/**
* Update the assignment plan to all the region servers
*
* @param plan
* @throws IOException
*/
private void updateAssignmentPlanToRegionServers(FavoredNodesPlan plan) throws IOException {
LOG.info("Start to update the region servers with the new assignment plan");
// Get the region to region server map
Map<ServerName, List<HRegionInfo>> currentAssignment =
this.getRegionAssignmentSnapshot().getRegionServerToRegionMap();
// track of the failed and succeeded updates
int succeededNum = 0;
Map<ServerName, Exception> failedUpdateMap = new HashMap<ServerName, Exception>();
for (Map.Entry<ServerName, List<HRegionInfo>> entry : currentAssignment.entrySet()) {
List<Pair<HRegionInfo, List<ServerName>>> regionUpdateInfos =
new ArrayList<Pair<HRegionInfo, List<ServerName>>>();
try {
// Keep track of the favored updates for the current region server
FavoredNodesPlan singleServerPlan = null;
// Find out all the updates for the current region server
for (HRegionInfo region : entry.getValue()) {
List<ServerName> favoredServerList = plan.getFavoredNodes(region);
if (favoredServerList != null
&& favoredServerList.size() == FavoredNodeAssignmentHelper.FAVORED_NODES_NUM) {
// Create the single server plan if necessary
if (singleServerPlan == null) {
singleServerPlan = new FavoredNodesPlan();
}
// Update the single server update
singleServerPlan.updateAssignmentPlan(region, favoredServerList);
regionUpdateInfos.add(
new Pair<HRegionInfo, List<ServerName>>(region, favoredServerList));
}
}
if (singleServerPlan != null) {
// Update the current region server with its updated favored nodes
BlockingInterface currentRegionServer =
((ClusterConnection) this.connection).getAdmin(entry.getKey());
UpdateFavoredNodesRequest request =
RequestConverter.buildUpdateFavoredNodesRequest(regionUpdateInfos);
UpdateFavoredNodesResponse updateFavoredNodesResponse =
currentRegionServer.updateFavoredNodes(null, request);
LOG.info(
"Region server "
+ ProtobufUtil.getServerInfo(null, currentRegionServer).getServerName()
+ " has updated "
+ updateFavoredNodesResponse.getResponse()
+ " / "
+ singleServerPlan.getAssignmentMap().size()
+ " regions with the assignment plan");
succeededNum++;
}
} catch (Exception e) {
failedUpdateMap.put(entry.getKey(), e);
}
}
// log the succeeded updates
LOG.info("Updated " + succeededNum + " region servers with " + "the new assignment plan");
// log the failed updates
int failedNum = failedUpdateMap.size();
if (failedNum != 0) {
LOG.error(
"Failed to update the following + "
+ failedNum
+ " region servers with its corresponding favored nodes");
for (Map.Entry<ServerName, Exception> entry : failedUpdateMap.entrySet()) {
LOG.error(
"Failed to update "
+ entry.getKey().getHostAndPort()
+ " because of "
+ entry.getValue().getMessage());
}
}
}
