protected void updateLoad(
final Map<ServerName, ServerAndLoad> map, final ServerName sn, final int diff) {
ServerAndLoad sal = map.get(sn);
if (sal == null) sal = new ServerAndLoad(sn, 0);
sal = new ServerAndLoad(sn, sal.getLoad() + diff);
map.put(sn, sal);
}
/**
* This assumes the RegionPlan HSI instances are the same ones in the map, so actually no need to
* even pass in the map, but I think it's clearer.
*
* @param list
* @param plans
* @return
*/
protected List<ServerAndLoad> reconcile(
List<ServerAndLoad> list,
List<RegionPlan> plans,
Map<ServerName, List<HRegionInfo>> servers) {
List<ServerAndLoad> result = new ArrayList<ServerAndLoad>(list.size());
Map<ServerName, ServerAndLoad> map = new HashMap<ServerName, ServerAndLoad>(list.size());
for (ServerAndLoad sl : list) {
map.put(sl.getServerName(), sl);
}
if (plans != null) {
for (RegionPlan plan : plans) {
ServerName source = plan.getSource();
updateLoad(map, source, -1);
ServerName destination = plan.getDestination();
updateLoad(map, destination, +1);
servers.get(source).remove(plan.getRegionInfo());
servers.get(destination).add(plan.getRegionInfo());
}
}
result.clear();
result.addAll(map.values());
return result;
}
/** Invariant is that all servers have between acceptable range number of regions. */
public boolean assertClusterOverallAsBalanced(List<ServerAndLoad> servers, int tablenum) {
int numServers = servers.size();
int numRegions = 0;
int maxRegions = 0;
int minRegions = Integer.MAX_VALUE;
for (ServerAndLoad server : servers) {
int nr = server.getLoad();
if (nr > maxRegions) {
maxRegions = nr;
}
if (nr < minRegions) {
minRegions = nr;
}
numRegions += nr;
}
if (maxRegions - minRegions < 2) {
// less than 2 between max and min, can't balance
return true;
}
int min = numRegions / numServers;
int max = numRegions % numServers == 0 ? min : min + 1;
for (ServerAndLoad server : servers) {
if (server.getLoad() < 0
|| server.getLoad() > max + tablenum / 2 + 1
|| server.getLoad() < min - tablenum / 2 - 1) return false;
}
return true;
}
/** Invariant is that all servers have between floor(avg) and ceiling(avg) number of regions. */
public void assertClusterAsBalanced(List<ServerAndLoad> servers) {
int numServers = servers.size();
int numRegions = 0;
int maxRegions = 0;
int minRegions = Integer.MAX_VALUE;
for (ServerAndLoad server : servers) {
int nr = server.getLoad();
if (nr > maxRegions) {
maxRegions = nr;
}
if (nr < minRegions) {
minRegions = nr;
}
numRegions += nr;
}
if (maxRegions - minRegions < 2) {
// less than 2 between max and min, can't balance
return;
}
int min = numRegions / numServers;
int max = numRegions % numServers == 0 ? min : min + 1;
for (ServerAndLoad server : servers) {
assertTrue(server.getLoad() >= 0);
assertTrue(server.getLoad() <= max);
assertTrue(server.getLoad() >= min);
}
}
protected TreeMap<ServerName, List<HRegionInfo>> mockUniformClusterServers(int[] mockCluster) {
int numServers = mockCluster.length;
TreeMap<ServerName, List<HRegionInfo>> servers = new TreeMap<ServerName, List<HRegionInfo>>();
for (int i = 0; i < numServers; i++) {
int numRegions = mockCluster[i];
ServerAndLoad sal = randomServer(0);
List<HRegionInfo> regions = uniformRegions(numRegions);
servers.put(sal.getServerName(), regions);
}
return servers;
}
protected String printStats(List<ServerAndLoad> servers) {
int numServers = servers.size();
int totalRegions = 0;
for (ServerAndLoad server : servers) {
totalRegions += server.getLoad();
}
float average = (float) totalRegions / numServers;
int max = (int) Math.ceil(average);
int min = (int) Math.floor(average);
return "[srvr="
+ numServers
+ " rgns="
+ totalRegions
+ " avg="
+ average
+ " max="
+ max
+ " min="
+ min
+ "]";
}
