Downgrade MongoDB - Enterprise to Community Edition

MongoDB Enterprise to Community Edition  - Implementation

Overview:

Shards 1(rs_0)

tommy1:27019 - Primary

tommy2:27019 - Secondary

tommy3:27019 - Secondary

Shards 2(rs_1)

tommy4:27019 - Primary

tommy5:27019 - Secondary

tommy6:27019 - Secondary

Shards 3(rs_3)

tommy7:27019 - Primary

tommy8:27019 - Secondary

tommy9:27019 - Secondary

ConfigDB:

tommy10:27018

tommy11:27018

tommy12:27018

Mongos:

tommy13:27017

Version : 3.0.5

Cluster size : 56.3GB

Implementation Plan:

1) Login as mongod user

Sudo -u mongod -i

Password

Note: just for reference

Existing path in Prod server bin - /var/lib/mongodb-mms-automation/mongodb-linux-x86_64-3.0.5-ent/bin/

Existing path in Prod server config - /data/automation-mongod.conf

Generic Path for bin - /usr/mongodb_3.0.5/bin/

Generic Path for config - /usr/mongodb_3.0.5/conf/

2) Create necessary directories in all the servers

# mkdir -p /usr/mongodb_3.0.5/bin/

# chmod 775 /usr/mongodb_3.0.5/bin/

# mkdir /usr/mongodb_3.0.5/conf/

# chmod 775 /usr/mongodb_3.0.5/conf/

3) Copy the New Binaries to all the servers in bin folder from - tommy13

Path - /usr/mongodb_3.0.5/bin/

Log in to tommy13 – run the below command in all the servers

# scp /tmp/mongodb-linux-x86_64-3.0.5.tgz [user account]@[hostname]:/tmp/

Then log in to each server, run the commands – ( have to run this in all servers)

# cd /tmp

# tar -zxvf mongodb-linux-x86_64-3.0.5.tgz

# cp -R /tmp/mongodb-linux-x86_64-3.0.5/* /usr/mongodb_3.0.5/

4) Copy the existing configuration files to the new path

Path - /usr/mongodb_3.0.5/conf/

For tommy13 - mongos

cp /var/lib/mongodb-mms-automation/workspace/mongos-cluster_mongos_0.conf /usr/mongodb_3.0.5/conf/

For tommy10 - config

cp /data/cluster_config_10/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy11 - config

cp /data/cluster_config_11/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy12 - config

cp /data/cluster_config_12/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy1 - primary

cp /data/cluster_rs_0_2/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy2 - secondary

cp /data/cluster_rs_0_1/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy3 - secondary

cp /data/cluster_rs_0_3/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy4 - primary

cp /data/cluster_rs_0_4/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy5 - secondary

cp /data/cluster_rs_1_4/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy6 - seconday

cp /data/cluster_rs_1_5/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy7 - primary

cp /data/cluster_rs_2_8/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy8 - secondary

cp /data/cluster_rs_2_7/automation-mongod.conf /usr/mongodb_3.0.5/conf/

For tommy9 secondary

cp /data/cluster_rs_2_9/automation-mongod.conf /usr/mongodb_3.0.5/conf/

5) Rename the config file names

tommy13 - mongos

# mv /usr/mongodb_3.0.5/conf/mongos-cluster_mongos_0.conf /usr/mongodb_3.0.5/conf/mongos.conf

tommy1, tommy2, tommy3, tommy4, 

tommy5, tommy6, tommy7, tommy8,

tommy9 - mongod

# mv /usr/mongodb_3.0.5/conf/automation-mongod.conf /usr/mongodb_3.0.5/conf/mongod.conf

tommy10, tommy11, tommy12 - config

# mv /usr/mongodb_3.0.5/conf/automation-mongod.conf /usr/mongodb_3.0.5/conf/mongod_config.conf

6) Open all config files in all servers and delete the first 2 lines which is hashed (#)

