@Override
public Decision canAllocate(
ShardRouting shardRouting, RoutingNode node, RoutingAllocation allocation) {
if (shardRouting.unassigned()) {
// only for unassigned - we filter allocation right after the index creation ie. for shard
// shrinking etc. to ensure
// that once it has been allocated post API the replicas can be allocated elsewhere without
// user interaction
// this is a setting that can only be set within the system!
IndexMetaData indexMd = allocation.metaData().getIndexSafe(shardRouting.index());
DiscoveryNodeFilters initialRecoveryFilters = indexMd.getInitialRecoveryFilters();
if (initialRecoveryFilters != null
&& RecoverySource.isInitialRecovery(shardRouting.recoverySource().getType())
&& initialRecoveryFilters.match(node.node()) == false) {
String explanation =
(shardRouting.recoverySource().getType() == RecoverySource.Type.LOCAL_SHARDS)
? "initial allocation of the shrunken index is only allowed on nodes [%s] that hold a copy of every shard in the index"
: "initial allocation of the index is only allowed on nodes [%s]";
return allocation.decision(Decision.NO, NAME, explanation, initialRecoveryFilters);
}
}
return shouldFilter(shardRouting, node, allocation);
}
