Q&A

Hello, I am planning for CCA 175 exam. Can i know what is the minimum hardware configuration is required? I mean what should be minimum RAM you require in order to give the exam?

Hi all, Currently using CDH 5.14.4 and looking to enable user authention on HiveServer2 using OpenLDAP. The two connection options I'm seeing are LDAP and LDAPS, but we currently don't have LDAPS configured with our OpenLDAP server. Hue supports LDAP with StartTLS so I figured Hive would too. I'm wondering if StartTLS is an option that I'm not finding documentation for or if its not supported.  Thanks for your help!  

Am trying to add a new host to a cloudera managed cluster using wizard ... but it keeps failing with message "/tmp/scm_prepare_node.fj3OyPGRConnection reset " and server logs shows ... 2019-03-06 19:37:18,074 INFO scm-web-300:com.cloudera.cmf.service.ServiceHandlerRegistry: Executing command GlobalHostInstall GlobalHostInstallCommandArgs{sshPort=22, userName=sw, password=REDACTED, passphrase=REDACTED, privateKey=REDACTED, parallelInstallCount=10, cmRepoUrl=null, gpgKeyCustomUrl=null, gpgKeyOverrideBundle=<none>, unlimitedJCE=true, javaInstallStrategy=NONE, agentUserMode=ROOT, cdhVersion=-1, cdhRelease=NONE>, cdhRepoUrl=null, buildCertCommand=, sslCertHostname=null, reqId=20, skipPackageInstall=false, skipCloudConfig=false, hosts=[hadoop.localdomain.38], existingHosts=[]}.2019-03-06 19:37:18,074 INFO scm-web-300:com.cloudera.cmf.command.flow.CmdStep: Executing command work: Execute 1 steps in sequence2019-03-06 19:37:18,074 INFO scm-web-300:com.cloudera.cmf.command.fl

can we deploy the HttpFS role on more than one node? is it best practice?   we had a problem with one of the namenodes (on node02) in our cluster and it was down for almost 20 hours.once node02  was up, the active namenode ,on node01, started to alert that its not syncronizedafter restart of the namenode on node02 the alert stopped now active namenode is on node01standby namenode is on node02we can see that new logs are created on opt/hadoop/dfs/nn/current  on the actine namenode on node01but no new files . on the standby namenode no node02 - is it OK ??

Hi, I recently started learning Hadoop/Cloudera. I have successfully installed single node Cloudera Manager on my test Linux workstation I am looking for the best or suggested IDEs for creating projects to run jobs on my Hadoop fs using Scala, Java, Python etc. Any how-to docs will be greately appreciated Regards All

All three namenode directories are pointing to same metadata./hadoop/hdfs/namenode/var/hadoop/hdfs/namenode/var/log/hadoop/hdfs/namenodeWhat is the use of having 3 directories pointing to same data?

I am loading a phoenix table but in hbase this table row key is shown as hex values. how can I correct this to see the ASCII values ? that is the integer valuesqlline version 1.1.80: jdbc:phoenix:localhost:2181:/hbase-unsecur> SELECT * FROM EXAMPLE;+--------+-------------+------------+| MY_PK  | FIRST_NAME  | LAST_NAME  |+--------+-------------+------------+| 12345  | John        | Doe        || 67890  | Mary        | Jane       |+--------+-------------+------------+2 rows selected (0.053 seconds)Version 1.1.2.2.6.5.0-292, r897822d4dd5956ca186974c10382e9094683fa29, Fri May 11 08:01:42 UTC 2018hbase(main):001:0> scan 'EXAMPLE'ROW                                              COLUMN+CELL \x80\x00\x00\x00\x00\x0009               &nbs

Hi Team,We have enabled Atlas in our environment. After that we started getting connection hanging to Hive/HS2/Knox Gateway.Hiveserver doesn't create new thread connections and stops responding. when we do restart of HS2 then the new jobs start but after sometime again connection goes in hung state.This issue was a result of recently configured atlas service on the cluster. After that followed below link and changed the configuration.https://community.hortonworks.com/content/supportkb/148579/failed-hive-internal-error-javautilconcurrentrejec.htmlatlas.hook.hive.maxThreads=50 from 5.atlas.hook.hive.minThreads=5.Even i checked my user limit for hive it has been set:root@hostname:~# su - hive$ ulimit -atime(seconds) unlimitedfile(blocks) unlimiteddata(kbytes) unlimitedstack(kbytes) 8192coredump(blocks) 0memory(kbytes) unlimitedlocked memory(kbytes) 64process 16000nofiles 32000vmemory(kbytes) unlimitedlocks

