AWS CloudWatch Flashcards
1
Q
What is an AWS CloudWatch Metric?
A
Is a time-ordered set of data points
2
Q
I have a custom application, can I publish a custom Metric to CloudWatch?
A
Yes, you can use the CLI or API.
3
Q
How long is data available in a Matric?
A
15 months before it is overwritten
4
Q
Can you send historical matric data to cloud watch?
A
Yes, you can send up to 2 weeks of historical data.
5
Q
If you do not provide a time stamp for a matric data point what will happen?
A
Cloud watch will add a timestamp based on DateTime received.
6
Q
What happens to data points less than 60 seconds?
A
They are available for 3hrs after this they are aggregated for long-term storage as a Statistic.
7
Q
What happens to data points of equal to 60 seconds?
A
They are available for 15 days and then aggregated for long-term storage.
8
Q
What is a CloudWatch dimension?
A
Is a key-value pair that identifies the matric, you can have up to 10 dimensions on a Metric.
9
Q
How many dimensions can I have?
A
Up to 10.
10
Q
What is a cloud watch namespace?
A
A namespace is a container for matric’s.
11
Q
Are cloudwatch namespaces isolated from each other?
A
Yes, AWS/EC2 is seperate from AWS/VPC
12
Q
Can i have 11 dimentions for a matric?
A
No there is a limit of up to 10.
13
Q
What is a namespace used for?
A
It holds one or more matric from a common source such as AWS/S3 or AWS/EC2.
14
Q
What is a statistic?
A
Statistics are the metric data points aggrigations over a time period. This happens to data that is of high resolution, below 60 seconds after 3hrs data is aggregated into a statistic.
15
Q
What will a stastic look like?
A
Minium, Maxum, Sum, Average, SampleCount
16
Q
Has a stat a unit of measure and what is it used for?
A
A stat unit of measure temms the data wnat is is, for example seconds, bytes, count, present.
17
Q
What is a CloudWatch metric statistic period?
A
It is the period of time the statistic represents.
18
Q
Are cloud watch metric stat period defined in seconds?
A
Yes periods are defiend in seconds, 360 is six minutes.
19
Q
Are aggrigated cloud watch metric stat be available when now using detailed monitoring?
A
No dfatiled stats are only available when using detailed monitoring.
20
Q
Can a CloudWatch metric statistic aggregate across regions?
A
No, data for the statistic comes from the region the statistic is being produced in.
21
Q
CloudWatch has a number of different functions, what are they?
A
Collect process, store and graphic metric from AWS systems. Also collect, process and store log files, dashboards, alarms and events.
22
Q
Cathy recently joined Concerto, she been set up on the corporate AWS account with no access to any AWS resources, Cathy needs read-only access to CloudWacth, how can I do this?
A
Create an inline policy for Cathy with read-only privileges to CloudWatch or add Cathy to an existing IAM group with read-only privileges.
23
Q
What will this IAM policy do with regard to AWSCloudWatch, { “Version”: “2012-10-17”, “Statement”:[{ “Effect”:”Allow”, “Action”:[“cloudwatch:GetMetricStatistics”,”cloudwatch:ListMetrics”], “Resource”:”*”, “Condition”:{ “Bool”:{ “aws:SecureTransport”:”true” } } } ] }
A
The policy is a resource-based policy and will allow (cloudwatch:GetMetricStatisticsdata and cloudwatch:ListMetrics) to be called only if SSL is true.
24
Q
What are the supported notification services for AWSCloudWatch?
A
SNS
25
With regard to CloudWatch logs, what is cloud watch logs main purpose?
Enables you to store log information sent from EC2 agents or through the API
26
How can I count the number of log events arriving at cloudwatch logs?
You can use a cloudwatch metric filter and sets it a pattern and matric name, this will send metric to cloudwatch metric.
27
If I wanted to log information from the OS in an EC2 instance, is it possible and what do I need to do?
Yes, it is possible, you have to add an agent to the EC2 instance and set up a log group and log stream.
28
I just installed a CloudWatch log agent on an EC2 instance, configured to send data through VPC IG and internet to CloudWatch, I also set up a log group and log stream, I am not getting data logs to AWS CloudWatch logs, what could be causing this?
The security group rules or ACL could be blocking,
29
On my VPC I need to be alerted when a connection is attempted from an external IP coming in from the internet, how could I do this?
