Notes

I am one of those people who function better by writing things down. One day, I realized that most of my notes don’t have to be private, so here they are - my second brain. Be warned that, if you stumble upon something here that doesn’t make sense to you, it isn’t meant to!

Get error rate for an AWS Step Function state machine through CloudWatch

Step Function emits the following execution metrics for each state machine: ExecutionsSucceeded. ExecutionsAborted. ExecutionsFailed. ExecutionsTimedOut. We can get the overall error rate for a given state machine by doing the following: aws cloudwatch get-metric-data \ --region us-east-1 \ --start-time 2020-06-01T00:00:00Z \ --end-time 2020-08-01T01:00:00Z \ --scan-by TimestampAscending \ --metric-data-queries ' [ { "Id": "executionsAborted1", "MetricStat": { "Metric": { "Namespace": "AWS/States", "MetricName": "ExecutionsAborted", "Dimensions": [ { "Name": "StateMachineArn", "Value": "<state-machine-ARN>" } ] }, "Period": 300, "Stat": "Sum" }, "ReturnData": false }, { "Id": "executionsFailed1", "MetricStat": { "Metric": { "Namespace": "AWS/States", "MetricName": "ExecutionsFailed", "Dimensions": [ { "Name": "StateMachineArn", "Value": "<state-machine-ARN>" } ] }, "Period": 300, "Stat": "Sum" }, "ReturnData": false }, { "Id": "executionsSucceeded1", "MetricStat": { "Metric": { "Namespace": "AWS/States", "MetricName": "ExecutionsSucceeded", "Dimensions": [ { "Name": "StateMachineArn", "Value": "<state-machine-ARN>" } ] }, "Period": 300, "Stat": "Sum" }, "ReturnData": false }, { "Id": "executionsTimedOut1", "MetricStat": { "Metric": { "Namespace": "AWS/States", "MetricName": "ExecutionsTimedOut", "Dimensions": [ { "Name": "StateMachineArn", "Value": "<state-machine-ARN>" } ] }, "Period": 300, "Stat": "Sum" }, "ReturnData": false }, { "Id": "errorRate", "Expression": "1 - (executionsSucceeded1)/(executionsSucceeded1 + executionsTimedOut1 + executionsFailed1 + executionsAborted1)" } ] '

Get error rate for AWS API Gateway through CloudWatch

Top-level error rate: aws cloudwatch get-metric-data \ --region us-east-1 \ --start-time 2020-08-01T00:00:00Z \ --end-time 2020-08-02T00:00:00Z \ --scan-by TimestampAscending \ --metric-data-queries ' [ { "Id": "m1", "MetricStat": { "Metric": { "Namespace": "AWS/ApiGateway", "MetricName": "5XXError", "Dimensions": [ { "Name": "ApiName", "Value": "<service-name>" }, { "Name": "Stage", "Value": "<stage-name>" } ] }, "Period": 300, "Stat": "Average" } } ] ' Or, for API-level, just add relevant dimensions: ...

List Metrics from AWS CloudWatch

List error-metrics for an AWS API Gateway service: aws cloudwatch list-metrics \ --region us-east-1 \ --namespace AWS/ApiGateway \ --metric-name 5XXError \ --dimensions ' [ { "Name": "ApiName", "Value": "<service-name>" } ] ' Or all metrics for AWS Step Functions: aws cloudwatch list-metrics \ --region us-east-1 \ --namespace AWS/States

Manage AWS KMS Grants

Create aws kms create-grant \ --region us-east-1 \ --key-id <key-ARN> \ --grantee-principal <grantee-principal-role-ARN> \ --operations Encrypt Decrypt GenerateDataKey \ --constraints EncryptionContextSubset={'foo'='bar'} Note: The list of valid --operations can be found here. If you don’t want to supply encryption context, just omit the --constraints parameter. List aws kms list-grants \ --region us-east-1 \ --key-id <key-ARN> Retire aws kms retire-grant \ --region us-east-1 \ --grant-id <grant-id> \ --key-id <key-ARN>

Env variable to set default AWS region

export AWS_DEFAULT_REGION=us-west-2

Limit coffee intake

How many times do I have to get burnt before I understand not to drink too much coffee. And, no, it won’t be different this one time either because I didn’t sleep well so am tired today or because I am drinking the second cup before noon. (On the latter, I don’t know why things are so bad for me. It’s probably has to do with the way I make coffee, with an Aeropress, which leaves a higher concentration of caffeine in the body.) ...

Child-care search in Seattle

To ask Cancelation policy. Do they support monthly freezes? Any subsidies for Microsoft or Amazon employees? If we gave some date today, how flexible are they with us changing it later on? Bright horizons Infant program: 6 weeks to 1 year old. Belltown: $150 non-refundable fee. Can put 3 location preferences but you have to pay the highest amount out of the 3. $3090 per month until July 2021. Only full time. M-F. 7 am to 5:30 pm currently. However much time is needed. Jan 2020 had a lengthy waitlist. SLU: Same. Interbay: Same. Kiddie Academy Queen Anne. Full-time only. M-F, 7 am to 6:30 pm. Can’t leave for 10+ hours. 4-6 weeks to 1 year. Jan-Feb very popular. ~20 or so families on the wait-pool, only have 16 spaces but not all available. ~4 available. $2760 per month. Month-to-month with 4 week notice. Once enrolled, your spot is available until the child graduates at 4-5 years. Prices change based on child’s age. For e.g., next is $2610. Enrollment: $150 wait-pool/registration fee. Virtual tour: They check temperature before taking the child in today. Parents aren’t currently allowed to visit their children. 2 infant class. Teacher to children ratio: 1:4. Max 8 children in one class. 1:7 to 1:5 and 11-14 respectively for toddlers. Mothers currently not allowed to come feed. Food is labeled and stored in refrigerator. Food for infants required every day. Once older (7+ months), they offer meals which are included in the tuition. Infant program: Crib per infant. Sheets changed daily. Infant daily report over email/app. Daily notes (such as naps, meals, etc.). Parents provide all diapers, meals, extra clothes etc. for infants. Fresh, organic and sometimes cross-cultural food. Later on, Spanish language, yoga, music etc. If parents want to influence, discuss with teacher. Bi-weekly plans. Toddler program: Family style dining. Designated meal, out and nap time. No freeze or vacation credit: continue paying or leave. No subsidies for us. The sooner you join the wait pool, the higher your chance of getting a spot whenever you you want and whenever one comes up.

Ted Talk - How to Achieve Your Most Ambitious Goals

I learnt a possibly powerful new idea in the following Ted Talk today. The speaker pitched that all you need to do to achieve big goals is break them down into small chunks and doing them one by one. Another way I’ve seen this idea before goes like this: how do you eat an elephant? One piece at a time. ...

Expectations from an E6-level Facebook interview

Scope of role. Work at the level of a 2-pizza team. Cross function influence. Collaboration > influence other team. Conflict resolution. Empathy - to understand other side of story. Empathy. Doing it the right way vs doing fast. Motivation. What do you do when you are blocked. Example where the other side won. What mistakes did you make? And, more importantly, what did you learn from them? How do you explain problems to the audience the way they can consume? 2 coding, 1 design, 1 behavioral. ...

Setup blog and email on custom domain for (almost) free

The number of ways you can setup a website/blog such as this can be overwhelming these days. In this post, I will talk about my requirements from my setup and an overview of how I solved them. Requirements I always wanted a small space for myself on the internet and I tried Blogger, WordPress and Twitter at various times to get there. (In fact, I once wrote about how I preferred WordPress to Blogger and would stick with it for long!) Following are some of the factors that are important to me. ...