Lennart Öhman
Inventor of OTP design patterns
Sjöland & Thyselius Telecom AB
Lennart Öhman is a member of the Sjöland & Thyselius management
team and works with project management and customer problem analysis as
well as “hand-on” technical development. Mr. Öhman works world-wide
using his international experience to both assist international
customers and market S&T services and products.Lennart started his
career as a systems developer at Ericsson, focusing on robust, fault
tolerant and non-stop systems written in Erlang. His first project was
the Mobility Server, the first Erlang system Ericsson took into
production. In conjunction with his work with the mobility server, he
invented what later became the OTP behaviours.
Lennart Öhman is Giving the Following Talks
A service fail over and take over system for Erlang/OTP
Erlang/OTP positions itself in the niche for building fault tolerant
software systems with redundancy over two or more independent nodes.
However Erlang/OTP comes with surprisingly little built in support to
make failover and takeover/migration of responsibilities between nodes
in a safe way. The Fail Over and Take Over System (FOTOS) presented in
this paper offers mechanisms to keep a consistent state over several
nodes, and also detect partial network failures preventing individual
nodes from making premature decisions. Applications cooperating over
the network can make use of the guaranteed consistent information to
make unanimous decisions when having to decide on to where now failed
services shall be failed-over, and also in a potentially ongoing
procedure where to resume the service.
