I have Hadoop-3.1.3 and I can upload a file in hadoop pseudo distributed mode, also can display the contents of file.
but when I call jps command i am getting the following output
10912 DataNode
13072 ResourceManager
4480 NodeManager
6584 Jps
664 Namenode
I am unable to find secondary name node, is there a problem with any configuration or hadoop installation?
You're assuming that secondary namenode is started with psuedo-distributed?
If the basic commands work, then its fine.
You need to look at log files to know if something is broken, before asking elsewhere....
In general, I always suggest you use Apache Ambari to provision a Hadoop cluster
You can start the Secondary NameNode manually and observe the start up logs to see if there's anything wrong:
hdfs secondarynamenode
If there's no error, run jps again and hopefully you see SecondaryNameNode listed.
I'd suggest running hdfs --help and checking out all of the options, there's a lot of good stuff there.
It is my first time in installing Hadoop on my Linux (Fedora distro) running on VM (using Parallel on my Mac). And I followed every step on this video and including the textual version of it.And then when I run it on localhost (or the equivalent value from hostname) in port 50070, I got the following message.
...can't establish a connection to the server at localhost:50070
When I run the jps by the way command I don't have the datanode and namenode unlike at the end of the textual version tutorial which has the following:
While mine has only the following processes running:
6021 NodeManager
3947 SecondaryNameNode
5788 ResourceManager
8941 Jps
When I run the hadoop namenode command I have some of the following [redacted] error:
Cannot access storage directory /usr/local/hadoop_store/hdfs/namenode
16/10/11 21:52:45 WARN namenode.FSNamesystem: Encountered exception loading fsimage
org.apache.hadoop.hdfs.server.common.InconsistentFSStateException: Directory /usr/local/hadoop_store/hdfs/namenode is in an inconsistent state: storage directory does not exist or is not accessible.
I tried to access by the way the above mentioned directories and it existed.
Any hint for this newbie? ;-)
You would need to give read and write permission to user with which you are running the services on directory /usr/local/hadoop_store/hdfs/namenode.
Once done, you should run format command using hadoop namenode -format
Then try to start your services.
delete files /app/hadoop/tmp/*
and try again formatting the namenode and then start-dfs.sh & start-yarn.sh
I installed hadoop 2.6.0 in my laptop running Ubuntu 14.04LTS. I successfully started the hadoop daemons by running start-all.sh and I run a WourdCount example successfully, then I tried to run a jar example that didn't work with me so I decide to format using hadoop namenode -format and start all over again but when I start all daemons using start-dfs.sh && start-yarn.sh then jps all daemons runs but not the datanode as shown bellow:
hdferas#feras-Latitude-E4310:/usr/local/hadoop$ jps
12628 NodeManager
12110 NameNode
12533 ResourceManager
13335 Jps
12376 SecondaryNameNode
How to solve that?
I have faced this issue and it is very easy to solve. Your datanode is not starting because after your namenode and datanode started running you formatted the namenode again. That means you have cleared the metadata from namenode. Now the files which you have stored for running the word count are still in the datanode and datanode has no idea where to send the block reports since you formatted the namenode so it will not start.
Here are the things you need to do to fix it.
Stop all the Hadoop services (stop-all.sh) and close any active ssh connections.
cat /usr/local/hadoop/etc/hadoop/hdfs-site.xml
This step is important, see where datanode's data is gettting stored. It is the value associated for datanode.data.dir. For me it is /usr/local/hadoop/hadoop_data/hdfs/datanode. Open your terminal and navigate to above directory and delete the directory named current which will be there under that directory. Make sure you are only deleting the "current" directory.
sudo rm -r /usr/local/hadoop/hadoop_data/hdfs/datanode/current
Now format the namenode and check whether everything is fine.
hadoop namenode -format
say yes if it asks you for anything.
jps
Hope my answer solves the issue. If it doesn't let me know.
Little advice: Don't format your namenode. Without namenode there is no way to reconstruct the data. If your wordcount is not running that is some other problem.
