// for each of the non system tables calculating new ranges
// which current node will handle after move to the new token
for (String table : tablesToProcess)
{
// replication strategy of the current keyspace (aka table)
AbstractReplicationStrategy strategy = Table.open(table).getReplicationStrategy();
// getting collection of the currently used ranges by this keyspace
Collection<Range<Token>> currentRanges = getRangesForEndpoint(table, localAddress);
// collection of ranges which this node will serve after move to the new token
Collection<Range<Token>> updatedRanges = strategy.getPendingAddressRanges(tokenMetadata_, newToken, localAddress);
// ring ranges and endpoints associated with them
// this used to determine what nodes should we ping about range data
Multimap<Range<Token>, InetAddress> rangeAddresses = strategy.getRangeAddresses(tokenMetadata_);
// calculated parts of the ranges to request/stream from/to nodes in the ring
Pair<Set<Range<Token>>, Set<Range<Token>>> rangesPerTable = calculateStreamAndFetchRanges(currentRanges, updatedRanges);
/**
* In this loop we are going through all ranges "to fetch" and determining
* nodes in the ring responsible for data we are interested in
*/
Multimap<Range<Token>, InetAddress> rangesToFetchWithPreferredEndpoints = ArrayListMultimap.create();
for (Range<Token> toFetch : rangesPerTable.right)
{
for (Range<Token> range : rangeAddresses.keySet())
{
if (range.contains(toFetch))
{
List<InetAddress> endpoints = snitch.getSortedListByProximity(localAddress, rangeAddresses.get(range));
// storing range and preferred endpoint set
rangesToFetchWithPreferredEndpoints.putAll(toFetch, endpoints);
}
}
}
// calculating endpoints to stream current ranges to if needed
// in some situations node will handle current ranges as part of the new ranges
Multimap<Range<Token>, InetAddress> rangeWithEndpoints = HashMultimap.create();
for (Range<Token> toStream : rangesPerTable.left)
{
Set<InetAddress> currentEndpoints = ImmutableSet.copyOf(strategy.calculateNaturalEndpoints(toStream.right, tokenMetadata_));
Set<InetAddress> newEndpoints = ImmutableSet.copyOf(strategy.calculateNaturalEndpoints(toStream.right, tokenMetaClone));
rangeWithEndpoints.putAll(toStream, Sets.difference(newEndpoints, currentEndpoints));
}
// associating table with range-to-endpoints map
rangesToStreamByTable.put(table, rangeWithEndpoints);