Ctest created HDFS-15124:
----------------------------
Summary: Crashing bugs in NameNode when using a valid
configuration for `dfs.namenode.audit.loggers`
Key: HDFS-15124
URL: https://issues.apache.org/jira/browse/HDFS-15124
Project: Hadoop HDFS
Issue Type: Bug
Components: namenode
Affects Versions: 2.10.0
Reporter: Ctest
I am using Hadoop-2.10.0.
The configuration parameter `dfs.namenode.audit.loggers` allows `default`
(which is the default value) and
`org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger`.
When I use `org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger`,
namenode will not be started successfully because of an
`InstantiationException` thrown from
`org.apache.hadoop.hdfs.server.namenode.FSNamesystem.initAuditLoggers`.
The root cause is that while initializing namenode, `initAuditLoggers` will be
called and it will try to call the default constructor of
`org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger` which doesn't have
a default constructor. Thus the `InstantiationException` exception is thrown.
Symptom
$ ./start-dfs.sh
2019-12-18 14:05:20,670 ERROR
org.apache.hadoop.hdfs.server.namenode.FSNamesystem: FSNamesystem
initialization failed.java.lang.RuntimeException:
java.lang.InstantiationException:
org.apache.hadoop.hdfs.server.namenode.top.TopAuditLoggerat
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.initAuditLoggers(FSNamesystem.java:1024)at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.<init>(FSNamesystem.java:858)at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFromDisk(FSNamesystem.java:677)at
org.apache.hadoop.hdfs.server.namenode.NameNode.loadNamesystem(NameNode.java:674)at
org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:736)at
org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:961)at
org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:940)at
org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1714)at
org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1782)Caused
by: java.lang.InstantiationException:
org.apache.hadoop.hdfs.server.namenode.top.TopAuditLoggerat
java.lang.Class.newInstance(Class.java:427)at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.initAuditLoggers(FSNamesystem.java:1017)...
8 moreCaused by: java.lang.NoSuchMethodException:
org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger.<init>()at
java.lang.Class.getConstructor0(Class.java:3082)at
java.lang.Class.newInstance(Class.java:412)
... 9 more
Detailed Root Cause
There is no default constructor in
`org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger`:
/**
* An \{@link AuditLogger} that sends logged data directly to the metrics
* systems. It is used when the top service is used directly by the name node
*/
@InterfaceAudience.Private
public class TopAuditLogger implements AuditLogger {
public static finalLogger LOG =
LoggerFactory.getLogger(TopAuditLogger.class);
private final TopMetrics topMetrics;
public TopAuditLogger(TopMetrics topMetrics) {
Preconditions.checkNotNull(topMetrics, "Cannot init with a null " +
"TopMetrics");
this.topMetrics = topMetrics;
}
@Override
public void initialize(Configuration conf) {
}
As long as the configuration parameter `dfs.namenode.audit.loggers` is set to
`org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger`, `initAuditLoggers`
will try to call its default constructor to make a new instance:
private List<AuditLogger> initAuditLoggers(Configuration conf) {
// Initialize the custom access loggers if configured.
Collection<String> alClasses =
conf.getTrimmedStringCollection(DFS_NAMENODE_AUDIT_LOGGERS_KEY);
List<AuditLogger> auditLoggers = Lists.newArrayList();
if (alClasses != null && !alClasses.isEmpty()) {
for (String className : alClasses) {
try {
AuditLogger logger;
if (DFS_NAMENODE_DEFAULT_AUDIT_LOGGER_NAME.equals(className)) {
logger = new DefaultAuditLogger();
} else {
logger = (AuditLogger) Class.forName(className).newInstance();
}
logger.initialize(conf);
auditLoggers.add(logger);
} catch (RuntimeException re) {
throw re;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}
`initAuditLoggers` tries to call the default constructor to make a new instance
in:
logger = (AuditLogger) Class.forName(className).newInstance();
This is very different from the default configuration, `default`, which
implements a default constructor so the default is fine.
How To Reproduce
The version of Hadoop: 2.10.0
Set the value of configuration parameter `dfs.namenode.audit.loggers` to
`org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger` in
"hdfs-site.xml"(the default value is `default`)
Start the namenode by running "start-dfs.sh"
The namenode will not be started successfully.
<property>
<name>dfs.namenode.audit.loggers</name>
<value>org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger</value>
<description>
List of classes implementing audit loggers that will receive audit events.
These should be implementations of
org.apache.hadoop.hdfs.server.namenode.AuditLogger.
The special value "default" can be used to reference the default audit
logger, which uses the configured log system. Installing custom audit
loggers
may affect the performance and stability of the NameNode. Refer to the
custom
logger's documentation for more details.
</description>
</property>
How To Fix
Add a default constructor for
`org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger`
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