You could use VPC flow logs and send the flow log data to cloudwatch logs, create a metric filter to send output to cloudwatch metrics, also create a CloudWatch alarm.
30
I have a log file, is it possible to upload this file to a cloudwatch stream?
Yes, you can use the cloudwatch logs API to upload this file into the log stream. PutLogEvents
31
Using CLI, how can I get a list of the logs in a log group?
aws logs filter-log-events --log-group-name CloudTrail/DefaultLogGroup
32
I need to analyze flow logs in AWS Kinesis, how can I do this?
I can configure AWS VPC FlowLogs to be sent to a CloudWatch log stream in a log group, I can subscribe to this stream and have the data delivered to AWS aws kinesis to be analyzed. PutSubscriptionFilter
33
When I use PutSubscriptionFilter in relation to AWS CloudWatch logs, what am I doing?
You are subscribing to the log stream so you can receive the incoming events as the arrive into the log stream.
34
With regard to AWS log stream's, what are the subscriptions endpoints I can use with PutSubscriptionFilte?
An Amazon Kinesis stream belonging to the same account as the subscription filter, for same-account delivery. A logical destination that belongs to a different account, for cross-account delivery. An Amazon Kinesis Firehose delivery stream that belongs to the same account as the subscription filter, for same-account delivery. An AWS Lambda function that belongs to the same account as the subscription filter, for same-account delivery.
35
With regard to AWS cloudwatch logs, how long can I retain the data for?
For ever
36
What is the default length of time I can retain data in cloudwatch logs
The default length is for ever
37
I need to conserve on cost's in relation to my cloud, i see cloudwatch logs is using quite an amouint of dat and it is growing year on year, i do not nee do keep data over a year, what cna I do usiong AWS functionality?
You can set the retention policy. PutRetentionPolicy ebables you to set the number of days you data is retained and available.
38
What is a Matric filter in Cloudwatch logs?
A matric filter enables you to create a pattern that will be matched on incoming log events and will add to a custom Cloudwatch metric.
39
How can I count the number of 404 code coming to my EC2 instance using only AWS services or features?
Can you set up VPC from logs with data sent to cloudwatch log group, set up a metric filter to add to a custom cloudwatch metric.
40
Where are flow logs sent to, a log group or a log stream?
Flow logs are sent to a log group?
41
Can I send flow logs to another destination?
Yes you can send to an S3 buckst
42
When sending logs to Cloudwatch log group, do you need IAM permissions?
Yes, you need an IAM role with permissions to publish to Cloudwatch or S3. This role will be assumed by VPC FlowLOgs service.
43
On VPC flow logs can I filter on the recorded traffic?
Yes, you can choose to record all, accept or reject traffic.
44
Will the flow logs have traffic to Amazon DNS servers?
No
45
Will the low logs have Windows licence activation traffic present?
No
46
Will DHCP requests be present in the flow logs?
No
47
How often will flowlogs send data to a Cloudwatch log group?
About every 10min.
48
What information will flow logs have?
The ENI (Network interface), Accepted or Rejected, src and dest address, src and dest port, protocol, num packets transferred during capture window, windows start time, windows end time, action, log-status (if all capturing was ok).
49
Can I Tag a log group?
No
50
Can I Tag a Cloud|Watch log stream?
No.
51
What is a Cloudwatch metric namespace?
Namespace is a container for Metrics, for example, the AWS/EC2 namespace contains all the metrics for EC2 instances.
52
What types of metrics are available for S3?
Storage and request.
53
How often are s3 storage metrics reported?
Once per day.
54
What intervals are S3 storage matric reported on?
about every 1 min, but only once a day.
55
56
What is a Clouswatch metric statistic used for?
It is used as an ag
gregation for matric data. An example is data points less then
57
For CloudWatch Metrics for S3, what is the metric for getting the size of the bucket?
BucketSizeBytes
58
For CloudWatch Metrics for S3, what is the metric for getting the number of objects?
NumberofObjects.
59
With regard to CloudWatch Metrics and S3, is BucketSizeBytes and NumberOfObjects a BucketMetric or a Request metric?
A bucket Metric.
60
With regard to CloudWatch Metrics and S3 how can I get Metric values with regard to the S3 requests?
