HBASE-7538 Improve snapshot related error and exception messages

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/hbase-7290@1445851 13f79535-47bb-0310-9956-ffa450edef68

hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java

@@ -2445,7 +2445,8 @@ Server {
       throw new ServiceException(e);
     }
 
-    LOG.debug("Starting snapshot for:" + request);
+    LOG.debug("Submitting snapshot request for:" +
+        SnapshotDescriptionUtils.toString(request.getSnapshot()));
     // get the snapshot information
     SnapshotDescription snapshot = SnapshotDescriptionUtils.validate(request.getSnapshot(),
       this.conf);
@@ -2515,7 +2516,8 @@ Server {
   @Override
   public IsSnapshotDoneResponse isSnapshotDone(RpcController controller,
       IsSnapshotDoneRequest request) throws ServiceException {
-    LOG.debug("Checking to see if snapshot from request:" + request + " is done");
+    LOG.debug("Checking to see if snapshot from request:" +
+        SnapshotDescriptionUtils.toString(request.getSnapshot()) + " is done");
     try {
       IsSnapshotDoneResponse.Builder builder = IsSnapshotDoneResponse.newBuilder();
       boolean done = snapshotManager.isSnapshotDone(request.getSnapshot());

hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/CloneSnapshotHandler.java

@@ -109,9 +109,9 @@ public class CloneSnapshotHandler extends CreateTableHandler implements Snapshot
       // 2. let the CreateTableHandler add the regions to meta
       return metaChanges.getRegionsToAdd();
     } catch (Exception e) {
-      String msg = "clone snapshot=" + snapshot + " failed";
+      String msg = "clone snapshot=" + SnapshotDescriptionUtils.toString(snapshot) + " failed";
       LOG.error(msg, e);
-      IOException rse = new RestoreSnapshotException(msg, e);
+      IOException rse = new RestoreSnapshotException(msg, e, snapshot);
 
       // these handlers aren't futures so we need to register the error here.
       this.monitor.receive(new ForeignException(NAME, rse));

hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/DisabledTableSnapshotHandler.java

@@ -36,6 +36,7 @@ import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescriptio
 import org.apache.hadoop.hbase.regionserver.HRegion;
 import org.apache.hadoop.hbase.snapshot.CopyRecoveredEditsTask;
 import org.apache.hadoop.hbase.snapshot.ReferenceRegionHFilesTask;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
 import org.apache.hadoop.hbase.snapshot.TableInfoCopyTask;
 import org.apache.hadoop.hbase.snapshot.TakeSnapshotUtils;
 import org.apache.hadoop.hbase.util.FSUtils;
@@ -86,7 +87,7 @@ public class DisabledTableSnapshotHandler extends TakeSnapshotHandler {
 
       // 2. for each region, write all the info to disk
       LOG.info("Starting to write region info and WALs for regions for offline snapshot:"
-          + snapshot);
+          + SnapshotDescriptionUtils.toString(snapshot));
       for (HRegionInfo regionInfo : regions) {
         // 2.1 copy the regionInfo files to the snapshot
         Path snapshotRegionDir = TakeSnapshotUtils.getRegionSnapshotDirectory(snapshot, rootDir,
@@ -113,11 +114,13 @@ public class DisabledTableSnapshotHandler extends TakeSnapshotHandler {
       monitor.rethrowException();
     } catch (Exception e) {
       // make sure we capture the exception to propagate back to the client later
-      String reason = "Failed due to exception:" + e.getMessage();
+      String reason = "Failed snapshot " + SnapshotDescriptionUtils.toString(snapshot)
+          + " due to exception:" + e.getMessage();
       ForeignException ee = new ForeignException(reason, e);
       monitor.receive(ee);
     } finally {
-      LOG.debug("Marking snapshot" + this.snapshot + " as finished.");
+      LOG.debug("Marking snapshot" + SnapshotDescriptionUtils.toString(snapshot)
+          + " as finished.");
 
       // 6. mark the timer as finished - even if we got an exception, we don't need to time the
       // operation any further

hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/RestoreSnapshotHandler.java

@@ -32,7 +32,6 @@ import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.catalog.CatalogTracker;
 import org.apache.hadoop.hbase.catalog.MetaEditor;
-import org.apache.hadoop.hbase.catalog.MetaReader;
 import org.apache.hadoop.hbase.errorhandling.ForeignException;
 import org.apache.hadoop.hbase.errorhandling.ForeignExceptionDispatcher;
 import org.apache.hadoop.hbase.master.MasterFileSystem;
@@ -100,7 +99,7 @@ public class RestoreSnapshotHandler extends TableEventHandler implements Snapsho
       this.masterServices.getTableDescriptors().add(hTableDescriptor);
 
