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https://issues.apache.org/jira/browse/HDFS-15398?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17128897#comment-17128897
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Ayush Saxena edited comment on HDFS-15398 at 6/9/20, 6:11 AM:
--------------------------------------------------------------
Check seems some thing like this reproduces for me :
{code:java}
@Test
public void testECWriteHang() throws Exception {
Configuration conf = new HdfsConfiguration();
conf.setLong(DFS_BLOCK_SIZE_KEY, 1 * 1024 * 1024);
try (MiniDFSCluster cluster = new
MiniDFSCluster.Builder(conf).numDataNodes(3).build()) {
cluster.waitActive();
final DistributedFileSystem dfs = cluster.getFileSystem();
// Create a file with EC policy
Path dir = new Path("/test");
dfs.mkdirs(dir);
dfs.enableErasureCodingPolicy("XOR-2-1-1024k");
dfs.setErasureCodingPolicy(dir, "XOR-2-1-1024k");
Path filePath = new Path("/test/file");
FSDataOutputStream out = dfs.create(filePath);
for (int i = 0; i < 1024 * 1024 * 2; i++) {
out.write(i);
}
dfs.setQuota(dir, 5, 0);
try {
for (int i = 0; i < 1024 * 1024 * 2; i++) {
out.write(i);
}
} catch (Exception e) {
dfs.delete(filePath, true);
} finally {
// The close should be success, shouldn't get stuck.
IOUtils.closeStream(out);
}
}
}
{code}
You can try using this, can add the test in same file as HDFS-15211
Will just {{ closeAllStreamers();}} work? I guess.
Rest of threads we should keep for {{closeImpl}} to close?
was (Author: ayushtkn):
Check seems some thing like this reproduces for me :
{code:java}
@Test
public void testECWriteHang() throws Exception {
Configuration conf = new HdfsConfiguration();
conf.setLong(DFS_BLOCK_SIZE_KEY, 1 * 1024 * 1024);
try (MiniDFSCluster cluster = new
MiniDFSCluster.Builder(conf).numDataNodes(3).build()) {
cluster.waitActive();
final DistributedFileSystem dfs = cluster.getFileSystem();
// Create a file with EC policy
Path dir = new Path("/test");
dfs.mkdirs(dir);
dfs.enableErasureCodingPolicy("XOR-2-1-1024k");
dfs.setErasureCodingPolicy(dir, "XOR-2-1-1024k");
Path filePath = new Path("/test/file");
FSDataOutputStream out = dfs.create(filePath);
for (int i = 0; i < 1024 * 1024 * 2; i++) {
out.write(i);
}
dfs.setQuota(dir, 5, 0);
try {
for (int i = 0; i < 1024 * 1024 * 2; i++) {
out.write(i);
}
} catch (Exception e) {
dfs.delete(filePath, true);
} finally {
// The close should be success, shouldn't get stuck.
IOUtils.closeStream(out);
}
}
}
{code}
You can try using this, can add the test in same file as HDFS-15211
> hdfs client may hang forever when writing EC file
> -------------------------------------------------
>
> Key: HDFS-15398
> URL: https://issues.apache.org/jira/browse/HDFS-15398
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: ec, hdfs-client
> Affects Versions: 3.2.0
> Reporter: Hongbing Wang
> Priority: Major
> Attachments: HDFS-15398.001.patch
>
>
> In the operation of writing EC files, when the client calls addBlock()
> applying for the second block group (or >= the second block group) and it
> happens to exceed quota at this time, the client program will hang forever.
> See the demo below:
> {code:java}
> $ hadoop fs -mkdir -p /user/wanghongbing/quota/ec
> $ hdfs dfsadmin -setSpaceQuota 2g /user/wanghongbing/quota
> $ hdfs ec -setPolicy -path /user/wanghongbing/quota/ec -policy RS-6-3-1024k
> Set RS-6-3-1024k erasure coding policy on /user/wanghongbing/quota/ec
> $ hadoop fs -put 800m /user/wanghongbing/quota/ec
> ^@^@^@^@^@^@^@^@^Z
> {code}
> In the case of blocksize=128M, spaceQuota=2g and EC 6-3 policy, a block group
> needs to apply for 1152M physical space to write 768M logical data.
