CloudWatch Monitoring Supported AWS Services

  • CloudWatch offers either basic or detailed monitoring for supported AWS services.
  • Basic monitoring means that a service sends data points to CloudWatch every five minutes.
  • Detailed monitoring means that a service sends data points to CloudWatch every minute.
  • If the AWS service supports both basic and detailed monitoring, the basic would be enabled by default and the detailed monitoring needs to be enabled for details metrics

AWS Services with Monitoring support

  • Auto Scaling
    • By default, basic monitoring is enabled when the launch configuration is created using the AWS Management Console and detailed monitoring is enabled when the launch configuration is created using using the AWS CLI or an API
    • Auto Scaling sends data to CloudWatch every 5 minutes by default, when created from Console.
    • For an additional charge, you can enable detailed monitoring for Auto Scaling, which sends data to CloudWatch every minute.
  • Amazon CloudFront
    • Amazon CloudFront sends data to CloudWatch every minute by default.
  • Amazon CloudSearch
    • Amazon CloudSearch sends data to CloudWatch every minute by default.
  • Amazon CloudWatch Events
    • Amazon CloudWatch Events sends data to CloudWatch every minute by default.
  • Amazon CloudWatch Logs
    • Amazon CloudWatch Logs sends data to CloudWatch every minute by default.
  • Amazon DynamoDB
    • Amazon DynamoDB sends data to CloudWatch every minute for some metrics and every 5 minutes for other metrics.
  • Amazon EC2 Container Service
    • Amazon EC2 Container Service sends data to CloudWatch every minute.
  • Amazon ElastiCache
    • Amazon ElastiCache sends data to CloudWatch every minute.
  • Amazon Elastic Block Store
    • Amazon Elastic Block Store sends data to CloudWatch every 5 minutes.
    • Provisioned IOPS SSD (io1) volumes automatically send one-minute metrics to CloudWatch.
  • Amazon Elastic Compute Cloud
    • Amazon EC2 sends data to CloudWatch every 5 minutes by default. For an additional charge, you can enable detailed monitoring for Amazon EC2, which sends data to CloudWatch every minute.
  • Elastic Load Balancing
    • Elastic Load Balancing sends data to CloudWatch every minute.
  • Amazon Elastic MapReduce
    • Amazon Elastic MapReduce sends data to CloudWatch every 5 minutes.
  • Amazon Elasticsearch Service
    • Amazon Elasticsearch Service sends data to CloudWatch every minute.
  • Amazon Kinesis Streams
    • Amazon Kinesis Streams sends data to CloudWatch every minute.
  • Amazon Kinesis Firehose
    • Amazon Kinesis Firehose sends data to CloudWatch every minute.
  • AWS Lambda
    • AWS Lambda sends data to CloudWatch every minute.
  • Amazon Machine Learning
    • Amazon Machine Learning sends data to CloudWatch every 5 minutes.
  • AWS OpsWorks
    • AWS OpsWorks sends data to CloudWatch every minute.
  • Amazon Redshift
    • Amazon Redshift sends data to CloudWatch every minute.
  • Amazon Relational Database Service
    • Amazon Relational Database Service sends data to CloudWatch every minute.
  • Amazon Route 53
    • Amazon Route 53 sends data to CloudWatch every minute.
  • Amazon Simple Notification Service
    • Amazon Simple Notification Service sends data to CloudWatch every 5 minutes.
  • Amazon Simple Queue Service
    • Amazon Simple Queue Service sends data to CloudWatch every 5 minutes.
  • Amazon Simple Storage Service
    • Amazon Simple Storage Service sends data to CloudWatch once a day.
  • Amazon Simple Workflow Service
    • Amazon Simple Workflow Service sends data to CloudWatch every 5 minutes.
  • AWS Storage Gateway
    • AWS Storage Gateway sends data to CloudWatch every 5 minutes.
  • AWS WAF
    • AWS WAF sends data to CloudWatch every minute.
  • Amazon WorkSpaces
    • Amazon WorkSpaces sends data to CloudWatch every 5 minutes.

