, if you wish.
  A rule defined on the Default Group folder specializes the type of any folder created in it.
  
  The type is set automatically by the folder rule to trx:transferTarget. This allows you add the required properties to define the replication target through the user interface.
2. Click Edit Properties on your new folder (Replica).
3. Specify the required properties:
  1. Specify the Endpoint Host, Endpoint Port, Username and Password.
  2. Click Enabled and Save.
4. Enable the replication service in your alfresco-global.properties file:
```
replication.enabled=true
```
  and restart the source repository.
In the target repository, enable the replication server and content receiver in the alfresco-global.properties file:
```
replication.enabled=true
transferservice.receiver.enabled=true
```
and restart the target repository.
On the source repository, create a replication job to test the target setup.
1. From the toolbar, click Admin Tools and select Replication Jobs from the menu.
2. Click Create Job.
3. Specify properties for Name, Payload, Transfer Target.
  Name is a new folder name; for example, Replication Job. Payload is the source content directory, and Transfer Target is the folder name that you set up in step 1 [7] (Replica).
4. Click Enabled.
5. Click Create Job.
6. Refresh the screen after a few minutes to see a status change.
Verify the replication job.
Log in to Alfresco Share on the target repository, select a transferred file and click Open in Source Repository to check that content has replicated.

Managing replication jobs

The Replication Jobs tool in Alfresco Share Admin Tools enables you to create and manage jobs for content replication.

A replication job specifies the content to be replicated; the day and time the job is to be performed; and the target location for the replicated content.

The job is controlled by the Replication Service, and it calls the Transfer Service, which allows folders and content to be automatically copied between repositories. A replication job can be run according to a schedule or on-demand.

By default, any replicated content is read-only in the target repository. This ensures the integrity of the content is not affected by uncontrolled updates.

Viewing a replication job

Select a replication job to view the job details and display the available actions.

Click Admin Tools, and then click Replication Jobs.
The Replication Jobs page displays a summary of recently run jobs and a list of existing replication jobs. In this list, use the menu provided to sort the jobs by Status, Name, and Last Run Date.
In the Jobs section, click a job to view its details.
The job appears highlighted in the list and its details appear on the right side of the page.

Creating a new replication job

You can create any number of replication jobs to suit your needs.

Click Admin Tools, and then click Replication Jobs.
In the Jobs section, click Create Job.
The Create New Replication Job page appears. Fields marked with an asterisk (*) are required.
Enter the details for the new replication job.
1. Enter a name for the job, and enter a description, if required.
2. In the Payload section, click Select.
  Navigate the repository and click Add to the right of each space that you want to include in the payload. This content will be replicated (copied) when the job is run. Click OK.
3. In the Transfer Target section, click Select.
  
  Navigate the Transfer Target Groups and click Select to the right of the target. Click OK.
  
  Note: Out of the box, one target group, Default Group, is available. Create additional target groups in Data Dictionary > Transfers > Transfer Target Group. A rule defined on the Transfer Target Groups folder specializes the type of any folder created within it.
  
  See Creating a new transfer target for content replication [5] for more information.
4. Specify when you want the replication job to run.
  Select the Schedule job check box, then enter the date and time the job is to run. Specify the repeat period for this job.
5. Select the Enabled check box to enable to replication job to run.
  
  Note: You must enable a replication job for it to be run.
Click Create Job.
The job created appears highlighted in the Jobs list. The job details appear on the right side of the page.

Managing existing jobs

The Replication Jobs page in Admin Tools displays a list of all existing replication jobs.

For each job in this list, you can perform any of the following actions to manage and maintain the jobs:

Run a job
Cancel a job
Edit a job
Delete a job

Running a replication job

The Run Job tool allows you to run a replication job. You can do this at any time. If a schedule is set for the job, it remains in place and will be run at the appropriate time.

Click Admin Tools, and then click Replication Jobs.
In the Jobs section, click the job that you want to run.
The job appears highlighted in the list and its details appear on the right side of the page.
Note: For a job to be run, it must be enabled.
Click Run Job.
The Status section on the right side of the page indicates that the job is running. The date and time the job started is displayed.

Canceling a replication job

You can cancel a job that is currently running, regardless of whether it was started automatically (that is, it is a scheduled job) or manually.

Click Admin Tools, and then click Replication Jobs.
In the Jobs section, click the currently running job that you want to cancel.
An icon () to the left of the job name indicates a job is currently running.
The Status section on the right side of the page indicates the start time of the selected job.

Note: If the job was already displayed, you might need to click Refresh to update the status.
Click Cancel Job.
The job is stopped and a report is created.

Editing a replication job

You can easily update existing replication jobs. In addition to changing the job details, you can use this feature to disable a job so that it will not be run.

Click Admin Tools, and then click Replication Jobs.
In the Jobs section, click the job you want to edit.
The job appears highlighted in the list and its details appear on the right side of the page.
Click Edit.
The Edit Replication Job page appears.
Edit the replication job as necessary. All job details—name, description, payload, transfer target, and schedule—are available for editing.
Add and remove source items as necessary. Click Remove to the right of a single item to remove it. Click Remove All beneath the list to remove all items.
Deselect the Enabled check box to prevent the job from being run.
Click Save.
The main page displays the updated job details.

Deleting a replication job

If you no longer need a replication job, you can delete it from the Jobs list. If there is a chance you might need the job again, you might prefer to edit the job and simply disable it.

Click Admin Tools, and then click Replication Jobs.
In the Jobs section, click the job you want to delete.
The job appears highlighted in the list and its details appear on the right side of the page.
Click Delete.
A message prompts you to confirm the deletion of the selected job.
Click Delete.
The selected job is deleted from the jobs list.

Viewing replication job reports

Two reports—local and remote—are available for each replication job run successfully.

The local report is the transfer report from the sending system, which manages the content being transferred to the receiving system. The local report details the speed at which the files were transferred and other related details.

The remote report is the transfer report from the receiving system. This report indicates whether files were created, updated, modified, or deleted as part of the transfer.

Click Admin Tools, and then click Replication Jobs.
In the Jobs section, click the job you want to view.
The job appears highlighted in the list and its details appear on the right side of the page.
Select a report:
- Click View Local Report.
- Click View Remote Report.
The selected report displays on the details page of the Repository Document Library.