Hi, We have CDH 5.15 on our production cluster with JDK 8,What is your recommendation about moving to G1GC or stay with the CMS,didn't find any clear instruction about it.Does it depend on the CDH version? or on the components I'm using? Thanks

Hi, We have CDH 5.15 on our production cluster with JDK 8,What is your recommendation about moving to G1GC or stay with the CMS,didn't find any clear instruction about it.Does it depend on the CDH version? or on the components I'm using? Thanks

Hi All,   We have sqooped data from MS-SQL 2008 into HDFS and created external tables . The record count shows same between the MS-SQL table and Hive tables. However, if i fire same query on MS-SQL table and Hive table, the output is different. The query is being fired through Hue(tested through Impala as well). Could you please help, if i missed something?   Regards. Sandeep Suman

How can I change the Apache kylin port ?The default listen port is 7070, I have salt-bootstrap running on the Azure VMs in that port.I went through kylin.properties and didn't find a relevant property for listen port.

Hello. I am trying to run a TPC-C benchmark on Impala with Kudu and therefore completed the necessary system installation and JDBC driver download. However, the driver documentation states that the AutoCommit feature is always set to true, which means explicit commits and rollbacks are not possible.  I am therefore wondering, if the TPC-C benchmark can be valid when using the Impala JDBC driver, as the TPC-C specification states that rollbacks must happen at a fixed rate? Is there a workaround that can be used instead? Thanks for your time.

helloWhen i start nifi with ambari i get this error Java Heap Space OutofMemory but when i start it with console by script nifi.sh i get no error

Hi Team,   Can anyone share if they have updated resource pool configurations in YARN using CM API, what end points were used if so. Thanks in advance.

Hello All,   I am trying to add sentry service to the cloudera CDH 5.12 cluster.   As part of that I created database and user and granted all privileges to the user for the sentry database.   But I am getting below error.   Logon denied for user/password. Able to find the database server and database, but logon request was rejected.   Please suggest.   Thanks,

@Geoffrey Shelton Okot, @mthiele,I want to install Kerberos on Hadoop cluster, i have seen the articleConfiguring Ambari and Hadoop for Kerberos using AD as the KDC - Videohttps://community.hortonworks.com/questions/103945/kerberos-setup-on-hdp-26.html and this is really helpful.I have couple of questions on this,1.Do I need to install Kerberos via command line before starting this task?2. Because i see krb5.conf file exists in my cluster and kerberos is not enabled, do I need to delete the conf files in all nodes and run"yum install -y krb5-server krb5-libs krb5-workstation" command then carry on the steps provided in the aboe article or i don't need to bother to about and straightaway start from Ambari for enabling process.3. As per the official doc. https://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.6.5/bk_security/content/configuring_amb_hdp_for_kerberos.html we need to enable Kerberos from Ambari,Now i need a clear idea 1st do I need to install kerberos using yum command and the

Using CDH 5.3.1 (without CM), I have a DataNode that seems to not start it's block report. The particular DN has 100x more RBW files than other DNs (some RBW files are a year old). The driving symptom is blocks reported missing, but the particular blocks are indeed under /finalized/ directory of the DN.  A few thousand files have missing blocks that are in this state and no alternative blocks/replicas are on the cluster, so we would like to recover these files. The missing blocks are NOT under /rbw/ dir., hence the concern over the "RemoteException in offerService" error.  Classpath and VERSION files look good compared to known-good DNs. See point-in-time logs entries below.  * Question: How can a /finalized/ block (replica) be considered missing after DN has been up for many hours?  * Question: what if I manually copy the finalized blk_* files in question to another DN? would that DN pick them up upon restart?  * Questio

