datablogs: NoSQL
Showing posts with label NoSQL. Show all posts
Showing posts with label NoSQL. Show all posts

Wednesday, February 2, 2022

Redis to Elasticache Migration in AWS

Comparing Redis , AWS Elasticache giving multiple options to cache the data in cloud . Its enhanced with two ways of Access control options in PaaS Service 

Below are the few mission handling features we loved in elastic cache ,

  • Detecting data failures and recovery the nodes automatically 
  • Multi AZ features with automatic failover to replication nodes 
  • Redis Cluster mode enabled supports data partitioning up to 500 shards in different zones
  • Redis managed backups , automatic failure detection and log files transfer to Kinesis Firehouse and cloud watch 
  • Easy online migration from any Redis source 
  • Encryption at rest and Encryption in transit are supported 
  • Data volume up to peta bytes with micro second response time  
Let start migrating data from Redis to Elasticache ,

Preparing our source and target Redis nodes for migration 

  1. Launched two EC2 machines and installed redis 5.x version 
  2. Configured replication between master and replica
        To avoid downtime , we are doing online migration from replication server . so we have modified below values in replica server . Its based on your source modify the below values

      3.Configured replication between master and replica
  • protected-mode no
  • bind 6379
  • requirepass should be disabled

       Note : Transferring source master or replica should not have AUTH configured and protected mode disabled 

      4.Launch Elastic cache instance with below steps 

Cluster Mode Disabled ( Redis Engine 5.0.5 or Higher ) 

Multi-AZ Should be Enabled 

Encrypt at rest and in-transit should be disabled

If we have not followed above all steps , we will get below popup while we start the migration 

Starting Migration 

In Elastic console Click --> Action --> Migrate data from endpoint 

Once clicked , we can type the Source Redis Endpoint ( Private IP ) and Port ( Customized Port ) in below console ,

Then click Start Migration and follow the logs from Events in same console , 

If we get any error , It will be printed in the events log

Once its started , Restart the Master of Elasticache node one time , In our case we need to restart the replica server because its our source

Once restarted verify the info replication in Elasticache nodes 

Once started successfully , we can't perform any other operation in Elasticache nodes ,

Verifying the Data Migration Progress 

We have inserted sample record in the EC2 Master Node and verified the same in the replica and as well as in Elasticache 

Data looks good , once all the data transferred from IaaS to PaaS . Complete the migration in the Elasticache console and point the application endpoints to Elasticache node 

Thanks for Reading !!!

Sunday, July 19, 2020

Cassandra Multi-Node Cluster setup in Ubuntu 16.04

Sharing simple steps to configure Cassandra cluster in few minutes ,

Prerequisite :

Install Java ( Jre ) from oracle site and verify java version , But our installing step will be take care of java installation as well

java --version

Installing Cassandra repository :

What are repositories ?

"Authentication keys" are usually obtained from the maintainer of the software repository. The maintainer will often place a copy of the authentication key on a public key server such as The key can then be retrieved using the command.

Install the Cassandra repository into /etc/apt/sources.list.d/cassandra.sources.list using below command

Depends on requirement , update the 36x values into below command

echo "deb 36x main" | sudo tee -a /etc/apt/sources.list.d/cassandra.sources.list

if we didn't know the public key to authenticate for download packages , just run apt-get update commands and get the authentication key for Cassandra software

root@datablogs:~# sudo apt-get update
Hit:1 xenial InRelease
Hit:2 xenial-updates InRelease
Hit:3 xenial-backports InRelease
Get:5 xenial-security InRelease [109 kB]
Hit:6 xenial-pgdg InRelease
Get:4 36x InRelease [267 B]
Ign:4 36x InRelease
Get:7 36x/main amd64 Packages [678 B]
Fetched 113 kB in 1s (79.6 kB/s)
Reading package lists... Done
W: GPG error: 36x InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 749D6EEC0353B12C
W: The repository ' 36x InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Here , 749D6EEC0353B12C is the public key . Add the public key to install Cassandra ,

root@datablogs:~# sudo apt-key adv --keyserver --recv-key 749D6EEC0353B12C
Executing: /tmp/tmp.HUY7Ncexdr/ --keyserver
gpg: requesting key 0353B12C from hkp server
gpg: key 0353B12C: public key "T Jake Luciani <>" imported
gpg: Total number processed: 1
gpg:               imported: 1  (RSA: 1)

Installing Apache Cassandra :

