mongo-compare-indexes

compare mongo indexes in two instances

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Use Case

You may need to compare the indexes between different servers/environments (e.g. it can be comparison of the local and dev server, or comparing production environment to staging or uat)

Usage (CLI)

This command requires two URLs provided for target and source mongodb servers to compare their indexes.

It can be done using environment variables TARGET_MONGO_URL and SOURCE_MONGO_URL.

You can define them before executing the command, e.g.

export TARGET_MONGO_URL="mongodb://user:pass@host:port/db_name"
export SOURCE_MONGO_URL="mongodb://localhost/db_name"

and then just run:

npx mongo-compare-indexes run

OR you can define the db URLs inline:

npx mongo-compare-indexes run [options] [source-mongodb-url] [target-mongodb-url]

Example:

npx mongo-compare-indexes run mongodb://localhost:27017/db_name_source mongodb://localhost:27017/db_name_target

Usage (code)

You can also use it within your project using getMissingIndexes method.

Here is an example:

import { getMissingIndexes } from 'mongo-compare-indexes';

async function run () {
  const targetUrl = process.env.TARGET_MONGO_URL; // you can replace it with your own variable
  const sourceUrl = process.env.SOURCE_MONGO_URL; // same here

  console.log("Starting MongoDB index comparison...");
  const missingIndexesResult = await getMissingIndexes(targetUrl, sourceUrl);
  const { missingIndexesSource, missingIndexesTarget } = missingIndexesResult;
  for (const index of missingIndexesSource) {
    console.log(`Missing in source: ${index.collection} - ${index.index_name}`);
  }
  for (const index of missingIndexesTarget) {
    console.log(`Missing in target: ${index.collection} - ${index.index_name}`);
  }
}

run();

Future considerations

• [ ] Add Unit tests
• [ ] Add support of --skip-missing-collections option to prevent showing _id indexes for the empty/missing collections
• [ ] Rewrite with TypeScript