Good day! We actively use software configuration management (SCM, for example saltstack, ansible, puppet/etc), and we decide add new host to cluster Cloudera hadoop through this system.Our steps:1. Add repo cat /etc/apt/sources.list.d/cloudera-manager.listdeb https://archive.cloudera.com/cm5/debian/jessie/amd64/cm/ jessie-cm5.13.0 contri  2. Install soft (cloudera-manager-daemons, cloudera-manager-agent) 3. Edit /etc/cloudera-scm-agent/config.ini [General]# Hostname of the CM server.server_host=main.test.com4. Start agent  After that we see that new host in cluster.Also I use this doc - https://www.cloudera.com/documentation/enterprise/5-13-x/topics/cm_mc_adding_hosts.htmlfor checking our steps in SCM.But we run into some trouble A. http://community.cloudera.com/t5/Cloudera-Manager-Installation/Bad-The-hostname-and-canonical-name-for-this-host-are-not/m-p/86905#M16122?eid=1&aid=1  - there I wrote some description about our error B.

I am looking for a way to migrate a Hive table from one Hadoop cluster to another cluster that is running on a different Kerberos REALM.

Hi, I'm trying to register for CCA175 exam but I have got a doubt. While doing the Checkout, I have to enter the personal information and there is one text field called "Account", do I have to enter my Community Nickname in the Account field or is it something else? Can anyone please provide me a confirmation on this as soon as possible? Thank you. Regards,Varun Chawla

I have a table stuck in 'DISABLING' state and one of the four table regions is stuck in 'OPENING' state. Hbase 2.0 hbck doesn't allow fixing tables../hbase zkcli, ls /hbase-unsecure/table/<table name> doesn't show anythingrestarting the hbase master, regionservers, and zookeeper doesn't resolveHow do I fix this issue.

I got this error while trying to install Cloudera manager on my Rhel7 workstation Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-: managerResolving Dependencies--> Running transaction check---> Package oracle-j2sdk1.8.x86_64 0:1.8.0+update141-1 will be installed--> Finished Dependency ResolutionDependencies Resolved================================================================================Package Arch Version Repository Size================================================================================Installing:oracle-j2sdk1.8 x86_64 1.8.0+update141-1 cloudera-manager 176 MTransaction Summary================================================================================Install 1 PackageTotal download size: 176 MInstalled size: 359 MDownloading packages:No Presto metadata available for cloudera-manager[Errno 14] curl#56 - "SSL received a record with an incorrect Message Authentication Code."Trying other mirror. 

 Hello all, I seem to have run into a Kudu 1.4 bug, and I am wondering if there is any work around other than upgrading.  I lost a tablet in my dev environment and wasn't aware of it for a while (24hours or so) which I just assumed I could just wipe the directories and rebuild it thinking all the replicas had already been replicated to other tablets well that wasn't the case. After getting the tablet backup I ran a ksck and noted I have two tables that are under-replicated, and I am seeing a lot of alerts like the one below.  Now I did see this https://issues.apache.org/jira/browse/KUDU-1613 and it says it's fixed in 1.7 but upgrading isn't an option at this time. T acc6adcd6b554b5cabfed268184591a9 P fa6625fcbb204fba86ac6d4007c3f695 -> Peer 13950e716d21404188b733521dbf4d97 (1.2.3.4.domain.com:7050): Couldn't send request to peer 13950e716d21404188b733521dbf4d97 for tablet acc6adcd6b554b5cabfed268184591a9. Error code: WRONG_SERVER_UUI

Hi,   We have a Kudu cluster with replication factor 3. All Kudu machines have time synchronization via NTP. Our application performs a SELECT from a Kudu table via Impala JDBC driver. The Impala Daemon is configured with the command-line option: --kudu_read_mode=READ_AT_SNAPSHOT. This operation fails:   [Simba][ImpalaJDBCDriver](500051) ERROR processing query/statement. Error Code: 0, SQL state: Unable to open scanner: Timed out: unable to retry before timeout: Remote error: Service unavailable: Timed out: could not wait for desired snapshot timestamp to be consistent: Tablet is lagging too much to be able to serve snapshot scan. Lagging by: 61148 ms, (max is 30000 ms):: Remote error: Service unavailable: Timed out: could not wait for desired snapshot timestamp to be consistent: Tablet is lagging too much to be able to serve snapshot scan. Lagging by: 30821 ms, (max is 30000 ms):, Query: SELECT COUNT(*) as `expr_0` FROM `ci_pdo_PDO_Func_Tests`.`alarm_relationship_rules`