Module resty.cassandra.policies.lb.req_dc_rr
Request and datacenter-aware round robin load balancing policy for OpenResty.
This policy will try to reuse the same node for the lifecycle of a given request if possible. It is mostly designed for use in OpenResty environments.
This ensures that the underlying connection pool to the node is reused as much as possible. If a new node is chosen for every query, there is no guarantee that each selected node will already have a pre-established connection. Since this policy reuses the same node for the lifecycle of a request, the chances of having to open a new connection are much reduced.
Since this policy is also datacenter-aware, it will prioritize nodes in the local datacenter as well (when no node has been elected for a given request yet).
Info:
- Author: kikito
Functions
| new (local_dc) | Create a request and DC-aware round robin policy. |
Functions
- new (local_dc)
-
Create a request and DC-aware round robin policy.
Instanciates a request and DC-aware round robin policy for
resty.cassandra.cluster.
Parameters:
- local_dc string Name of the local/closest datacenter.
Returns:
-
table
policy: A DC-aware round robin policy.Usage:
local Cluster = require "resty.cassandra.cluster" local req_dc_rr = require "resty.cassandra.policies.lb.req_dc_rr" local policy = req_dc_rr.new("my_local_cluster_name") local cluster = assert(Cluster.new { lb_policy = policy })