agents: in-flight node exclusion prevents concurrent collisions

Track which nodes are being processed across all concurrent agents.
When an agent claims seeds, it adds them and their strongly-connected
neighbors (score = link_strength * node_weight > 0.15) to a shared
HashSet. Concurrent agents filter these out when running their query,
ensuring they work on distant parts of the graph.

This replaces the eager-visit approach with a proper scheduling
mechanism: the daemon serializes seed selection while parallelizing
LLM work. The in-flight set is released on completion (or error).

Previously: core-personality rewritten 12x, irc-regulars 10x, same
node superseded 12x — concurrent agents all selected the same
high-degree hub nodes. Now they'll spread across the graph.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

poc-memory/src/agents/daemon.rs

@@ -80,24 +80,96 @@ fn job_targeted_agent(
 }
 
 /// Run a single consolidation agent (replay, linker, separator, transfer, health).
+/// Shared set of node keys currently being processed by agents.
+/// Prevents concurrent agents from working on overlapping graph regions.
+type InFlightNodes = Arc<Mutex<std::collections::HashSet<String>>>;
+
 fn job_consolidation_agent(
     ctx: &ExecutionContext,
     agent_type: &str,
     batch_size: usize,
+    in_flight: &InFlightNodes,
 ) -> Result<(), TaskError> {
     let agent = agent_type.to_string();
     let batch = batch_size;
     let job_name = format!("c-{}", agent);
     let job_name2 = job_name.clone();
+    let in_flight = Arc::clone(in_flight);
     run_job(ctx, &job_name, || {
         ctx.log_line("loading store");
         let mut store = crate::store::Store::load()?;
-        ctx.log_line(&format!("running agent: {} (batch={})", agent, batch));
+
+        // Claim seeds: lock in-flight set, run query excluding it,
+        // add selected seeds + strongly-connected neighbors, then unlock.
+        let mut claimed_keys: Vec<String>;
+        let graph = store.build_graph();
+        {
+            let mut locked = in_flight.lock().unwrap();
+            ctx.log_line(&format!("running agent: {} (batch={}, {} in-flight)",
+                agent, batch, locked.len()));
+
+            // Run the agent's query, filtering out in-flight nodes
+            let def = super::defs::get_def(&agent)
+                .ok_or_else(|| format!("no .agent file for {}", agent))?;
+            let query = &def.query;
+            let keys = if !query.is_empty() {
+                use crate::query::engine as search;
+                let mut stages = search::Stage::parse_pipeline(query)?;
+                let padded = batch + locked.len().min(100);
+                if !stages.iter().any(|s| matches!(s, search::Stage::Transform(search::Transform::Limit(_)))) {
+                    stages.push(search::Stage::Transform(search::Transform::Limit(padded)));
+                }
+                let results = search::run_query(&stages, vec![], &graph, &store, false, padded);
+                results.into_iter()
+                    .map(|(k, _)| k)
+                    .filter(|k| !locked.contains(k))
+                    .take(batch)
+                    .collect::<Vec<_>>()
+            } else {
+                vec![]
+            };
+            if keys.is_empty() {
+                return Err("query returned no results (after exclusion)".into());
+            }
+
+            // Claim seeds + strongly-connected neighbors.
+            // Only exclude neighbors with score > threshold to avoid
+            // blacking out the graph via high-degree hub nodes.
+            claimed_keys = Vec::with_capacity(batch * 20);
+            for key in &keys {
+                claimed_keys.push(key.clone());
+                locked.insert(key.clone());
+                for (nbr, strength) in graph.neighbors(key) {
+                    let weight = store.nodes.get(nbr.as_str())
+                        .map(|n| n.weight).unwrap_or(0.1);
+                    if strength * weight > 0.15 {
+                        claimed_keys.push(nbr.clone());
+                        locked.insert(nbr.clone());
+                    }
+                }
+            }
+        }
+        // in_flight lock released — run LLM without holding it
+
         let log = |msg: &str| {
             ctx.log_line(msg);
             log_event(&job_name2, "progress", msg);
         };
-        super::knowledge::run_and_apply_with_log(&mut store, &agent, batch, "consolidate", &log)?;
+        // Use run_one_agent_with_keys — we already selected seeds above,
+        // no need to re-run the query.
+        let result = super::knowledge::run_one_agent_with_keys(
+            &mut store, &agent, &claimed_keys, batch, "consolidate", &log, false,
+        ).map(|_| ());
+
+        // Release all claimed keys (seeds + neighbors)
+        {
+            let mut locked = in_flight.lock().unwrap();
+            for key in &claimed_keys {
+                locked.remove(key);
+            }
+        }
+
+        result?;
         ctx.log_line("done");
         Ok(())
     })
@@ -661,6 +733,10 @@ pub fn run_daemon() -> Result<(), String> {
 