> Therefore, writing 800M data will exceed quota when applying for the second
> block group. At this point, the client will be hang forever.
> The exception stack of client is as follows:
> {code:java}
> java.lang.Thread.State: TIMED_WAITING (parking)
> at sun.misc.Unsafe.park(Native Method)
> - parking to wait for <0x000000008009d5d8> (a
> java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
> at
> java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078)
> at
> java.util.concurrent.LinkedBlockingQueue.poll(LinkedBlockingQueue.java:467)
> at
> org.apache.hadoop.hdfs.DFSStripedOutputStream$MultipleBlockingQueue.takeWithTimeout(DFSStripedOutputStream.java:117)
> at
> org.apache.hadoop.hdfs.DFSStripedOutputStream.waitEndBlocks(DFSStripedOutputStream.java:453)
> at
> org.apache.hadoop.hdfs.DFSStripedOutputStream.allocateNewBlock(DFSStripedOutputStream.java:477)
> at
> org.apache.hadoop.hdfs.DFSStripedOutputStream.writeChunk(DFSStripedOutputStream.java:541)
> - locked <0x000000008009f758> (a
> org.apache.hadoop.hdfs.DFSStripedOutputStream)
> at
> org.apache.hadoop.fs.FSOutputSummer.writeChecksumChunks(FSOutputSummer.java:217)
> at
> org.apache.hadoop.fs.FSOutputSummer.flushBuffer(FSOutputSummer.java:164)
> - locked <0x000000008009f758> (a
> org.apache.hadoop.hdfs.DFSStripedOutputStream)
> at
> org.apache.hadoop.fs.FSOutputSummer.flushBuffer(FSOutputSummer.java:145)
> - locked <0x000000008009f758> (a
> org.apache.hadoop.hdfs.DFSStripedOutputStream)
> at
> org.apache.hadoop.hdfs.DFSStripedOutputStream.closeImpl(DFSStripedOutputStream.java:1182)
> - locked <0x000000008009f758> (a
> org.apache.hadoop.hdfs.DFSStripedOutputStream)
> at
> org.apache.hadoop.hdfs.DFSOutputStream.close(DFSOutputStream.java:847)
> - locked <0x000000008009f758> (a
> org.apache.hadoop.hdfs.DFSStripedOutputStream)
> at
> org.apache.hadoop.fs.FSDataOutputStream$PositionCache.close(FSDataOutputStream.java:72)
> at
> org.apache.hadoop.fs.FSDataOutputStream.close(FSDataOutputStream.java:101)
> at org.apache.hadoop.io.IOUtils.cleanupWithLogger(IOUtils.java:280)
> at org.apache.hadoop.io.IOUtils.closeStream(IOUtils.java:298)
> at org.apache.hadoop.io.IOUtils.copyBytes(IOUtils.java:77)
> at org.apache.hadoop.io.IOUtils.copyBytes(IOUtils.java:129)
> at
> org.apache.hadoop.fs.shell.CommandWithDestination$TargetFileSystem.writeStreamToFile(CommandWithDestination.java:485)
> at
> org.apache.hadoop.fs.shell.CommandWithDestination.copyStreamToTarget(CommandWithDestination.java:407)
> at
> org.apache.hadoop.fs.shell.CommandWithDestination.copyFileToTarget(CommandWithDestination.java:342)
> at
> org.apache.hadoop.fs.shell.CommandWithDestination.processPath(CommandWithDestination.java:277)
> at
> org.apache.hadoop.fs.shell.CommandWithDestination.processPath(CommandWithDestination.java:262)
> {code}
> When an exception occurs in addBlock, the program will call
> DFSStripedOutputStream.closeImpl() -> flushBuffer() -> writeChunk() ->
> allocateNewBlock() -> waitEndBlocks(), waitEndBlocks will enter an infinite
> loop because the queue in endBlocks is empty.
> {code:java}
> private void waitEndBlocks(int i) throws IOException {
> while (getStripedDataStreamer(i).isHealthy()) {
> final ExtendedBlock b = coordinator.endBlocks.takeWithTimeout(i);
> if (b != null) {
> StripedBlockUtil.checkBlocks(currentBlockGroup, i, b);
> return;
> }
> }
> }
> {code}
> So I close all stripedDataStreamer to fix it When an exception occurs in
> addBlock.
>
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