I had this issue when formatting namenode too. What i did to solve the issue was:
Find your dfs.name.dir location. Consider for example, your dfs.name.dir is /home/hadoop/hdfs.
(a) Now go to, /home/hadoop/hdfs/current.
(b) Search for the file VERSION. Open it using a text editor.
(c) There will be a line namespaceID=122684525 (122684525 is my ID, yours will be different). Note the ID down.
Now find your hadoop.tmp.dir location. Mine is /home/hadoop/temp.
(a) Go to /home/hadoop/temp/dfs/data/current.
(b) Search for the file VERSION and open it using a text editor.
(c) There will be a line namespaceID=. The namespaceID in this file and previous one must be same.
(d) This is the main reason why my datanode was not started. I made them both same and now datanode starts fine.
Note: copy the namespaceID from /home/hadoop/hdfs/current/VERSION to
/home/hadoop/temp/dfs/data/current/VERSION. Dont do it in reverse.
Now do start-dfs.sh && start-yarn.sh. Datanode will be started.
You Just need To Remove All The Contents Of DataNode Folder And Format The Datanode By Using The Following Command
hadoop namenode -format
Even I had same issue and checked the log and found below error
Exception - Datanode log
FATAL org.apache.hadoop.hdfs.server.datanode.DataNode: Exception in secureMain
java.io.IOException: All directories in dfs.datanode.data.dir are invalid: "/usr/local/hadoop_store/hdfs/datanode/
Ran the below command to resolve the issue
sudo chown -R hduser:hadoop /usr/local/hadoop_store
Note - I have create the namenode and datanode under the path /usr/local/hadoop_store
The above problem is occurred due to format the namenode (hadoop namenode -format) without stopping the dfs and yarn daemons. While formating namenode, the question given below is appeared and you press Y key for this.
Re-format filesystem in Storage Directory /tmp/hadoop-root/dfs/name ? (Y or N)
Solution,
You need to delete the files within the current(directory name) directory of dfs.name.dir, you mention in hdfs.site.xml. In my system dfs.name.dir is available in /tmp/hadoop-root/dfs/name/current.
rm -r /tmp/hadoop-root/dfs/name/current
By using the above comment I removed files inside in the current directory. Make sure you are only deleting the "current" directory.Again format the namenode after stopped the dfs and yarn daemons (stop-dfs.sh & stop-yarn.sh). Now datanode will start normally!!
at core-site.xml check for absolute path of temp directory, If this is not pointed correctly or not created (mkdir). The data node cant be started.
add below property in yarn-site.xml
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
<value>org.apache.hadoop.mapred.ShuffleHandler</value>
</property>
not the right way to do it. but surely works~
remove files from your datanode ,namenode and tmp folder. any files/folders created inside these are owned by hadoop and may have some reference to the last run datanode details which may have failed or locked due to which the datanode does not star at the next attempt
I got the same issue (DataNode & TaskTracker would not come up).
RESOLUTION:
DELETE EVERY "CURRENT" SUB-DIRECTORY UNDER: data, name, and namesecondary to resolve DataNode/taskTracker not showing when you start-all.sh, then jps
(My dfs.name.dir location is: /home/training/hadoop-temp/dfs/data/current; /home/training/hadoop-temp/dfs/name/current; /home/training/hadoop-temp/dfs/namesecondary/current
Make sure you stop services: stop-all.sh
1. Go to each "current" sub-directory under data, name, namesecondary and remove/delete (example: rm -r name/current)
2. Then format: hadoop namenode -format
3. mkdir current under /home/training/hadoop-temp/dfs/data/current
4. Take the directory and contents from /home/training/hadoop-temp/dfs/name/current and copy into the /data/current directory
EXAMPLE: files under:
/home/training/hadoop-temp/dfs/name/current
[training#CentOS current]$ ls -l
-rw-rw-r--. 1 training training 9901 Sep 25 01:50 edits
-rw-rw-r--. 1 training training 582 Sep 25 01:50 fsimage
-rw-rw-r--. 1 training training 8 Sep 25 01:50 fstime
-rw-rw-r--. 1 training training 101 Sep 25 01:50 VERSION
5. Change the storageType=NAME_NODE in VERSION to storageType=DATA_NODE in the data/current/VERSION that you just copied over.