     let graph_health: Arc<Mutex<Option<GraphHealth>>> = Arc::new(Mutex::new(None));
 
+    // Nodes currently being processed by agents — prevents concurrent
+    // agents from working on overlapping graph regions.
+    let in_flight: InFlightNodes = Arc::new(Mutex::new(std::collections::HashSet::new()));
+
     log_event("daemon", "started", &format!("pid {}", std::process::id()));
     eprintln!("poc-memory daemon started (pid {})", std::process::id());
 
@@ -932,6 +1008,7 @@ pub fn run_daemon() -> Result<(), String> {
     let llm_sched = Arc::clone(&llm);
     let last_daily_sched = Arc::clone(&last_daily);
     let graph_health_sched = Arc::clone(&graph_health);
+    let in_flight_sched = Arc::clone(&in_flight);
     let log_dir_sched = task_log_dir.clone();
     const CONSOLIDATION_INTERVAL: Duration = Duration::from_secs(6 * 3600); // 6 hours
 
@@ -990,13 +1067,14 @@ pub fn run_daemon() -> Result<(), String> {
                 for (i, (agent_type, batch)) in runs.iter().enumerate() {
                     let agent = agent_type.to_string();
                     let b = *batch;
+                    let in_flight_clone = Arc::clone(&in_flight_sched);
                     let task_name = format!("c-{}-{}:{}", agent, i, today);
                     let mut builder = choir_sched.spawn(task_name)
                         .resource(&llm_sched)
                         .log_dir(&log_dir_sched)
                         .retries(1)
                         .init(move |ctx| {
-                            job_consolidation_agent(ctx, &agent, b)
+                            job_consolidation_agent(ctx, &agent, b, &in_flight_clone)
                         });
                     if let Some(dep) = prev_by_type.get(*agent_type) {
                         builder.depend_on(dep);
@@ -1107,6 +1185,7 @@ pub fn run_daemon() -> Result<(), String> {
         let choir_rpc = Arc::clone(&choir);
         let llm_rpc = Arc::clone(&llm);
         let log_dir_rpc = task_log_dir.clone();
+        let in_flight_rpc = Arc::clone(&in_flight);
         daemon.add_rpc_handler(move |cmd, _ctx| {
             if !cmd.starts_with("run-agent ") { return None; }
             let parts: Vec<&str> = cmd.splitn(4, ' ').collect();
@@ -1175,6 +1254,7 @@ pub fn run_daemon() -> Result<(), String> {
             while remaining > 0 {
                 let batch = remaining.min(batch_size);
                 let agent = agent_type.to_string();
+                let in_flight_clone = Arc::clone(&in_flight_rpc);
                 let task_name = format!("c-{}-rpc{}:{}", agent, ts, today);
                 let mut builder = choir_rpc.spawn(task_name)
                     .resource(&llm_rpc)
@@ -1184,7 +1264,7 @@ pub fn run_daemon() -> Result<(), String> {
                         if is_rename {
                             job_rename_agent(ctx, batch)
                         } else {
-                            job_consolidation_agent(ctx, &agent, batch)
+                            job_consolidation_agent(ctx, &agent, batch, &in_flight_clone)
                         }
                     });
                 if let Some(ref dep) = prev {

poc-memory/src/agents/defs.rs

@@ -404,10 +404,13 @@ pub fn resolve_placeholders(
 }
 
 /// Run a config-driven agent: query → resolve placeholders → prompt.
+/// `exclude` filters out nodes (and their neighborhoods) already being
+/// worked on by other agents, preventing concurrent collisions.
 pub fn run_agent(
     store: &Store,
     def: &AgentDef,
     count: usize,
+    exclude: &std::collections::HashSet<String>,
 ) -> Result<super::prompts::AgentBatch, String> {
     let graph = store.build_graph();
 
