Versions Compared

Version Old Version 19 New Version Current
Changes made by

SungEun Kim

이하늘

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Info
  • If the application failed to shut down, or if the handles of the files to be replicated were demoted to open, writes to these unorganized files on the target could fail, even if the demotion was successful. This is because if the target's files are already open in read mode, the FSR engine has no control over them because it doesn't have write permissions. To prevent this from happening, FSR 1.2 forces all already open file handles to be closed upon file locking.
  • We've also decided to deprecate the read-only locking feature previously provided by FSR, to prevent potential issues where a read-only lock would cause the target's engine to fail to write due to allowing reading. Filelocks now only provide full locking (locking all open, read, and write).


Switchover


A switchover is the manual exchange of access to resources from one system to another within a replication cluster. It is the process of demoting a source node and promoting a target node to the source node role to enable data for a service. Also known as manual switchover, the opposite of this is failover, which is an automatic response to a failure.

Demote the resource on the source node.

...

Resource roles can be changed based on operational circumstances, but sometimes you may want to keep a role persistent. (FSR 1.2.4 and later)
A resource with persist-_role set will continue to have the resource role explicitly specified(with the fsradm command) at the time of restart. This works in any situation where the replication service or system reboots, causing the resource to restart.

Code Block
{
	...
	"options": {
		"persist-_role": true,
		...
	}

}


One-way Replications

If you always want only one-way replication/backup from the primary to the secondary node, without switching over, consider the target-_only attribute on the standby node side. (FSR 1.2.4 and later)

  • Set the persist-_role attribute described above in the resource options section to fix the roles of the primary and secondary nodes.
  • Set the target-_only attribute on the standby node side to force the replication/synchronization direction from the primary node to the standby node only.

A target-_only node is prohibited from having the source role in all replication/sync operations, including explicit commands, and can only have the target role. Any manual synchronization or promotion commands that act as a source role are blocked (but promotion is allowed on replication disconnect).

...

Code Block
{
	...
	"options": {
		"persist-_role": true,
		...
	}

	"nodes": [
	{
		"name": "active",
		...
	},
	{
		"name": "standby",
		"target-_only": true
		...
	}
}


Info
titleVerify data on target-only nodes

After disconnecting replication

  • You can view the data by unlocking the file.
  • You can also verify the data by promoting it.
    • At the time you promote to verify data, an SB has occurred, so to get replication back to normal, demote again and process as Resolve SB.

...