Further Review 1 Flashcards
What is a spot fleet
How do you define a spot fleet launch pool?
When does a spot fleet stop launching instances?
What are the 3 strategies to allocate spot instances in a fleet and when would you use each?
Set of Spot Instances + (Optional) On-Demand Instances that will will try to meet the target capacity with price constraints
Pools are defined with instance types, OS and AZ. There can be multiple pools.
When the capacity or max cost is reached.
Lowest prices - Use for small jobs where the likelihood of interruption is low
Diversified - (The Spot Instances are distributed across all Spot capacity pools.) If your fleet is large or runs for a long time, you can improve the AVAILABILITY of your fleet by distributing the Spot Instances across multiple pools using the diversified strategy
Capacity - (pool with optimal number of instances). strategy for workloads where the possibility of disruption must be minimized because restarting the job would be expensive and the preference for certain instance types matters. The capacity-optimized strategy automatically launches Spot Instances into the most available pools by looking at real-time capacity data and predicting which are the most available.
What is a placement group?
What are the types of placement groups and what are they good for?
A placement group gives you control over the EC2 Instance placement strategy.
Cluster - Cluster instances into a low latency group in a single AZ. Same rack. High failure risk
Useful for big data jobs that need to complete fast
Application that needs extremely low latency and high network throughput
Spread - Spreads instances across underlying hardware (max 7 instances per group per AZ) - Used to minimize the failure risk.
Critical applications
Minimize failure risk
Spans across AZs
Limit to how big your placement group can be (7 instances per AZ)
Partition - Spreads instances across many different partitions (Which rely on different sets of racks) within an AZ. Scales to 100s of EC2 instances per group
A partition failure won’t affect other partitions
Big data applications that are partition aware Hadoop, Cassandra, Kafka
What are your responsibilities when it comes to security for RDS?
Check ports, IP, Security groups inbound rules
In database user creation and permissions or manage through IAM
Creating a database with or without public access
Assure parameter groups or DB is configured to allow only SSL connections
What are the responsibilities of AWS when it comes to security for RDS?
No SSH access
No manual DB patching
No manual OS paching
No way to audit the underlying instance.
What are some of the features of Redis for HA and scaling?
Multi AZ with Auto-failover
Read Replicas to scale reads and have high availability
