Emmanuel emmanuelnk

Migrating from one role to another can be very confusing in Postgres. This is a personal guide with a collection of queries to help aid in this effort.

Definitions

old_role -- Refers to a postgres role that currently owns objects.
new_role -- Refers to a postgres role that will soon own previous objects.
postgres -- Refers to the admin user role.
role_database -- Refers to a database that the old_role currently owns but will soon be owned by new_role

Some useful queries

See all the tables a given role in a db owns:

Queries

General Performance

This query runs against Lambda function logs to get the following information:

InvocationCount -- This is the number of times the Lambda function was invoked.
ColdStartCount -- This is the number of times the Lambda function had initialization overhead (cold start).
InitDuration (min, avg, max) -- This is the amount of time it took the Lambda function to initialize (cold start time).
Duration (min, avg, max) -- This is the amount of time it took the Lambda function to run after initialization.
AllocatedMemory -- This is the amount of memory allocated to the Lambda function in MB.
MaxMemoryUsed (min, avg, max) -- This is the max amount of memory that the Lambda function used during its invocation in MB.

Install Dependencies
```
brew install jq
brew install hub
```
Log into hub (from any repo just do hub pr list)
- use your github username for username
- use a personal access token for password (token should have repo access)

If you have a job or step that has many outputs that you would like to set as envs (in the shell), do this:

name:

workflow_dispatch:

jobs:
  test:
 runs-on: ubuntu-latest

Cloudwatch does not provide metrics on how many workers you are running in a MWAA Environment. Fortunately we can get this information from Cloudwatch Insights using the MWAA_ENVIRONMENT_NAME-Worker log group. Every log stream has the ip address of the worker in the @logStream field

Open the relevant MWAA_ENVIRONMENT_NAME-Workerlog group
Open in CloudWatch Insights and paste and run the following query for your desired time range.
you can then add the visualization to your desired Cloudwatch dashboard

fields @timestamp

A collection of useful Athena Queries

Web Application Firewall

Create WAF logs with projection (no need to partition)

See the docs for reference
Replace the values BUCKET_NAME, AWS_ACCOUNT_NUMBER, AWS_REGION, WEB_ACL_NAME accordingly
Replace 'projection.date.range' = '2023/01/01/00/00,NOW', with the date your WAF logging begins (find in S3)
Query

	1. Install oh-my-zsh
	sh -c "$(wget https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh -O -)"

	2. Clone necessary plugins.
	git clone https://github.com/zsh-users/zsh-autosuggestions $ZSH_CUSTOM/plugins/zsh-autosuggestions
	git clone https://github.com/zsh-users/zsh-history-substring-search ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-history-substring-search
	git clone https://github.com/zsh-users/zsh-syntax-highlighting.git ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting

	3. Add plugins to ~/.zshrc as
	plugins = ( [plugins...] zsh-autosuggestions zsh-history-substring-search zsh-syntax-highlighting)

	export interface AlbAccessLogFormat {
	/**
	* The type of request or connection. The possible values are as follows (ignore any other values):
	*
	* * http — HTTP
	* * https — HTTP over TLS
	* * h2 — HTTP/2 over TLS
	* * grpcs— gRPC over TLS
	* * ws — WebSockets
	* * wss — WebSockets over TLS

	function log_cmd()
	{
	"$@"
	ret=$?

	if [[ $ret -eq 0 ]]
	then
	echo "$(date -u +"%Y-%m-%dT%H:%M:%SZ") user[ $USER ] status[ Success ] code[ $ret ] cmd[ $@ ]" >> bash_command.log
	else
	echo "$(date -u +"%Y-%m-%dT%H:%M:%SZ") user[ $USER ] status[ Error ] code[ $ret ] cmd[ $@ ]" >> bash_command.log