CID Entry Points

Entry Point - is fundamental part to describe service which is expected to run in production.

Entry Point is not equal to service instance. There can be more than one instance per single entry point definition. Please check Deployment section for details of instance count auto-configuration.

Configuration

Entry points are expected to be set in project futoin.json manifest as .entryPoints.{name}. However, they can be set and/or tuned in deployment configuration as well.

The amount of options below may look very difficult to understand, but they cover almost all possible cases found in real life. Most of configuration comes from each tool as reasonable default!

Main options:

• .tool - associated Runtime tool.
• .path - file or directory entry point location relative to project root.
• .tune - additional configuration for fine tuning.

Resource allocation constraints:

• Overall:

  • .tune.minMemory - minimal memory per instance of given entry point without connections.
  • .tune.maxMemory - maximal memory per instance (for very specific cases).
  • .tune.maxTotalMemory - maximal memory for all instances of given entry point (for very specific cases).
  • .tune.debugOverhead - extra memory per instance in “dev” deployment.
  • .tune.cpuWeight = 100 - arbitrary positive integer (affects cgroup limits).
  • .tune.memWeight = 100 - arbitrary positive integer (affect memory distribution).

• Per connection:

  • .tune.connMemory - extra memory per one connection.
  • .tune.debugConnOverhead - extra memory per connection in “dev” deployment.
  • .tune.connFD = 16 - file descriptors per connection (affects max file descriptor limit).

• Web server integration:

  • .tune.internal = false - if true, then resource is not exposed
  • .tune.socketTypes = [‘unix’, ‘tcp’, ‘tcp6’] - supported listen socket types
  • .tune.socketProtocol = one of [‘http’, ‘fcgi’, ‘wsgi’, ‘rack’, ‘jsgi’, ‘psgi’]
  • .tune.socketType - generally, for setup in deployment config
  • .tune.socketPort - default/base port to assign to service (optional)
  • .tune.maxRequestSize - maximal size of single request (mostly applicable to HTTP request)

• Misc.:

  • .tune.scalable - if false then it’s not allowed to start more than one instance globally.
  • .tune.reloadable - if true then reload WITHOUT INTERRUPTION is supported.
  • .tune.multiCore - if true then single instance can span multiple CPU cores.
  • .tune.exitTimeoutMS - how many milliseconds to wait after SIGTERM before sending SIGKILL.
  • .tune.maxInstances - limit number of instances per deployment.

Tool tune

It’s important to note that tool tune is specific only to entry point where it is defined. It’s also possible to apply tool tune for whole project using .toolTune configuration described in Tools sections.

Examples

A typical configuration is much simpler:

{
  "entryPoints": {
    "web": {
      "path": "public",
      "tool": "nginx"
    },
    "app": {
      "path": "config.ru",
      "tool": "puma",
      "tune": {
        "connMemory": "32M",
        "minMemory": "256M"
      }
    }
  }
}