tommy13 - mongos

# vi /usr/mongodb_3.0.5/conf/mongos.conf

tommy1, tommy2, tommy3, tommy4, 

tommy5, tommy6, tommy7, tommy8,

tommy9 - mongod

# vi /usr/mongodb_3.0.5/conf/mongod.conf

tommy10, tommy11, tommy12 - config

# vi /usr/mongodb_3.0.5/conf/mongod_config.conf

6) Disable the balancer

> login to tommy13 server

> connect to mongos

> mongo admin --port 27017

# mongos> sh.getBalancerState()

true

# mongos> sh.stopBalancer()

# mongos> sh.getBalancerState()

false

7) Downgrade secondary members of the replica set in each shard 1

1st secondary

login to tommy2 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27019

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongod -f /usr/mongodb_3.0.5/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

2nd secondary

login to tommy3 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27019

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongod -f /usr/mongodb_3.0.5/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

8) Step down the primary in shard 1.

login to tommy1 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27019

Step down the primary

# rs.stepDown()

when the server become secondary

# use admin

# db.shutdownServer()

start the server with the new binaries and new config file

# /var/lib/mongodb/mongodb_3.0.5/bin/mongod -f /var/lib/mongodb/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

9) Downgrade secondary members of the replica set in each shard 2

1st secondary

login to tommy5 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27019

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongod -f /usr/mongodb_3.0.5/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

2nd secondary

login to tommy6 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27019

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongod -f /usr/mongodb_3.0.5/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

10) Step down the primary in shard 2.

login to tommy4 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27019

Step down the primary

# rs.stepDown()

when the server become secondary

# use admin

# db.shutdownServer()

start the server with the new binaries and new config file

# /var/lib/mongodb/mongodb_3.0.5/bin/mongod -f /var/lib/mongodb/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

11) Downgrade secondary members of the replica set in each shard 3

1st secondary

login to tommy8 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27019

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongod -f /usr/mongodb_3.0.5/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

2nd secondary

login to tommy9 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27019

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongod -f /usr/mongodb_3.0.5/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

12) Step down the primary in shard 3.

login to tommy7 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27019

Step down the primary

# rs.stepDown()

when the server become secondary

# use admin

# db.shutdownServer()

start the server with the new binaries and new config file

# /var/lib/mongodb/mongodb_3.0.5/bin/mongod -f /var/lib/mongodb/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

13) Downgrade the SCCC config servers in reverse order

> Reverse order based on the configDB option in mongos config file

configDB: tommy10:27018, tommy11:27018, tommy12:27018

> Downgrade Config3, followed by config2 and then config1 so

> Downgrade tommy12, followed by tommy11 and then tommy10

tommy12

login to tommy12 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27018

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongod -f /usr/mongodb_3.0.5/conf/mongod_config.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

tommy11

login to tommy11 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27018

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongod -f /usr/mongodb_3.0.5/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

tommy10

login to tommy10 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27018

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongod -f /usr/mongodb_3.0.5/conf/mongod.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

14) Downgrade the mongos instances.

login to tommy13 server

check the process

# ps aux | grep mongo

Remove MongoDB automation agent

# sudo rpm -e mongodb-mms-automation-agent-manager

connect to mongo

# mongo admin --port 27017

# db.shutdownServer()

start the server with the new binaries and new config file

# /usr/mongodb_3.0.5/bin/mongos -f /usr/mongodb_3.0.5/conf/mongos.conf

connect to mongo and wait for the member to recover to SECONDARY state before downgrading the next secondary - to check

# rs.status()

15) Re-enable the balancer.

- Once the downgrade of sharded cluster components is complete, re-enable the balancer.

- login to tommy13 server

- connect to mongo

# mongo --port 27017

# mongos> sh.getBalancerState()

false

# mongos> sh.startBalancer()

# mongos> sh.getBalancerState()

true

Note: This implementation is done before the migration of Config Server from SCCC to ReplicaSet