AWS Certification Exam Practice Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. What is the minimum time Interval for the data that Amazon CloudWatch receives and aggregates?
    1. One second
    2. Five seconds
    3. One minute
    4. Three minutes
    5. Five minutes
  2. In the ‘Detailed’ monitoring data available for your Amazon EBS volumes, Provisioned IOPS volumes automatically send _____ minute metrics to Amazon CloudWatch.
    1. 3
    2. 1
    3. 5
    4. 2
  3. Using Amazon CloudWatch’s Free Tier, what is the frequency of metric updates, which you receive?
    1. 5 minutes
    2. 500 milliseconds.
    3. 30 seconds
    4. 1 minute
  4. What is the type of monitoring data (for Amazon EBS volumes) which is available automatically in 5-minute periods at no charge called?
    1. Basic
    2. Primary
    3. Detailed
    4. Local
  5. A user has created an Auto Scaling group using CLI. The user wants to enable CloudWatch detailed monitoring for that group. How can the user configure this?
    1. When the user sets an alarm on the Auto Scaling group, it automatically enables detail monitoring
    2. By default detailed monitoring is enabled for Auto Scaling (Detailed monitoring is enabled when you create the launch configuration using the AWS CLI or an API)
    3. Auto Scaling does not support detailed monitoring
    4. Enable detail monitoring from the AWS console
  6. A user is trying to understand the detailed CloudWatch monitoring concept. Which of the below mentioned services provides detailed monitoring with CloudWatch without charging the user extra?
    1. AWS Auto Scaling
    2. AWS Route 53
    3. AWS EMR
    4. AWS SNS
  7. A user is trying to understand the detailed CloudWatch monitoring concept. Which of the below mentioned services does not provide detailed monitoring with CloudWatch?
    1. AWS EMR
    2. AWS RDS
    3. AWS ELB
    4. AWS Route53
  8. A user has enabled detailed CloudWatch monitoring with the AWS Simple Notification Service. Which of the below mentioned statements helps the user understand detailed monitoring better?
    1. SNS will send data every minute after configuration
    2. There is no need to enable since SNS provides data every minute
    3. AWS CloudWatch does not support monitoring for SNS
    4. SNS cannot provide data every minute
  9. A user has configured an Auto Scaling group with ELB. The user has enabled detailed CloudWatch monitoring on Auto Scaling. Which of the below mentioned statements will help the user understand the functionality better?
    1. It is not possible to setup detailed monitoring for Auto Scaling
    2. In this case, Auto Scaling will send data every minute and will charge the user extra
    3. Detailed monitoring will send data every minute without additional charges
    4. Auto Scaling sends data every minute only and does not charge the user

References

AWS EC2 EBS Monitoring

EBS Monitoring

Amazon Web Services (AWS) support EBS monitoring by automatically providing data, such as Amazon CloudWatch metrics and volume status checks to help monitor EBS volumes

CloudWatch Monitoring

  • CloudWatch metrics are statistical data that you can use to view, analyze, and set alarms on the operational behavior of the EBS volumes
  • CloudWatch provides the below by default
    • Basic – Data, in 5-minute periods at no charge, which includes data from the root devices volumes for EBS backed instances
    • Detailed – Provisioned IOPS (SSD) volumes send one-minute metrics
  • EBS Metrics
    • VolumeReadBytes & VolumeWriteBytes
      • Provides information on the I/O operations in a specified period of time, in bytes
    • VolumeReadOps & VolumeWriteOps
      • Total number (count) of I/O operations in a specified period of time
    • VolumeTotalReadTime & VolumeTotalWriteTime
      • Total number of seconds spent by all operations that completed in a specified period of time
    • VolumeIdleTime
      • Total number of seconds, in a specific period, when the volume was idle (no read and write operations)
    • VolumeQueueLength
      • Number of read and write operations, in a specific period, waiting to be completed
    • VolumeThroughputPercentage (Provisioned IOPS (SSD) volumes only)
      • Percentage of I/O operations per second (IOPS) delivered of the total IOPS provisioned
    • VolumeConsumedReadWriteOps (Provisioned IOPS (SSD) volumes only)
      • Total amount of read and write operations (normalized to 256K capacity units) consumed in a specified period of time

Volume Status Checks Monitoring

EC2 EBS Volume Status Check Monitoring

  • Volume status checks are automated tests that run every 5 minutes and return a pass or fail status.
  • Volume check status
    • Ok – all the status checks passed
    • Impaired – if the status checks failed
    • Insufficient-Data – checks are still in progress
    • Warning – the I/O performance of the volume is below expectations
  • When Amazon EBS determines the volume’s data is potentially inconsistent, it disables the I/O to the EBS volume from the attached EC2 instance to prevent any data corruption. This leads to the status check to fail and the volume status to be impaired. Amazon waits for the I/O to be enabled, giving you an opportunity to perform consistency checks
  • If the auto disabling of I/O is not needed, it can be overridden by enabling the Auto-Enabled IO flag, which would make the EBS volume auto available immediately after impaired status
  • Events would be fire for notification whenever the I/O for an EBS volume is disabled
  • I/O performance status checks, applicable only for Provisioned IOPS (SSD) volumes, compares actual volume performance with the expected volume performance and alerts if performing below expectations. This status check is performed every 1 minutes, however is collected by CloudWatch every 5 mins.
  • While initializing Provisioned IOPS (SSD) volumes that were restored from snapshots, the performance of the volume may drop below 50 percent of its expected level, which causes the volume to display a warning state in the I/O Performance status check. This is expected and can be ignored.

