A practical approach on designing offline online sync system

I had the opportunity to implement a offline online sync system for a customer who is running a chain shop in Bangladesh. Network connectivity is not persistent so I had to come up with a practical solution. I explained my journey in this slide and this video series.

Ep1 https://youtu.be/5O8fMzTLKsY
Ep 2 https://youtu.be/MnSne7fjIuQ
Ep 3 https://youtu.be/jqoFjhcp1xA

Transcript

1. Designing offline online sync system How to design and implement a (partial) offline–online sync system
2. Why we need offline support? Connection is bound to fail, sometimes
3. Common Ideas • Database : built-in support • Couchbase • PouchDB • Firestore • Cloud vendors • Database replication • Handle the replication by managing master and slave model • Database is inside of the browser • Use local-storage and PWA
4. Problems • CouchDB is not traditional database, so hard to use it in traditional business scenarios • Same issue goes with any other built-in sync supported databases • Database replication has • Security issue • Conflict issue • Business logic handling issue • Browser based system • Not possible if the dropdowns have too many items. • Browser has storage limitation. • SQLite can be shared with anyone • New browser needs to load all required data • Background processing in the browser can hamper performance
5. Plan • Try to find which features are actually needed in offline • Sale entry • Follow the git style • Pull • Then push • Try to leverage the infrastructure and user base • Azure cloud messaging (Queue) • Visit outlets and setup necessary software. Teach the user to run the command
6. Code Database Queue Code Database Queue Client Timer service Local machine in a branch Cloud components Trigger
7. Azure Cloud Branch 1 Branch 2 Branch 3 Branch 4 Branch 5 Branch 6
8. Codes Pseudo demo
9. Find me • Facebook: https://www.facebook.com/foyzulsacademy • Blog: https://dev.to/foyzulkarim • Twitter: https://twitter.com/foyzul_karim • GitHub: https://github.com/foyzulkarim • LinkedIn: https://www.linkedin.com/in/foyzul • Email: foyzulkarim@gmail.com