Monthly Archives: January 2017

Notifications 2.0

Roadmap is growing, more data is coming in and more travelers are becoming dependend on our services which is a great! However, everything comes with a price. The huge amount of data that Roadmap is currently processing is going to increase with the time and therefore, it is absolutely important to have a stable platform in place that can handle and support the growth.

To achieve this goal we have taken a closer look into our backend processes and namely, how the current flow works with different types of data that we process as well as into the bottlenecks that we face when it comes to communicating to the travelers.

We have learned that we need to change a big part of our system to be stable, scalable and high available. Our main focus was based on two core processes – Timeline and Notifications.
Within this blog I will dive into the migration of Notifications; How did this work in the past, what kind of issues did we encounter and how did we gain control over these issues in the current process, bearing in mind we want to extend the process in a most efficient way in the (near) future. Continue reading Notifications 2.0

Replication: Snapshot Agent fails on date conversion

In the previous post I wrote, I explained how to setup replication from an on-premise SQL Server instance to an Azure SQL database. While doing this, I came across a very strange issue (or maybe even bug) when setting up replication.

 
The problem child
After working on reproducing the issue for a day, and trying to reduce the issue to a small-scale problem, I came to the conclusion that the problem was (probably) caused by a single primary key on a table in the database:


CREATE TABLE dbo.BuggedTable
	([Day] DATE NOT NULL,
	 SomeId VARCHAR(50) NOT NULL,
	 Amount INT NOT NULL,
	 CONSTRAINT PK_BuggedTable PRIMARY KEY CLUSTERED 
		([Day] ASC,
		SomeId ASC
		)
	)
GO

 
Creating publication & subscriber
The setup of the publication and subscriber wasn’t that difficult. As I said before, there are a few things you need to configure differently then you would do for SQL Server to SQL Server replication.

So I won’t talk you through the whole process again, but refer you to the articles instead. Continue reading Replication: Snapshot Agent fails on date conversion