Management Tools | Amazon CloudWatch Flashcards
What is Amazon CloudWatch?
General
Amazon CloudWatch | Management Tools
Amazon CloudWatch is a monitoring service for AWS cloud resources and the applications you run on AWS. You can use Amazon CloudWatch to collect and track metrics, collect and monitor log files, and set alarms. Amazon CloudWatch can monitor AWS resources such as Amazon EC2 instances, Amazon DynamoDB tables, and Amazon RDS DB instances, as well as custom metrics generated by your applications and services, and any log files your applications generate. You can use Amazon CloudWatch to gain system-wide visibility into resource utilization, application performance, and operational health. You can use these insights to react and keep your application running smoothly.
What can I use to access CloudWatch?
General
Amazon CloudWatch | Management Tools
Amazon CloudWatch can be accessed via API, command-line interface, AWS SDKs, and the AWS Management Console.
Which operating systems does Amazon CloudWatch support?
General
Amazon CloudWatch | Management Tools
Amazon CloudWatch receives and provides metrics for all Amazon EC2 instances and should work with any operating system currently supported by the Amazon EC2 service.
What access management policies can I implement for CloudWatch?
General
Amazon CloudWatch | Management Tools
Amazon CloudWatch integrates with AWS Identity and Access Management (IAM) so that you can specify which CloudWatch actions a user in your AWS Account can perform. For example, you could create an IAM policy that gives only certain users in your organization permission to use GetMetricStatistics. They could then use the action to retrieve data about your cloud resources.
You can’t use IAM to control access to CloudWatch data for specific resources. For example, you can’t give a user access to CloudWatch data for only a specific set of instances or a specific LoadBalancer. Permissions granted using IAM cover all the cloud resources you use with CloudWatch. In addition, you can’t use IAM roles with the Amazon CloudWatch command line tools.
What is Amazon CloudWatch Logs?
General
Amazon CloudWatch | Management Tools
Amazon CloudWatch Logs lets you monitor and troubleshoot your systems and applications using your existing system, application and custom log files.
With CloudWatch Logs, you can monitor your logs, in near real time, for specific phrases, values or patterns. For example, you could set an alarm on the number of errors that occur in your system logs or view graphs of latency of web requests from your application logs. You can then view the original log data to see the source of the problem. Log data can be stored and accessed indefinitely in highly durable, low-cost storage so you don’t have to worry about filling up hard drives.
What kinds of things can I do with CloudWatch Logs?
General
Amazon CloudWatch | Management Tools
CloudWatch Logs is capable of monitoring and storing your logs to help you better understand and operate your systems and applications. You can use CloudWatch Logs in a number of ways.
Real time application and system monitoring: You can use CloudWatch Logs to monitor applications and systems using log data. For example, CloudWatch Logs can track the number of errors that occur in your application logs and send you a notification whenever the rate of errors exceeds a threshold you specify. CloudWatch Logs uses your log data for monitoring; so, no code changes are required.
Long term log retention: You can use CloudWatch Logs to store your log data indefinitely in highly durable and cost effective storage without worrying about hard drives running out of space. The CloudWatch Logs Agent makes it easy to quickly move both rotated and non rotated log files off of a host and into the log service. You can then access the raw log event data when you need it.
What platforms does the CloudWatch Logs Agent support?
General
Amazon CloudWatch | Management Tools
The CloudWatch Logs Agent is supported on Amazon Linux, Ubuntu, CentOS, Red Hat Enterprise Linux, and Windows. This agent will support the ability to monitor individual log files on the host.
Does the CloudWatch Logs Agent support IAM roles?
Pricing
Amazon CloudWatch | Management Tools
Yes. The CloudWatch Logs Agent is integrated with Identity and Access Management (IAM) and includes support for both access keys and IAM roles.
How much does Amazon CloudWatch cost?
Pricing
Amazon CloudWatch | Management Tools
Please see our pricing page for the latest information.