@@ -417,13 +420,20 @@ pub fn run_agent(
         let has_limit = stages.iter().any(|s|
             matches!(s, search::Stage::Transform(search::Transform::Limit(_))));
         if !has_limit {
-            stages.push(search::Stage::Transform(search::Transform::Limit(count)));
+            // Request extra results to compensate for exclusion filtering
+            let padded = count + exclude.len().min(100);
+            stages.push(search::Stage::Transform(search::Transform::Limit(padded)));
         }
-        let results = search::run_query(&stages, vec![], &graph, store, false, count);
+        let results = search::run_query(&stages, vec![], &graph, store, false, count + exclude.len().min(100));
-        if results.is_empty() {
+        let filtered: Vec<String> = results.into_iter()
-            return Err(format!("{}: query returned no results", def.agent));
+            .map(|(k, _)| k)
+            .filter(|k| !exclude.contains(k))
+            .take(count)
+            .collect();
+        if filtered.is_empty() {
+            return Err(format!("{}: query returned no results (after exclusion)", def.agent));
         }
-        results.into_iter().map(|(k, _)| k).collect::<Vec<_>>()
+        filtered
     } else {
         vec![]
     };

poc-memory/src/agents/knowledge.rs

@@ -41,7 +41,20 @@ pub fn run_and_apply_with_log(
     llm_tag: &str,
     log: &dyn Fn(&str),
 ) -> Result<(), String> {
-    let result = run_one_agent(store, agent_name, batch_size, llm_tag, log, false)?;
+    run_and_apply_excluded(store, agent_name, batch_size, llm_tag, log, &Default::default())
+}
+
+/// Like run_and_apply_with_log but with an in-flight exclusion set.
+/// Returns the keys that were processed (for the daemon to track).
+pub fn run_and_apply_excluded(
+    store: &mut Store,
+    agent_name: &str,
+    batch_size: usize,
+    llm_tag: &str,
+    log: &dyn Fn(&str),
+    exclude: &std::collections::HashSet<String>,
+) -> Result<(), String> {
+    let result = run_one_agent_excluded(store, agent_name, batch_size, llm_tag, log, false, exclude)?;
 
     // Mark conversation segments as mined after successful processing
     if agent_name == "observation" {
@@ -88,18 +101,25 @@ pub fn run_one_agent(
     llm_tag: &str,
     log: &dyn Fn(&str),
     debug: bool,
+) -> Result<AgentResult, String> {
+    run_one_agent_excluded(store, agent_name, batch_size, llm_tag, log, debug, &Default::default())
+}
+
+/// Like run_one_agent but excludes nodes currently being worked on by other agents.
+pub fn run_one_agent_excluded(
+    store: &mut Store,
+    agent_name: &str,
+    batch_size: usize,
+    llm_tag: &str,
+    log: &dyn Fn(&str),
+    debug: bool,
+    exclude: &std::collections::HashSet<String>,
 ) -> Result<AgentResult, String> {
     let def = super::defs::get_def(agent_name)
         .ok_or_else(|| format!("no .agent file for {}", agent_name))?;
 
     log("building prompt");
-    let agent_batch = super::defs::run_agent(store, &def, batch_size)?;
+    let agent_batch = super::defs::run_agent(store, &def, batch_size, exclude)?;
-
-    // Eagerly record visits so concurrent agents pick different seeds.
-    // The not-visited query filter checks this timestamp.
-    if !agent_batch.node_keys.is_empty() {
-        store.record_agent_visits(&agent_batch.node_keys, agent_name).ok();
-    }
 
     run_one_agent_inner(store, agent_name, &def, agent_batch, llm_tag, log, debug)
 }

poc-memory/src/agents/prompts.rs

@@ -428,5 +428,5 @@ pub fn consolidation_batch(store: &Store, count: usize, auto: bool) -> Result<()
 pub fn agent_prompt(store: &Store, agent: &str, count: usize) -> Result<AgentBatch, String> {
     let def = super::defs::get_def(agent)
         .ok_or_else(|| format!("Unknown agent: {}", agent))?;
-    super::defs::run_agent(store, &def, count)
+    super::defs::run_agent(store, &def, count, &Default::default())
 }