I am pretty new to Oracle Golden Gate, wanted to understand if it possible to create a bidirectional sync between Oracle 12x and Cassandra(DSE) using Oracle Golden Gate? Searched several places in internet but most examples are replicating data between Oracle databases. I started wondering if it is even possible to do so. Can anyone help me with any documentation?
There is a separate module called Oracle GoldenGate for BigData. It supports many NoSQL replication targets.
One of the supported BigData databases is also Apache Cassandra.
There is a separate manual explaining how to use it.
There is no separate module that allows you to connect Apache Cassandra as the source of your replication. If you need such replication you need to provide some intermediate step. The source of replication for Oracle GoldenGate can only be a database (Oracle, TimesTen, DB2, Informix, MySQL, MS SQL Server, NonStop SQL/MX, SAP/Sybase ASE, Teradata) or a JMS queue.
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I would like to expose the data table from my oracle database and expose into apache kafka. is it technicaly possible?
As well i need to stream data change from my oracle table and notify it to Kafka.
do you know good documentation of this use case?
thanks
You need Kafka Connect JDBC source connector to load data from your Oracle database. There is an open source bundled connector from Confluent. It has been packaged and tested with the rest of the Confluent Platform, including the schema registry. Using this connector is as easy as writing a simple connector configuration and starting a standalone Kafka Connect process or making a REST request to a Kafka Connect cluster. Documentation for this connector can be found here
To move change data in real-time from Oracle transactional databases to Kafka you need to first use a Change Data Capture (CDC) proprietary tool which requires purchasing a commercial license such as Oracle’s Golden Gate, Attunity Replicate, Dbvisit Replicate or Striim. Then, you can leverage the Kafka Connect connectors that they all provide. They are all listed here
Debezium, an open source CDC tool from Redhat, is planning to work on a connector that is not relying on Oracle Golden Gate license. The related JIRA is here.
You can use Kafka Connect for data import/export to Kafka. Using Kafka Connect is quite simple, because there is no need to write code. You just need to configure your connector.
You would only need to write code, if no connector is available and you want to provide your own connector. There are already 50+ connectors available.
There is a connector ("Golden Gate") for Oracle from Confluent Inc: https://www.confluent.io/product/connectors/
At the surface this is technically feasible. However, understand that the question has implications on downstream applications.
So to comprehensively address the original question regarding technical feasibility, bear in mind the following:
Are ordering/commit semantics important? Particularly across tables.
Are continued table changes across instance crashes (Kafka/CDC components) important?
When the table definition changes - do you expect the application to continue working, or will resort to planned change control?
Will you want to move partial subsets of data?
What datatypes need to be supported? e.g. Nested table support etc.
Will you need to handle compressed logical changes - e.g. on update/delete operations? How will you address this on the consumer side?
You can consider also using OpenLogReplicator. This is a new open source tool which reads Oracle database redo logs and sends messages to Kafka. Since it is written in C++ it has a very low latency like around 10ms and yet a relatively high throughput ratio.
It is in an early stage of development but there is already a working version. You can try to make a POC and check yourself how it works.
We have an Oracle Database that resides tables. We would like to implement a new project as I mentioned in title; Oracle to Cassandra real-time replication.
But this new Cassandra environment would be as a reporting service. From the application (in-house), datas is inserted to Oracle production environment. Then our custom service (or what ever) will read delta and insert to Cassandra (this would be like Goldengate may be).
Briefly, does the Cassandra will answer our needs for this scenario?
In our case, we have 20 oracle DBs in different locations (these 20 dbs has similar implementation) 1 central report DB that is daily refresh from these 20 DBs. We use "outdated" snapshot technology, every night our central single report DB (REPORTDB) with fast refresh option, we gather the daily delta from these 20 dbs within oracle ss. we need a structure that reads data from 20 dbs and real-time injection to new cassandra database just like REPORDB
These days you can run spark jobs on Cassandra, thanks to Datastax so yes it can be used as a reporting tool. It's best utilized as a key value store if your number of writes are high compared to your reads.
Reading delta is not real time so you should try using Oracle's AQs. I've been doing real time replication of Oracle to Cassandra using Oracle's AQ and Apache Storm for almost 4 years now and it's running flawlessly.