       // 2. Execute the on-disk Restore
-      LOG.debug("Starting restore snapshot=" + snapshot);
+      LOG.debug("Starting restore snapshot=" + SnapshotDescriptionUtils.toString(snapshot));
       Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshot, rootDir);
       RestoreSnapshotHelper restoreHelper = new RestoreSnapshotHelper(
           masterServices.getConfiguration(), fs,
@@ -115,10 +114,11 @@ public class RestoreSnapshotHandler extends TableEventHandler implements Snapsho
       MetaEditor.mutateRegions(catalogTracker, hrisToRemove, hris);
 
       // At this point the restore is complete. Next step is enabling the table.
-      LOG.info("Restore snapshot=" + snapshot.getName() + " on table=" +
+      LOG.info("Restore snapshot=" + SnapshotDescriptionUtils.toString(snapshot) + " on table=" +
         Bytes.toString(tableName) + " completed!");
     } catch (IOException e) {
-      String msg = "restore snapshot=" + snapshot + " failed. re-run the restore command.";
+      String msg = "restore snapshot=" + SnapshotDescriptionUtils.toString(snapshot)
+          + " failed. Try re-running the restore command.";
       LOG.error(msg, e);
       monitor.receive(new ForeignException(masterServices.getServerName().toString(), e));
       throw new RestoreSnapshotException(msg, e);
@@ -141,7 +141,8 @@ public class RestoreSnapshotHandler extends TableEventHandler implements Snapsho
   public void cancel(String why) {
     if (this.stopped) return;
     this.stopped = true;
-    String msg = "Stopping restore snapshot=" + snapshot + " because: " + why;
+    String msg = "Stopping restore snapshot=" + SnapshotDescriptionUtils.toString(snapshot)
+        + " because: " + why;
     LOG.info(msg);
     CancellationException ce = new CancellationException(why);
     this.monitor.receive(new ForeignException(masterServices.getServerName().toString(), ce));

hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/SnapshotManager.java

@@ -304,12 +304,14 @@ public class SnapshotManager implements Stoppable {
          "No snapshot name passed in request, can't figure out which snapshot you want to check.");
     }
 
+    String ssString = SnapshotDescriptionUtils.toString(expected);
+
     // check to see if the sentinel exists
     TakeSnapshotHandler handler = getTakeSnapshotHandler(expected);
     if (handler == null) {
       // doesn't exist, check if it is already completely done.
       if (!isSnapshotCompleted(expected)) {
-        throw new UnknownSnapshotException("Snapshot:" + expected.getName()
+        throw new UnknownSnapshotException("Snapshot " + ssString
             + " is not currently running or one of the known completed snapshots.");
       }
       // was done, return true;
@@ -320,15 +322,16 @@ public class SnapshotManager implements Stoppable {
     try {
       handler.rethrowException();
     } catch (ForeignException e) {
-      throw new HBaseSnapshotException("Snapshot error from RS", e, expected);
+      throw new HBaseSnapshotException("Snapshot " + ssString +  " had an error from RS", e,
+          expected);
     }
 
     // check to see if we are done
     if (handler.isFinished()) {
-      LOG.debug("Snapshot '" + expected.getName() + "' has completed, notifying client.");
+      LOG.debug("Snapshot '" + ssString + "' has completed, notifying client.");
       return true;
     } else if (LOG.isDebugEnabled()) {
-      LOG.debug("Sentinel isn't finished with snapshot '" + expected.getName() + "'!");
+      LOG.debug("Snapshoting '" + ssString + "' is still in progress!");
     }
     return false;
   }
@@ -370,14 +373,18 @@ public class SnapshotManager implements Stoppable {
 
     // make sure we aren't already running a snapshot
     if (isTakingSnapshot()) {
-      throw new SnapshotCreationException("Already running another snapshot:"
+      throw new SnapshotCreationException("Rejected taking "
-          + this.handler.getSnapshot(), snapshot);
+          + SnapshotDescriptionUtils.toString(snapshot)
+          + " because we are already running another snapshot "
+          + SnapshotDescriptionUtils.toString(this.handler.getSnapshot()), snapshot);
     }
 
