Reviews-API

A REST API micro-service which provides an API to the Atelier e-Commerce application. The service queries an SQL database. The database and the server have been optimized to look-thourgh 20mil+ items of data and transform it in a way in which it is digestable for a front-end application that has already been designed and built.

This service makes use of caching by implementing Redis. The caching takes into account data-integrity and only caches when it is possible to sacrifice speed for integrity.

Schema

I chose MySql for my database so that I could normalize the data as best as possible.

Data Flow

Local

The system itself would not be accessed off of any local computer but prior to hosting, that is how the system was originally implemented.

Queries executed by the meta reviews endpoint:

db.getAllReviews(product_id) =
SELECT rating, recommend FROM
reviews WHERE product_id=${id} AND
reported=1 ORDER BY id DESC

db.getCharacteristics(product_id) =
SELECT characteristics.id, product_id,
name, value FROM characteristics LEFT JOIN
characteristics_reviews ON characteristics.id =
characteristics_reviews.characteristic_id
WHERE product_id=${id}

Tested the meta reviews endpoint using artillery.io. The tests showed that locally the server and database can easily handel 1000 users per second.

meta reviews endpoint =
Summary report @ 22:29:54(-0400) 2021-06-29
  Scenarios launched:  1000
  Scenarios completed: 1000
  Requests completed:  1000
  Response time (msec):
    min: 1
    max: 136
    median: 3
    p95: 113
    p99: 123
  Scenario counts:
    0: 1000 (100%)
  Codes:
    200: 1000

Deployed

The deployed system makes use of 2 EC2 instances. One hosts the MySql database and the other hosts the endpoints and redis server. The above two images shows the ideal scenario in which redis would be useful. All of the complex queries would not be needed if the same product is asked for within 5 seconds. I set the life-span of each cache to 5 seconds to perseve data integrity.

Stress Test

Stress tested 100 users per second: Stress tested 500 users per second: Stress tested 1000 users per second:

Endpoints

GET /reviews

Retrieves a list of reviews for the specified product.

Parameter	Type	Description
page	integer	Selects the page of results to return. Default 1.
count	integer	Specifies how many results per page to return. Default 5.
sort	text	Changes the sort order of reviews to be based on "newest", "helpful", or "relevant".
product_id	integer	Specifies the product for which to retrieve reviews.

RESPONSE

Response: Status 200 OK

{
    "product": "11005",
    "page": 0,
    "count": "100",
    "results": [
        {
            "review_id": 63948,
            "rating": 1,
            "summary": "Similique in itaque et id nostrum soluta.",
            "recommend": 1,
            "response": null,
            "body": "Qui quia vel voluptatum. Accusantium porro mollitia
            enim rerum expedita fugit aspernatur.
            Ex illum architecto nihil nulla. Vel voluptatem velit.
            Quam sint ipsum nemo repellat architecto non natus ut delectus.
            Voluptate dicta natus qui provident molestias.",
            "date": "2021-06-24T04:00:00.000Z",
            "reviewer_name": "Winfield_Schowalter",
            "helpfulness": 1,
            "photos": [
                "https://images.unsplash.com/photo-1465877783223-
                4eba513e27c6?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=
                format&fit=crop&w=1650&q=80"
            ]
        },
        {
            "review_id": 63947,
            "rating": 1,
            "summary": "Accusantium id possimus voluptas.",
            "recommend": 1,
            "response": null,
            "body": "Qui placeat et. Omnis incidunt sed non ex rerum quo aut. Quam magni commodi.",
            "date": "2021-06-24T04:00:00.000Z",
            "reviewer_name": "Lauretta_Abshire",
            "helpfulness": 6,
            "photos": []
        },
        ...
    ]
}

GET /reviews/meta

Retrieves meta data for a product.

Parameter	Type	Description
page	integer	Selects the page of results to return. Default 1.

RESPONSE

Response: Status 200 OK

{
    "product_id": "11004",
    "ratings": {
        "2": 1,
        "3": 1,
        "4": 14
    },
    "recommended": {
        "0": 11,
        "1": 5
    },
    "Fit": {
        "id": 36720,
        "value": 2.3
    },
    "Length": {
        "id": 36721,
        "value": 2.7
    },
    "Comfort": {
        "id": 36722,
        "value": 4.4
    },
    "Quality": {
        "id": 36723,
        "value": 3.8
    }
}

POST /reviews

Add's a review to the list of reviews.

Parameter	Type	Description
product_id	integer	Required ID of the product to post the review for
rating	integer	Integer (1-5) indicating the review rating
summary	text	Summary text of the review
body	text	Continued or full text of the review
recommend	bool	Value indicating if the reviewer recommends the product
name	text	Username for question asker
email	text	Email address for question asker
photos	[text]	Array of text urls that link to images to be shown
characteristics	object	Object of keys representing characteristic_id and values representing the review value for that characteristic. { "14": 5, "15": 5 //...}

RESPONSE

Response: Status 201 CREATED

PUT /reviews/:review_id/helpful

Updates a review and adds to the helpful counter

Parameter	Type	Description
reveiw_id	integer	Required ID of the review to update

RESPONSE

Response: Status 204 NO CONTENT

PUT /reviews/:review_id/report

Reports a review so that the next time get is called on the product, the review will not show up.

Parameter	Type	Description
reveiw_id	integer	Required ID of the review to update

RESPONSE

Response: Status 204 NO CONTENT