Start updating the repository and install Cassandra cluster , Java Packages included with installation

root@datablogs:~# sudo apt-get update
Hit:1 xenial InRelease
Hit:2 xenial-updates InRelease
Hit:3 xenial-backports InRelease
Get:5 xenial-security InRelease [109 kB]
Hit:6 xenial-pgdg InRelease
Get:4 36x InRelease [267 B]
Fetched 112 kB in 1s (95.7 kB/s)
Reading package lists... Done
root@datablogs:~# sudo apt-get install cassandra
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  ca-certificates-java fontconfig-config fonts-dejavu-core java-common libavahi-client3 libavahi-common-data libavahi-common3 libcups2 libfontconfig1 libjpeg-turbo8
  libjpeg8 liblcms2-2 libnspr4 libnss3 libnss3-nssdb libopts25 libpcsclite1 libpython-stdlib libpython2.7-minimal libpython2.7-stdlib libxi6 libxrender1 libxtst6 ntp
  openjdk-8-jre-headless python python-minimal python2.7 python2.7-minimal x11-common
Suggested packages:
  cassandra-tools default-jre cups-common liblcms2-utils pcscd ntp-doc libnss-mdns fonts-dejavu-extra fonts-ipafont-gothic fonts-ipafont-mincho fonts-wqy-microhei
  fonts-wqy-zenhei fonts-indic python-doc python-tk python2.7-doc binutils binfmt-support
The following NEW packages will be installed:
  ca-certificates-java cassandra fontconfig-config fonts-dejavu-core java-common libavahi-client3 libavahi-common-data libavahi-common3 libcups2 libfontconfig1
  libjpeg-turbo8 libjpeg8 liblcms2-2 libnspr4 libnss3 libnss3-nssdb libopts25 libpcsclite1 libpython-stdlib libpython2.7-minimal libpython2.7-stdlib libxi6
  libxrender1 libxtst6 ntp openjdk-8-jre-headless python python-minimal python2.7 python2.7-minimal x11-common
0 upgraded, 31 newly installed, 0 to remove and 9 not upgraded.
Need to get 63.1 MB of archives.
After this operation, 167 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 xenial-updates/main amd64 libjpeg-turbo8 amd64 1.4.2-0ubuntu3.4 [111 kB]
Get:2 xenial-updates/main amd64 x11-common all 1:7.7+13ubuntu3.1 [22.9 kB]
Get:3 xenial/main amd64 libxtst6 amd64 2:1.2.2-1 [14.1 kB]

Configuring Apache Cassandra :

Needs to configure required variables in cassandra.yaml file ,

cluster_name: Name of the cluster

cluster_name: 'Test Cluster' ( Should be same in all Cassandra nodes ) 

-seeds: This is a comma-delimited list of the IP address of each node in the cluster

- seeds: "172.31.x.20,172.31.x.21,172.31.x.22,172.31.x.23,172.31.x.24,172.31.x.25"

listen_address: This is IP address that other nodes in the cluster will use to connect to this one. It defaults to localhost and needs changed to the IP address of the node

listen_address: 10.225.x.20 ( Cassandra Node 1 Address )

rpc_address: This is the IP address for remote procedure calls. It defaults to localhost. If the server’s host name is properly configured, leave this as is. Otherwise, change to server’s IP address or the loop back address (

rpc_address: 10.225.x.20 ( Cassandra Node 1 Address )

Once updated variables , restart Cassandra cluster in each nodes

Cluster status :

Verify Cassandra running status using below command ,

nodetool status 

Monday, December 23, 2019

Docker with Percona Backup for MongoDB

Sounds interesting from Percona Backup tool for MongoDB !!! I just wants to try and explore the tool with docker on today !!! Docker is first time for me , but in few days docker become favorite one to use for all kind of HA scenario works

Lets move into today's practices and issues ,

Note : Percona Backup for MongoDB supports Percona Server for MongoDB or MongoDB Community Server version 3.6 or higher with MongoDB replication enabled

Step 1 : Launched the Ubuntu 16.04 machine from AWS , then updated the latest packages and installed the docker 

sudo apt-get update 

sudo apt install

sudo systemctl start docker

sudo systemctl enable docker  

Once docker installed with latest package verify the docker version using docker --version 

Step 2 : Installed two docker mongo containers with replica set enabled 

docker run --detach --name datablogs-mongo-primary --volume /var/lib/mongo:/data/db --volume /etc/mongodb.conf:/etc/mongo.conf --publish 44444:27017 mongo --replSet datablogs-repl-set

docker run --detach --name datablogs-mongo-secondary --volume /var/lib/mongo-slave:/data/db --volume /etc/mongodb-slave.conf:/etc/mongo.conf --publish 55555:27017 mongo --replSet datablogs-repl-set

We need to access the mongoDB instances outside the world , so I have publised the mongo db ports with different one 
                                                             --publish 44444:27017

                                                             --publish 55555:27017

To access the mongoDB , we need to check the IP Address of both containers using below command

docker inspect datablogs-mongo-primary | grep IPAddress

docker inspect datablogs-mongo-secondary | grep IPAddress

-- usage of extensions refer with docker help

Step 3 : Configure mongo replica 

We need to login with docker command line and configure and start the replication between mongo servers . login into primary mongo container and execute below commands in mongo shell ,

docker exec -it datablogs-mongo-primary /bin/bash

config = {"_id" : "datablogs-repl-set","members" : [{"_id" : 0,"host" : ""},{"_id" : 1,"host" : ""}]};


