Package com.clickhouse.client

Interface ClickHouseNodeManager

All Superinterfaces:
Function<ClickHouseNodeSelector,ClickHouseNode>, Serializable
All Known Implementing Classes:
ClickHouseCluster, ClickHouseNodes
public interface ClickHouseNodeManager extends Function<ClickHouseNodeSelector,ClickHouseNode>, Serializable
Node manager is responsible for managing list of nodes and their status. It also runs scheduled tasks in background for node discovery and health check.

  • Method Details

    • getNodes

      List<ClickHouseNode> getNodes()
      Gets a copy of nodes, which in most cases are in healthy status. However, this really depends on how ClickHouseLoadBalancingPolicy manages node status. In first-alive policy, it's acutally a full list regardless node status.
      Returns:
      non-null nodes

    • getNodes

      List<ClickHouseNode> getNodes(ClickHouseNodeSelector selector, int groupSize)
      Gets a copy of filtered nodes.
      Parameters:
      selector - node selector for filtering out nodes, null means no filter
      groupSize - maximum number of nodes to get, zero or negative value means all
      Returns:
      non-null nodes

    • getFaultyNodes

      List<ClickHouseNode> getFaultyNodes()
      Gets a copy of faulty nodes.
      Returns:
      non-null faulty nodes

    • getFaultyNodes

      List<ClickHouseNode> getFaultyNodes(ClickHouseNodeSelector selector, int groupSize)
      Gets a copy of filtered faulty nodes.
      Parameters:
      selector - node selector for filtering out nodes, null means no filter
      groupSize - maximum number of nodes to get, zero or negative value means all
      Returns:
      non-null faulty nodes

    • getPolicy

      ClickHouseLoadBalancingPolicy getPolicy()
      Gets load balancing policy.
      Returns:
      non-null load balancing policy

    • getNodeSelector

      ClickHouseNodeSelector getNodeSelector()
      Gets node selector for filtering out nodes.
      Returns:
      non-null node selector

    • scheduleDiscovery

      Optional<ScheduledFuture<?>> scheduleDiscovery()
      Schedule node discovery task immediately. Nothing will happen when task scheduler does not exist(e.g. getPolicy().getScheduler() returns null) or there's a task running for node discovery.
      Returns:
      optional future for retrieving the running task

    • scheduleHealthCheck

      Optional<ScheduledFuture<?>> scheduleHealthCheck()
      Schedule node discovery task immediately. Nothing will happen when task scheduler does not exist(e.g. getPolicy().getScheduler() returns null) or there's a task running for health check.
      Returns:
      optional future for retrieving the running task

    • suggestNode

      ClickHouseNode suggestNode(ClickHouseNode server, Throwable failure)
      Suggests a different node in order to recover from a failure, which is usually a connection error.
      Parameters:
      server - node related to the failure(e.g. the node couldn't be connected)
      failure - recoverable failure
      Returns:
      non-null node which may or may not be same as the given one

    • update

      void update(ClickHouseNode node, ClickHouseNode.Status status)
      Updates node status to one of ClickHouseNode.Status. It simply delegates the call to getPolicy().update(node, status) in a thread-safe manner.
      Parameters:
      node - non-null node to update
      status - non-null status of the node

    • shutdown

      void shutdown()
      Shuts down scheduled tasks if any.