Hadoop on Google Compute Engine - hadoop

I am trying to setup hadoop cluster in Google Compute Engine through "Launch click-to-deploy software" feature .I have created 1 master and 1 slave node and tried to start the cluster using start-all.sh script from master node and i got error "permission denied(publickey)" .
I have generated public and private keys in both slave and master nodes .
currently i logged into the master with my username, is it mandatory to login into master as "hadoop" user .If so ,what is the password for that userid .
please let me know how to overcome this problem .

The deployment creates a user hadoop which owns Hadoop-specific SSH keys which were generated dynamically at deployment time; this means since start-all.sh uses SSH under the hood, you must do the following:
sudo su hadoop
/home/hadoop/hadoop-install/bin/start-all.sh
Otherwise, your "normal" username doesn't have SSH keys properly set up so you won't be able to launch the Hadoop daemons, as you saw.
Another thing to note is that the deployment should have already started all the Hadoop daemons automatically, so you shouldn't need to manually run start-all.sh unless you're rebooting the daemons after some manual configuration updates. If the daemons weren't running after the deployment ran, you may have encountered some unexpected error during initialization.

Related

Secondary Name Node not starting on hadoop

I have installed Hadoop via command line in GCP as well as all its components and my secondary name doesn't run when I execute JPS. All the other Daemons run fine. What could be the problem?

start-all.sh command not found

I have just installed Cloudera VM setup for hadoop. But when I open the command prompt and want to start all daemons for hadoop using command 'start-all.sh' , I get an error stating "bash : start-all.sh: command not found".
I have tried 'start-dfs.sh' too yet still gives the same error. When I use 'jps' command, I can see that none of the daemons have been started.
You can find start-all.sh and start-dfs.sh scripts in bin or sbin folders. You can use the following command to find that. Go to hadoop installation folder and run this command.
find . -name 'start-all.sh' # Finds files having name similar to start-all.sh
Then you can specify the path to start all the daemons using bash /path/to/start-all.sh
If you're using the QuickStart VM then the right way to start the cluster (as #cricket_007 hinted) is by restarting it in the Cloudera Manager UI. The start-all.sh scripts will not work since those only apply to the Hadoop servers (Name Node, Data Node, Resource Manager, Node Manager ...) but not all the services in the ecosystem (like Hive, Impala, Spark, Oozie, Hue ...).
You can refer to the YouTube video and the official documentation Starting, Stopping, Refreshing, and Restarting a Cluster

Installing Hive 2.1.0 Interactive Query (LLAP) on Kerberized HDP 2.6.2 environment

I had a lot of issues surrounding the installation/activation of Hive 2.1.0 on our HDP 2.6.2 cluster. But finally I got it working, so I wanted to share the steps involved with the community. I got these steps from different sources, which I will also mention below each step. My specifications:
Clustered HDP 2.6.2 (hortonworks) environment
Kerberos
Hive 1.2.1000 -> Hive 2.1.0
Step 1: Enable Hive Interactive Query
Follow the steps on the Hortonworks website. This includes enabling YARN pre-emption and some other Yarn settings. After adjusting YARN your can enable Hive Interactive Query via Ambari. You also have to specify a default queue that is at least 20% of your total cluster capacity.
Source
Step 2: Kerberos related settings
Make sure you add the following settings to the custom hiveserver2-interactive site in Ambari. Where ${REALMNAME} is the name of your LDAP realm.
hive.llap.zk.sm.keytab.file=/etc/security/keytabs/hive.llap.zk.sm.keytab
hive.llap.zk.sm.principal=hive/_HOST#${REALMNAME}
hive.llap.daemon.keytab.file=/etc/security/keytabs/hive.service.keytab
hive.llap.daemon.service.principal=hive/_HOST#${REALMNAME}
Now you have to put those 2 keytabs (basically the same keytabs) on every YARN node. This can be done manually or through Ambari (Kerberos service). Make sure those keytabs are chown hive:hadoop and have a chmod 440 (group read).
Note: you also need a user hive on all those nodes.
Source
Step 3: Zookeeper configuration
It could be that Hive is not recognized by Zookeeper, this will give acl errors when trying to start the HiveServer2 Interactive. To cope with this issue I added the right hive acl nodes through a zookeeper client host.
su -
# First, authenticate with the hive keytab
kinit hive/'hostname' -kt /etc/security/keytabs/hive.service.keytab
# Second, connect to a zookeeper client on your cluster
/usr/hdp/current/zookeeper-server/bin/zkCli.sh -server ${ZOOKEEPER_CLIENT}
# Third, check the current status of the user-hive acl
getAcl /llap-sasl/user-hive
# Fourth, If this is not there create the following nodes
create /llap-sasl/user-hive "" sasl:hive:cdrwa,world:anyone:r
create /llap-sasl/user-hive/llap0 "" sasl:hive:cdrwa,world:anyone:r
create /llap-sasl/user-hive/llap0/workers "" sasl:hive:cdrwa,world:anyone:r
# Fifth, change the llap-sasl node to add the user hive
setAcl /llap-sasl sasl:hive:cdrwa,world:anyone:r
Source 1, Source 2
Basically, this should work for Kerberized environments. If you got errors related to ACL, go back to your Zookeeper settings and look if everything is fine. If you have errors related to a missing Hive user, you should look of the hive user is added correctly to the nodes. If you have an error related to Kerberos (principal or keytabs) look if the keytabs are on the designated (YARN) nodes with the correct rights.

Adding new Spark workers on AWS EC2 - access error

I have the existing oeprating Spark cluster that was launched with spark-ec2 script. I'm trying to add new slave by following the instructions:
Stop the cluster
On AWS console "launch more like this" on one of the slaves
Start the cluster
Although the new instance is added to the same security group and I can successfully SSH to it with the same private key, spark-ec2 ... start call can't access this machine for some reason:
Running setup-slave on all cluster nodes to mount filesystems, etc...
[1] 00:59:59 [FAILURE] xxx.compute.amazonaws.com
Exited with error code 255 Stderr: Permission denied (publickey).
, obviously, followed by tons of other errors while trying to deploy Spark stuff on this instance.
The reason is that Spark Master machine doesn't have an rsync access for this new slave, but the 22 port is open...
The issue was that SSH key generated on Spark Master was not transferred to this new slave. Spark-ec2 script with start command omits this step. The solution is to use launch command with --resume options. Then the SSH key is transferred to the new slave and everything goes smooth.
Yet another solution is to add the master's public key (~/.ssh/id_rsa.pub) to the newly added slaves ~/.ssh/authorized_keys. (Got this advice on Spark mailing list)

my hadoop cluster, different host use different user, How do I configure slavers?

master host ip:192.168.10.10 user:hadoopm
slaver host ip:192.168.10.11 user:slaver1
slaver host ip:192.168.10.12 user:slaver2
hadoop version 1.0
How do I configure ?
because namenode use start-all.sh script ,it will ssh to datanode use the same username(hadoopm), but the datanode(slaver) has no name (hadoopm), so it will start fail.
and i must use diffrent username between master and slave。
so how do i configure ???
You can just create a user on each node, then all your slaves will share same user.
on debian , add users .

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