S3 has a list of Metrics available where you can get Metrics for AllRequets, GetRequetss, PutRequets, DeleteRequetss,
61
What CLI command would I used to get S3 Metric information?
aws cloudwatch get-metric-statistics
62
With regard to CloudWatch Metrics, what is a dimension and what is it used for?
A dimension is a set of key-value pairs on a Metric that are used to give the metric extra information that can be used to filter. An example is an S3 Metric has a dimension called StorageType that holds the storage type infolike GLACIER, STANDARD, you know from this that matric is of type X.
63
How can we search and filter the published Cloudwatch log and turn results into numerical Cloudwatch Metrics?
Using Cloudwatch Metric filters, with these filters we can use a pattern syntax to find things like 400 responses and turn this into a Metric data point.
64
When we create a Cloudwatch filter what are the inputs?
filter pattern, name, namespace, metric value, default value.
65
How can I share my log data with another account?
Subscriptions: It is possible to share your log data with another account, the important thing here is data can only be shared with an account with Knesis, Kenisi is the only supported endpoint Cloudwatch supports.
66
I want to share my log data with a Kenisis log aggregator in another account, what do I need to do?
1. aws kinesis create-stream
2. aws logs put-subscription-filter 3.
67
What is cCloudWatch Log Subscription Filter used for?
It establishes a subscription on a log group and filters using a filter-pattern the traffic and delivers this traffic to another account-kinesis ARN destination.
68
I need to share my logs with another account with a lambda expression, can I use CloudWatch Logs subscriptions?
No, currently the only supported delivery resource in another account is Kenesis
69
Is it possible to share my CloudWatch logs with Lambda?
Yes, I can share my logs with Lambda using a SunscriptionFilter, this will start to deliver my logs to the Lambda resource as a stream.
70
What is a ClouWatch Logs Subscription filter?
This is a filter that when created enables you to subscribe to a CloudWatch logs log group and have the data streamed to an endpoint, supported endpoints are,
1. Lambda in the same account
2. Kinesis in the same account
3. Kinesis in a separate account
4. ElasticSerch (ES) in same account
71
In a CloudWatch logs subscription, what is the filter pattern used for?
This is used to filter only the logs info you want and this log data will be streamed to the destination.
72
What be AWS service logs published directly S3?
VPC Flow Logs.
73
I need to get a quick dump of a current AWS CloudWatch log group, how can I do this?
You can use the AWS CloudWatch create-export-task in the CLI to export the data to an S3 bucket.
74
I need to secure the data in the AWS CloudWatch log group, how can I do this?
You can use AWS logs associate-kms-key with the AWS CloudWatch logs log group, dat from the point on will be encrypted.
75
Can I tag an AWS CloudWatch log stream?
Yes
76
How can I measure the number of events into CloudWatch logs?
CloudWatch logs send metrics to CloudWatch, like,
* IncomingLogsEvents,
* ForwaredBytes
* IncomingBytes
77
What should I be considered when centralizing logging?
Retention, how long, some orgs need as long as 5years, this would mean that we need to look at s3, lifecycles and glacier.
Automate the install of the shipping agent on instances, for auto-scaled instances.
Ensure solution supports hybrid (AWS, Azure, on-prem)
78
For centralized logging what services can I use?
AWS S3 and glacier, for storage and archive
AWS CloudWatch for capture and basic analytics
AWS ElasticSearch
Kinesis Firehose
79
How can dimensions can I have on a CloudWatch metric?
10
80
For log management what, what should I be doing for all the logs in the system?
We should be centrally managing the log files in one place, where we can deal with security and each of searching.
81
What does this policy do?
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"logs:ListTagsLogGroup",
"logs:DescribeLogGroups",
"logs:DescribeLogStreams",
"logs:DescribeSubscriptionFilters",
"logs:StartQuery",
"logs:GetLogEvents",
"logs:DescribeMetricFilters",
"logs:FilterLogEvents",
"logs:GetLogGroupFields"
],
"Resource": [
"arn:aws:logs:\*:\*:log-group:kt-test-lfg",
"arn:aws:logs:\*:\*:log-group:\*:\*:\*"
]
},
{
"Sid": "VisualEditor1",
"Effect": "Allow",
"Action": [
"logs:DescribeQueries",
"logs:DescribeExportTasks",
"logs:GetLogRecord",
"logs:GetQueryResults",
"logs:StopQuery",
"logs:TestMetricFilter",
"logs:DescribeResourcePolicies",
"logs:GetLogDelivery",
"logs:DescribeDestinations",
"logs:ListLogDeliveries"
],
"Resource": "\*"
}
]
}
Enables you to view only a specific log stream.
