I am new to DynamoDB and trying to learn, while going through the docs I got a doubt whether DynamoDB is version agnostic or not also I want to know wether it is backwards compatible or not?
In addition I also want to know how to download local DynamoDB of different versions if possible and how can I change the version of DynamoDB in the webservice of aws ?
dynamoDB is a cloud hosted datastore. It it not a piece of software that you can download or install. As far as I know, there is no version, and you can't/don't have to select any version anywhere.
At most you can use some docker containers that mimics the behavior of dynamoDB to some extend. They are useful for testing and dev purposes, but keep in mind they are just mocks.
Related
There is a lot of confusion when it comes to ionic 2 storage. There was a lot of changes in the new ionic version as Storage was moved to #ionic/strage . I am new to Ionic so some of the things are confusing for me. I have web-development background. From the documentation,
A simple key-value Storage module for Ionic apps based on LocalForage,
with out-of-the-box support for SQLite. This utility makes it easy to
use the best storage engine available without having to interact with
it directly. Currently the ordering is SQLite, IndexedDB, WebSQL, and
LocalStorage.
Installation
npm install #ionic/storage
If you'd like to use SQLite as a storage engine, install a SQLite plugin (only works while running in a simulator or on device):
cordova plugin add cordova-sqlite-storage --save
What I would like to know is, what happens when I run this in browser ? Where does it store the data? What would happen if I dont use cordova-sqlite-storage ? Where does it store the data then?
Ionic also supports SQLite plugin natively to store data in SQLite database .
import { SQLite } from 'ionic-native'
How is it different from Storage other than the fact that there is a fallback to IndexedDB, WebSQL, and LocalStorage ?
I hope my thoughts are in the right direction. A clear answer on how these modules work would be really helpful.
Ionic Storage is the first module written with proper web fallback in mind.
One near-term goal we have with Ionic is enabling devs to build 99% of their app in the browser. It's a much faster workflow. This means support for native plugins that have web fallbacks, as well as better mocking for ones that don't. - Max Lynch on Twitter
By default when running, #ionic/storage will prioritize the storage methods this way:
When running in a native app context, Storage will prioritize using
SQLite, as it's one of the most stable and widely used file-based
databases, and avoids some of the pitfalls of things like localstorage
and IndexedDB, such as the OS deciding to clear out such data in low
disk-space situations.
When running in the web or as a Progressive Web App, Storage will attempt to use IndexedDB, WebSQL, and localstorage, in that order.
- Official Documentation
So when your app is running in the browser (or on a device without the SQLite plugin) it will detect that SQLite is not available and will use IndexedDB/WebSQL instead.
How is it different from Storage other than the fact that there is a fallback to IndexedDB, WebSQL, and LocalStorage?
The SQLite plugin gives you low-level access to an SQLite database, which means you have to care about creating/updating your schemas, and write queries.
#ionic/storage is a wrapper which abstract away the differences of LocalForge and SQLite and provide a simple, unified API to store key/value pairs.
Also it takes care of serializing/deserializing of your objects.
From my understanding of the Ionic 2 RC Storage module, when you are running in the browser you are now only able to store key-value pairs (LocalStorage). You are currently not able to store anything more than that, so you should check out other options like PouchDB and LocalForage if you need full SQL support. This definitely isn't ideal for progressive web apps.
I am wondering if it is feasible to deploy wordpress as a series of lambda functions on AWS API gateway. Any pointers on the feasibility/gotchas would be greatly appreciated!
Thanks in advance,
PKK
You'll have a lot of things to consider with persistence and even before that, Lambda doesn't support PHP. I'd probably look at Microsoft Azure Functions instead that do support PHP and do have persistent storage.
While other languages (such as Go, Rust, Swift etc.) can be "wrapped" to run in AWS Lambda with relative ease, compiling PHP targeting the same platform and running it is a bit different (and certainly more painstaking). Think about all the various PHP modules you'd need for starters. Moreover, I can't imagine performance will be as good as something like a Go binary.
