feat: new router and benchmark setup

src/main.rs

@@ -123,6 +123,10 @@ enum Cmd {
         /// routers are then run at that cluster size.
         #[arg(long, default_value = "cache_score")]
         auto_probe_router: String,
+        /// Maximum number of routers to simulate concurrently.
+        /// `0` means auto-detect from available CPU parallelism.
+        #[arg(long, default_value_t = 0)]
+        jobs: usize,
         #[command(flatten)]
         overrides: ConfigOverrides,
     },
@@ -168,6 +172,7 @@ fn main() -> Result<()> {
             auto_target_ttft_mean,
             auto_candidates,
             auto_probe_router,
+            jobs,
             overrides,
         } => cmd_ablate(
             &config,
@@ -177,6 +182,7 @@ fn main() -> Result<()> {
             auto_target_ttft_mean,
             &auto_candidates,
             &auto_probe_router,
+            jobs,
             &overrides,
         ),
         Cmd::Validate { config, overrides } => cmd_validate(&config, &overrides),
@@ -218,6 +224,7 @@ fn cmd_ablate(
     auto_target_ttft_mean: f64,
     auto_candidates: &str,
     auto_probe_router: &str,
+    jobs: usize,
     overrides: &ConfigOverrides,
 ) -> Result<()> {
     let mut base = load(path, overrides)?;
@@ -254,12 +261,7 @@ fn cmd_ablate(
         sorted.sort_unstable();
         let probe_mode = RouterMode::parse(auto_probe_router)
             .with_context(|| format!("parsing --auto-probe-router='{auto_probe_router}'"))?;
-        let chosen = auto_select_instances(
-            &base,
-            &sorted,
-            probe_mode,
-            auto_target_ttft_mean,
-        )?;
+        let chosen = auto_select_instances(&base, &sorted, probe_mode, auto_target_ttft_mean)?;
         eprintln!(
             "[ablate] auto-instances chose num_instances={} (target ttft_mean ≤ {:.3}s, probe_router={})",
             chosen,
@@ -270,7 +272,7 @@ fn cmd_ablate(
     }
 
     eprintln!(
-        "[ablate] routers={} evict_policies={} num_instances={}",
+        "[ablate] routers={} evict_policies={} num_instances={} jobs={}",
         modes
             .iter()
             .map(RouterMode::as_str)
@@ -282,8 +284,13 @@ fn cmd_ablate(
             .collect::<Vec<_>>()
             .join(","),
         base.cluster.num_instances,
+        if jobs == 0 {
+            "auto".to_string()
+        } else {
+            jobs.to_string()
+        },
     );
-    let all = driver::ablate_fixed_placement(&base, &modes, &policies)?;
+    let all = driver::ablate_fixed_placement_with_parallelism(&base, &modes, &policies, jobs)?;
     let agg_path = std::path::Path::new(&base.sim.output_dir).join("ablation.json");
     std::fs::create_dir_all(&base.sim.output_dir)?;
     std::fs::write(&agg_path, serde_json::to_string_pretty(&all)?)?;
@@ -479,7 +486,9 @@ fn cmd_oracle(
         eprintln!(
             "[oracle] input_length filter [{}, {}] kept {}/{} requests",
             cfg.sim.input_length_min.unwrap_or(0),
-            cfg.sim.input_length_max.map_or("∞".to_string(), |v| v.to_string()),
+            cfg.sim
+                .input_length_max
+                .map_or("∞".to_string(), |v| v.to_string()),
             records.len(),
             raw_count,
         );