Clarification of Sqoop and Flume - hadoop

I am very new to big data and i have little confusion regarding Sqoop and Flume
So i get that difference between the Sqoop and Flume
Sqoop is for transferring bulk data from RDBMS
Flume is for streaming of data such as log files
My confusion is because big data architecture i am looking at (which i have no virtual copy of) grouped structured data and its transferred by Sqoop and Unstructured streamed by Flume.
My question regard that is does that mean Flume is only for streaming?
What about high frequency data? and does Flume support transfer of unstructured data that are non-log files (i.e. audio, video) or would Sqoop be able to handle that?
Final question is can Sqoop work with federated data sources? if yes with both real and virtual?
Thanks,

Apache Flume is a distributed, reliable, and available system for efficiently collecting, aggregating and moving large amounts of log data from many different sources to a centralized data store.
The use of Apache Flume is not only restricted to log data aggregation. Since data sources are customizable, Flume can be used to transport massive quantities of event data including but not limited to network traffic data, social-media-generated data, email messages and pretty much any data source possible.
Apache Sqoop is a tool designed for efficiently transferring bulk data between Apache Hadoop and structured datastores such as relational databases(it imports data, transform the data in Hadoop MapReduce, and then export the data).
Sqoop automates most of this process, relying on the database to describe the schema for the data to be imported. Sqoop uses MapReduce to import and export the data, which provides parallel operation as well as fault tolerance.
Source: sqoop-vs-flume-battle-of-the-hadoop
Reference: INGESTION AND STREAMING
Flume is efficient with streams and if you want to just dump data from RDBMS why not use sqoop?
By high frequency data if you mean social media yes flume can handle it. Unstructured data yes, flume may handle that too.

sqoop is essentially a tool to ingest data in HDFS from RDBMS. Under the hood, it generates simple Java code which submit a query to a RDBMS and writes the result to HDFS. This means that you can import with sqoop everything which can be accessed via JDBC connection and which has a Java driver available. For this reason, you can't use it for files (like logs) or things like that.
Then sqoop can't handle video or audio files.
Flume, instead, is used to monitor and ingesting in real time informations. You can ingest everything for which there is a Flume source available (https://flume.apache.org/FlumeUserGuide.html#flume-sources).

Related

GCP Hadoop data warehouse?

I know Google BigQuery is a data warehouse but is Dataproc, Big Table, Pub/Sub considered a data warehouse? Would that make Hadoop a data warehouse?
A "Data warehouse" is mostly an information systems concept that describes a centralized and trusted source of (e.g. company/business) data.
From Wikipedia: "DWs are central repositories of integrated data from one or more disparate sources. They store current and historical data in one single place that are used for creating analytical reports for workers throughout the enterprise."
Regarding your questions, a simple answer would be:
Google BigQuery is a query execution (and/or data processing) engine that you can use over data stores of different kinds.
Google BigTable is a database service that can be used to implement a
data warehouse or any other data store.
Google DataProc is a data processing service composed by common Hadoop processing components like MapReduce (or Spark, if you consider it part of Hadoop).
Hadoop is a framework/platform for data storage and processing comprised of
different components (e.g. data storage via HDFS, data processing via MapReduce). You could use an Hadoop platform to build a Data Warehouse, e.g. by using MapReduce to process data and load it into ORC files that will be stored in HDFS and that can be queried by Hive. But it would only be appropriate to call it a data warehouse if it is a "centralized, single version of the truth about data" ;)
Dataproc could be working as a data lake as it's a Hadoop cluster, but it could be considered as a Data warehouse as some tools can consult its information.
BigTable stores up to petabytes of data, however, it's designed for applications that need very high throughput and scalability. Nevertheless, due to its high storage capacity and stream processing/analytics, it could be considered as a data warehouse too.
Pub/Sub it's not a data warehouse as it's a publish-subscribe service.

How to build a big data platform to receive and store big data in Hadoop

I am trying to build up a big data platform to receive and store in Hadoop large amount of heterogeneous data like (documents,videos,images,sensors data, etc) then implement classification process.
So what architecture can help me as I’m currently using
VMware VSphere EXSi
Hadoop
Habse
Thrift
XAMPP
All these working fine but I don’t know how to receive a large amount of data and how to store the data because I discovered that Hbase is a column-oriented data base and it’s not data warehouse.
You have to customize solution for type of Big Data ( Structured, Semi-Structured and Un-Structured)
You can use HIVE/HBASE for structured data if total data size <= 10 TB
You can use SQOOP to import structured data from traditional RDBMS database Oracle, SQL Server etc.
You can use FLUME for processing Un-structured data.
You can use Content Management System to process Un-structured data & Semi-Structured data - Tera Or Peta bytes of data. If you are storing un-structured data, I prefer to store the data in CMS and use meta data information in NoSQL database like HBASE
To process Big data streaming, you can use PIG.
Have a look at Structured Data and Un-Structured data handling in Hadoop

How to get data from HDFS? Hive?

