Index: hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/RecoverableZooKeeper.java =================================================================== --- hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/RecoverableZooKeeper.java (revision 1577027) +++ hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/RecoverableZooKeeper.java (working copy) @@ -720,4 +720,37 @@ public String getIdentifier() { return identifier; } + + /** + * BFS Traversal of all the children under path, with the entries in the list, in the same order as + * that of the traversal. This is an idempotent operation. Retry before throwing exception + * + * @return List of children znodes under the path + */ + public List getAllChildrenBFS(String path) throws KeeperException, InterruptedException { + TraceScope traceScope = null; + try { + traceScope = Trace.startSpan("RecoverableZookeeper.getAllChildrenBFS"); + RetryCounter retryCounter = retryCounterFactory.create(); + while (true) { + try { + return org.apache.zookeeper.ZKUtil.listSubTreeBFS(zk, path); + } catch (KeeperException e) { + switch (e.code()) { + case CONNECTIONLOSS: + case SESSIONEXPIRED: + case OPERATIONTIMEOUT: + retryOrThrow(retryCounter, e, "getAllChildrenBFS"); + break; + + default: + throw e; + } + } + retryCounter.sleepUntilNextRetry(); + } + } finally { + if (traceScope != null) traceScope.close(); + } + } } Index: hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java =================================================================== --- hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java (revision 1577027) +++ hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java (working copy) @@ -1328,20 +1328,76 @@ } /** - * Delete all the children of the specified node but not the node itself. + * Delete all the children of the specified node but not the node itself. Sets no watches. Throws + * all exceptions besides dealing with deletion of children. * - * Sets no watches. Throws all exceptions besides dealing with deletion of - * children. + * If hbase.zookeeper.useMulti is true, use ZooKeeper's multi-update functionality. + * Otherwise, run the list of operations sequentially. + * + * @throws KeeperException */ public static void deleteChildrenRecursively(ZooKeeperWatcher zkw, String node) - throws KeeperException { - List children = ZKUtil.listChildrenNoWatch(zkw, node); - if (children == null || children.isEmpty()) return; - for(String child : children) { - deleteNodeRecursively(zkw, joinZNode(node, child)); + throws KeeperException { + deleteChildrenRecursivelyMultiOrSequential(zkw, false, node); + } + + /** + * Delete all the children of the specified nodes but not the nodes itself. Sets no watches. Throws + * all exceptions besides dealing with deletion of children. + * + * If hbase.zookeeper.useMulti is true, use ZooKeeper's multi-update functionality. + * Otherwise, run the list of operations sequentially. + * + * If all of the following are true: + * - runSequentialOnMultiFailure is true + * - hbase.zookeeper.useMulti is true + * - on calling multi, we get a ZooKeeper exception that can be handled by a sequential call(*) + * Then: + * - we retry the operations one-by-one (sequentially) + * + * @throws KeeperException + */ + public static void deleteChildrenRecursivelyMultiOrSequential(ZooKeeperWatcher zkw, + boolean runSequentialOnMultiFailure, String... pathRoots) throws KeeperException { + try { + if (pathRoots == null || pathRoots.length <= 0) { + LOG.warn("Given path is not valid!"); + return; + } + List opList = new ArrayList(); + List ops = new ArrayList(opList.size()); + for (String eachRoot : pathRoots) { + List children = getChildren(zkw, eachRoot); + for (String child : children) { + ops.add(ZKUtilOp.deleteNodeFailSilent(child)); + } + } + // atleast one element should exists + if (ops.size() > 0) { + multiOrSequential(zkw, ops, runSequentialOnMultiFailure); + } + } catch (InterruptedException ie) { + zkw.interruptedException(ie); } } + private static List getChildren(ZooKeeperWatcher zkw, final String path) + throws InterruptedException, KeeperException { + List tree = new ArrayList(); + try { + tree = zkw.getRecoverableZooKeeper().getAllChildrenBFS(path); + } catch (KeeperException.NoNodeException nne) { + LOG.debug("Given znode: " + path + " doesn't exists, ignoring!"); + } + List children = new ArrayList(tree.size()); + // Delete the leaves first and eventually get rid of the root + // Root element will be skipped and not added to this list + for (int i = tree.size() - 1; i > 0; --i) { + children.add(tree.get(i)); + } + return children; + } + /** * Represents an action taken by ZKUtil, e.g. createAndFailSilent. * These actions are higher-level than ZKOp actions, which represent