How to use isitfit, in detail


The AWS CLI should be configured with the account's access keys:

aws configure

The AWS user/role should have at least the following AWS-managed policies attached:

Policy Reason
AWSCloudTrailReadOnlyAccess to get history of create/modify for EC2/Redshift resources
AmazonEC2ReadOnlyAccess to list EC2 instances and get their details
AmazonRedshiftReadOnlyAccess to list Redshift clusters and get their details
CloudWatchReadOnlyAccess to get CPU metrics
ResourceGroupsandTagEditorFullAccess to push tags

If you have a Datadog account, check the section Datadog integration for how to fetch memory metrics from Datadog.

Displaying help menus

To get help hints in the command-line use the --help option as follows

> isitfit --help
> isitfit cost --help
> isitfit cost analyze --help

For a full list of commands and options, check

Display version

Check the version of isitfit

isitfit version

Cost-weighted average utilization

Check the Concepts page for an exercise that explains this calculation in more detail.

> isitfit cost analyze

Field                            Value
-------------------------------  -----------
Analysis start date              2019-06-07
Analysis end date                2019-09-05
EC2 Regions                      2 (us-east-1, us-west-2)
EC2 machines (total)             8
EC2 machines (analysed)          3
EC2 Billed cost                  165 $
EC2 Used cost                    9 $
EC2 CWAU = Used / Billed         6 %
Redshift Regions                 1
Redshift clusters (total)        2
Redshift clusters (analysed)     2
Redshift Billed cost             100 $
Redshift Used cost               34 $
Redshift CWAU                    34 %

For reference:
* CWAU >= 70% is well optimized
* CWAU <= 30% is underused

Save intermediate EC2 results to CSV files with:

> isitfit cost analyze --save-details

(output truncated)

Detail file 1/2: Per ec2 and day: /tmp/isitfit-cost-analyze-ec2-details-1-xd_gg2we.csv
Detail file 2/2: Per ec2 only   : /tmp/isitfit-cost-analyze-ec2-details-2-138d1ip7.csv

(output truncated)

> head -n 1 /tmp/isitfit-cost-analyze-ec2-details-1-xd_gg2we.csv
region     instance_id  Timestamp   SampleCount  Average  Minimum  Maximum  Unit    instanceType  API Name  cost_hourly  nhours
us-west-2  i-02432bc7   2019-08-29  1440.0       0.4859   0.3278   21.9999  Percent t2.micro      t2.micro  0.0136705882  24.0

> head -n 1 /tmp/isitfit-cost-analyze-ec2-details-2-138d1ip7.csv
instance_id  capacity     used
i-024...        29.54     0.14

Note that isitfit cost analyze will prompt the user for the number of days on which to perform the analysis. By default, it's 7 days. To skip the prompt, just use the --ndays option, eg isitfit cost --ndays=7 analyze.

Find all recommended type changes

> isitfit cost optimize

Recommended savings: -74 $ (over next 3 months)

EC2 Details
| region    | instance_id         | instance_type   | classification_1   | classification_2                   |   cost_3m | recommended_type   |   savings | tags                                             |
| us-west-2 | i-069a7808addd143c7 | t2.medium       | Underused          | Burstable intraday, No memory data |       117 | t2.small           |       -59 | Name = ******                                    |
| us-west-2 | i-34ca2fc2          | t2.nano         | Normal             | No memory data                     |        14 |                    |         0 | opsworks:layer:php-app = PHP App Server          |
|           |                     |                 |                    |                                    |           |                    |           | opsworks:stack = ******************              |
|           |                     |                 |                    |                                    |           |                    |           | opsworks:instance = ********************         |
|           |                     |                 |                    |                                    |           |                    |           | Name = *************                             |
Saving final results to /tmp/isitfit-full-41o1b4o8.csv
Save complete

Redshift cluster classification
| Region    | ClusterIdentifier   | NodeType   |   NumberOfNodes |   CpuMaxMax |   CpuMinMin |   Cost | classification   |
| us-east-1 | redshift-cluster-1  | dc2.large  |               2 |           0 |           0 |   0.25 | Normal           |
| us-east-1 | redshift-cluster-2  | dc2.large  |               3 |          56 |           0 |   0.25 | Normal           |

Notice that the full final results are saved to a csv file, indicated in the line under the table: Saving final results to /tmp/isitfit-full-...csv

Also, intermediate results of the optimization are streamed to a csv file during the optimization. The filename is indicated in the command output, before the table, as Results will be streamed to /tmp/isitfit-9t0x0jj7.csv. This is useful to start processing results while the optimization is running.

