MongoDB ChangeStreams Counter

If you want know how many Change there are in your collections MongoDB, you can use this Docker container for this.

The application subscribes to the changes of the collection that you indicate and will keep a count of the changes that have occurred. The number of changes will be stored every X seconds in another collection of the database or in another MongoDB database that you specify.

Get Started

It can be easily launched with Docker using the image: rafa93m/mongodb-changestreams-counter:latest

Environment Variables

Name	Required	Default Value	Description
URI_MONGODB_SRC	Yes	-	Connection string for Source MongoDB database in standard format
URI_MONGODB_DST	No	The same database that you indicated in URI_MONGODB_SRC	Connection string for Destination MongoDB database in standard format
COLLECTION_SRC	Yes	-	Name of the source collection from which you want to obtain the number of changes
COLLECTION_DST	No	collection named changestream_count	Name of the collection in which you want to save the count
COMMIT_SECONDS	No	10 seconds	Value in seconds of how long the count is saved in the database

Data

If you run multiple containers, you can view count of any collections. An example of data stored on $COLLECTION_DST

/* 1 */
{
	 "_id" : ObjectId("6198127141999760038e467e"),
	 "date" : ISODate("2021-11-19T21:09:05.175Z"),
	 "collection" : "collection_test_1",
	 "count" : 31
}

/* 2 */
{
	 "_id" : ObjectId("6198129041999760038e467f"),
	 "date" : ISODate("2021-11-19T21:09:36.096Z"),
	 "collection" : "collection_test_2",
	 "count" : 28
}

/* 3 */
{
	 "_id" : ObjectId("619812af41999760038e4680"),
	 "date" : ISODate("2021-11-19T21:10:07.034Z"),
	 "collection" : "collection_test_1",
	 "count" : 127
}

Volume

This container has a volume in /app/data that it is recommended to map. In it the token of the last change of the Change Streams that has been read is saved, in this way if the container is restarted it is able to recover the count in the last change that was read.

Docker Compose

An example of a Docker Compose to monitor a collection can be the following.

version: '3.9'
services:
  changestreamsstats-coltest:
    image: rafa93m/mongodb-changestreams-counter:latest
    environment:
      URI_MONGODB_SRC: "mongodb+srv://user-1:password-1@cluster0.000z.mongodb.net/dbtest?retryWrites=true&w=majority"
      URI_MONGODB_DST: "mongodb+srv://user-2:password-2@cluster0.001z.mongodb.net/dbcount?retryWrites=true&w=majority"
      COLLECTION_SRC: "collection_test_1"
      COLLECTION_DST: "changestream_counter_1"
      COMMIT_SECONDS: 15
    volumes:
      - ./data:/app/data
    restart: unless-stopped