Session Worker

The session worker provides process-level isolation for session d'agents. Instead of running all sessions in un seul process, PRX can spawn dedicated worker processes that contain failures et enforce resource limits au OS level.

Motivation

Process isolation provides several benefits:

• Fault containment -- a crash in one session ne fait pcomme unffect others
• Resource limits -- enforce per-session memory and CPU limits via cgroups or OS mechanisms
• Security boundary -- sessions with different trust levels run in separate address spaces
• Graceful degradation -- the main process can restart failed workers

Architecture

┌──────────────┐
│  Main Process │
│  (Supervisor) │
│               │
│  ┌──────────┐ │    ┌─────────────┐
│  │ Session A ├─┼───►│ Worker Proc │
│  └──────────┘ │    └─────────────┘
│  ┌──────────┐ │    ┌─────────────┐
│  │ Session B ├─┼───►│ Worker Proc │
│  └──────────┘ │    └─────────────┘
└──────────────┘

The main process acts comme un supervisor, communicating with workers via IPC (Unix domain sockets or pipes).

Communication Protocol

Workers communicate avec le supervisor using a length-prefixed JSON protocol over the IPC channel:

1. Spawn -- supervisor sends session configuration vers le worker
2. Messages -- bidirectional streaming of user/agent messages
3. Heartbeat -- periodic health checks
4. Shutdown -- graceful termination signal

Configuration

[agent.worker]
enabled = false
ipc_socket_dir = "/tmp/prx-workers"
heartbeat_interval_secs = 10
max_restart_attempts = 3

Limitees de ressources

When running on Linux, the session worker can apply cgroup-based resource limits:

[agent.worker.limits]
memory_limit_mb = 256
cpu_shares = 512

Voir aussi Pages

• Agent Runtime -- Architecture overview
• Agent Loop -- Core execution cycle
• Security Sandbox -- Sandbox backends