82
How can we push the logs to form a Linux instance to a log group?
Install the agent on agent and point at a log group.
83
I want to reach out to another accounts cloudwatch and get access to the logs, how cna I do this?
Create a subscription filter and point at the other account kenisis
84
I need to monitor an instance operating system, how can I do this?
You can install the cloud whatch agent on the instance and have it post data to cloudwatch.
85
I need to monitor the memory of an instance, how can I do this?
Install the cloudwatch agent on the instance and post the data to cloudwatch.
86
Do I need to collect the logs from an instances operating system, how cna I do this?
I can install the cloud watch agent on the instance and post the log data to cloud watch logs.
87
What does the cloudwatch agent allow you to collect?
Operating system metrics and logs.
88
What are the different product features in CloudWatch?
- CloudWatch Metrics
- Cloud Watch Logs
- CloudWatch Events
- CloudWatch Alarm
89
What is a CloudWatch NameSpace?
It is a group of metrics for a service like EC2.
90
What is a log stream?
It belongs to a log group and is a set of log messages
91
Where do we get logs form in CloudWatch messages?
- CloudWatch Log Agent
- RDS.
92
What are cloudwatch logs insights?
This is a tool (web portal) inside CloudWatch logs that enables you to run queries.
93
What is a CloudWatch Metric filter used for?
The uses pattern matching in the CloudWatch Logs to generate a metric that is pushed into CloudWatch metrics. You will give it a metric namespace and metric name.
94
What is a CloudWatch event?
CloudWatch events enable you to select a service in AWS to receive events form, service name, event type. Like Ec2 instance state change. You will also select a target lambda function to respond to the event.
95
What is cloudwatch?
It is a suite of products related to monitoring, like,
- CloudWatch Metrics (Performance info)
- CloudWatch Logs (Log info)
- Alarms
- Events
- ServiceLense
- Synthetics
- Contributer Insights
96
What is a log stream?
A log stream is a sequence of log events that share the same source. Each separate source of logs into CloudWatch Logs makes up a separate log stream.
97
What is a log group?
A log group is a group of log streams that share the same retention, monitoring, and access control settings.
98
I wnat to analyze my CloudWatch logs in near real-time, how cna I do this?
You can use subscriptions to get access to a real-time feed of log events from CloudWatch Logs and have it delivered to other services such as a Amazon Kinesis stream, Amazon Kinesis Data Firehose stream, or AWS Lambda.
99
If I am publishing metrics into CloudWatch metrics at a rate of less then 60sec, how long are they available for?
- 3hrs
- After thet 3Hrs they are aggregated
100
If I am publishing metrics into CloudWatch metrics at a rate of every 60sec, how long are they available for?
- 15 days
- After this period thet are aggregated
101
If I am publishing metrics into CloudWatch metrics at a rate of 300sec, how long are they available for?
- 63 days
- After which they are aggrigated
102
If I am publishing metrics into CloudWatch metrics at a rate of 1hr, how long are they available for?
- 15 months
- After which thye are aggregated
103
What is a CloudWatch data point?
It is a point in time and consist of,
- Timestamp
- Unit
Min
- Max
- Average
104
What is a dimension?
It is a set of up to 10 key, value pares in a metric.
105
Is it possible to publish your own custom metric into a costume namespace?
Yes 100%, you can publish custom namespaces and metrics through the API, CLI, ect.
106
Why user wnat to be able to check one a day and see the S3 usage cost, how can do this?
You can create a dashboard, add a widget for the S3 usage cost.
107
I wnat to have a message sent to me when the 10G of storage is used in S3 and alos have the fact that this occurred saved to DynamoDB, how cna I do this?
Use CoudWatch alarms select S3 metric and set a threshold of 10GiB, create and select an SNS topic and have email subscriber of the topic to send an email, alos have lambda be a subscriber of this topic and have lambda save to the DynamoDB.
