Triangle MUG - Back to Basic: Replica Sets

Getting everybody on the same page

• Creating a 3-member Replica Set
• Member Roles
• Replica Set settings
• Changing Replica Set settings
• Connection String

Preparing your lab environment

• mkdir -p mdb/{3_Node_Arbiter,3_Node,5_Node}

• mlaunch init --replicaset --nodes 2 --arbiter --dir mdb/3_Node_Arbiter

• mlaunch stop --dir mdb/3_Node_Arbiter

• mlaunch init --replicaset --nodes 3 --dir mdb/3_Node

• mlaunch stop --dir mdb/3_Node

• mlaunch init --replicaset --nodes 5 --dir mdb/5_Node

• mlaunch stop --dir mdb/5_Node

Playing Time

Note: This session requires mongoDB and mtools to be installed on your system

a) 3-member Replica Set - Connection using a single IP/Hostname

• Connecting to a replica set pointing to the IP/Hostname of the primary member
• Bring primary node down
• What happen to your connection?

b) 3-member Replica Set - Connection using a connection string

• Connecting to a replica set using a connection string
• Bring primary node down
• What happen to your connection?

c) 3-member Replica Set w/ arbiter and writeConcern: majority

• Bring the secondary node down
• Insert a document into a collection using writeConcern majority

d) 3-member Replica Set w/ writeConcern: majority

• Bring two secondary nodes down
• Insert a document into a collection using writeConcern majority

e) 5-member Replica Set w/ delayed member

• Bring 2 secondary nodes down (any two but the delayed member)
• Insert a document into a collection using writeConcern majority