Supported execution models

laminarmq supports two execution models:

• General async execution model used by various async runtimes in the Rust ecosystem (e.g. tokio, async-std etc.)
• Thread per core execution model (hereafter referred to as TPC sometimes)

In the thread-per-core execution model individual processor cores are limited to single threads. This model encourages design that minimizes inter-thread contention and locks, thereby improving tail latencies in software services. Read: The Impact of Thread per Core Architecture on Application Tail Latency.

In the thread per core execution model, we have to leverage application level partitioning such that each individual thread is responsible for a subset of requests and/or responsibilities. We also have to complement this model with proper routing of requests to the threads to ensure locality of requests. In our case this translates to having each thread be responsible for only a subset of the partition replicas in a node. Requests pertaining to a partition replica are always routed to the same thread. The following sections will go into more detail as to how this is achieved.

We realize that although the thread per core execution model has some inherent advantages, being compatible with the existing Rust ecosystem will significantly increase adoption. Therefore, we have designed our system with reusable components which can be organized to suit both execution models.