ACCUMULO-4012 possible infinite loop when the base transaction is removed before scanning it
Project: http://git-wip-us.apache.org/repos/asf/accumulo/repo Commit: http://git-wip-us.apache.org/repos/asf/accumulo/commit/d301f4e2 Tree: http://git-wip-us.apache.org/repos/asf/accumulo/tree/d301f4e2 Diff: http://git-wip-us.apache.org/repos/asf/accumulo/diff/d301f4e2 Branch: refs/heads/master Commit: d301f4e29361522dab8a8e036a22553d62daa0a6 Parents: 7f50f60 Author: Eric C. Newton <eric.new...@gmail.com> Authored: Tue Sep 29 14:41:30 2015 -0400 Committer: Eric C. Newton <eric.new...@gmail.com> Committed: Tue Sep 29 14:41:30 2015 -0400 ---------------------------------------------------------------------- .../java/org/apache/accumulo/fate/ZooStore.java | 27 ++++++++++++++++---- 1 file changed, 22 insertions(+), 5 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/accumulo/blob/d301f4e2/fate/src/main/java/org/apache/accumulo/fate/ZooStore.java ---------------------------------------------------------------------- diff --git a/fate/src/main/java/org/apache/accumulo/fate/ZooStore.java b/fate/src/main/java/org/apache/accumulo/fate/ZooStore.java index 72220f8..6f5ea70 100644 --- a/fate/src/main/java/org/apache/accumulo/fate/ZooStore.java +++ b/fate/src/main/java/org/apache/accumulo/fate/ZooStore.java @@ -17,6 +17,7 @@ package org.apache.accumulo.fate; import static com.google.common.base.Charsets.UTF_8; +import static com.google.common.util.concurrent.Uninterruptibles.sleepUninterruptibly; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; @@ -33,6 +34,7 @@ import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; +import java.util.concurrent.TimeUnit; import org.apache.accumulo.fate.zookeeper.IZooReaderWriter; import org.apache.accumulo.fate.zookeeper.ZooUtil.NodeExistsPolicy; @@ -40,6 +42,8 @@ import org.apache.accumulo.fate.zookeeper.ZooUtil.NodeMissingPolicy; import org.apache.zookeeper.KeeperException; import org.apache.zookeeper.KeeperException.NoNodeException; import org.apache.zookeeper.KeeperException.NodeExistsException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; //TODO use zoocache? - ACCUMULO-1297 //TODO handle zookeeper being down gracefully - ACCUMULO-1297 @@ -47,6 +51,7 @@ import org.apache.zookeeper.KeeperException.NodeExistsException; public class ZooStore<T> implements TStore<T> { + private static final Logger log = LoggerFactory.getLogger(ZooStore.class); private String path; private IZooReaderWriter zk; private String lastReserved = ""; @@ -194,6 +199,7 @@ public class ZooStore<T> implements TStore<T> { } } + @Override public void reserve(long tid) { synchronized (this) { reservationsWaiting++; @@ -249,26 +255,37 @@ public class ZooStore<T> implements TStore<T> { } } + private static final int RETRIES = 10; + @SuppressWarnings("unchecked") @Override public Repo<T> top(long tid) { verifyReserved(tid); - while (true) { + for (int i = 0; i < RETRIES; i++) { + String txpath = getTXPath(tid); try { - String txpath = getTXPath(tid); - String top = findTop(txpath); - if (top == null) - return null; + String top; + try { + top = findTop(txpath); + if (top == null) { + return null; + } + } catch (KeeperException.NoNodeException ex) { + throw new RuntimeException(ex); + } byte[] ser = zk.getData(txpath + "/" + top, null); return (Repo<T>) deserialize(ser); } catch (KeeperException.NoNodeException ex) { + log.debug("zookeeper error reading " + txpath + ": " + ex.toString(), ex); + sleepUninterruptibly(100, TimeUnit.MILLISECONDS); continue; } catch (Exception e) { throw new RuntimeException(e); } } + return null; } private String findTop(String txpath) throws KeeperException, InterruptedException {
