lean is enabled by default to provide better performance. Despite the performance, we loss all useful Mongoose magic methods, getter and setter. A particular magic method which I leverage all the time is
virtual. To make avail of
lean mode, there is an official plugin —
mongoose-lean-virtuals. Since lean mode is enabled to enhance performance, I wonder how this plugin would impact the performance. Thus, I created a simple profiler to discern the performance implication of using such plugin.
(optional) A Quick Primer
This section is also available in my another article.
What is Lean mode in Mongoose?
What is Virtual?
Virtuals are attributes derived during query, which the values are not actually persisted in MongoDB. Since virtual is one of Mongoose magic attributes, it is disabled by default.
Profiling Impact of mongoose-lean-virtuals
mongoose-lean-virtuals preserves lean mode while keeping virtuals enabled. This provokes my interest about its performance implication. I am curious to know how this plugin would impact the performance. Thus, I prepared a simple profiler.
In my test environment, I used:
- MongoDB 4.0.5 with Docker Compose
- Mongoose 5.4.3
- mongoose-lean-virtuals 0.3.4
- Node 8.15.0
I used IMDB title dataset to populate my MongoDB test instance. Test Queries
I performed a series of
find() requests on MongoDB in different modes:
- Lean mode on
- Lean mode on with virtual enabled
- Lean mode off
Test Schema and Virtual
The schema used in the test is modeled after the basic title of IMDB movies.
Mongoose Schema Of IMDB Movie Title
In the schema, I added a virtual attribute
isLong which returns
true if the run-time is longer than 30 mins. This is a fairly simple virtual, it should not be adding too much of computational load in our queries.
Once the data is ready, I run the script which perform the aforementioned queries repeatedly and gather the results by averaging them.
The snippet is the script I ran to measure the query time.
Replicating The Test
The steps to replicate the test are written in my Github repo — mongoose_lean_virtuals_profiler. It also comes with
docker-compose.yml I used. Feel free to try it on your own.
The test ran 10 times and the query time are averaged out.
Average Query Time In Different Lean Modes In Milliseconds
From the screenshot, without Lean mode, the average
find() time is ~2.75 mins. Whereas with lean mode, average query time are approximately ~1.5 mins without virtual and ~1.6 mins with virtual.
This test is not conducted in a strict environment. The purpose of this test is merely to identify the presence of any significant impact on query time when
mongoose-lean-virtuals is applied.
Apparently, given your virtual methods doesn’t perform any computational-intense operation, the impact of using
mongoose-lean-virtuals is fairly acceptable. With the results, I am confident that using this plugin would not introduce significant performance issue in my feathers.js apps.
First published on 2019-01-15
Republished on Codeburst.io