npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

dynalite-test

v1.2.0

Published

An implementation of Amazon's DynamoDB built on LevelDB

Downloads

2

Readme

dynalite

Build Status

An implementation of Amazon's DynamoDB, focussed on correctness and performance, and built on LevelDB (well, @rvagg's awesome LevelUP to be precise).

This project aims to match the live DynamoDB instances as closely as possible (and is tested against them in various regions), including all limits and error messages.

NB: Schema changes in v1.x

If you've been using v0.x with a saved path on your filesystem, you should note that the schema has been changed to separate out indexes. This means that if you have tables with indexes on the old schema, you'll need to update them – this should just be a matter of getting each item and writing it again – a Scan/BatchWriteItem loop should suffice to populate the indexes correctly.

Why not Amazon's DynamoDB Local?

Good question! These days it's actually pretty good, and considering it's now probably used by countless AWS devs, it'll probably be well supported going forward. Unless you specifically can't, or don't want to, use Java, or you're having problems with it, you'll probably be better off sticking with it! Originally, however, DynamoDB Local didn't exist, and when it did, differed a lot from the live instances in ways that caused my company issues. Most of those issues have been addressed in time, but DynamoDB Local does still differ in a number of ways from the live DynamoDB instances – (see below) for details.

Example

$ dynalite --help

Usage: dynalite [--port <port>] [--path <path>] [options]

A DynamoDB http server, optionally backed by LevelDB

Options:
--help                Display this help message and exit
--port <port>         The port to listen on (default: 4567)
--path <path>         The path to use for the LevelDB store (in-memory by default)
--ssl                 Enable SSL for the web server (default: false)
--createTableMs <ms>  Amount of time tables stay in CREATING state (default: 500)
--deleteTableMs <ms>  Amount of time tables stay in DELETING state (default: 500)
--updateTableMs <ms>  Amount of time tables stay in UPDATING state (default: 500)
--maxItemSizeKb <kb>  Maximum item size (default: 400)

Report bugs at github.com/mhart/dynalite/issues

Or programmatically:

// Returns a standard Node.js HTTP server
var dynalite = require('dynalite'),
    dynaliteServer = dynalite({path: './mydb', createTableMs: 50})

// Listen on port 4567
dynaliteServer.listen(4567, function(err) {
  if (err) throw err
  console.log('Dynalite started on port 4567')
})

Once running, here's how you use the AWS SDK to connect (after configuring the SDK):

var AWS = require('aws-sdk')

var dynamo = new AWS.DynamoDB({endpoint: 'http://localhost:4567'})

dynamo.listTables(console.log.bind(console))

Installation

With npm do:

$ npm install -g dynalite

TODO

  • Implement DynamoDB Streams
  • Implement ReturnItemCollectionMetrics on all remaining endpoints
  • Implement size info for tables and indexes
  • Add ProvisionedThroughput checking
  • See open issues on GitHub for any further TODOs

Problems with Amazon's DynamoDB Local (UPDATED 2016-04-19)

Part of the reason I wrote dynalite was due to the existing mock libraries not exhibiting the same behaviour as the live instances. Amazon then released their DynamoDB Local Java, but the early versions were still very different. The latest version I checked (2016-04-19) is much better, but still has a few differences.

Some of these are documented, but most aren't - the items below are a rough list of the issues found, vaguely in order of importance:

  • Does not return nested attributes correctly for UpdateItem
  • Does not calculate size limits accurately for BatchGetItem/Query/Scan result sets
  • Does deal with ALL_ATTRIBUTES correctly for global index on Query/Scan
  • Does not prevent primary keys in QueryFilter and FilterExpression for Query
  • Does not detect duplicate values in AttributesToGet
  • Does not return LastEvaluatedKey when size just over limit for Query/Scan
  • Does not return ConsistentRead property in UnprocessedKeys in BatchGetItem even if requested
  • Doesn't return ConsumedCapacity (documented - but makes it very hard to calculate expected usage)
  • Often returns 500 instead of 400 (or similarly appropriate status)
  • Different serialization and validation error messages from live instances (makes it hard to debug)
  • Does not return application/json if application/json is requested
  • Does not return Query/Scan items in same order when using hash key or hash GlobalSecondaryIndex (shouldn't rely on this anyway)