Changing payload replication type

You can change the payload replication type based on your requirements.

About this task

In Global Mailbox, the default replication type is delayed (asynchronous).
Attention: Immediate (synchronous) payload replication makes the system less fault tolerant as file operations such as, file uploads are dependent upon a majority of data centers. The minimum recommended number of data centers to use with immediate replication is 3. Immediate replication should not be used in a 2 datacenter deployment as the majority of 2 data centers is 2 and bringing down 1 data center for maintenance prevents file uploads. Majority is calculated by dividing the total number of data centers by 2, rounding down, then adding one. For example, with 3 data centers, divide by 2 giving 1.5, round down giving 1, then add 1, giving 2.

To change replication type:

Procedure

  1. In each data center, locate the global.properties file in shared storage.
    Important: Shared storage only replicates files within a data center. Therefore, you must modify the global.properties file in each data center independently.
  2. Open the global.properties file in a text editor.
  3. Change value for com.ibm.mailbox.replication.type as required. Valid values are:
    • For synchronous replication type the value type is Immediate.
    • For an asynchronous replication type the value type is Delayed.
    Important: If you change the global.properties or datacenter.properties, the file must be copied to all Global Mailbox instances. By default, the properties files are stored on a data center-specific distributed file system (shared storage), in which case, only changes to global.properties must be copied between data centers.
    Important: When you change replication type to Immediate, a majority of data centers must be operational for files to be accepted. This includes the following components: Global Mailbox Management Node, shared storage, Cassandra, ZooKeeper and WebSphere® MQ.
  4. Restart the Global Mailbox Client adapter (GMCA) in each Sterling B2B Integrator.
    You must restart in a rolling mode, that is, stop and start GMCA in one node, before moving to the next.
    Important: Issuing the stop request to the GMCA instructs Sterling B2B Integrator to refuse new requests and gracefully clean up state associated with the adapter. Optionally, Sterling B2B Integrator can be soft-stopped instead, which allows all pending protocol actions to complete or be saved for resumption before the adapter shuts down.