Does the Amazon CloudWatch monitoring charge change depending on which type of Amazon EC2 instance I monitor?
Pricing
Amazon CloudWatch | Management Tools
No, the Amazon CloudWatch monitoring charge does not vary by Amazon EC2 instance type.
Do your prices include taxes?
Pricing
Amazon CloudWatch | Management Tools
Except as otherwise noted, our prices are exclusive of applicable taxes and duties, including VAT and applicable sales tax. Learn more.
Why does my AWS monthly bill for CloudWatch appear different between July 2017 and previous months?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
Prior to July 2017, charges for CloudWatch were split under two different sections in your AWS bill and Cost and Usage Reports. For historical reasons, charges for CloudWatch Alarms, CloudWatch Metrics, and CloudWatch API usage were reported under the “Elastic Compute Cloud” (EC2) detail section of your bill, while charges for CloudWatch Logs and CloudWatch Dashboards are reported under the “CloudWatch” detail section. To help consolidate and simplify your monthly AWS CloudWatch usage and billing, we moved the charges for your CloudWatch Metrics, Alarms, and API usage from the “EC2” section of your bill to the “CloudWatch” section, effectively bringing together all of your CloudWatch monitoring charges under the “CloudWatch” section. Note that this has no impact to your total AWS bill amount. Your bill and Cost and Usage Reports will now simply display charges for CloudWatch under a single section.
Additionally, there is a Billing Metric in CloudWatch named “Estimated Charges” that can be viewed as Total Estimated Charge or broken down By Service. The “Total Estimated Charge” metric will not change. However, the “EstimatedCharges” metric broken down by Service will change for dimension ServiceName equal to “AmazonEC2” and dimension ServiceName equal to “AmazonCloudWatch”. Due to the billing consolidation, you may see that your AmazonEC2 billing metric decrease and AmazonCloudWatch billing metric increase as usage and billing charges get moved out of EC2 and into CloudWatch.
What can I measure with Amazon CloudWatch Metrics?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
Amazon CloudWatch allows you to monitor AWS cloud resources and the applications you run on AWS. Metrics are provided automatically for a number of AWS products and services, including Amazon EC2 instances, EBS volumes, Elastic Load Balancers, Auto Scaling groups, EMR job flows, RDS DB instances, DynamoDB tables, ElastiCache clusters, RedShift clusters, OpsWorks stacks, Route 53 health checks, SNS topics, SQS queues, SWF workflows, and Storage Gateways. You can also monitor custom metrics generated by your own applications and services.
What is the retention period of all metrics?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
CloudWatch launched High Resolution Custom Metrics on July 26, 2017. This enables you to publish and store custom metrics down to 1-second resolution. Extended retention of metrics was launched on November 1, 2016, and enabled storage of all metrics for customers from the previous 14 days to 15 months. CloudWatch retains metric data as follows:
Data points with a period of less than 60 seconds are available for 3 hours. These data points are high-resolution custom metrics.
Data points with a period of 60 seconds (1 minute) are available for 15 days
Data points with a period of 300 seconds (5 minute) are available for 63 days
Data points with a period of 3600 seconds (1 hour) are available for 455 days (15 months)
Data points that are initially published with a shorter period are aggregated together for long-term storage. For example, if you collect data using a period of 1 minute, the data remains available for 15 days with 1-minute resolution. After 15 days this data is still available, but is aggregated and is retrievable only with a resolution of 5 minutes. After 63 days, the data is further aggregated and is available with a resolution of 1 hour. If you need availability of metrics longer than these periods, you can use the GetMetricStatistics API to retrieve the datapoints for offline or different storage.
The feature is currently available in US East (N. Virginia), US West (Oregon), US West (N. California), EU (Ireland), EU (Frankfurt), S. America (São Paulo), Asia Pacific (Singapore), Asia Pacific (Tokyo), Asia Pacific (Seoul), Asia Pacific (Mumbai), Asia Pacific (Sydney), EU (London), Canada (Central), US East (Ohio), and China (Beijing).
