Object creational design patterns
Object creation patterns deal with the creation of objects. Through these patterns you get finer control on how objects are being created and made available. These patterns essentially give you controls such as limiting the number of instances of the … read the rest.
Real-time message processing systems
Real-time message processing or stream processing systems are a need today. There are many examples in the world of IOT, Mobile push messaging, social media, etc.
- Heart of such systems is an enterprise class stream processing system such as Kafka,
Mobile databases for mobile apps
Mobile apps pose a unique challenge. Well designed app has to be seamlessly functional both online and offline. Yes, I meant offline, meaning no network connection. One design option to achieve this is to move a write-enabled replica database into … read the rest.
Factors determining the right database technology
| Factors | Comments |
| Read-heavy or write-heavy or balanced? How many reads/writes per second for the current user base? How does this change when the user base increases? |
|
Factors influencing caching decision
- How often the data changes
- How expensive to re-create data.
- How frequent the data is used.
Factors influencing the decision of having multiple SCM (GIT) repositories for the same project
I recently faced the situation of deciding whether to go with single repository or multiple repositories for the same project. No unanimity in dev community on which is preffered. Often, it boils down the choice of people involved.
In my … read the rest.
Disaster Recovery Strategies
The following are the commonly followed strategies in the increasing order of Recovery Time Objective (Time taken to restore once disaster strikes) and cost.
- Backup and Restore – Complete offline. High recovery time and data loss. Less expensive.
- Pilot light
Disaster Recovery planning – Key terms
Recovery Time Objective (RTO) – The time it takes to restore the system after the disaster strikes. It’s usually expressed in hours.
Recovery Point Objective (RPO) – The acceptable amount of data loss if disaster strikes. It’s also expressed in … read the rest.
Horizontally scaling systems (Scale out)
Just thought to record the horizontal scaling options I came across so far.
- Connected and stateless – Requests in this scenario are synchronous (connected), meaning request is processed immediately and response served. Till then connection to kept open. Servers are
Sample fault tolerant deployment in AWS
Architecture courtesy: acloud.guru
Sample AWS fault tolerant architecture in AWS demonstrated using wordpress deployment.
- Hosted in single region.
- 2 security groups setup in a VPC. One web facing – Web DMZ and other private – RDS security group.
- 2 Availability
Accessing logs through browser in AEM 6.2
Format
http://localhost:4502/system/console/slinglog/tailer.txt?tail=<N> &name=/logs/<log-file-name>
Examples
http://localhost:4502/system/console/slinglog/tailer.txt?tail=500&name=/logs/error.log
http://localhost:4502/system/console/slinglog/tailer.txt?tail=500&name=/logs/request.log
Now Open – AWS Asia Pacific (Mumbai) Region
Great news for cloud computing in India. AWS operationalised its new region in Mumbai. Now, we have one more reason to serve Indian end-users from cloud. We don’t have to go to Singapore to host our servers.
Check out more … read the rest.
AEM Multi Site Manager (MSM) – A scenario
Context
Let’s take an example of a hardware business ABC having presence all over North American continent with United States as it central office. ABC sells it hardware through different brand names. ABC procured AEM license and wants to set … read the rest.
Factors driving AEM DAM content hierarchy
- MIME type / meta data schema / Meta data profile / Processing profile – Anything to do with treatment of assets and their metadata.
- Permissions (ACL).
- Brand, regional and language factors.
- Content life cycle esp. archival requirements.
- Browsing behavior.
- Less
Factors driving the site structure design in AEM
- Multi regional, multi lingual needs (MSM – Multi Site Management).
- Content re-use (Through live copy, language copy).
- Content distribution (Roll out).
- Translations
- Access Control (Permissions).
- SEO.
- Consistency and cache selective invalidation.
- URLs
- Site browsing in author site console.
Integration related questionnaire during requirements discovering
What systems to be integrated?
- Internal enterprise system? First party.
- Partner / Vendor system? Second party.
- 3rd party system?
For all integration, the following details would help understand the fundamentals
- What is the system to be integrated with my system?
EC2 spot price graphs
Graphical view of AWS EC2 spot price trend. Check the below link
Business discovery guidelines
Business discovery starts with the initiation of software project. Goal of business discovery is to mostly two fold
- Understand the customer’s business needs.
- Setup the required project management parameters in defining and executing the project.
Tasks
- Kick off the project