Package com.linkedin.venice.meta

Interface OnlineInstanceFinder

All Known Subinterfaces:

RoutingDataRepository

All Known Implementing Classes:

HelixBaseRoutingRepository, HelixCustomizedViewOfflinePushRepository, HelixExternalViewRepository

public interface OnlineInstanceFinder

Look up online instances related to a topic's partition. It's used in Venice router to help route requests to a certain host. Check out VeniceVersionFinder and VeniceHostFinder for more details. Currently, there are 2 implementations based on different sources of metadata: 1. HelixCustomizedViewOfflinePushRepository used in Router. 2. HelixExternalViewRepository used in Controller and Server.

Method Summary

Modifier and Type	Method	Description
java.util.Map<ExecutionStatus,java.util.List<Instance>>	getAllInstances(java.lang.String kafkaTopic, int partitionId)	Query instances that belong to given kafka topic and partition.
int	getNumberOfPartitions(java.lang.String kafkaTopic)	Query number of partition in given kafka topic.
java.util.List<Instance>	getReadyToServeInstances(PartitionAssignment partitionAssignment, int partitionId)	Look for ready to serve instances on the given partition assignment.
java.util.List<Instance>	getReadyToServeInstances(java.lang.String kafkaTopic, int partitionId)	Query instances that belong to given kafka topic and partition.
java.util.List<Instance>	getWorkingInstances(java.lang.String kafkaTopic, int partitionId)	Query instances that are online (in leader or follower state), but not necessarily ready to serve yet.

Method Detail

getReadyToServeInstances

java.util.List<Instance> getReadyToServeInstances(java.lang.String kafkaTopic,
                                                  int partitionId)

Query instances that belong to given kafka topic and partition. All of instances in result are ready to serve.

getReadyToServeInstances

java.util.List<Instance> getReadyToServeInstances(PartitionAssignment partitionAssignment,
                                                  int partitionId)

Look for ready to serve instances on the given partition assignment. This is normally used to predict if a potential partition assignment will cause any replica unavailability issue

getWorkingInstances

java.util.List<Instance> getWorkingInstances(java.lang.String kafkaTopic,
                                             int partitionId)

Query instances that are online (in leader or follower state), but not necessarily ready to serve yet.

getAllInstances

java.util.Map<ExecutionStatus,java.util.List<Instance>> getAllInstances(java.lang.String kafkaTopic,
                                                                              int partitionId)

Query instances that belong to given kafka topic and partition.

Returns:

a map that has HelixState as the key and list of instances as the value

getNumberOfPartitions

int getNumberOfPartitions(java.lang.String kafkaTopic)

Query number of partition in given kafka topic.