Once we initiated the replication primary mongo shell will be changed 

Step 4 : Install Percona Backup and Configure 

Before proceeding this activity , we need to update and upgrade the packages using apt-get on each mongo containers

Installed the percona backup for mongoDB with below reference URL , we need to follow percona site for proper installation 

Once installed the pbm tool , login each mongo containers  set storage path and start the pbm agent . I have used local storage path for mongo backup

storage.yaml : 

type: filesystem
path: /tmp
pbm store set --config=storage.yaml --mongodb-uri="mongodb://"

pbm-agent --mongodb-uri mongodb:// &

Step 5 : Backup and restore the collections using pbm 

Once completed the setup running the backup in secondary mongo server 

pbm backup --mongodb-uri mongodb://

Dropped the datablogs db and restored the backup using pbm

Finally verfied the db and collections in primary server 

Am Really happy tested percona backup for mongoDB with Docker today !!! Keep learning !!!

Monday, November 25, 2019

Database Clusters with MongoDB Sharding

MongoDB supports horizontal scaling of the data with the help of the shared key. Shared key selection should be good and poor shared key split the data in only a single shared 

Today have tried a simple setup of MongoDB sharding with two shared nodes, sharing the simple steps to configure the same. Initially prepared with server lists and IP addresses of each server to avoid confusion by myself 

Launched 6 ubuntu servers and installed mongo in all the servers, set hostname accordingly. As above 2 mongo shared, 1 mongo router and 3 mongo config servers have been launched. Before installing mongo update the system with the latest packages 

sudo apt-get update && sudo apt-get upgrade

Then start installing the MongoDB in all the servers 

  1.sudo apt-key adv --keyserver hkp:// --recv E52529D4
2.sudo bash -c 'echo "deb xenial/mongodb-org/4.0 multiverse" > /etc/apt/sources.list.d/mongodb-org-4.0.list'

3.sudo apt update 

4.sudo apt install mongodb-org

5.systemctl enable mongod.service 

6.systemctl start mongod.service

For secure authentication, MongoDB recommends the X.509 certificate to secure connections between production systems. we need to create a key file for secure authentication between the members of your replica set.

Initially in primary config server create the key file with OpenSSL and copy the same SSL file to another server in the same location

1.openssl rand -base64 756 > mongo-keyfile
2.sudo mkdir /data/mongo
3.sudo mv ~/mongo-keyfile /data/mongo
4.sudo chmod 400 /data/mongo/mongo-keyfile
5.sudo chown mongodb:mongodb /data/mongo/mongo-keyfile

Once a key file is created, add value in all the /etc/mongod.conf. Its should be same as below because mongod.conf file is case sensitive

  keyFile: /opt/mongo/mongodb-keyfile

sudo systemctl restart mongod

Main Components : 

Config Server: This stores metadata and configuration settings for the rest of the cluster

Query Router: The Mongols daemon acts as an interface between the client application and the cluster shards. It’s like a listener of mongo instances

Shard: A database server that holds a portion of your data. Items in the database are divided among shards either by range or hashing

Steps involving in the configuration : 

   1.Configure the config servers
   2.Configure the Query Router
   3.Configure the sharding 

1.Configure the config servers 

Using single config server is not enough to maintain the metadata at the time of the disaster, we are setting up one primary and two secondary replica set 

On each config server, edit below values in mongod.conf. bind IP values will be different for each server 

Then restart mongo service using below command on each config servers 

sudo systemctl restart mongod

Once restarted initiate the config server using below command, please replace the hostnames accordingly 

And do check the rs.status of config server replica sets 

Configuring the config server is completed, let's move on next steps 

2.Configure the Query Router

Using the config server metadata information, send read and write queries to the correct shards 

Create /etc/mongos.conf file and add the below lines 

Create a new systemd unit file for mongos called /lib/systemd/system/mongos.service

Once we created files, needs to enable systemctl for mongos.service using below commands

1.sudo systemctl stop mongod
2.sudo systemctl enable mongos.service
3.sudo systemctl start mongos
4.systemctl status mongos

3.Configure the sharding servers

On each shared server, edit below values in mongod.conf. Bind IP values will be different for each server and restart the mongod service 

Once everything is completed, using mongo query router address login into any one of shared servers, I have created a separate admin user for MongoDB. If required create it 

mongo -u adminuser -p --authenticationDatabase admin

Connect mongos interface and add the shared nodes, if you have replica set for shared nodes steps will be different to add shared 

It’s done, shared000 and shared001 are added. There are many links available for sharding the database and collections to mangos. Tried with below examples for my test and its working as expected 

Thanks for reading !!!