EC2 EBS Volume Status

Volume Events Monitoring

  • Amazon EBS generates events for volume status checks
  • Each event includes a start time that indicates the time at which the event occurred, and a duration that indicates how long I/O for the volume was disabled
  • Events description can be Awaiting Action (to enabled I/O), IO enabled, IO Auto-Enabled, or whether the status check resulted in Normal, Degraded, Severely Degraded or stalled status

AWS Certification Exam Practice Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. A user has configured CloudWatch monitoring on an EBS backed EC2 instance. If the user has not attached any additional device, which of the below mentioned metrics will always show a 0 value?
    1. DiskReadBytes
    2. NetworkIn
    3. NetworkOut
    4. CPUUtilization
  2. What does it mean if you have zero IOPS and a non-empty I/O queue for all EBS volumes attached to a running EC2 instance?
    1. The I/O queue is buffer flushing.
    2. Your EBS disk head(s) is/are seeking magnetic stripes.
    3. The EBS volume is unavailable. (EBS volumes are unavailable when all of the attached volumes perform zero read write IO, with pending IO in the queue Refer link)
    4. You need to re-mount the EBS volume in the OS.
  3. While performing the volume status checks, if the status is insufficient-data, what does it mean?
    1. checks may still be in progress on the volume
    2. check has passed
    3. check has failed

References

AWS ELB Monitoring

Following Features can be used for Monitoring Elastic Load Balancer

Cloud Watch Metrics

  • Elastic Load Balancing publishes data points to Amazon CloudWatch about your load balancers and back-end instances
  • Elastic Load Balancing reports metrics to CloudWatch only when requests are flowing through the load balancer. If there are requests flowing through the load balancer, Elastic Load Balancing measures and sends its metrics in 60-second intervals. If there are no requests flowing through the load balancer or no data for a metric, the metric is not reported.

Following metrics are available

  • HealthyHostCount, UnHealthyHostCount
    • Number of healthy and unhealthy instances registered with the load balancer.
    • Most useful statistics are average, min, and max
  • RequestCount
    • Number of requests completed or connections made during the specified interval (1 or 5 minutes).
    • Most useful statistic is sum
  • Latency
    • Time elapsed, in seconds, after the request leaves the load balancer until the headers of the response are received.
    • Most useful statistic is average
  • SurgeQueueLength
    • Total number of requests that are pending routing.
    • Load balancer queues a request if it is unable to establish a connection with a healthy instance in order to route the request.
    • Maximum size of the queue is 1,024. Additional requests are rejected when the queue is full.
    • Most useful statistic is max, because it represents the peak of queued requests.
  • SpilloverCount
    • The total number of requests that were rejected because the surge queue is full. Should ideally be 0
    • Most useful statistic is sum.
  • HTTPCode_ELB_4XX, HTTPCode_ELB_5XX
    • Client and Server error code generated by the load balancer
    • Most useful statistic is sum.
  • HTTPCode_Backend_2XX, HTTPCode_Backend_3XX, HTTPCode_Backend_4XX, HTTPCode_Backend_5XX
    • Number of HTTP response codes generated by registered instances
    • Most useful statistic is sum.

Elastic Load Balancer access logs

  • Elastic Load Balancing provides access logs that capture detailed information about all requests sent to your load balancer.
  • Each log contains information such as the time the request was received, the client’s IP address, latencies, request paths, and server responses.
  • Elastic Load Balancing captures the logs and stores them in the Amazon S3 bucket
  • Access logging is disabled by default and can be enabled without any additional charge. You are only charged for S3 storage

CloudTrail Logs

  • AWS CloudTrail can be used to capture all calls to the Elastic Load Balancing API made by or on behalf of your AWS account and either made using Elastic Load Balancing API directly, or indirectly through the AWS Management Console or AWS CLI
  • CloudTrail stores the information as log files in an Amazon S3 bucket that you specify.
  • Logs collected by CloudTrail can be used to monitor the activity of your load balancers and determine what API call was made, what source IP address was used, who made the call, when it was made, and so on

AWS Certification Exam Practice Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. An admin is planning to monitor the ELB. Which of the below mentioned services does not help the admin capture the monitoring information about the ELB activity
    1. ELB Access logs
    2. ELB health check
    3. CloudWatch metrics
    4. ELB API calls with CloudTrail
  2. A customer needs to capture all client connection information from their load balancer every five minutes. The company wants to use this data for analyzing traffic patterns and troubleshooting their applications. Which of the following options meets the customer requirements?
    1. Enable AWS CloudTrail for the load balancer.
    2. Enable access logs on the load balancer.
    3. Install the Amazon CloudWatch Logs agent on the load balancer.
    4. Enable Amazon CloudWatch metrics on the load balancer
  3. Your supervisor has requested a way to analyze traffic patterns for your application. You need to capture all connection information from your load balancer every 10 minutes. Pick a solution from below. Choose the correct answer:
    1. Enable access logs on the load balancer
    2. Create a custom metric CloudWatch filter on your load balancer
    3. Use a CloudWatch Logs Agent
    4. Use AWS CloudTrail with your load balancer

References

Elastic Load Balance developer guide