Ripples

Ripples is a program written in C designed for high performant transaction processing. Application demonstrates a software architecture that optimizes processing via several ways:

• CPU affinity for transaction processing
• Vector based socket reads and writes (wherever possible)
• Vector based transaction processing.
• Non blocking transaction handling threads.
• Optimized sharing of resources between threads.

Optimizations minimize data (packet) traversal through the kernel, minimize context switching, and minimize CPU cache misses. Architecture also demonstrates how a resource (object) could be efficiently shared amongst threads without the use of locks, and how to move blocking operations to dedicated threads.

Ripples implements a basic authoritative name server. The basic application functionality is that it listens for DNS queries (requests) over UDP and TCP transport protocols, and provides answers (responses). There are numerous settings that could be used to fine tune software behavior to match requirements and optimize behavior.

DNS response behavior is as such:

• All A query types are responded to with IP address of 127.0.0.1.
• All other query types are responded to with rcode NOTIMPL.
• Authority section in answers is populated with ns.example.com.
• Additional section is populated with ns.example.com A record of 127.0.0.1 and AAAA record of ::1 .

For more details see:

• Architecture
• Usage
• Build
• Code Layout
• Debugging
• TCP