High Availability, Scaling, Workload Isolation Flashcards
(20 cards)
High Availability
The ability of a database system to remain operational and accessible with minimal downtime, often achieved through redundancy and failover
Replica Set
a group of nodes that maintain the same data set, providing redundancy and automatic failover for high availability
Primary vs Secondary Node
Primary: the replica set member that accepts all write operations, replicating data to secondary nodes
Secondary Node: a replica set member that replicates data from the primary node and can serve read operations or become primary during failover
Failover
Process where a replica set automatically elects a new primary node if the current primary fails
Arbiter
A lightweight node in a replica set that participates in elections but does not store data, used to break ties in voting
Write Concern
setting that specifies the number of nodes that must acknowledge a write operation to ensure data durability
Scalability
the ability of a database to handle increased load (more users, data, queries) by adding resources or distributing workload
Sharding
Method for horizontal scaling by distributing data across multiple servers (shards) based on a shard key
shard
a single partition of a database, storing a subset of the data in a sharded cluster
Shard Key
The field used by MongoDB to determine how data is distributed across shards, critical for efficient sharding
Horizontal Scaling
Adding more servers (nodes or shards) to a database system to increase capacity, as opposed to upgrading a single server
Vertical Scaling
Increasing the resources (CPU, RAM, storage) of a single server to handle more load, limited by hardware constraints
Workload Isolation
The practice of separating different types of database workloads (e.g. transactional, analytical) to prevent resource contention and optimize performance
Read/Write Separation
Directing read operations to secondary nodes and write operations to the primary node in a MongoDB replica set to isolate workloads and improve performance
Dedicated Workload Clusters
Using separate MongoDB clusters or replica sets for distinct workloads (e.g. one for OLTP, another for analytics) to ensure resource isolation
OLTP
Online Transaction Processing
A workload type focused on high speed, transactional operations (e.g. inserts, updates), requiring low latency and high availability
OLAP
Oline Analytical Processing
Workload type focused on complex queries and data anlysis, often requiring significant compute resources and isolated from transactional workloads
Analytics Node
A dedicated secondary node in a MongoDB replica set configured for analytical queries, isolating resource intensive OLAP workloads from transactional operations
Zone Sharding
MongoDB sharding strategy that assigns data to specific shards based on tags, enabling workload isolation by directing queries to designated shards
Resource Contention
Competition for system resouces (CPU, memory, disk) between workloads, mitigated through workload isolation techniques like read/write separation or dedicated clusters