If you can do something clever with the Phalcon framework and come up with an easy build and deploy process, then maayyyybee.
Though, you'd probably need to really overhaul something like WordPress which was not designed for this at all. It still uses some pretty old conventions due to the age of the project and while that is all well and good for your typical PHP server, it's a different ball game in the sense of this "portable" PHP installation.
Keep in mind that PHP sessions are relied upon as well and so you're going to need to move those elsewhere due to the lack of persistence with AWS Lambda. You can probably find some sort of plugin for WordPress that works with Redis?? I have to imagine something like that has been built by now... But there will be many complications.
I would seriously consider using Azure Functions to begin with OR using Docker and forgoing the pricing model that cloud functions offers. You can still find some pretty cheap and scalable hosting out there.
What I've done previously was use AWS ECS (Docker) with EFS (network storage) for persistence and RDS for the database. While this doesn't carry the same pricing model as Lambda, it is still cost efficient. You can set up your ECS Service to autoscale up and down. So that way you're running the bare minimum until you need more.
I've written a more in depth article about it here: https://serifandsemaphore.io/how-to-host-wordpress-like-a-boss-b5993fcfbd8e#.n6fbnf8ii ... but it's basically just the idea of running WordPress in Docker and using EFS to offload the persistent storage issues. You can swap many of the pieces of the puzzle out if you like. Use a database hosted in some other Docker service or Compose or where ever. That part need not be RDS for example. Even your storage could be handled in a different way, though EFS worked pretty well! The only major thing to note about EFS is the write speed. Most WordPress sites are read heavy though. Your mileage will vary depending on your needs.
Is it possible? Yes, anything is possible with enough time and effort. Is it worth it? That is a question best to ask yourself.
PHP can be run on Lambda as per the documentation located here: https://aws.amazon.com/blogs/compute/scripting-languages-for-aws-lambda-running-php-ruby-and-go/ .
The bigger initial problem as stated in other comments is a persistent file system. S3 for media storage is doable via Wordpress plugin (again from the comments) but any other persistent storage for the request / script execution is the initial biggest hurdle. Tackle one problem at a time till you get to the end!
I'm planning to work on a social site and I would like to leverage both a document and graph database for all of the desired features. Is there a way to get Meteor.js or Sail.js (or any better) to work with ArangoDB or OrientDB? Or should I just stick with the bundled MongoDB and integrate something like allegrograph DB?
Sails.js has support for both of the databases you mention:
https://www.npmjs.com/package/sails-orientdb
https://github.com/rosmo/sails-arangodb
In addition to MongoDB, Postgres, and dozens of others.
Sails.js is a classic mvc client-server web application framwork, basically its ruby on rails implemented for node.js + webscockets, so mostly all you need to make it work with any backend database is make changes to the orm.
Meteor is a very different beast, it is a very opinionated realtime end to end web framework including client server and database, by behing very very opinionated it solves many of the common issues in realtime application, where you need to implement a mechanisms for very quickly updating all your clients of each others actions and take care of things like latency compensation, data collision resolution, and real time client version managment, This is implemented by using web sockets and the mongoDB's write ahead logging for triggres of data updates, making meteor somewhat coupled with mongo.
But you can make orientdb work pretty well with meteor using the new orientDB live query api. It is a pubsub implementation for query results, and can be used for efficent updates pushed from the db through the server directly to the client with very little overhead on the server. This is far from production ready and only currently works on the orient db 2.1 rc5 version.
I have implemented a small meteor demo application as an example https://github.com/imdark/meteor-orientdb-demo
Please check on Meteorpedia the Alternative Database Post, they mention neo4j-livedata and minineo4j.
Here is the Atmosphere package: ostrio:neo4jdriver
Is there a specific economic or technological reason why you consider not to use the very well integrated mongoDB as the database of choice?