108
I need to monitor a metric value and have it alarm when it goes over a threshold, but this metric value is complex in at present we get lots offals positives because the values fluctuate during the week but over the month they are stable, what change could I make to improve on this?
You could switch the alarm to anomaly detection.
109
I wnat alarms with statistical and machine learning algorithms, is this possible in AWS, explain?
Yes 100%, you can have cloudwatch alarms with statistical and machine learning algorithms.
110
How does statistical and machine learning work for ClodWatch alarms?
These algorithms continuously analyze metrics of systems and applications, determine normal baselines, and surface anomalies with minimal user intervention.
111
How many weeks of data dose Cloudwatch alarm anomaly detection use?
2weeks
112
I wnat to ensure that when a Cloudwatch alarm triggers that it will only trigger when the data points have been above for a period, how cna I do this?
You cna set the alarm only triggers when above day for 5 periods (period is a say 2 data points, you can select the number of data points)
113
I think I had an alarm today at 1 PM, but not 100% sure, it is possible to check?
Yes 100% alarms when triggered are saved to the Aloudwact alarm history and you view in the Portal.
114
I know Cloudwatch alarms can trigger on SNS, can the CW alarm trigger on lambda direct without using SNS?
Yes each alarm has actions you can select and use, each action you can have triggers on lambda, SNS
115
I have a load balancer and I wnat to have an email sent what the latency goes over 200ms, how can I do this?
Create a cloud watch alarm and have it trigger SNS.
116
I wnat to have every service in AWS trigger on at least one monitored value and send an email when above a threshold, how can I do this?
Most all services in AWS have metrics and you can create an alarm on these metric value and have SNS messages send to a whole host of supported subscribers.
117
How can I have autoscaling increase or decrease based on a metric?
Cloudwatch alarms support action and one of the actions available is the ability to increase or decrease an autoscaling group.
118
What actions can I take on a CloudWatch alarm?
- SAN
- Autoscaling group
- ECS
-- EC2
119
I wnat to have an email sent to me when the EC2 CPU Idle % goes over 60%, how cna I easily do this?
Add cloudwatch agent to the EC2 and have it send metrics to CloudWatch, create a CW Alarm and have it triggered on the 60%, create SNS topic and have it trigger on the alarm, subscribe to the SNS topic.
120
I have a datacenter with 1000 servers and I wnat to monitor there CPU and Memory, create Alarms and take automated actions, how can I do this?
- Install cloudwatch agent on the servers
- Use Cloudwatch metrics to capture CPU and Memory
- Create CloudWatch alarms to trigger actions like automation
- Use SSM for automated action or Lambda.
121
I have 100s of millions of raspberry pi sensors all around the world, I need to be able to easily monitor the level on a dashboard and alos set thresholds and send an email when threshold are triggered, I also need dashboards, how can I do this?
You can use CloudWact, write the Rasberry Pi code to send matrics via CloudWatch API to CW. Use CW dashboard to display and graph. Use CW alarms to trigger an SNS and sent emails.
122
Is it possible to have Alarms trigger events in cloud watch?
Yes, 100%, very important feature as events enable you to perform may the tasks.
123
For cloudwatch is there one or two agents for cloud watch logs and cloudwatch metrics?
Two separate agents.
124
What is a log group?
It is a group of log streams thet shares the same retention, monitoring and access control.
125
Is retention set on the log group or log stream?
Log group and is applied to all the streams in the log group, keep in mind the retention is the time the log stream will be retained.
126
What is a log stream?
It is a sequence of log events and a log event is like '1/1/2020 Error EC2 instance X has an issue with C: drive'
127
Where can I store my CloudTrail logs?
You can store them in S3, but you also have the option to have them sent and stored in ClouWatch Logs?
128
Are cloudwatch events near realtime?
Yes, cloudwatch events are near real-time.
129
What are the concepts of the cloudwatch event?
- Events
- Rules
- Targets
130
How does cloud watch events work?
It receives operational events form AWS services and allows you to create rules and define targets.
131
When using cloudwatch events can I have multiple events targets or only one?
multiple, just select add.
132
What types of event buses can you have?
AWS Default
SAAS Provider
Custom
133
What is the default AWS EventBus used for?
It is used when you create CloudWatch events, it is the bus thet receives standard AWS events like EC2 stopping.
134
What is a custom event bus?
Can receive events from your custom applications and service
135
