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