From a26494b0281945564b03c9f0668b59bee62241c8 Mon Sep 17 00:00:00 2001
From: Andras Schmelczer <andras@schmelczer.dev>
Date: Sat, 4 Apr 2026 09:48:05 +0100
Subject: [PATCH] Fix memory pressure

---
 r5-java/run.sh                                |  6 +++---
 r5-java/src/main/java/propertymap/Router.java | 11 ++++++++---
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/r5-java/run.sh b/r5-java/run.sh
index be44d81..10adce7 100755
--- a/r5-java/run.sh
+++ b/r5-java/run.sh
@@ -22,8 +22,8 @@ set -euo pipefail
 #   --demo   only compute Bank + TCR, transit only (quick test)
 
 # --- Defaults ---
-THREADS=12
-HEAP=24g
+THREADS=8
+HEAP=40g
 NETWORK_DIR=property-data/r5-network
 OUTPUT_BASE=property-data/travel-times
 R5_DIR=r5-java
@@ -131,7 +131,7 @@ fi
 echo ""
 echo "--- Starting batch computation ---"
 DATA_DIR="$NETWORK_DATA_DIR" NETWORK_CACHE_DIR="$NETWORK_DIR" \
-java -Xmx"$HEAP" -cp "$OUT_DIR:$LIB_DIR/*" propertymap.App \
+java -Xms"$HEAP" -Xmx"$HEAP" -cp "$OUT_DIR:$LIB_DIR/*" propertymap.App \
     --postcodes property-data/arcgis_data.parquet \
     --places property-data/places.parquet \
     --output-dir "$OUTPUT_BASE" \
diff --git a/r5-java/src/main/java/propertymap/Router.java b/r5-java/src/main/java/propertymap/Router.java
index e332114..20b9fc6 100644
--- a/r5-java/src/main/java/propertymap/Router.java
+++ b/r5-java/src/main/java/propertymap/Router.java
@@ -34,8 +34,11 @@ public class Router {
     private static final int DEPARTURE_TO_TIME = 8 * 3600 + 30 * 60;   // 08:30
     private static final int MAX_TRIP_DURATION_MINUTES = 90;
 
-    /** R5 PathResult throws if destinations > 5000. Chunks must be smaller when recording paths. */
-    private static final int PATH_MAX_DESTINATIONS = 5000;
+    /**
+     * R5 PathResult throws if destinations > 5000. Chunks must be smaller when recording paths.
+     * Kept well below R5's limit to reduce per-chunk memory (fewer destinations = smaller PathResult).
+     */
+    private static final int PATH_MAX_DESTINATIONS = 2000;
 
     // Percentile indices in R5 result arrays (order must match task.percentiles in buildTask)
     private static final int PERCENTILE_BEST = 0;   // 5th percentile (transit only)
@@ -383,7 +386,9 @@ public class Router {
 
         if (recordPaths) {
             task.includePathResults = true;
-            task.nPathsPerTarget = 3;
+            // We only use the most common RouteSequence (see extractPaths), so 1 path
+            // per target is sufficient and cuts path memory by ~67% vs 3.
+            task.nPathsPerTarget = 1;
         }
 
         configureMode(task, mode);