How to remove duplicate files using Apache Nifi? - apache-nifi

I have a couple of EC2 servers set-up, with the same EFS mounted on each of these instances.
Have also setup Apache Nifi independently on each of the 2 machines. Now, when I try to make a data flow to copy files from the EFS mounted folder, I get duplicated files on both the servers.
Is there some way in Apache Nifi using which I can churn out duplicate items, since both of them are firing at the same time. Cron is not useful enough as at some point the servers will collide at the same time.

For Detecting Duplicate file you can use DetectDuplicate Processor.

Related

How to archive data stored in HDFS files on another (non-distributed) server?

I have a project folder containing approx. 50 GB of parquet files on a hadoop cluster (CDH 5.14), which I need to archive and move to another host (non-distributed with Windows or Linux). This is only a one time job - I do not plan to bring the data back to HDFS any time soon, however there should be a way to deploy it back to a distributed file system. What would be the optimal way to do it? Unfortunately, I don't have another hadoop cluster or a cloud environment where I could place this data.
I would appreciate any hints.
The optimal solution can depend on the actual data (e.g. Tables, many/few flat files). If you know how they got in there, looking at the inverse could be a logical first step.
For example, if you just use put to place the files, consider using get.
If you use Nifi to get it in, try Nifi to get it out.
After the data is on your Linux box, you can use SCP or something like FTP or a mounted drive to move it to the desired computer.

hazelcast-jet deployment and data ingestion

I have a distributed system running on AWS EC2 instances. My cluster has around 2000 nodes. I want to introduce a stream processing model which can process metadata being periodically published by each node (cpu usage, memory usage, IO and etc..). My system only cares about the latest data. It is also OK with missing a couple of data points when the processing model is down. Thus, I picked hazelcast-jet which is an in-memory processing model with great performance. Here I have a couple of questions regarding the model:
What is the best way to deploy hazelcast-jet to multiple ec2 instances?
How to ingest data from thousands of sources? The sources push data instead of being pulled.
How to config client so that it knows where to submit the tasks?
It would be super useful if there is a comprehensive example where I can learn from.
What is the best way to deploy hazelcast-jet to multiple ec2 instances?
Download and unzip the Hazelcast Jet distribution on each machine:
$ wget https://download.hazelcast.com/jet/hazelcast-jet-3.1.zip
$ unzip hazelcast-jet-3.1.zip
$ cd hazelcast-jet-3.1
Go to the lib directory of the unzipped distribution and download the hazelcast-aws module:
$ cd lib
$ wget https://repo1.maven.org/maven2/com/hazelcast/hazelcast-aws/2.4/hazelcast-aws-2.4.jar
Edit bin/common.sh to add the module to the classpath. Towards the end of the file is a line
CLASSPATH="$JET_HOME/lib/hazelcast-jet-3.1.jar:$CLASSPATH"
You can duplicate this line and replace -jet-3.1 with -aws-2.4.
Edit config/hazelcast.xml to enable the AWS cluster discovery. The details are here. In this step you'll have to deal with IAM roles, EC2 security groups, regions, etc. There's also a best practices guide for AWS deployment.
Start the cluster with jet-start.sh.
How to config client so that it knows where to submit the tasks?
A straightforward approach is to specify the public IPs of the machines where Jet is running, for example:
ClientConfig clientConfig = new ClientConfig();
clientConfig.getGroupConfig().setName("jet");
clientConfig.addAddress("54.224.63.209", "34.239.139.244");
However, depending on your AWS setup, these may not be stable, so you can configure to discover them as well. This is explained here.
How to ingest data from thousands of sources? The sources push data instead of being pulled.
I think your best option for this is to put the data into a Hazelcast Map, and use a mapJournal source to get the update events from it.

