package voldemort.tools;
import java.io.File;
import java.io.IOException;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import joptsimple.OptionException;
import joptsimple.OptionParser;
import joptsimple.OptionSet;
import org.apache.log4j.Logger;
import voldemort.cluster.Cluster;
import voldemort.cluster.Zone;
import voldemort.store.StoreDefinition;
import voldemort.utils.CmdUtils;
import voldemort.utils.RebalanceUtils;
import voldemort.utils.Utils;
import voldemort.xml.ClusterMapper;
import voldemort.xml.StoreDefinitionsMapper;
import com.google.common.base.Joiner;
/*
* This tool accepts a source cluster.xml-stores.xml pair and a zone id that
* ought to be dropped. It then intelligently moves the partitions that are
* hosted in the zone being removed to the other zones such that it leads to no
* data movement.
*
* The partitions are moved to nodes in the surviving zones that is zone-nry to
* that partition in the surviving zone.
*
* Finally it drops the zone and the corresponding nodes that belong to the zone
* and writes a final-cluster.xml and final-stores.xml in the output directory.
*/
public class ZoneClipperCLI {
private static final Logger logger = Logger.getLogger(ZoneClipperCLI.class);
private static OptionParser parser;
private static void setupParser() {
parser = new OptionParser();
parser.accepts("help", "Print usage information");
parser.accepts("current-cluster", "Path to current cluster xml")
.withRequiredArg()
.describedAs("cluster.xml");
parser.accepts("current-stores", "Path to current stores xml")
.withRequiredArg()
.describedAs("stores.xml");
parser.accepts("output-dir", "Specify the output directory for the new cluster.xml")
.withRequiredArg()
.ofType(String.class)
.describedAs("path");
parser.accepts("drop-zoneid", "Zone id that you want to drop.")
.withRequiredArg()
.describedAs("zoneid-to-drop")
.ofType(Integer.class);
}
private static void printUsage() {
StringBuilder help = new StringBuilder();
help.append("ZoneClipperCLI\n");
help.append(" Drops specific zone and corresponding nodes from the cluster\n");
help.append("Options:\n");
help.append(" Required:\n");
help.append(" --current-cluster <clusterXML>\n");
help.append(" --current-stores <storesXML>\n");
help.append(" --drop-zoneid zoneId \n");
help.append(" Optional:\n");
help.append(" --output-dir [ Output directory is where we store the final cluster/stores xml ]\n");
try {
parser.printHelpOn(System.out);
} catch(IOException e) {
e.printStackTrace();
}
System.out.print(help.toString());
}
private static void printUsageAndDie(String errMessage) {
printUsage();
Utils.croak("\n" + errMessage);
}
private static OptionSet getValidOptions(String[] args) {
OptionSet options = null;
try {
options = parser.parse(args);
} catch(OptionException oe) {
printUsageAndDie("Exception when parsing arguments : " + oe.getMessage());
}
if(options.has("help")) {
printUsage();
System.exit(0);
}
Set<String> missing = CmdUtils.missing(options,
"current-cluster",
"current-stores",
"drop-zoneid");
if(missing.size() > 0) {
printUsageAndDie("Missing required arguments: " + Joiner.on(", ").join(missing));
}
return options;
}
public static void main(String[] args) throws Exception {
setupParser();
OptionSet options = getValidOptions(args);
int dropZoneId = CmdUtils.valueOf(options, "drop-zoneid", Zone.UNSET_ZONE_ID);
String outputDir = null;
if(options.has("output-dir")) {
outputDir = (String) options.valueOf("output-dir");
}
/*
* A. Generate the clipped cluster.xml
*/
String initialClusterXML = (String) options.valueOf("current-cluster");
Cluster initialCluster = new ClusterMapper().readCluster(new File(initialClusterXML));
// Create a list of current partition ids. We will use this set to
// compare partitions ids in final cluster
Set<Integer> originalPartitions = new HashSet<Integer>();
for(Integer zoneId: initialCluster.getZoneIds()) {
originalPartitions.addAll(initialCluster.getPartitionIdsInZone(zoneId));
}
// Get an intermediate cluster where partitions that belong to the zone
// that is being dropped have been moved to the existing zones
Cluster intermediateCluster = RebalanceUtils.vacateZone(initialCluster, dropZoneId);
Cluster finalCluster = RebalanceUtils.dropZone(intermediateCluster, dropZoneId);
// Make sure everything is fine
if(initialCluster.getNumberOfPartitions() != finalCluster.getNumberOfPartitions()) {
logger.error("The number of partitions in the initial and the final cluster is not equal \n");
}
Set<Integer> finalPartitions = new HashSet<Integer>();
for(Integer zoneId: finalCluster.getZoneIds()) {
finalPartitions.addAll(finalCluster.getPartitionIdsInZone(zoneId));
}
// Compare to original partition ids list
if(!originalPartitions.equals(finalPartitions)) {
logger.error("The list of partition ids in the initial and the final cluster doesn't match \n ");
}
// Finally write the final cluster to a xml file
RebalanceUtils.dumpClusterToFile(outputDir,
RebalanceUtils.finalClusterFileName,
finalCluster);
/*
* B. Generate the clipped stores.xml
*/
logger.info("Generating the adjusted stores.xml..");
String initialStoresXML = (String) options.valueOf("current-stores");
List<StoreDefinition> initialStoreDefs = new StoreDefinitionsMapper().readStoreList(new File(initialStoresXML));
List<StoreDefinition> finalStoreDefs = RebalanceUtils.dropZone(initialStoreDefs, dropZoneId);
RebalanceUtils.dumpStoreDefsToFile(outputDir,
RebalanceUtils.finalStoresFileName,
finalStoreDefs);
}
}