somandal commented on code in PR #15050: URL: https://github.com/apache/pinot/pull/15050#discussion_r1960750727
########## pinot-controller/src/main/java/org/apache/pinot/controller/helix/core/rebalance/TableRebalancer.java: ########## @@ -559,6 +588,147 @@ private RebalanceResult doRebalance(TableConfig tableConfig, RebalanceConfig reb } } + private long calculateTableSizePerReplicaInBytes(String tableNameWithType) { + long tableSizePerReplicaInBytes = -1; + if (_tableSizeReader == null) { + LOGGER.warn("tableSizeReader is null, cannot calculate table size for table {}!", tableNameWithType); + return tableSizePerReplicaInBytes; + } + try { + TableSizeReader.TableSubTypeSizeDetails tableSizeDetails = + _tableSizeReader.getTableSubtypeSize(tableNameWithType, 30_000); + tableSizePerReplicaInBytes = tableSizeDetails._reportedSizePerReplicaInBytes; + } catch (InvalidConfigException e) { + String errMsg = String.format("Caught exception while trying to fetch table size details for table: %s", + tableNameWithType); + LOGGER.error(errMsg, e); + } + return tableSizePerReplicaInBytes; + } + + private RebalanceSummaryResult calculateDryRunSummary(Map<String, Map<String, String>> currentAssignment, + Map<String, Map<String, String>> targetAssignment, String tableNameWithType, String rebalanceJobId) { + LOGGER.info("Calculating rebalance summary for table: {} with rebalanceJobId: {}", + tableNameWithType, rebalanceJobId); + int existingReplicationFactor = 0; + int newReplicationFactor = 0; + Map<String, Set<String>> existingServersToSegmentMap = new HashMap<>(); + Map<String, Set<String>> newServersToSegmentMap = new HashMap<>(); + + for (Map.Entry<String, Map<String, String>> entrySet : currentAssignment.entrySet()) { + existingReplicationFactor = entrySet.getValue().size(); + for (Map.Entry<String, String> segmentEntrySet : entrySet.getValue().entrySet()) { + existingServersToSegmentMap.putIfAbsent(segmentEntrySet.getKey(), new HashSet<>()); + existingServersToSegmentMap.get(segmentEntrySet.getKey()).add(entrySet.getKey()); + } + } + + for (Map.Entry<String, Map<String, String>> entrySet : targetAssignment.entrySet()) { + newReplicationFactor = entrySet.getValue().size(); + for (Map.Entry<String, String> segmentEntrySet : entrySet.getValue().entrySet()) { + newServersToSegmentMap.putIfAbsent(segmentEntrySet.getKey(), new HashSet<>()); + newServersToSegmentMap.get(segmentEntrySet.getKey()).add(entrySet.getKey()); + } + } + RebalanceSummaryResult.RebalanceChangeInfo replicationFactor + = new RebalanceSummaryResult.RebalanceChangeInfo(existingReplicationFactor, newReplicationFactor); + + int existingNumServers = existingServersToSegmentMap.keySet().size(); + int newNumServers = newServersToSegmentMap.keySet().size(); + RebalanceSummaryResult.RebalanceChangeInfo numServers + = new RebalanceSummaryResult.RebalanceChangeInfo(existingNumServers, newNumServers); + + List<InstanceConfig> instanceConfigs = _helixDataAccessor.getChildValues( + _helixDataAccessor.keyBuilder().instanceConfigs(), true); + Map<String, List<String>> instanceToTagsMap = new HashMap<>(); + for (InstanceConfig instanceConfig : instanceConfigs) { + instanceToTagsMap.put(instanceConfig.getInstanceName(), instanceConfig.getTags()); + } + + Map<String, RebalanceSummaryResult.ServerSegmentChangeInfo> serverSegmentChangeInfoMap = new HashMap<>(); + int segmentsNotMoved = 0; + int numServersGettingDataAdded = 0; + for (Map.Entry<String, Set<String>> entry : newServersToSegmentMap.entrySet()) { + String server = entry.getKey(); + Set<String> segmentMap = entry.getValue(); + int totalNewSegments = segmentMap.size(); + + Set<String> newSegmentList = new HashSet<>(segmentMap); + Set<String> existingSegmentList = new HashSet<>(); + int segmentsUnchanged = 0; + int totalExistingSegments = 0; + RebalanceSummaryResult.ServerStatus serverStatus = RebalanceSummaryResult.ServerStatus.ADDED; + if (existingServersToSegmentMap.containsKey(server)) { + totalExistingSegments = existingServersToSegmentMap.get(server).size(); + existingSegmentList.addAll(existingServersToSegmentMap.get(server)); + Set<String> intersection = new HashSet<>(existingServersToSegmentMap.get(server)); + intersection.retainAll(newSegmentList); + segmentsUnchanged = intersection.size(); + segmentsNotMoved += segmentsUnchanged; + serverStatus = RebalanceSummaryResult.ServerStatus.UNCHANGED; + } + newSegmentList.removeAll(existingSegmentList); + int segmentsAdded = newSegmentList.size(); + int segmentsDeleted = existingSegmentList.size() - segmentsUnchanged; + numServersGettingDataAdded += segmentsAdded > 0 ? 