BEFORE:
[training#CentOS dfs]$ cat data/current/VERSION
namespaceID=1018374124
cTime=0
storageType=NAME_NODE
layoutVersion=-32
AFTER:
[training#CentOS dfs]$ cat data/current/VERSION
namespaceID=1018374124
cTime=0
storageType=DATA_NODE
layoutVersion=-32
6. Make sure each subdirectory below has the same files that name/current has for data, name, namesecondary
[training#CentOS dfs]$ pwd
/home/training/hadoop-temp/dfs/
[training#CentOS dfs]$ ls -l
total 12
drwxr-xr-x. 5 training training 4096 Sep 25 01:29 data
drwxrwxr-x. 5 training training 4096 Sep 25 01:19 name
drwxrwxr-x. 5 training training 4096 Sep 25 01:29 namesecondary
7. Now start the services: start-all.sh
You should see all 5 services when you type: jps
I am using hadoop-2.6.0.I resolved using:
1.Deleting all files within
/usr/local/hadoop_store/hdfs
command : sudo rm -r /usr/local/hadoop_store/hdfs/*
2.Format hadoop namenode
command : hadoop namenode -format
3.Go to ..../sbin directory(cd /usr/local/hadoop/sbin)
start-all.sh
use command==> hduser#abc-3551:/$ jps
Following services would be started now :
19088 Jps
18707 ResourceManager
19043 NodeManager
18535 SecondaryNameNode
18329 DataNode
18159 NameNode
When I had this same issue, the 'Current' folder wasn't even being created in my hadoop/data/datanode folder. If this is the case for you too,
~copy the contents of 'Current' from namenode and paste it into datanode folder.
~Then, open VERSION for datanode and change the storageType=NAME_NODE to storageType=DATA_NODE
~run jps to see that the datanode continues to run
i executed a hadoop mapreduce program successfully in CDH4, but where can i see my output ? , Can someone tell me how to see output through browser like: It will be helpfull to me
on terminal
hadoop dfs -ls /inputfile
it will give result like
Found 2 items
-rw-r--r-- 3 user17 supergroup 0 2014-11-27 16:47 /inputfile/_SUCCESS
-rw-r--r-- 3 user17 supergroup 24441 2014-11-27 16:47 /inputfile/part-00000
hadoop dfs -cat /inputfile/part-00000
NameNode and DataNode each run an internal web server in order to display basic information about the current status of the cluster. With the default configuration, the NameNode front page is at http://namenode-name:50070/. It lists the DataNodes in the cluster and basic statistics of the cluster. The web interface can also be used to browse the file system (using "Browse the file system" link on the NameNode front page).
if you want see output on web please see. http://gethue.com/#
I’ve 2 nodes cluster (v1.04), master and slave. On the master, in Tool.run() we add two files to the DistributedCache using addCacheFile(). Files do exist in HDFS.
In the Mapper.setup() we want to retrieve those files from the cache using
FSDataInputStream fs = FileSystem.get( context.getConfiguration() ).open( path ).
The problem is that for one file a FileNotFoundException is thrown, although the file exists on the slave node:
attempt_201211211227_0020_m_000000_2: java.io.FileNotFoundException: File does not exist: /somedir/hdp.tmp.dir/mapred/local/taskTracker/distcache/-7769715304990780/master/tmp/analytics/1.csv
ls –l on the slave:
[hduser#slave ~]$ ll /somedir/hdp.tmp.dir/mapred/local/taskTracker/distcache/-7769715304990780/master/tmp/ analytics/1.csv
-rwxr-xr-x 1 hduser hadoop 42701 Nov 22 10:18 /somedir/hdp.tmp.dir/mapred/local/taskTracker/distcache/-7769715304990780/master/tmp/ analytics/1.csv
My questions are:
Shouldn't all files exist on all nodes?
What should be done to fix that?
Thanks.
Solved - should have beed used:
FileSystem.getLocal( conf )
Thanks to Harsh J from Hadoop mailing list.