ETL process in AWS using EC2-s and EFS

I am a data engineer with experience in designing n creating data integration and ELT processes. Below is my use case, and I need to move my process to aws and would like your opinion?
My files to be processed are in s3. I need to process those files using Hadoop. I have existing logic written in hive, just need to migrate the same to aws. Is the below approach correct/ feasible?
Spin up a fleet of ec2 instances, initially say 5, enable autoscaling.
Create an EFS, and mount it on the ec2 instances.
Copy file from s3 to EFS as Hadoop tables.
Run hive queries on top of the data in EFS and create new tables.
Once the process is completed, move/ export the final reports table from EFS to s3 (somehow). Not sure that whether this is possible or not, if this is not possible then this entire solution is not feasible.
6.Terminate EFS and EC2 instances.
If the above method is correct, How does the Hadoop orchestration happen using EFS?
Thanks,
KR
Spin up a fleet of ec2 instances, initially say 5, enable autoscaling.
I'm not sure you need the autoscaling.
why?
let's say you start a "big" query which takes lot's of time & cpu.
auto-scale will start more instances , but how will it start run "fraction" of the query on the new machine?
all machines need to be ready before you run the query . just keep it in mind.
Or in other words: only the machines that available now will handle the query.
Copy file from s3 to EFS as Hadoop tables.
There isn't any problem with this idea.
just keep in mind , you can keep the data in EFS .
if EFS is too pricy for you ,
Please check options for provision EBS-magnetic with Raid 0 .
You will gain great speeds at minimal costs.
The rest is okay, and this is one of the ways to do "on demand" interactive analytics.
Please take a look into AWS Athena.
It's a service which allows you to run queries on s3 objects .
You can use Json and even Parquet (which is much more efficient !)
This service may be enough for your need .
Good luck !

Running multiple elasticsearch instances

I need to setup 2 Elasticsearch instances:
one for kibana logs (my separate application will throw logs at it)
one for search for my production application
My plan is to create a separate folders with elasticsearch in them. They dont talk to each other which means they are separate databases and if one goes down, the other still runs. Is this good solution or should I use only one elasticsearch folder with muliple elasticsearch.yaml configuration files? What is the best practice for multiple elasticsearch instances?
The best practice is to NOT run two Elasticsearch instances on the SAME server.
Your production search will probably need a lot of ram to work fast and stay responsive. You don't want your logging system interfere with that.

How to rsync to all Amazon EC2 servers?

I have a Scalr EC2 cluster, and want an easy way to synchronize files across all instances.
For example, I have a bunch of files in /var/www on one instance, I want to be able to identify all of the other hosts, and then rsync to each of those hosts to update their files.
ls /etc/aws/hosts/app/
returns the IP addresses of all of the other instances
10.1.2.3
10.1.33.2
10.166.23.1
Ideas?
As Zach said you could use S3.
You could download one of many clients out there for mapping drives to S3. (search for S3 and webdav).
If I was going to go this route I would setup an S3 bucket with all my shared files and use jetS3 in a cronJob to sync each node's local drive to the bucket (pulling down S3 bucket updates). Then since I normally use eclipse & ant for building, I would create a ANT job for deploying updates to the S3 bucket (pushing updates up to the S3 bucket).
From http://jets3t.s3.amazonaws.com/applications/synchronize.html
Usage: Synchronize [options] UP <S3Path> <File/Directory>
(...)
or: Synchronize [options] DOWN
UP : Synchronize the contents of the Local Directory with S3.
DOWN : Synchronize the contents of S3 with the Local Directory
...
I would recommend the above solution, if you don't need cross-node file locking. It's easy and every system can just pull data from a central location.
If you need more cross-node locking:
An ideal solution would be to use IBM's GPFS, but IBM doesn't just give it away (at least not yet). Even though it's designed for High Performance interconnects it also has the ability to be used over slower connections. We used it as a replacement for NFS and it was amazingly fast ( about 3 times faster than NFS ). There maybe something similar that is open source, but I don't know. EDIT: OpenAFS may work well for building a clustered filesystem over many EC2 instances.
Have you evaluated using NFS? Maybe you could dedicate one instance as an NFS host.

Resources