aws-mon-pgsql

Bash script that reports custom metric data about PostgreSQL(RDS) performance to Amazon CloudWatch

This script is intended for use with Amazon EC2 instances running Linux operating systems for monitoring Amazon RDS for PostgreSQL instances.

The scripts have been tested on the following Amazon Machine Images (AMIs) for both 32-bit and 64-bit versions:

• Amazon Linux 2014.9
• Red Hat Enterprise Linux 6.4
• Ubuntu Server 13.10

The scripts have been tested on the following RDS engines:

• PostgreSQL 9.3.5

The script is written in simple Bash, so you can use it very easily.

Metrics of This Script

This script can report the following metrics:

• status
• cache hit
• session
• transaction
• lock
• tupple read
• tupple write
• block read
• buffer write

Prerequisites

This script requires AWS Command Line Interface.

Amazon Linux

Instances that you launch using the Amazon Linux AMI already include the CLI tools.

All you have to do is to install git and postgresql-client.

yum install git postgresql

RHEL, Ubuntu

RHEL

Install git and postgresql-client.

yum install git postgresql

Ubuntu

Install git, unzip, jre and postgresql-client.

apt-get install git unzip default-jre postgresql-client

RHEL, Ubuntu

You can install AWS Command Line Interface with following steps:

pip install awscli

Getting Started

Download "aws-mon-pgsql.sh" or clone repository:

git clone https://github.com/moomindani/aws-mon-pgsql.git
cd aws-mon-pgsql

Make ".pgpass" in order to connect postgres without password:

echo "postgres.xxx.ap-northeast-1.rds.amazonaws.com:5432:postgres:postgres:password" > ~/.pgpass
chmod 600 ~/.pgpass

Use the script:

./aws-mon-pgsql.sh --help

Using the Script

This script collects status, cache hit, session, transaction, lock, tupple read, tupple write, block read, buffer write data on the target RDS. It then makes a remote call to Amazon CloudWatch to report the collected data as custom metrics.

Option

Name	Description
--help	Displays usage information.
--version	Displays the version number.
--verify	Checks configuration and prepares a remote call.
--verbose	Displays details of what the script is doing.
--debug	Displays information for debugging.
--from-cron	Use this option when calling the script from cron.
--profile VALUE	Use a specific profile from your credential file.
--id	Specifies database instance identifier.
-h	Specifies database server host.
-p	Specifies database server port.
-U	Specifies database user.
-d	Specifies database name.
--status	Reports the status of the database instance.
--query-execution	Reports whether select query is executed successfully or not.
--query-execution-timeout	Specifies timeout for query execution.
--cache-hit	Reports cache hit ratio.
--session-active	Reports the number of sessions whose status is active.
--session-idle	Reports the number of sessions whose status is idle.
--session-wait	Reports the number of sessions whose status is wait.
--txn-commit	Reports the number of transactions committed. (Run at least twice with same options)
--txn-rollback	Reports the number of transactions rollbacked. (Run at least twice with same options)
--locks-acquired	Reports the number of locks acquired.
--locks-wait	Reports the number of locks wait.
--tup-inserted	Reports the number of tupples inserted. (Run at least twice with same options)
--tup-updated	Reports the number of tupples updated. (Run at least twice with same options)
--tup-deleted	Reports the number of tupples deleted. (Run at least twice with same options)
--tup-returned	Reports the number of tupples returned. (Run at least twice with same options)
--tup-fetched	Reports the number of tupples fetched. (Run at least twice with same options)
--blks-read	Reports the number of blocks not included in shared memory and read from disk. (Needs to run at least twice with same options)
--blks-hit	Reports the number of blocks included in shared memory. (Run at least twice with same options)
--buffers-checkpoint	Reports the number of buffers written for checkpoint. (Run at least twice with same options)
--buffers-clean	Reports the number of buffers written for cleaning. (Run at least twice with same options)
--buffers-backend	Reports the number of buffers written for backend. (Run at least twice with same options)
--all-items	Reports all items.

Examples

The following examples assume that you have already configured awscli with "aws configure".

To perform a simple test run without posting data to CloudWatch

• Run the following command:

./aws-mon-pgsql.sh --id postgres -h postgres.xxx.ap-northeast-1.rds.amazonaws.com -p 5432 -U postgres -d postgres --status-check-failed --verify --verbose

To collect the status and send them to CloudWatch

• Run the following command:

./aws-mon-pgsql.sh --id postgres -h postgres.xxx.ap-northeast-1.rds.amazonaws.com -p 5432 -U postgres -d postgres --status-check-failed  --verbose

To collect all available session metrics and send them to CloudWatch

• Run the following command:

./aws-mon-pgsql.sh --id postgres -h postgres.xxx.ap-northeast-1.rds.amazonaws.com -p 5432 -U postgres -d postgres --session-active --session-idle --session-wait --verbose

To collect the cache hit ratio and send them to CloudWatch

• Run the following command:

./aws-mon-pgsql.sh --id postgres -h postgres.xxx.ap-northeast-1.rds.amazonaws.com -p 5432 -U postgres -d postgres --cache-hit --verbose

To collect all available tupple metrics and send them to CloudWatch

• Run the following command:

./aws-mon-pgsql.sh --id postgres -h postgres.xxx.ap-northeast-1.rds.amazonaws.com -p 5432 -U postgres -d postgres --tup-inserted --tup-updated --tup-deleted --tup-returned --tup-fetched --verbose
(wait a few seconds...)
./aws-mon-pgsql.sh --id postgres -h postgres.xxx.ap-northeast-1.rds.amazonaws.com -p 5432 -U postgres -d postgres --tup-inserted --tup-updated --tup-deleted --tup-returned --tup-fetched --verbose

To set a cron schedule for metrics reported to CloudWatch

1. Start editing the crontab using the following command:

crontab -e

2. Add the following command to report all items to CloudWatch every five minutes:

*/5 * * * *  ~/aws-mon-pgsql/aws-mon-pgsql.sh --id postgres -h postgres.xxx.ap-northeast-1.rds.amazonaws.com -p 5432 -U postgres -d postgres --all-items --from-cron