Enabling and Disabling Handoff
Riak KV provides a command-line interface for enabling and disabling handoff on the fly, without needing to set your configuration and restart the node. To enable handoff:
riak-admin handoff enable <inbound|outbound|both> <nodename> You must specify two things when enabling handoff:
- whether you’d like to enable inbound handoff, outbound handoff, or both
- the node to be targeted by the command (or all nodes)
You can select a target node using either the --node or the -n flag. You can select a direction by specifying inbound, outbound, or both. The following equivalent commands would enable outbound handoff on the node riak3@100.0.0.1:
riak-admin handoff enable outbound --node riak3@100.0.0.1 riak-admin handoff enable outbound -n riak3@100.0.0.1 These two equivalent commands would enable inbound handoff on the node riak5@100.0.0.1:
riak-admin handoff enable inbound --node riak5@100.0.0.1 riak-admin handoff enable inbound -n riak5@127.0.0.1 Alternatively, you can enable handoff on all nodes at the same time using either the -a or --all flag. This command would enable both inbound and outbound handoff on all nodes:
riak-admin handoff enable both --all As for enabling handoff, the riak-admin disable command requires that you specify both both a node or nodes to be targeted by the command and whether you’d like to disable inbound handoff, outbound handoff, or both. The disable command works just like enable. This command would disable all forms of handoff on all nodes, to give just one example:
riak-admin handoff disable both --all Other Command-line Tools
In addition to enabling and disabling handoff, the riak-admin interface enables you to retrieve a summary of handoff-related activity and other information.
summary
The summary command provides high-level information about active handoffs in a cluster.
riak-admin handoff summary This will return a table that will provide the following information about each node in your cluster:
| Header | Description |
|---|---|
Node | The name of the node |
Total | Total number of active transfers throughout the entire cluster |
Ownership | Total number of ownership exchanges |
Resize | Total handoffs related to ring resizing operations (This should always be 0, as the Resize Ring feature has been deprecated) |
Hinted | Total number of hinted handoffs |
Repair | Total repair-related handoffs. More information can be found here. |
details
This command provides information only about active transfers.
riak-admin handoff details If no transfers are currently underway, this command will output No ongoing transfers. Otherwise, you will something like this:
config
This command displays the values for handoff-specific configurable parameters on each node in the cluster, including:
transfer_limithandoff.outboundhandoff.inboundhandoff.port
Descriptions of those parameters can be found in the sections above.