What is the minimum resolution for the data that Amazon CloudWatch receives and aggregates?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
The minimum resolution supported by CloudWatch is 1-second data points, which is a high-resolution metric, or you can store metrics at 1-minute granularity. Sometimes metrics are received by Cloudwatch at varying intervals, such as 3-minute or 5-minute intervals. If you do not specify that a metric is high resolution, by setting the StorageResolution field in the PutMetricData API request, then by default CloudWatch will aggregate and store the metrics at 1-minute resolution.
Depending on the age of data requested, metrics will be available at the resolutions defined in the retention schedules above. For example, if you request for 1-minute data for a day from 10 days ago, you will receive the 1440 data points. However, if you request for 1-minute data from 5 months back, the UI will automatically change the granularity to 1-hour and the GetMetricStatistics API will not return any output.
Can I delete any metrics?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
CloudWatch does not support metric deletion. Metrics expire based on the retention schedules described above.
Will I lose the metrics data if I disable monitoring for an Amazon EC2 instance?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
No. You can always retrieve metrics data for any Amazon EC2 instance based on the retention schedules described above. However, the CloudWatch console limits the search of metrics to 2 weeks after a metric is last ingested to ensure that the most up to date instances are shown in your namespace.
Can I access the metrics data for a terminated Amazon EC2 instance or a deleted Elastic Load Balancer?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
Yes. Amazon CloudWatch stores metrics for terminated Amazon EC2 instances or deleted Elastic Load Balancers for 15 months.
Why does the graphing of the same time window look different when I view the metrics in 5 minute and 1 minute periods?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
If you view the same time window in a 5 minute period versus a 1 minute period, you may see that data points are displayed in different places on the graph. For the period you specify in your graph, Amazon CloudWatch will find all the available data points and calculates a single, aggregate point to represent the entire period. In the case of a 5 minute period, the single data point is placed at the beginning of the 5 minute time window. In the case of a 1 minute period, the single data point is placed at the 1 minute mark. We recommend using a 1 minute period for troubleshooting and other activities that require the most precise graphing of time periods.
What is a Custom Metric?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
You can use Amazon CloudWatch to monitor data produced by your own applications, scripts, and services. A custom metric is any metric you provide to Amazon CloudWatch. For example, you can use custom metrics as a way to monitor the time to load a web page, request error rates, number of processes or threads on your instance, or amount of work performed by your application. You can get started with custom metrics by using the PutMetricData API, our sample monitoring scripts for Windows and Linux, CloudWatch collectd plugin, as well as a number of applications and tools offered by AWS partners.
What resolution can I get from a Custom Metric?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
A custom metric can be one of the following:
Standard resolution, with data having one-minute granularity
High resolution, with data at a granularity of one second
By default, metrics are stored at 1-minute resolution in CloudWatch. You can define a metric as high-resolution by setting the StorageResolution parameter to 1 in the PutMetricData API request. If you do not set the optional StorageResolution parameter, then CloudWatch will default to storing the metrics at 1-minute resolution.
When you publish a high-resolution metric, CloudWatch stores it with a resolution of 1 second, and you can read and retrieve it with a period of 1 second, 5 seconds, 10 seconds, 30 seconds, or any multiple of 60 seconds.
Custom metrics follow the same retention schedule listed above.
What metrics are available at high resolution?
AWS Resource and Custom Metrics Monitoring
Amazon CloudWatch | Management Tools
Currently, only custom metrics that you publish to CloudWatch are available at high resolution. High-resolution custom metrics are stored in CloudWatch at 1-second resolution. High resolution is defined by the StorageResolution parameter in the PutMetricData API request, with a value of 1, and is not a required field. If you do not specify a value for the optional StorageResolution field, then CloudWatch will store the custom metric at 1-minute resolution by default.
