Github user arunmahadevan commented on a diff in the pull request:
https://github.com/apache/storm/pull/664#discussion_r37161325
--- Diff:
external/storm-hdfs/src/main/java/org/apache/storm/hdfs/bolt/HdfsBolt.java ---
@@ -88,35 +99,94 @@ public void doPrepare(Map conf, TopologyContext
topologyContext, OutputCollector
@Override
public void execute(Tuple tuple) {
- try {
- byte[] bytes = this.format.format(tuple);
- synchronized (this.writeLock) {
- out.write(bytes);
- this.offset += bytes.length;
-
- if (this.syncPolicy.mark(tuple, this.offset)) {
- if (this.out instanceof HdfsDataOutputStream) {
- ((HdfsDataOutputStream)
this.out).hsync(EnumSet.of(SyncFlag.UPDATE_LENGTH));
- } else {
- this.out.hsync();
- }
- this.syncPolicy.reset();
+ boolean forceRotate = false;
+ synchronized (this.writeLock) {
+ boolean forceSync = false;
+ if (TupleUtils.isTick(tuple)) {
+ LOG.debug("TICK! forcing a file system flush");
+ forceSync = true;
+ }
+ else {
+ try {
+ writeAndAddTuple(tuple);
+ } catch (IOException e) {
+ //If the write failed, try to sync anything already
written
+ LOG.info("Tuple failed to write, forcing a flush of
existing data.");
+ this.collector.reportError(e);
+ forceSync = true;
+ this.collector.fail(tuple);
}
}
- this.collector.ack(tuple);
+ if (this.syncPolicy.mark(tuple, this.offset) || forceSync) {
+ try {
+ syncAndAckTuples();
+ } catch (IOException e) {
+ LOG.warn("Data could not be synced to filesystem,
failing this batch of tuples");
+ this.collector.reportError(e);
+ //Force rotation to get a new file handle
+ forceRotate = true;
+ for (Tuple t : tupleBatch)
+ this.collector.fail(t);
+ tupleBatch.clear();
+ }
+ }
+ }
- if(this.rotationPolicy.mark(tuple, this.offset)){
- rotateOutputFile(); // synchronized
- this.offset = 0;
- this.rotationPolicy.reset();
+ if(this.rotationPolicy.mark(tuple, this.offset) || forceRotate) {
+ try {
+ rotateAndReset();
+ } catch (IOException e) {
+ this.collector.reportError(e);
+ LOG.warn("File could not be rotated");
+ //At this point there is nothing to do. In all likelihood
any filesystem operations will fail.
+ //The next tuple will almost certainly fail to write
and/or sync, which force a rotation. That
+ //will give rotateAndReset() a chance to work which
includes creating a fresh file handle.
}
- } catch (IOException e) {
- this.collector.reportError(e);
- this.collector.fail(tuple);
}
}
+ private void rotateAndReset() throws IOException {
--- End diff --
What would be the behavior if the file system goes into an irrecoverable
state where writes are continuously failing? Wont it end up creating a lot of
empty files? You might want to consider cleaning this up and also killing the
task by throwing a runtime exception after 'n' failures and hope that the new
worker might be able to start writing successfully.
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