Java MetaReader.Visitor方法代码示例

import org.apache.hadoop.hbase.catalog.MetaReader; //导入方法依赖的package包/类
void fixupDaughters(final MonitoredTask status) throws IOException, KeeperException {
  final Map<HRegionInfo, Result> offlineSplitParents =
    new HashMap<HRegionInfo, Result>();
  // This visitor collects offline split parents in the .META. table
  MetaReader.Visitor visitor = new MetaReader.Visitor() {
    @Override
    public boolean visit(Result r) throws IOException {
      if (r == null || r.isEmpty()) return true;
      HRegionInfo info =
        MetaReader.parseHRegionInfoFromCatalogResult(
          r, HConstants.REGIONINFO_QUALIFIER);
      if (info == null) return true; // Keep scanning
      if (info.isOffline() && info.isSplit()) {
        offlineSplitParents.put(info, r);
      }
      // Returning true means "keep scanning"
      return true;
    }
  };
  // Run full scan of .META. catalog table passing in our custom visitor
  MetaReader.fullScan(this.catalogTracker, visitor);
  // Now work on our list of found parents. See if any we can clean up.
  int fixups = 0;
  for (Map.Entry<HRegionInfo, Result> e : offlineSplitParents.entrySet()) {
    String node = ZKAssign.getNodeName(zooKeeper, e.getKey().getEncodedName());
    byte[] data = ZKUtil.getData(zooKeeper, node);
    if (data == null) { // otherwise, splitting is still going on, skip it
      fixups += ServerShutdownHandler.fixupDaughters(
        e.getValue(), assignmentManager, catalogTracker);
    }
  }
  if (fixups != 0) {
    LOG.info("Scanned the catalog and fixed up " + fixups +
      " missing daughter region(s)");
  }
}
 

import org.apache.hadoop.hbase.catalog.MetaReader; //导入方法依赖的package包/类
/**
 * Run janitorial scan of catalog <code>.META.</code> table looking for
 * garbage to collect.
 * @throws IOException
 */
void scan() throws IOException {
  // TODO: Only works with single .META. region currently.  Fix.
  final AtomicInteger count = new AtomicInteger(0);
  // Keep Map of found split parents.  There are candidates for cleanup.
  // Use a comparator that has split parents come before its daughters.
  final Map<HRegionInfo, Result> splitParents =
    new TreeMap<HRegionInfo, Result>(new SplitParentFirstComparator());
  // This visitor collects split parents and counts rows in the .META. table
  MetaReader.Visitor visitor = new MetaReader.Visitor() {
    @Override
    public boolean visit(Result r) throws IOException {
      if (r == null || r.isEmpty()) return true;
      count.incrementAndGet();
      HRegionInfo info = getHRegionInfo(r);
      if (info == null) return true; // Keep scanning
      if (info.isSplitParent()) splitParents.put(info, r);
      // Returning true means "keep scanning"
      return true;
    }
  };
  // Run full scan of .META. catalog table passing in our custom visitor
  MetaReader.fullScan(this.server.getCatalogTracker(), visitor);
  // Now work on our list of found parents. See if any we can clean up.
  int cleaned = 0;
  for (Map.Entry<HRegionInfo, Result> e : splitParents.entrySet()) {
    if (cleanParent(e.getKey(), e.getValue())) cleaned++;
  }
  if (cleaned != 0) {
    LOG.info("Scanned " + count.get() + " catalog row(s) and gc'd " + cleaned +
      " unreferenced parent region(s)");
  } else if (LOG.isDebugEnabled()) {
    LOG.debug("Scanned " + count.get() + " catalog row(s) and gc'd " + cleaned +
    " unreferenced parent region(s)");
  }
}
 

import org.apache.hadoop.hbase.catalog.MetaReader; //导入方法依赖的package包/类
void fixupDaughters(final MonitoredTask status) throws IOException {
  final Map<HRegionInfo, Result> offlineSplitParents =
    new HashMap<HRegionInfo, Result>();
  // This visitor collects offline split parents in the .META. table
  MetaReader.Visitor visitor = new MetaReader.Visitor() {
    @Override
    public boolean visit(Result r) throws IOException {
      if (r == null || r.isEmpty()) return true;
      HRegionInfo info =
        MetaReader.parseHRegionInfoFromCatalogResult(
          r, HConstants.REGIONINFO_QUALIFIER);
      if (info == null) return true; // Keep scanning
      if (info.isOffline() && info.isSplit()) {
        offlineSplitParents.put(info, r);
      }
      // Returning true means "keep scanning"
      return true;
    }
  };
  // Run full scan of .META. catalog table passing in our custom visitor
  MetaReader.fullScan(this.catalogTracker, visitor);
  // Now work on our list of found parents. See if any we can clean up.
  int fixups = 0;
  for (Map.Entry<HRegionInfo, Result> e : offlineSplitParents.entrySet()) {
    fixups += ServerShutdownHandler.fixupDaughters(
        e.getValue(), assignmentManager, catalogTracker);
  }
  if (fixups != 0) {
    LOG.info("Scanned the catalog and fixed up " + fixups +
      " missing daughter region(s)");
  }
}