Monitoring the ELB for performance and availability

Question 1

Latency

Answer 1

• • Time it takes to receive a response
• • Measure the AVG and MAX values to spot abnormal activity
• • good metrics to determine if our Elastic Load Balancer is healthy

Question 2

BackendConnectionErrors

Answer 2

• -Number of connections that were not successfully established between our load balancer and registered instances
• • Measure SUM and use the different between the minimum and maximums to spot issues.

Question 3

SurgeQueueLength

Answer 3

• • Measures the total number of requests that are waiting to be routed by the load balancer
• • Queue can hold a total of 1024 requests
• • Measure the MAX to see the peak of queued requests
• • AVG can also be used with MIN and MAX to get a range.

Question 4

SpilloverCount

Answer 4

if the SurgeQueueLength is full, request “spill over” and get dropped
Mesure the SUM.

Question 5

Pre-warming

Answer 5

if you are expecting a sudden and very large increase in traffic, you need to pre-warm your ELB to avoid dropped requests.

Question 6

metrics not automatically reported to Amazon CloudWatch from EC2

Answer 6

amount of memory; amount of swap space used; how much disk space is available.

Question 7

best describes burstable performance for t2.micro instances

Answer 7

gives you a baseline performance and CPU credits that allow you to burst above this baseline if needed.