mORMot Open Source

HollosCs

Member

Registered: 2015-12-08

Posts: 56

mORMot starting way

Hi!

I'm new in ORM. My current application use SQLite database with direct access shared folder, more client.
This is not working very well and I think rewrite the whole db access client-server / ORM.
Looking for ORM tool and I think the mORMot is will perfect for me (read many good news, info).

What is the starting point and direction/technology with mORMot framework, for the below goal?
-one server app
-more client (concurrent read, write, delete)
-using the exists database

the pc-s are connected in LAN, but later need access from internet with mobile app.

Sorry for my poor English.
Thx,
Csaba

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,238

Website

Re: mORMot starting way

Running SQlite3 concurrently on a shared network folder would never work as expected.
See https://www.sqlite.org/howtocorrupt.html

2.1 Filesystems with broken or missing lock implementations
SQLite depends on the underlying filesystem to do locking as the documentation says it will. But some filesystems contain bugs in their locking logic such that the locks do not always behave as advertised. This is especially true of network filesystems and NFS in particular. If SQLite is used on a filesystem where the locking primitives contain bugs, and if two or more threads or processes try to access the same database at the same time, then database corruption might result.

Take a look at
- the FAQ http://synopse.info/files/html/Synopse% … l#TITL_123
- the samples

HollosCs

Member

Registered: 2015-12-08

Posts: 56

Re: mORMot starting way

New question: application run as server, communication is interface based.
When raise an error in server side, how manage this?
Server stop? Must restart it manually? What is recommended pattern?

Thx

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,238

Website

Re: mORMot starting way

See http://synopse.info/files/html/Synopse% … l#TITL_165

HollosCs

Member

Registered: 2015-12-08

Posts: 56

Re: mORMot starting way

Thanks, I understand it.

New q.: How can I replace/update a running service? Is there a safe stopping mechanism or pattern?

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,238

Website

Re: mORMot starting way

Usually, stopping and restarting a service is very fast.
So you could just shut the service down, then update the executables, and run it again.
We do it in seconds, on our clouds.
All clients should reconnect automatically when the service restarts.

HollosCs

Member

Registered: 2015-12-08

Posts: 56

Re: mORMot starting way

Thanks! Great news!