content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.bookkeeper.client;
  
  import com.google.common.util.concurrent.RateLimiter;
  import java.io.IOException;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.Semaphore;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.concurrent.atomic.AtomicReference;
  import java.util.stream.Collectors;
  import org.apache.bookkeeper.bookie.BookieShell.UpdateLedgerNotifier;
  import org.apache.bookkeeper.client.api.LedgerMetadata;
  import org.apache.bookkeeper.meta.LedgerManager;
  import org.apache.bookkeeper.net.BookieId;
  import org.apache.bookkeeper.versioning.Versioned;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Encapsulates updating the ledger metadata operation.
   */
  public class UpdateLedgerOp {
  
      private static final Logger LOG = LoggerFactory.getLogger(UpdateLedgerOp.class);
      private final LedgerManager lm;
      private final BookKeeperAdmin admin;
  
      public UpdateLedgerOp(final BookKeeper bkc, final BookKeeperAdmin admin) {
          this.lm = bkc.getLedgerManager();
          this.admin = admin;
      }
  
      /**
       * Update the bookie id present in the ledger metadata.
       *
       * @param oldBookieId
       *            current bookie id
       * @param newBookieId
       *            new bookie id
       * @param rate
       *            number of ledgers updating per second (default 5 per sec)
       * @param limit
       *            maximum number of ledgers to update (default: no limit). Stop
       *            update if reaching limit
       * @param progressable
       *            report progress of the ledger updates
       * @throws IOException
       *             if there is an error when updating bookie id in ledger
       *             metadata
       */
      public void updateBookieIdInLedgers(final BookieId oldBookieId, final BookieId newBookieId,
                                          final int rate, int maxOutstandingReads, final int limit,
                                          final UpdateLedgerNotifier progressable)
              throws IOException, InterruptedException {
  
          final AtomicInteger issuedLedgerCnt = new AtomicInteger();
          final AtomicInteger updatedLedgerCnt = new AtomicInteger();
          final CompletableFuture<Void> finalPromise = new CompletableFuture<>();
          final Set<CompletableFuture<?>> outstanding =
              Collections.newSetFromMap(new ConcurrentHashMap<CompletableFuture<?>, Boolean>());
          final RateLimiter throttler = RateLimiter.create(rate);
          final Semaphore outstandingReads = new Semaphore(maxOutstandingReads);
          final Iterator<Long> ledgerItr = admin.listLedgers().iterator();
  
          // iterate through all the ledgers
          while (ledgerItr.hasNext() && !finalPromise.isDone()
                 && (limit == Integer.MIN_VALUE || issuedLedgerCnt.get() < limit)) {
              // semaphore to control reads according to update throttling
              outstandingReads.acquire();
  
              final long ledgerId = ledgerItr.next();
              issuedLedgerCnt.incrementAndGet();
  
              CompletableFuture<Versioned<LedgerMetadata>> writePromise = lm.readLedgerMetadata(ledgerId)
                  .thenCompose((readMetadata) -> {
                      AtomicReference<Versioned<LedgerMetadata>> ref = new AtomicReference<>(readMetadata);
                      return new MetadataUpdateLoop(
                              lm, ledgerId,
                              ref::get,
                              (metadata) -> {
                                  return metadata.getAllEnsembles().values().stream()
                                      .flatMap(Collection::stream)
                                      .anyMatch(b -> b.equals(oldBookieId));
                              },
                              (metadata) -> {
                                  return replaceBookieInEnsembles(metadata, oldBookieId, newBookieId);
                              },
                              ref::compareAndSet, throttler).run();
                  });
  
              outstanding.add(writePromise);
              writePromise.whenComplete((metadata, ex) -> {
                          if (ex != null
                              && !(ex instanceof BKException.BKNoSuchLedgerExistsOnMetadataServerException)) {
                              String error = String.format("Failed to update ledger metadata %s, replacing %s with %s",
                                                           ledgerId, oldBookieId, newBookieId);
                              LOG.error(error, ex);
                              finalPromise.completeExceptionally(new IOException(error, ex));
                          } else {
                              LOG.info("Updated ledger {} metadata, replacing {} with {}",
                                       ledgerId, oldBookieId, newBookieId);
  
                              updatedLedgerCnt.incrementAndGet();
                              progressable.progress(updatedLedgerCnt.get(), issuedLedgerCnt.get());
                          }
                          outstandingReads.release();
                          outstanding.remove(writePromise);
                      });
          }
  
          CompletableFuture.allOf(outstanding.stream().toArray(CompletableFuture[]::new))
              .whenComplete((res, ex) -> {
                      if (ex != null) {
                          finalPromise.completeExceptionally(ex);
                      } else {
                          finalPromise.complete(null);
                      }
                  });
  
          try {
              finalPromise.get();
              LOG.info("Total number of ledgers issued={} updated={}",
                       issuedLedgerCnt.get(), updatedLedgerCnt.get());
          } catch (ExecutionException e) {
              String error = String.format("Error waiting for ledger metadata updates to complete (replacing %s with %s)",
                                           oldBookieId, newBookieId);
              LOG.info(error, e);
              if (e.getCause() instanceof IOException) {
                  throw (IOException) e.getCause();
              } else {
                  throw new IOException(error, e);
              }
          }
      }
  
      private static LedgerMetadata replaceBookieInEnsembles(LedgerMetadata metadata,
                                                             BookieId oldBookieId,
                                                             BookieId newBookieId) {
          LedgerMetadataBuilder builder = LedgerMetadataBuilder.from(metadata);
          for (Map.Entry<Long, ? extends List<BookieId>> e : metadata.getAllEnsembles().entrySet()) {
              List<BookieId> newEnsemble = e.getValue().stream()
                  .map(b -> b.equals(oldBookieId) ? newBookieId : b)
                  .collect(Collectors.toList());
              builder.replaceEnsembleEntry(e.getKey(), newEnsemble);
          }
  
          return builder.build();
      }
  }
  