I am new to Hadoop. I ran a map reduce on my data and now I want to query it so I can put it into my website. Is Apache Hive the best way to do that? I would greatly appreciate any help.
Keep in mind that Hive is a batch processing system, which under the hoods converts the SQL statements to bunch of MapReduce jobs with stage builds in between. Also, Hive is a high latency system i.e. based on your dataset sizes you are looking at minutes to hours or even days to process a complicated query.
So, if you want to serve the results from your MapReduce job output in your website, its highly recommended you export the results back to a RDBMS using sqoop and then take it from there.
Or, if the data itself is huge and cannot be exported back to RDBMS. Then another option you could think of is using a NoSQL system like HBase.
welcome to Hadoop!
I highly recommend you watch Cloudera Essentials for Apache Hadoop | Chapter 5: The Hadoop Ecosystem and familiarize yourself with the different ways to transfer data inbound and outbound from your HDFS cluster. The video is easy-to-watch and describes advantages / disadvantages to each tool, but this outline should give you the basics of the Hadoop Ecosystem:
Flume - Data integration and import of flat files into HDFS. Designed for asynchronous data streams (e.g., log files). Distributed, scalable, and extensible. Supports various endpoints. Allows preprocessing on data before loading to HDFS.
Sqoop - Bidirectional transfer of structured data (RDBMS) and HDFS. Permits incremental import to HDFS. RDBMS must support JDBC or ODBC.
Hive - SQL-like interface to Hadoop. Requires table structure. JDBC and/or ODBC is required.
Hbase - Allows interactive access of HDFS. Sits on top of HDFS and apply structure to data. Allows for random reads, scales horizontally with cluster. Not a full query language; only permits get/put/scan operations (can be used with Hive and/or Impala). Row-key indexes only on data. Does not use Map Reduce paradigm.
Impala - Similar to Hive, high-performance SQL Engine for querying vast amounts of data stored in HDFS. Does not use Map Reduce. Good alternative to Hive.
Pig - Data flow language for transforming large datasets. Permits schema optionally defined at runtime. PigServer (Java API) permits programmatic access.
Note: I assume the data you are trying to read already exists in HDFS. However, some of the products in the Hadoop ecosystem may be useful for your application or as a general reference, so I included them.
If you're only looking to get data from HDFS then yes, you can do so via Hive.
However, you'll most beneficiate from it if your data are already organized (for instance, in columns).
Lets take an example : your map-reduce job produced a csv file named wordcount.csv and containing two rows : word and count. This csv file is on HDFS.
Let's now suppose you want to know the occurence of the word "gloubiboulga". You can simply achieve this via the following code :
CREATE TABLE data
(
word STRING,
count INT,
text2 STRING
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ",";
LOAD DATA LOCAL INPATH '/wordcount.csv'
OVERWRITE INTO TABLE data;
select word, count from data where word=="gloubiboulga";
Please note that while this language looks highly like SQL, you'll still have to learn a few things about it.

Hadoop vs. NoSQL-Databases

As I am new to Big Data and the related technologies my question is, as the title implies:
When would you use Hadoop and when would you use some kind of NoSQL-Databases to store and analyse massive amounts of data?
I know that Hadoop is a Framework and that Hadoop and NoSQL differs.
But you can save lots of data with Hadoop on HDFS and also with NoSQL-DBs like MongoDB, Neo4j...
So maybe the use of Hadoop or of a NoSQL-Database depends if you just want to analyse data or if you just want to store data?
Or is it just that HDFS can save lets say RAW data and a NoSQL-DB is more structured (more structured than raw data and less structured than a RDBMS)?
Hadoop in an entire framework of which one of the components can be NOSQL.
Hadoop generally refers to cluster of systems working together to analyze data. You can take data from NOSQL and parallel process them using Hadoop.
HBase is a NOSQL that is part of Hadoop ecosystem. You can use other different NOSQL too.
Your question is missleading you are comparing Hadoop, which is a framework, to a database ...
Hadoop is containing a lot of features (including NoSQL database named HBase) in order to provide you a big data environment. If you're having a massive quantity of data you will probably use Hadoop (for the MapReduce functionalities or the datawarehouse capabilities) but it's not sure, depending on what you're processing and how you want to process it. If you're just storing a lot of data and don't need other feature (batch data processing or data transformations ...) a simple NoSQL database is enough.

Data moving from RDBMS to Hadoop, using SQOOP and FLUME

I am in the process of learning Hadoop and stuck with few concepts on moving data from Relational database to Hadoop and vice versa.
I have transferred files from MySQL to HDFS using SQOOP import queries. The files I transferred were structured datasets and not any server log data. I recently read that we usually use flume for moving log files into Hadoop,
My question is:
1. Can we use SQOOP as well for moving log files?
2. If yes, which of SQOOP or FLUME is more preferred for log files and why?
1) Sqoop can be used to transfer data between any rdbms and hdfs. To use scoop the data has to be structured usually specified by schema of database from where data is being imported or exported.Log files are not always structured,depending on source and type of log so sqoop is not used for moving log files.
2)Flume can collect, aggregate data from many different kinds of customizable data sources. It gives more flexibility in controlling what specific events to capture and use in user defined work flow before storing in say hdfs.
I hope it clarified difference between sqoop and flume.
SQOOP is designed to transfer data from RDMS to HDFS whereas FLUME is for moving large amounts of log data.
Both are different and specialized for different purposes.
Like
You can use SQOOP to import data via JDBC ( which you can not do in FLUME ),
and
You can use FLUME to say something like "I want to tail 200 lines of log file from this server".
Read more about FLUME here
http://flume.apache.org/
SQOOP not only transfers data from RDBMS but also from NOSql databases like MongoDB. You can directly transfer data to HDFS or Hive.
Transferring data to Hive you need not have to create table beforehand.. It takes the scheme from database itself.
Flume is used to fetch log data or streaming data

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