Find only the first 1 underused instances

> isitfit cost optimize --n=1

| instance_id         | instance_type   | classification_1   | classification_2                   |   cost_3m | recommended_type   |   savings | tags                                             |
| i-069a7808addd143c7 | t2.medium       | Underused          | Burstable intraday, No memory data |       117 | t2.small           |       -59 | Name = ******                                    |

Note that isitfit cost optimize will prompt the user for the number of days on which to perform the analysis. By default, it's 7 days. To skip the prompt, just use the --ndays option, eg isitfit cost --ndays=7 optimize.

Allow changing the EC2 family to achieve more savings

isitfit cost optimize --allow-ec2-different-family

Filtering on region

Filter all output from isitfit cost analyze or isitfit cost optimize on a certain region by using the --filter-region option as follows

isitfit cost --filter-region=us-east-1 analyze
isitfit cost --filter-region=us-east-1 optimize

Filtering on tags

Filter optimizations for a particular tag name or tag value

> isitfit cost optimize --filter-tags=inexistant

Apply the same filtering of tag name/value to the cost-weighted average utilization

> isitfit cost analyze --filter-tags=inexistant

Dumping tags to CSV

To dump the EC2 tags in tabular format into a CSV file:

> isitfit tags dump

Counting EC2 instances
Found a total of 8 EC2 instances
Scanning EC2 instances: 9it [00:01,  8.72it/s]                                                                                                                                                              
Converting tags list into dataframe
Dumping data into /tmp/isitfit-tags-9vgd_bzy.csv
Consider `pip3 install visidata` and then `vd /tmp/isitfit-tags-9vgd_bzy.csv` for further filtering or exploration.
More details about visidata at

Pushing tags from CSV

To push EC2 tags from a CSV file:

  1. Attached the policy ResourceGroupsandTagEditorFullAccess to the user/role executing isitfit

  2. Export a tags dump (csv file)

> isitfit tags dump
  1. Edit the csv file
  2. Simulate the push of the edited csv
> isitfit tags push path/to/csv
  1. Perform actual push to AWS EC2
> isitfit tags push path/to/csv --not-dry-run

Generating suggested tags


This generates some tags that are implied from the instance name.

For example, if there are 3 instances that share the word "app" in their names, then "app" is used as a suggested tag.

This helps to squeeze some information out of the instance names to add some tags for convenient filtering.

The algorithm runs locally on your own machine.

To use it:

isitfit tags suggest

Non-default awscli profile

To specify a particular profile from ~/.aws/credentials, set the AWS_PROFILE environment variable.

For example

AWS_PROFILE=autofitcloud isitfit cost analyze

As of version 0.14, there is no need to set AWS_DEFAULT_REGION when using isitfit cost because it will already scan all regions for EC2/Redshift.

You'd still need to use it for isitfit tags though.

To specify a single region to scan, check the section Filtering on region.

Assumed roles

To get isitfit to use a specific role, just issue aws sts assume-role ... and continue using isitfit as usual.

It will pick up the environment variables set by assume-role: AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_SESSION_TOKEN.

Another way is to specify the role in the ~/.aws/credentials file as follows, and then set AWS_PROFILE to the role's profile name (a_role in the example below)

role_arn = arn:aws:iam::123456789:role/foo-bar
source_profile = profile_that_can_assume_role

aws_access_key_id = ABCDEF
aws_secret_access_key = 123abc456

Check the boto3 configuration docs (sections Environment Variables and Shared Credentials File) for more details.

Caching results with redis

Caching in isitfit makes re-runs more efficient.

To use caching, install a local redis server:

apt-get install redis-server

Set up the environment variables to point to this local redis server

export ISITFIT_REDIS_HOST=localhost

Use isitfit as usual

isitfit cost analyze
isitfit cost optimize

Consider saving the environment variables in the ~/.bashrc file.

Datadog integration

isitfit fetches memory metrics from Datadog if available.

To use it:

For example

isitfit cost analyze
isitfit cost optimize

Consider saving the environment variables in the ~/.bashrc file.

Also, the isitfit cost analyze or isitfit cost optimize commands display a table that summarizes the EC2 metrics datasource (datadog or cloudwatch, with preference for datadog), similar to the below:

Status of metric sources (for service ec2)
| datadog   | cloudwatch   |   ID |
| ok        | no need      |   10 |
| no data   | ok           |    5 |
| no data   | no data      |    2 |
Details at /tmp/isitfit/isitfit-sourceStatus-a547va3l.csv

Share results by email

Use the --share-email option to share results by email. Currently only supported by isitfit cost analyze

Example usage

isitfit cost analyze

To send to multiple emails, repeat the --share-email=foo option. The maximum allowed number of emails is 3.

If the --share-email option is skipped, isitfit prompts the user for an email after the results are displayed in the terminal, eg after the isitfit cost analyze results. To skip this prompt altogether, use the --skip-share-email flag as follows:

isitfit --skip-prompt-email cost analyze


The output from isitfit can be controlled with 2 levels of verbosity:

isitfit --verbose cost analyze  # show more output
isitfit --debug   cost optimize # show even more output