/**
* Only handles reroute but *without* any reassignment of unassigned shards or rebalancing. Does
* make sure to handle removed nodes, but only moved the shards to UNASSIGNED, does not reassign
* them.
*/
public RoutingAllocation.Result rerouteWithNoReassign(ClusterState clusterState, boolean debug) {
RoutingNodes routingNodes = clusterState.routingNodes();
// shuffle the unassigned nodes, just so we won't have things like poison failed shards
routingNodes.unassigned().shuffle();
RoutingAllocation allocation =
new RoutingAllocation(
allocationDeciders,
routingNodes,
clusterState.nodes(),
clusterInfoService.getClusterInfo());
allocation.debugDecision(debug);
boolean changed = false;
// first, clear from the shards any node id they used to belong to that is now dead
changed |= deassociateDeadNodes(allocation);
// create a sorted list of from nodes with least number of shards to the maximum ones
applyNewNodes(allocation);
// elect primaries *before* allocating unassigned, so backups of primaries that failed
// will be moved to primary state and not wait for primaries to be allocated and recovered
// (*from gateway*)
changed |= electPrimariesAndUnassignedDanglingReplicas(allocation);
if (!changed) {
return new RoutingAllocation.Result(false, clusterState.routingTable());
}
return new RoutingAllocation.Result(
true,
new RoutingTable.Builder()
.updateNodes(routingNodes)
.build()
.validateRaiseException(clusterState.metaData()));
}
public RoutingAllocation.Result reroute(
ClusterState clusterState, AllocationCommands commands, boolean explain)
throws ElasticsearchException {
RoutingNodes routingNodes = clusterState.routingNodes();
// we don't shuffle the unassigned shards here, to try and get as close as possible to
// a consistent result of the effect the commands have on the routing
// this allows systems to dry run the commands, see the resulting cluster state, and act on it
RoutingAllocation allocation =
new RoutingAllocation(
allocationDeciders,
routingNodes,
clusterState.nodes(),
clusterInfoService.getClusterInfo());
// don't short circuit deciders, we want a full explanation
allocation.debugDecision(true);
// we ignore disable allocation, because commands are explicit
allocation.ignoreDisable(true);
RoutingExplanations explanations = commands.execute(allocation, explain);
// we revert the ignore disable flag, since when rerouting, we want the original setting to take
// place
allocation.ignoreDisable(false);
// the assumption is that commands will move / act on shards (or fail through exceptions)
// so, there will always be shard "movements", so no need to check on reroute
reroute(allocation);
return new RoutingAllocation.Result(
true,
new RoutingTable.Builder()
.updateNodes(routingNodes)
.build()
.validateRaiseException(clusterState.metaData()),
explanations);
}
/**
* Reroutes the routing table based on the live nodes.
*
* <p>
*
* <p>If the same instance of the routing table is returned, then no change has been made.
*/
public RoutingAllocation.Result reroute(ClusterState clusterState, boolean debug) {
RoutingNodes routingNodes = clusterState.routingNodes();
// shuffle the unassigned nodes, just so we won't have things like poison failed shards
routingNodes.unassigned().shuffle();
RoutingAllocation allocation =
new RoutingAllocation(
allocationDeciders,
routingNodes,
clusterState.nodes(),
clusterInfoService.getClusterInfo());
allocation.debugDecision(debug);
if (!reroute(allocation)) {
return new RoutingAllocation.Result(false, clusterState.routingTable());
}
return new RoutingAllocation.Result(
true,
new RoutingTable.Builder()
.updateNodes(routingNodes)
.build()
.validateRaiseException(clusterState.metaData()));
}