I have read many posts and watched video to understand Microservices precisely however I found Martin Fowler’s explanation about Microservices most helpful. This blog post is just the recap & summary of what I understood about Microservices Architecture.
Characteristics of Microservices
Build services in form of Components
Components can be independently replaceable and upgradable
Components can be combination of Libraries and Services
Services can be built in other languages and services can inter communicate
Organized keeping business rules in mind
Traditionally (Monolithic), Services were organized considering technical aspects like different services related to UI, Database, Server etc
Microservices, suggests to group it as per business capabilities like shipping, Order, Catalog etc
Smart end points and dump pipe
In ESB (aka spaghetti box 😉 lol), we tend to add all smartness in ESB itself and endpoint is just a dump where consumer gets preprocessed data
MicroServices on other hand encourages dump pipe (ESB) and smart endpoints
Decentralized Governance or Data Governance
Every Service should be responsible for their own database & persistence
Can’t communicate to other databases directly, it should be via API’s only (These are mostly inspired by Amazon’s 2 Pizza team size)
Every service can have different languages or tools
Continuous Delivery is very important for each services to make sure there is no or minimal down time
Top class monitoring capabilities to perform analysis of degraded performance or downtime
Important to have roll back plan and ability to spin up new server in case of service or service fail
Design for failure
As there could be many microservices, its inevitable that they would fail.
Companies like Netflix, they have a application (chaos monkey) which randomly goes out and fail their microservices deliberately
Its important to perform these kind of exercises to understand how resilient their network and microservices are.
Step by step guide to setup Git Server using Bitvise SSH Server
Recently for one of client, I was in need to setup Git on their intranet. Being healthcare industry and compliance issue, source code could not leave company network and therefore needed in-house solution for Source Code Management (SCM) and automate builds.
In this blog post, I will explain how did we setup Git server that is accessible from anywhere in company network.
We need below two software installed on system which will act as a Git Server.
Using Symbolic Link to move high storage folders to new location like moving Google Chrome AppData folder to other location
Few months back I bought a new high end laptop with i7 processor and 16GB of RAM. Decided to give a shot to “SSD hard disc” over conventional hard disc. Performance of my system is incredibly fast, I have SQL Server, Jenkins, Command line Dataloader jobs, Apex static code analyzer all running almost at same time. Windows OS boots up in almost 2-3 seconds only, as compared to 15-25 sec previously. However because of decision of “SSD Drive” I had to compromise storage capacity. My “C” drive is only around 150 GB however D drive has lot of space. After analyzing many folders, I found that google chrome browser creates its temporary folder in “C” drive even though I have installed it explicitly in “D” drive. I wanted to move “Appdata” folder of google chrome to “D” drive to make sure I have enough space in “c” drive.
We have already discussed basics of selenium and how we can use this tool for automated testing. Here we will see how we can take advantage of Selenium to test workflow field update. in this article we will create a simple workflow rule on Lead object and update “Description” field by adding fields “Number of Employees” and “Number of Locations”. We can use selenium to test if workflow is working or not ?
In previous article, I have explained that how to use Jenkins to setup Continuous integration for Salesforce.
Now, once Jenkins is up and its doing its job to build Salesforce changes. Next task is to monitor build result. We already setup post deployment task by creating chatter message to notify everyone about build result, however there is one more excellent way to be aware about result and its small desktop client named “CCTray”.
You can download CCTray from here. Once installed, follow below steps to setup.
the Eclipse SSH key is not matching the SSH key(s) that is associated with your Heroku account. To fix this error, you can: – Associate your SSH key to your Heroku account by going to “Preferences” OR – If the SSH Key is correct, restart Eclipse
One of many features of HTML5 is capability to store data on client machine with the help of “Indexed Database API“. Using this technique web developers can add offline capabilities to their application. Currently almost every modern browser supports “IndexedDB”.
Lets start with Example on Indexed DB :
Very first step in IndexedDB is opening database. Below Code Sample will explain the process.
Tutorial of Streaming API in Salesforce with Source code and Demo Video – Implementation of Bayeux protocol and CometD using JQuery and JSON
Push technology is a model of Internet-based communication in which information transfer is initiated from a server to the client. Also called the publish/subscribe model, this type of communication is the opposite of pull technology in which a request for information is made from a client to the server. The information that’s sent by the server is typically specified in advance. When using Streaming API, you specify the information the client receives by creating a PushTopic. The client then subscribes to the PushTopic channel to be notified of events that match the PushTopic criteria.
In push technology, the server pushes out information to the client after the client has subscribed to a channel of information. In order for the client to receive the information, the client must maintain a connection to the server. Streaming API uses the Bayeux protocol and CometD, so the client to server connection is maintained through long polling.
The Bayeux protocol and CometD both use long polling.
Bayeux is a protocol for transporting asynchronous messages, primarily over HTTP.
CometD is a scalable HTTP-based event routing bus that uses an AJAX push technology pattern known as Comet. It implements the Bayeux protocol.
There is nice jQuery plugin available on web which implements Bayeux protocol and CometD.