HDFS-3376. DFSClient fails to make connection to DN if there are many unusable cached sockets. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1335115 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Todd Lipcon 2012-05-07 16:42:19 +00:00
parent d3599de399
commit eca2c850a5
3 changed files with 50 additions and 1 deletions

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@ -606,6 +606,9 @@ Release 2.0.0 - UNRELEASED
HDFS-3357. DataXceiver reads from client socket with incorrect/no timeout
(todd)
HDFS-3376. DFSClient fails to make connection to DN if there are many
unusable cached sockets (todd)
BREAKDOWN OF HDFS-1623 SUBTASKS
HDFS-2179. Add fencing framework and mechanisms for NameNode HA. (todd)

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@ -864,7 +864,13 @@ protected BlockReader getBlockReader(InetSocketAddress dnAddr,
// Allow retry since there is no way of knowing whether the cached socket
// is good until we actually use it.
for (int retries = 0; retries <= nCachedConnRetry && fromCache; ++retries) {
Socket sock = socketCache.get(dnAddr);
Socket sock = null;
// Don't use the cache on the last attempt - it's possible that there
// are arbitrarily many unusable sockets in the cache, but we don't
// want to fail the read.
if (retries < nCachedConnRetry) {
sock = socketCache.get(dnAddr);
}
if (sock == null) {
fromCache = false;

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@ -17,10 +17,12 @@
*/
package org.apache.hadoop.hdfs;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_MAX_BLOCK_ACQUIRE_FAILURES_KEY;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SOCKET_REUSE_KEEPALIVE_KEY;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SOCKET_WRITE_TIMEOUT_KEY;
import static org.junit.Assert.*;
import java.io.InputStream;
import java.io.PrintWriter;
import java.net.InetSocketAddress;
import java.net.Socket;
@ -40,6 +42,8 @@
import org.junit.Before;
import org.junit.Test;
import com.google.common.io.NullOutputStream;
public class TestDataTransferKeepalive {
Configuration conf = new HdfsConfiguration();
private MiniDFSCluster cluster;
@ -56,6 +60,8 @@ public class TestDataTransferKeepalive {
public void setup() throws Exception {
conf.setInt(DFS_DATANODE_SOCKET_REUSE_KEEPALIVE_KEY,
KEEPALIVE_TIMEOUT);
conf.setInt(DFS_CLIENT_MAX_BLOCK_ACQUIRE_FAILURES_KEY,
0);
cluster = new MiniDFSCluster.Builder(conf)
.numDataNodes(1).build();
@ -143,6 +149,40 @@ public void testSlowReader() throws Exception {
IOUtils.closeStream(stm);
}
}
@Test(timeout=30000)
public void testManyClosedSocketsInCache() throws Exception {
// Make a small file
DFSTestUtil.createFile(fs, TEST_FILE, 1L, (short)1, 0L);
// Insert a bunch of dead sockets in the cache, by opening
// many streams concurrently, reading all of the data,
// and then closing them.
InputStream[] stms = new InputStream[5];
try {
for (int i = 0; i < stms.length; i++) {
stms[i] = fs.open(TEST_FILE);
}
for (InputStream stm : stms) {
IOUtils.copyBytes(stm, new NullOutputStream(), 1024);
}
} finally {
IOUtils.cleanup(null, stms);
}
DFSClient client = ((DistributedFileSystem)fs).dfs;
assertEquals(5, client.socketCache.size());
// Let all the xceivers timeout
Thread.sleep(1500);
assertXceiverCount(0);
// Client side still has the sockets cached
assertEquals(5, client.socketCache.size());
// Reading should not throw an exception.
DFSTestUtil.readFile(fs, TEST_FILE);
}
private void assertXceiverCount(int expected) {
// Subtract 1, since the DataXceiverServer