In addition to Travis answer I also recommend waterline-orientdb for Sails.js.
As we're developing a greedy real-time monitoring application on Meteor, we reached the limit of our single MongoDB instance.
We migrated the DB to a sharded cluster with 2 shards for now, but we might expand up to 6 shards. (I have 2 BladeE chassis with 28 servers)
How do we configure Meteor Oplog Tailing on a mongo db cluster with sharding enabled?
Thanks,
Now there is a good news :) You can use sharded MongoDB database with Meteor easily with a bit of tweaking
Although Meteor core development team hasn't yet add Oplog Tailing support for sharding to their RoadMap, the workaround is so simple. You just add these 2 Meteor packages: cultofcoders:redis-oplog and disable-oplog, add another Redis server, tweak your code a bit and you are good to go.
The reason why Oplog Tailing doesn't work with sharded MongoDB database is just because core development team hasn't yet planed to support it. In fact, it's now possible to add support for sharded database. If you add a bunch of new records and read the Oplogs with tailable cursors from all shards, you will notice that MognoDB balancer will move data, lets say, from shard01 to shard02 where record id 0001 got removed from shard01 and added to shard02. This situation seems to be confusing for Meteor as it doesn't know whether records are actually removed/added by users or by MongoDB balancer. However there is a way to know whether users or MongoDB balancer removed/added the data because we can distinguish by fromMigrate flag — read more about this at MongoDB official site blog — so what we can do for now is to wait for update from core development team or work around with few tricks.
And the most promising workaround I've found so far is Meteor package called cultofcoders:redis-oplog. It's opensource and available on Github (Please check up their repository for full documentation. It's very-easy-to-use). The idea behind this package is to use another Redis server as pub and sub system — it doesn't store any data. it's just for pub and sub — instead of Meteor's which heavily rely on Oplog. This way, we don't have to worry about Oplog for sharded database that Meteor hasn't yet supported. Redis is mature and has been being used in production by many big companies. It's fully compatible with Meteor and you don't have to change the way you use Meteor. However you have to tweak your code a bit when updating collection's data in order to publish changes to Redis, and then the package cultofcoders:redis-oplog will handle the rest.
Seems Meteor does not yet support sharded mongoDB setups with > 1 shard: https://forums.meteor.com/t/mongodb-sharding-and-livequery/3712
I’m using EE for the first time. I design/develop on two machines, so I use private github repos for all my client work. I’d like to run this EE project on SQLite locally while I’m developing and designing, and then switch it to MySQL once I’m ready to deploy to the staging environment for client review. That way, I can track DB changes easily between machines, as there is a lot of content on this particular site, and exporting/importing DB tables every time I switch machines (three or more times a day) is getting old.
I realize I could use the client’s MySQL DB remotely, but would rather keep everything local, if at all possible. So, how can I run EE with SQLite?
This question (or something similar) was made almost three years ago here. The accepted answer hints at possible support in EE v2.0+ (via CodeIgniter’s then-new database abstraction), but I can’t find any recent information (official or otherwise) on how to make it happen.
I short: no. Active Record is not universally-used throughout EE, and especially not in third party add-ons. In fact, the documentation for the Database class does not mention Active Record at all.
I'd suggest just installing MySQL locally.
I don't think you'll have much luck with non-MySQL DBs — MySQL statements are hard-coded into EE, despite the EE 2.0 promises of a fully-fledged CI app with various DB connectors.
I think your best results might be to find a centralized host for your dev DB. EE is especially painful to work with on multiple machines because of the DB — the whole thing is really built with "one server, one developer" as the primary use case.
You can simplify it a bit by keeping your templates saved as files, and rigging your settings to be server-agnostic. I also keep little scripts around to quickly dump/import the DB when I have to, which makes moving the site around in a git repo a little easier. A few details here: http://www.viget.com/inspire/expressionengine-on-multiple-machines/