1 : 0; + + serverSegmentChangeInfoMap.put(server, new RebalanceSummaryResult.ServerSegmentChangeInfo(serverStatus, + totalNewSegments, totalExistingSegments, segmentsAdded, segmentsDeleted, segmentsUnchanged, + instanceToTagsMap.getOrDefault(server, null))); + } + + for (Map.Entry<String, Set<String>> entry : existingServersToSegmentMap.entrySet()) { + String server = entry.getKey(); + if (!serverSegmentChangeInfoMap.containsKey(server)) { + serverSegmentChangeInfoMap.put(server, new RebalanceSummaryResult.ServerSegmentChangeInfo( + RebalanceSummaryResult.ServerStatus.REMOVED, 0, entry.getValue().size(), 0, entry.getValue().size(), 0, + instanceToTagsMap.getOrDefault(server, null))); + } + } + + RebalanceSummaryResult.RebalanceChangeInfo numSegmentsInSingleReplica + = new RebalanceSummaryResult.RebalanceChangeInfo(currentAssignment.size(), targetAssignment.size()); + + int existingNumberSegmentsTotal = existingReplicationFactor * currentAssignment.size(); + int newNumberSegmentsTotal = newReplicationFactor * targetAssignment.size(); + RebalanceSummaryResult.RebalanceChangeInfo numSegmentsAcrossAllReplicas + = new RebalanceSummaryResult.RebalanceChangeInfo(existingNumberSegmentsTotal, newNumberSegmentsTotal); + + int totalSegmentsToBeMoved = newNumberSegmentsTotal - segmentsNotMoved; + + long tableSizePerReplicaInBytes = calculateTableSizePerReplicaInBytes(tableNameWithType); + long averageSegmentSizeInBytes = tableSizePerReplicaInBytes <= 0 ? tableSizePerReplicaInBytes + : tableSizePerReplicaInBytes / ((long) currentAssignment.size()); + long totalEstimatedDataToBeMovedInBytes = tableSizePerReplicaInBytes <= 0 ? tableSizePerReplicaInBytes + : ((long) totalSegmentsToBeMoved) * averageSegmentSizeInBytes; + double estimatedTimeToRebalanceInSec = getEstimatedTimeToRebalanceInSec(totalEstimatedDataToBeMovedInBytes, + numServersGettingDataAdded); + + RebalanceSummaryResult.ServerInfo serverInfo = new RebalanceSummaryResult.ServerInfo(numServersGettingDataAdded, + numServers, serverSegmentChangeInfoMap); + RebalanceSummaryResult.SegmentInfo segmentInfo = new RebalanceSummaryResult.SegmentInfo(totalSegmentsToBeMoved, + averageSegmentSizeInBytes, totalEstimatedDataToBeMovedInBytes, estimatedTimeToRebalanceInSec, + replicationFactor, numSegmentsInSingleReplica, numSegmentsAcrossAllReplicas); + + LOGGER.info("Calculated rebalance summary for table: {} with rebalanceJobId: {}", tableNameWithType, + rebalanceJobId); + return new RebalanceSummaryResult(serverInfo, segmentInfo); + } + + private static double getEstimatedTimeToRebalanceInSec(long totalEstimatedDataToBeMovedInBytes, + int numServersGettingDataAdded) { + double estimatedTimeToRebalanceInSec = totalEstimatedDataToBeMovedInBytes == 0 ? 0.0 : -1.0; + if (totalEstimatedDataToBeMovedInBytes > 0 && numServersGettingDataAdded > 0) { + // Do some processing to figure out what the time to download might be + // Assume that data is evenly distributed across all servers + long totalDataPerServerInBytes = totalEstimatedDataToBeMovedInBytes / numServersGettingDataAdded; + // TODO: Pick a good threshold to calculate estimated time to rebalance. For now assume 100 MB/s data download + // + process rate + estimatedTimeToRebalanceInSec = ((double) totalDataPerServerInBytes) / (100.0D * 1024.0D * 1024.0D); Review Comment: yeah, this is a tricky field for sure. I've removed it for now, but added a TODO for adding it back once we have a better understanding of a good estimate. This field was an ask for this summary PR. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org