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Posted to common-commits@hadoop.apache.org by cl...@apache.org on 2019/06/28 23:06:34 UTC
[hadoop] 31/50: HDFS-14017. [SBN read]
ObserverReadProxyProviderWithIPFailover should work with HA configuration.
Contributed by Chen Liang.
This is an automated email from the ASF dual-hosted git repository.
cliang pushed a commit to branch branch-3.2
in repository https://gitbox.apache.org/repos/asf/hadoop.git
commit 03a2c60a4b6d14a9789c398d2cc0d902a4274621
Author: Chen Liang <cl...@apache.org>
AuthorDate: Fri Nov 16 17:30:29 2018 -0800
HDFS-14017. [SBN read] ObserverReadProxyProviderWithIPFailover should work with HA configuration. Contributed by Chen Liang.
---
.../hadoop/hdfs/client/HdfsClientConfigKeys.java | 3 +
.../ObserverReadProxyProviderWithIPFailover.java | 97 +++++++++++++++++++---
2 files changed, 89 insertions(+), 11 deletions(-)
diff --git a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java
index a812670..20ea776 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java
@@ -187,6 +187,9 @@ public interface HdfsClientConfigKeys {
String DFS_PROVIDED_ALIASMAP_INMEMORY_RPC_ADDRESS =
"dfs.provided.aliasmap.inmemory.dnrpc-address";
+ String DFS_CLIENT_FAILOVER_IPFAILOVER_VIRTUAL_ADDRESS =
+ Failover.PREFIX + "ipfailover.virtual-address";
+
/**
* These are deprecated config keys to client code.
*/
diff --git a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/server/namenode/ha/ObserverReadProxyProviderWithIPFailover.java b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/server/namenode/ha/ObserverReadProxyProviderWithIPFailover.java
index 1dbd02c..751bc3b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/server/namenode/ha/ObserverReadProxyProviderWithIPFailover.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/server/namenode/ha/ObserverReadProxyProviderWithIPFailover.java
@@ -17,24 +17,99 @@
*/
package org.apache.hadoop.hdfs.server.namenode.ha;
-import java.io.IOException;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.protocol.ClientProtocol;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.DFS_CLIENT_FAILOVER_IPFAILOVER_VIRTUAL_ADDRESS;
/**
- * ObserverReadProxyProvider with IPFailoverProxyProvider
- * as the failover method.
+ * Extends {@link ObserverReadProxyProvider} to support NameNode IP failover.
+ *
+ * For Observer reads a client needs to know physical addresses of all
+ * NameNodes, so that it could switch between active and observer nodes
+ * for write and read requests.
+ *
+ * Traditional {@link IPFailoverProxyProvider} works with a virtual
+ * address of the NameNode. If active NameNode fails the virtual address
+ * is assigned to the standby NameNode, and IPFailoverProxyProvider, which
+ * keeps talking to the same virtual address is in fact now connects to
+ * the new physical server.
+ *
+ * To combine these behaviors ObserverReadProxyProviderWithIPFailover
+ * should both
+ * <ol>
+ * <li> Maintain all physical addresses of NameNodes in order to allow
+ * observer reads, and
+ * <li> Should rely on the virtual address of the NameNode in order to
+ * perform failover by assuming that the virtual address always points
+ * to the active NameNode.
+ * </ol>
+ *
+ * An example of a configuration to leverage
+ * ObserverReadProxyProviderWithIPFailover
+ * should include the following values:
+ * <pre>{@code
+ * fs.defaultFS = hdfs://mycluster
+ * dfs.nameservices = mycluster
+ * dfs.ha.namenodes.mycluster = ha1,ha2
+ * dfs.namenode.rpc-address.mycluster.ha1 = nn01-ha1.com:8020
+ * dfs.namenode.rpc-address.mycluster.ha2 = nn01-ha2.com:8020
+ * dfs.client.failover.ipfailover.virtual-address.mycluster = nn01.com:8020
+ * dfs.client.failover.proxy.provider.mycluster =
+ * org.apache...ObserverReadProxyProviderWithIPFailover
+ * }</pre>
+ * Here {@code nn01.com:8020} is the virtual address of the active NameNode,
+ * while {@code nn01-ha1.com:8020} and {@code nn01-ha2.com:8020}
+ * are the physically addresses the two NameNodes.
+ *
+ * With this configuration, client will use
+ * ObserverReadProxyProviderWithIPFailover, which creates proxies for both
+ * nn01-ha1 and nn01-ha2, used for read/write RPC calls, but for the failover,
+ * it relies on the virtual address nn01.com
*/
-public class
-ObserverReadProxyProviderWithIPFailover<T extends ClientProtocol>
-extends ObserverReadProxyProvider<T> {
+public class ObserverReadProxyProviderWithIPFailover<T extends ClientProtocol>
+ extends ObserverReadProxyProvider<T> {
+ private static final Logger LOG = LoggerFactory.getLogger(
+ ObserverReadProxyProviderWithIPFailover.class);
+
+ /**
+ * By default ObserverReadProxyProviderWithIPFailover
+ * uses {@link IPFailoverProxyProvider} for failover.
+ */
public ObserverReadProxyProviderWithIPFailover(
- Configuration conf, URI uri, Class<T> xface,
- HAProxyFactory<T> factory) throws IOException {
- super(conf, uri, xface, factory,
- new IPFailoverProxyProvider<T>(conf, uri, xface,factory));
+ Configuration conf, URI uri, Class<T> xface, HAProxyFactory<T> factory) {
+ this(conf, uri, xface, factory,
+ new IPFailoverProxyProvider<>(conf,
+ getFailoverVirtualIP(conf, uri.getHost()), xface, factory));
+ }
+
+ @Override
+ public boolean useLogicalURI() {
+ return true;
+ }
+
+ public ObserverReadProxyProviderWithIPFailover(
+ Configuration conf, URI uri, Class<T> xface, HAProxyFactory<T> factory,
+ AbstractNNFailoverProxyProvider<T> failoverProxy) {
+ super(conf, uri, xface, factory, failoverProxy);
+ }
+
+ private static URI getFailoverVirtualIP(
+ Configuration conf, String nameServiceID) {
+ String configKey = DFS_CLIENT_FAILOVER_IPFAILOVER_VIRTUAL_ADDRESS
+ + "." + nameServiceID;
+ String virtualIP = conf.get(configKey);
+ LOG.info("Name service ID {} will use virtual IP {} for failover",
+ nameServiceID, virtualIP);
+ if (virtualIP == null) {
+ throw new IllegalArgumentException("Virtual IP for failover not found,"
+ + "misconfigured " + configKey + "?");
+ }
+ return URI.create(virtualIP);
}
-}
\ No newline at end of file
+}
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