SysOps Associate Exam Flashcards
What services can CloudWatch Monitor?
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 Storage Gateways.
What EC2 Metrics can CloudWatch monitor by default?
CPU
Network
Disk
Status Check
Can CloudWatch Monitor Ram (memory) by default?
No
What is the default monitoring interval of CloudWatch?
5 minutes
Enabling this level of monitoring allows CloudWatch to monitor every minute instead of the default 5.
Detailed Monitoring
When can CloudWatch Detailed Monitoring be turned on?
At launch or after the instance is running or stopped
By default, how far back will CloudWatch show metrics in the console?
2 weeks after a metric is last ingested
How can I get CloudWatch metric data older than 2 weeks?
Use GetMetricStatistics API call
How long are EC2 and ELB metrics available after termination?
2 weeks
Can CloudWatch default metrics be any less than 1 minute?
No
List the two types of EC2 status checks
System Status Check
Instance Status Check
How do you repair an EC2 System Status Check?
Stop and Start to resolve the issue
How do you repair an EC2 Instance Status Check?
Reboot the instance to resolve the issue
How many IOPS/GiB can an General Purpose SSD provide?
3 IOPS/GiB
What is the maximum volume size and IOPS of a General Purpose SSD?
16 TiB
10,000 IOPS
EBS volume can consume _% to __% of IOPS when attached for the first time to an instance.
5% to 50%
Do new EBS volumes need to be pre-warmed?
No
(Outdated but potentially important)
How can you pre-warm a new EBS volume?
Write to all blocks
How can you pre-warm an existing EBS volume with data in it from S3?
Read all blocks
EBS _____________ Metrics show how many read/write request in queue which can slow down performance.
volumeQueueLength
EBS Queue length should be ______if this is more, then upgrade to more ______.
Zero
IOPS
What are the 4 EBS Volume status checks?
Ok
Warning
Impaired
Insufficient Data
[EBS Volume Status Checks]
What does the EBS volume status ‘OK’ mean?
EBS Volume is normal
[EBS Volume Status Checks]
What does the EBS volume status ‘Warning’ mean?
EBS Volume is Degraded or Severely Degraded
[EBS Volume Status Checks]
What does the EBS volume status ‘Impaired’ mean?
EBS Volume is Stalled/Not Available
[EBS Volume Status Checks]
What does the EBS volume status ‘Insufficient Data’ mean?
Insufficient Data on EBS Volume
What two ways can RDS metrics be monitored?
Cloudwatch
RDS Events
What are the 8 key RDS metrics?
DatabaseConnections DiskQueueDepth FreeStorageSpace ReplicaLog ReadIOPS WriteIOPS ReadLatency WriteLatency
How frequently does ELB report metrics by default?
Every minute
Does ELB report metrics if there is no traffic?
No
What are the two key ELB metrics?
SurgeQueueLength
SpillOverCount
What is the ELB metric SurgeQueueLength?
No. of requests pending for submission
What is the ELB metric SpillOverCount?
No. of requests that got rejected when queue was full
What are the two types of Elasticache?
Memcache
Reddis
Memcache is _________ and can handle a CPU load of up to __%.
Multithreaded
90%
Reddis is _________ and can only handle a low CPU utilization of ___%
Not Multithreaded
(90/no. of nodes)%
Swap Usage is the amount of ______ file usage
Swap
Swap size = _____ size
RAM
Memcache swap use should be __ Mb but not more than __Mb
0; 50
If Memcache swap size is greater than 50Mb what API call should you check?
memchached_connections_overhead
Reddis uses _____ memory which means what?
Reserve memory; No swap usage metrics
General rule of Evictions in Elasticache says if a _____ item is added then an ____ item must be removed.
new item; old item;
To handle evictions for Memcache, how should you scale?
Scale up
Scale out
How do you decide you eviction threshold with Memcache?
Based on your application
To handle evictions for Reddis, how should you scale?
Scale Up
How do you decide you eviction threshold with Reddis?
There is no standard threshold
If there is a concurrent Connection issue with Memcache and/or Reddis, what does this indicate?
Large traffic spike or application is not releasing connection
Which services offer root access?
Elastic Beanstalk
EMR
EC2
Opswork
To handle a sudden spike in ELB, you need to contact AWS support with what details?
Timeline
Requests/Second
Request/Response Size
OpsWork consists of ________ and ________.
Stacks; Layers
OpsWorks runs on _____.
Chef
In OpsWork, layers contain AWS resources such as…
EC2
ELB
RDS
In OpsWork, layers are like _____, ______, and _______ layer.
Web; Application; Database
In OpsWork, each stack will have how many layers?
1 or more
What are the preconfigured layers in OpsWork?
Application
Database
Load Balancers
Caching
What happens to any EC2 instance added outside of the OpsWork stack in ELB?
OpsWork will remove
How can you simulate a CloudWatch Alarm?
Use the CLI to trigger an alarm
What are the three CloudWatch alarm states?
OK
ALARM
INSUFFICIENT_DATA
What does the CloudWatch Alarm state ‘OK’ mean?
Metrics is within threshold
What does the CloudWatch Alarm state ‘ALARM’ mean?
Metrics is outside of threshold
What does the CloudWatch Alarm state ‘INSUFFICIENT_DATA’ mean?
Not enough data available
What is the only way you can temporarily disable a CloudWatch Alarm?
Using the CLI
CloudWatch doesn’t have Aggregate metrics available. Instead it has which five metrics?
average min max sum data samples
What do you need to enable first before you can setup a billing alarm on CloudWatch?
Billing Alert
What is the default timestamp in CloudWatch and how can you change it?
UTC;
Change it to local timezone in the console
CloudWatch detailed monitoring is not available for which services?
EMR and SNS
To send your own metrics to cloudwatch, use the ____________ command with __________ parameter.
put-metrics-data
statics-value
In CloudWatch, the size of HTTP GET request is __ and POST request is ____ and it is mandatory to pass what?
8KB
40KB
Mandatory to pass namespace
[Review Question]
When sending metrics to Cloudwatch it can have ___ weeks past time stamp and ____ hours future time stamp.
2 week; 2 hours
If you are sending metrics to CloudWatch and there is no timestamp, what will CloudWatch mark the timestamp as?
In case of no timestamp , CloudWatch will mark timestamp as current timestamp