Package com.yugabyte.ysql

Interface LoadBalancer

All Known Implementing Classes:

ClusterAwareLoadBalancer, TopologyAwareLoadBalancer

public interface LoadBalancer

An interface for any load balancing policy to implement. The LoadBalanceService invokes the implemented methods while processing a new connection request.

See Also:

• LoadBalanceService
• ClusterAwareLoadBalancer
• TopologyAwareLoadBalancer

Method Summary

Modifier and Type	Method	Description
String	getLeastLoadedServer(boolean newRequest, List<String> failedHosts, ArrayList<String> timedOutHosts)
int	getRefreshListSeconds()
boolean	isHostEligible(Map.Entry<String,LoadBalanceService.NodeInfo> e, Byte requestFlags)

Method Details

isHostEligible

boolean isHostEligible(Map.Entry<String,LoadBalanceService.NodeInfo> e,
 Byte requestFlags)

Parameters:

e - The LoadBalanceService.NodeInfo object for the host

requestFlags - The attributes for the load balancer to make use of

Returns:

true, if a host is eligible to be considered for a connection request

getLeastLoadedServer

String getLeastLoadedServer(boolean newRequest,
 List<String> failedHosts,
 ArrayList<String> timedOutHosts)

Parameters:

newRequest - whether this invocation is first for a new connection request

failedHosts - list of host names which have been known to be down

timedOutHosts - list of host names where connections were attempted but timed out

Returns:

the name of a host with the least number of connections, as per the driver's stats

getRefreshListSeconds

int getRefreshListSeconds()

Returns:

the value of the property "yb-servers-refresh-interval" specified either in the url or as a property