Friday, November 4, 2016

[New Certification] Oracle Big Data 2017 Certified Implementation Specialist

Hi all,

Now I am excited to announce my new certificate on Big Data :)

This week I succesfully passed Oracle 1z0-449 exam which is Oracle Big Data 2017 Implementation Essentials and certified as "Oracle Big Data 2017 Certified Implementation Specialist"

It is an honor for me with working my experiences and see it gets a value..

As I always say, Enjoy & Share..



Monday, September 19, 2016

[ElasticSearch] ElasticSearch Cluster Installation & memory problems

Hi everyone,

Today I will make my 1st post about ElasticSearch..

In this work, i will install ElasticSearch (Cluster) on 3 nodes and talk about memory problems we got during installation.

Unable to lock JVM memory (ENOMEM). This can result in part of the JVM being swapped out. Increase RLIMIT_MEMLOCK (ulimit).

ElasticSearch 1.7.1, Linux 6

Tuesday, September 13, 2016

[Big Data] First steps on Oracle Big Data SQL - helpful troubleshooting

Hi everyone,

In this post I will talk about usage of  Oracle Big Data SQL service on Exadata and some practices..

As we all know, using Oracle Big Data SQL, you can query data stored in a Hadoop cluster using from your Oracle database.

However, you need to take care of some problems related with Kerberos and some configuration issues with Exadata side.

Oracle BDS 3.0, BDA v4.5, Exadata 12c image

[Big Data - SPARK] Fixing environment problems when running spark-submit jobs from client ( Spark 1.6)

Hi everyone,

Today i will publish my first post about Apache Spark..

The problem I face is when we run a spark job from client machine or an edgenode, we get jars not found errors even if we create UberJar or classpath not founds errors.

In this post, I am gonna talk about how to set client environment in order to submit spark jobs succesfully and show how to debug a java process in detail..

Spark version : 1.6, CDH 5.7.1

[Big Data] About Cloudera Utilization Report

Hi everyone,

After a long post, I'm back :)

In this post, I am gonna talk about Cloudera new feature : Cloudera Utilization Report.. How to enable it on test cluster...

We can already have a look about cluster situation from charts or YARN pages , now starting with CDH 5.7 , we can have a detailed report for it.

Monday, May 30, 2016

[Big Data] Purge Leftovers on Hadoop - High Block Count warnings & Some Practices

Hi everyone,

Today,  i will talk about scraps on Hadoop system. We all know that Hadoop deletes remainders after operations succesfully finishes!:) But you should always check block counts. It caused by small size files and causes poor performance issues.

It is highly possible that you see High Block Count warnings on Cloudera Manager main page,
You can check block counts per datanode from following on CM -> HDFS service -> Active NameNode Web UI-> Live Nodes

Or this link http://#ACTIVE_NAME_NODE_IP#:50070/dfshealth.html#tab-datanode

In this work, i will point some practices about how to get rid of small files, ( most of them :) )

Sunday, May 29, 2016

[Big Data] FLAFKA & 2 topics - 2 hdfs sinks on a Kerberos Secured Cluster

Hi All,

After a long time , i started to complete my drafts :)

Here i will show an example for Flafka, which use Kafka as topics (messages) receiver and writes informations to HDFS via Flume.. After that i will query the logs via HIVE external table.

Thursday, March 3, 2016

[ TROUG ] My presentation - Oracle DataGuard 12c Hot Features - at TROUG HA SIG 2016

Hi people,

After some break, i made a presentation about hot features of Oracle Dataguard 12c at TROUG event

In this event, there were many brillant presentations at event and lots of dba guys met.

You can find more information on 

I will add my presentation later on slideshare and update this page.

You can find this topics at my presentation

- General info about Oracle DataGuard
- FarSync Instance
- DataGuard Broker Enhancements
- ActiveDataGuard option
- ...

Ok, That's all.

Thanks for reading.

Enjoy & share.

Monday, February 1, 2016

[BigData] About error saying "Couldn't find log associated with operation handle: OperationHandle [opType=EXECUTE_STATEMENT, getHandleIdentifier()=XXXXX"


I will talk about an error when people run query on HUE and get following error. Interesting part is that when a developer gets this error, another developer in same team works succesfully. In this post, i will investigate the error from HIVE server logs and the solution.

"Fetching results ran into the following error(s):
Couldn't find log associated with operation handle: OperationHandle [opType=EXECUTE_STATEMENT, getHandleIdentifier()=b1d336e8-3c7e-42f3-9f2a-3f3b9cb4fa21]
Bad status for request TFetchResultsReq"

[HIVE] How to move a table, hard and easy way ?

Hi ,

After some break, i am ready for new posts about authorization issues. In this post, i will try to move a table between HIVE databases in two ways. Choose which one works for you :)

Thursday, January 21, 2016

[BigData] Training Environment for BigData & How to start Oracle BDA Lite 4.2.1 succesfully


For all Oracle lovers and swimmers in BigData ocean :)

Now we have a safe amusement park for big data training purpose thanks to Oracle.

You can easily open Oracle BDA Lite VM as a virtual machine your terminals and start testing several hadoop tools and architectures within a lite version of a complete appliance.

[NoSQL] How to install an Oracle NoSQL Database

Hi people,

After a 2 weeks break, i am here to write again :)

In this post, i will create an Oracle NoSQL database on some nodes of Oracle BigData Appliance. Also, i will talk about NoSQL structures and do installation. After setup, i will populate and query the db and show how to secure an Oracle NoSQL database.

Tuesday, January 12, 2016

[DB Admin ~ BDA Admin] Big Data Okyanusuna Açılırken...

"En uzun yolculuklar bile, 
            tek bir adımla başlar.” 
-       Lao Tzu

Merhaba arkadaşlar,

Bu yazımda bir DBA’in BigData ile imtihanından ve Oracle Big Data Appliance (BDA) konfigürasyon serüveninden bahsedeceğim. Keyifli bir yazı yazmaya çalıştım . :)  Umarım bigdata çalışmalarına başlayan kişiler için faydalı olur.

Tuesday, January 5, 2016

[BigData] Authorization with Apache Sentry


Security is a hot topic in big data systems and Oracle integrates security to hadoop ecosystem with Apache Sentry.
Sentry is used in Oracle BigData Appliance in order to satisfy security concerns and authorize SQL access. Sentry supports role-based access control and unified authorization for HUE, impala and hive.

In this post , i will talk about sentry tool and make some authorization settings for OS groups.



All bloggers and Oracle lovers!!

Now we are very happy to announce TROUG Days 2016!!!

We want to welcome you with many professionals on their fields and open-mind visitors in this big Oracle event in TURKEY.

Have a look at questionnaire for hotels selection

Have a good year!

Enjoy & Share