问题
I am following this link to set up Nifi putHDFS to write to Azure Data Lake.Connecting to Azure Data Lake from a NiFi dataflow
The Nifi is within HDF 3.1 VM and the Nifi version is 1.5.
We got the jar files mentioned in the above link, from a HD Insight(v 3.6, which supports hadoop 2.7) head node, these jars are:
adls2-oauth2-token-provider-1.0.jar
azure-data-lake-store-sdk-2.1.4.jar
hadoop-azure-datalake.jar
jackson-core-2.2.3.jar
okhttp-2.4.0.jar
okio-1.4.0.jar
And they are copied to the folder /usr/lib/hdinsight-datalake of the HDF cluster Nifi host(we only have 1 host in the cluster). And the putHDFS config(picture) is as attached(exactly as the link above)putHDFS attributes.
But in the nifi log we are getting this:
Caused by: java.lang.NoSuchMethodError: org.apache.hadoop.conf.Configuration.reloadExistingConfigurations()V at org.apache.hadoop.fs.adl.AdlConfKeys.addDeprecatedKeys(AdlConfKeys.java:112) at org.apache.hadoop.fs.adl.AdlFileSystem.(AdlFileSystem.java:92) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:348) at org.apache.nifi.processors.hadoop.AbstractHadoopProcessor$ExtendedConfiguration.getClassByNameOrNull(AbstractHadoopProcessor.java:490) at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:2099) at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:2193) at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2654) at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667) at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:370) at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:172) at org.apache.nifi.processors.hadoop.AbstractHadoopProcessor$1.run(AbstractHadoopProcessor.java:322) at org.apache.nifi.processors.hadoop.AbstractHadoopProcessor$1.run(AbstractHadoopProcessor.java:319) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:422) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1698) at org.apache.nifi.processors.hadoop.AbstractHadoopProcessor.getFileSystemAsUser(AbstractHadoopProcessor.java:319) at org.apache.nifi.processors.hadoop.AbstractHadoopProcessor.resetHDFSResources(AbstractHadoopProcessor.java:281) at org.apache.nifi.processors.hadoop.AbstractHadoopProcessor.abstractOnScheduled(AbstractHadoopProcessor.java:205) ... 16 common frames omitted
The AdlConfKeys class is from the hadoop-azure-datalake.jar file above. From the above exception, it seems to me this AdlConfKeys is loading an older version of the org.apache.hadoop.conf.Configuration class, which does not have the reloadExistingConfigurations method. However we cannot find out from where this older class gets loaded. This HDF 3.1 has the hadoop-common-XXXX.jar in multiple locations, all those on version 2.7 something has the org.apache.hadoop.conf.Configuration containing the method reloadExistingConfigurations, only those on version 2.3 don't have this method.(I decompiled both 2.7 and 2.3 jars to find out)
[root@NifiHost /]# find . -name *hadoop-common*
(the output is a lot more than below, however I removed some for display purpose, most of them are on 2.7, only 2 of them are on version 2.3):
./var/lib/nifi/work/nar/extensions/nifi-hadoop-libraries-nar-1.5.0.3.1.0.0-564.nar-unpacked/META-INF/bundled-dependencies/hadoop-common-2.7.3.jar
./var/lib/ambari-agent/cred/lib/hadoop-common-2.7.3.jar
./var/lib/ambari-server/resources.backup/views/work/WORKFLOW_MANAGER{1.0.0}/WEB-INF/lib/hadoop-common-2.7.3.2.6.2.0-205.jar
./var/lib/ambari-server/resources.backup/views/work/HUETOAMBARI_MIGRATION{1.0.0}/WEB-INF/lib/hadoop-common-2.3.0.jar
./var/lib/ambari-server/resources/views/work/HUETOAMBARI_MIGRATION{1.0.0}/WEB-INF/lib/hadoop-common-2.3.0.jar
./var/lib/ambari-server/resources/views/work/HIVE{1.5.0}/WEB-INF/lib/hadoop-common-2.7.3.2.6.4.0-91.jar
./var/lib/ambari-server/resources/views/work/CAPACITY-SCHEDULER{1.0.0}/WEB-INF/lib/hadoop-common-2.7.3.2.6.4.0-91.jar
./var/lib/ambari-server/resources/views/work/TEZ{0.7.0.2.6.2.0-205}/WEB-INF/lib/hadoop-common-2.7.3.2.6.2.0-205.jar
./usr/lib/ambari-server/hadoop-common-2.7.2.jar
./usr/hdf/3.1.0.0-564/nifi/ext/ranger/install/lib/hadoop-common-2.7.3.jar
./usr/hdf/3.0.2.0-76/nifi/ext/ranger/install/lib/hadoop-common-2.7.3.jar
So I really don't know how Nifi managed to find a hadoop-common jar file or something else containing the Configuration class does not have the method reloadExistingConfigurations(). We do not have any customized Nar files deployed to Nifi either, everything is pretty much default from whatever HDF 3.1 has on Nifi.
Please advise. I've been spending a whole day on this but can't fix the issue. Appreciate your help.
回答1:
I think the Azure JARs you are using require a newer version of hadoop-common than the 2.7.3 one that NiFi is using.
If you look at the Configuration class from 2.7.3 there is no "reloadExistingConfiguration" method:
https://github.com/apache/hadoop/blob/release-2.7.3-RC2/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java
It appears to be introduced sometime during 2.8.x:
https://github.com/apache/hadoop/blob/release-2.8.3-RC0/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java
来源：https://stackoverflow.com/questions/49059136/nifi-java-lang-nosuchmethoderror-org-apache-hadoop-conf-configuration-reloadexi