I don't understand this Oracle/Cassandra architecture running alongside.
Either Oracle suits your needs then you should stick with it. Or it doesn't and you need scalability/high availability then switch to Cassandra.
Can you elaborate on the reasons that make you choose Cassandra for the reporting service ?
I have a requirement to ingest the data from an Oracle database to Hadoop in real-time.
What's the best way to achieve this on Hadoop?
The important problem here is getting the data out of the Oracle DB in real time. This is usually called Change Data Capture, or CDC. The complete solution depends on how you do this part.
Other things that matter for this answer are:
What is the target for the data and what are you going to do with it?
just store plain HDFS files and access for adhoc queries with something like Impala?
store in HBase for use in other apps?
use in a CEP solution like Storm?
...
What tools is your team familiar with
Do you prefer the DIY approach, gluing together existing open-source tools and writing code for the missing parts?
or do you prefer a Data integration tool like Informatica?
Coming back to CDC, there are three different approaches to it:
Easy: if you don't need true real-time and have a way to identify new data with an SQL query that executes fast enough for the required data latency. Then you can run this query over and over and ingest its results (the exact method depends on the target, the size of each chunk, and the preferred tools)
Complicated: Roll your own CDC solution: download the database logs, parse them into series of inserts/updates/deletes, ingest these to Hadoop.
Expensive: buy a CDC solution, that does this for you (like GoldenGate or Attunity)
Expanding a bit on what #Nickolay mentioned, there are a few options, but the best would be too opinion based to state.
Tungsten (open source)
Tungsten Replicator is an open source replication engine supporting a variety of different extractor and applier modules. Data can be extracted from MySQL, Oracle and Amazon RDS, and applied to transactional stores, including MySQL, Oracle, and Amazon RDS; NoSQL stores such as MongoDB, and datawarehouse stores such as Vertica, Hadoop, and Amazon rDS.
Oracle GoldenGate
Oracle GoldenGate is a comprehensive software package for real-time data integration and replication in heterogeneous IT environments. The product set enables high availability solutions, real-time data integration, transactional change data capture, data replication, transformations, and verification between operational and analytical enterprise systems. It provides a handler for HDFS.
Dell Shareplex
SharePlex™ Connector for Hadoop® loads and continuously replicates changes from an Oracle® database to a Hadoop® cluster. This gives you all the benefits of maintaining a real-time or near real-time copy of source tables
Apache Sqoop is a data transfer tool to transfer bulk data from any RDBMS with JDBC connectivity(supports Oracle also) to hadoop HDFS.
We are upgrading our infrastructure and for that we are migrating from Oracle 10g to 11g.
We are using Oracle GoldenGate for data replication and it does not support replication of AQ messages as far as we know.
For Persistent queue, we have import/export option available. But there are some Buffered queues as well need to be replicated.
can anyone guide how we can avoid data loss in this situation.
Appreciate any help.
Oracle GoldenGate can replicate only "logged" data change so it is impossible to replicate non-persistent queues by definition.
Other Oracle product that deals with queues replication is "Oracle Streams". If you unable to use Oracle Streams for that purpose; other solution might be complete replica of the AQ with another Oracle product "Oracle Coherence" - distributed cache, what is fault tolerant by definition and can do same job with of course code changes required.
It is not a problem to implement a queue on Oracle or any other vendor distributed cache. I believe that you may see significant performance improvement in this case.
What are the available hadoop remote data sources connectivity options?
I know about drivers for MongoDB, MySQL and Vertica connectivity but my question is what are other available data sources that have driver for hadoop connectivity?
These are the few I am aware of :
Oracle
ArcGIS Geodatabase
Teradata
Microsoft SQL Server 2008 R2 Parallel Data Warehouse (PDW)
PostgreSQL
IBM InfoSphere warehouse
Couchbase
Netezza
Tresata
But I am still wondering about the intent of this question. Every data source fits into a particular use case. Like, Couchbase for document data storage, Tresata for financial data storage and so on. Are you going to decide your store based on the connector availability??I don't think so.
Your list will be too long to be useful.
Just one reference: cascading gives you access to almost anything you want to access. More, you're not limited with Java. For example there is scalding component which provides very good framework for Scala programmers.