     // make sure we aren't running a restore on the same table
     if (isRestoringTable(snapshot.getTable())) {
-      throw new SnapshotCreationException("Restore in progress on the same table snapshot:"
+      throw new SnapshotCreationException("Rejected taking "
-          + this.handler.getSnapshot(), snapshot);
+          + SnapshotDescriptionUtils.toString(snapshot)
+          + " because we are already have a restore in progress on the same snapshot "
+          + SnapshotDescriptionUtils.toString(this.handler.getSnapshot()), snapshot);
     }
 
     try {
@@ -388,7 +395,7 @@ public class SnapshotManager implements Stoppable {
       // recreate the working directory for the snapshot
       if (!fs.mkdirs(workingDir)) {
         throw new SnapshotCreationException("Couldn't create working directory (" + workingDir
-            + ") for snapshot.", snapshot);
+            + ") for snapshot" , snapshot);
       }
     } catch (HBaseSnapshotException e) {
       throw e;
@@ -481,7 +488,7 @@ public class SnapshotManager implements Stoppable {
     if (assignmentMgr.getZKTable().isEnabledTable(snapshot.getTable())) {
       LOG.debug("Table enabled, starting distributed snapshot.");
       snapshotEnabledTable(snapshot);
-      LOG.debug("Started snapshot: " + snapshot);
+      LOG.debug("Started snapshot: " + SnapshotDescriptionUtils.toString(snapshot));
     }
     // For disabled table, snapshot is created by the master
     else if (assignmentMgr.getZKTable().isDisabledTable(snapshot.getTable())) {

hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/TakeSnapshotHandler.java

@@ -143,14 +143,14 @@ public abstract class TakeSnapshotHandler extends EventHandler implements Snapsh
       // complete the snapshot, atomically moving from tmp to .snapshot dir.
       completeSnapshot(this.snapshotDir, this.workingDir, this.fs);
     } catch (Exception e) {
-      LOG.error("Got exception taking snapshot", e);
+      String reason = "Failed taking snapshot " + SnapshotDescriptionUtils.toString(snapshot)
-      String reason = "Failed due to exception:" + e.getMessage();
+          + " due to exception:" + e.getMessage();
-      LOG.error("Got exception taking snapshot", e);
+      LOG.error(reason, e);
       ForeignException ee = new ForeignException(reason, e);
       monitor.receive(ee);
       // need to mark this completed to close off and allow cleanup to happen.
-      cancel("Failed to take snapshot '" + snapshot.getName() + "' due to exception");
+      cancel("Failed to take snapshot '" + SnapshotDescriptionUtils.toString(snapshot)
-
+          + "' due to exception");
     } finally {
       LOG.debug("Launching cleanup of working dir:" + workingDir);
       try {
@@ -188,15 +188,16 @@ public abstract class TakeSnapshotHandler extends EventHandler implements Snapsh
   /**
    * Snapshot the specified regions
    */
-  protected abstract void snapshotRegions(List<Pair<HRegionInfo, ServerName>> regions) throws IOException,
+  protected abstract void snapshotRegions(List<Pair<HRegionInfo, ServerName>> regions)
-      KeeperException;
+      throws IOException, KeeperException;
 
   @Override
   public void cancel(String why) {
     if (finished) return;
 
     this.finished = true;
-    LOG.info("Stop taking snapshot=" + snapshot + " because: " + why);
+    LOG.info("Stop taking snapshot=" + SnapshotDescriptionUtils.toString(snapshot) + " because: "
+        + why);
     CancellationException ce = new CancellationException(why);
     monitor.receive(new ForeignException(master.getServerName().toString(), ce));
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/SnapshotDescriptionUtils.java

@@ -342,4 +342,19 @@ public class SnapshotDescriptionUtils {
           + ") to completed directory(" + finishedDir + ").", snapshot);
     }
   }
+
+  /**
+   * Returns a single line (no \n) representation of snapshot metadata.  Use this instead of
+   * {@link SnapshotDescription#toString()}.  We don't replace SnapshotDescrpition's toString
+   * because it is auto-generated by protoc.
+   * @param ssd
+   * @return Single line string with a summary of the snapshot parameters
+   */
+  public static String toString(SnapshotDescription ssd) {
+    if (ssd == null) {
+      return null;
+    }
+    return "{ ss=" + ssd.getName() + " table=" + ssd.getTable()
+        + " type=" + ssd.getType() + " }";
+  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/TableInfoCopyTask.java

@@ -58,7 +58,8 @@ public class TableInfoCopyTask extends SnapshotTask {
   public Void call() throws Exception {
     LOG.debug("Running table info copy.");
     this.rethrowException();
-    LOG.debug("Attempting to copy table info for snapshot:" + this.snapshot);
+    LOG.debug("Attempting to copy table info for snapshot:"
+        + SnapshotDescriptionUtils.toString(this.snapshot));
     // get the HTable descriptor
     HTableDescriptor orig = FSTableDescriptors.getTableDescriptor(fs, rootDir,
       Bytes.toBytes(this.snapshot.getTable()));