Snapshot of verae-nats-cluster (optimal NATS config study)

scripts/maximize-ns1-study.sh

@@ -0,0 +1,102 @@
+#!/usr/bin/env bash
+# Maximize nats LXC resources + RAM-disk JetStream, run the NS1 study, then
+# put product streams back on ZFS. Cores/RAM/max_mem stay raised.
+# Must run on NS1.GEORGELAMBERT.ORG.
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+export PATH="/usr/sbin:/usr/bin:/bin:/usr/local/bin:$PATH"
+
+HOST="$(hostname -f 2>/dev/null || hostname)"
+case "$HOST" in
+  NS1.GEORGELAMBERT.ORG|NS1|ns1.georgelambert.org|ns1) ;;
+  *)
+    echo "refusing: maximize-ns1-study.sh must run on NS1, got '$HOST'" >&2
+    exit 1
+    ;;
+esac
+
+CORES="${CORES:-8}"
+MEMORY="${MEMORY:-16384}"
+TMPFS_SIZE="${TMPFS_SIZE:-8G}"
+NATS_VMS=(511 512 513)
+ALL_VMS=(510 511 512 513)
+
+apply_resources() {
+  local v
+  for v in "${ALL_VMS[@]}"; do
+    echo "pct set $v --cores $CORES --memory $MEMORY"
+    sudo pct set "$v" --cores "$CORES" --memory "$MEMORY"
+  done
+}
+
+patch_max_mem() {
+  local v
+  for v in "${NATS_VMS[@]}"; do
+    sudo pct exec "$v" -- sed -i -E 's/max_mem:[[:space:]]*[0-9]+[MmGg]/max_mem: 8G/' /etc/nats/nats.conf
+    sudo pct exec "$v" -- grep -n max_mem /etc/nats/nats.conf
+  done
+}
+
+mount_tmpfs() {
+  local v
+  for v in "${NATS_VMS[@]}"; do
+    sudo pct exec "$v" -- bash -lc "
+set -e
+systemctl stop nats-server
+mkdir -p /var/lib/nats/jetstream
+if ! mountpoint -q /var/lib/nats/jetstream; then
+  mount -t tmpfs -o size=${TMPFS_SIZE} nats-js /var/lib/nats/jetstream
+fi
+chown nats:nats /var/lib/nats/jetstream
+chmod 755 /var/lib/nats/jetstream
+systemctl start nats-server
+mount | grep jetstream
+"
+  done
+}
+
+unmount_tmpfs() {
+  local v
+  for v in "${NATS_VMS[@]}"; do
+    sudo pct exec "$v" -- bash -lc '
+set -e
+systemctl stop nats-server || true
+if mountpoint -q /var/lib/nats/jetstream; then
+  umount /var/lib/nats/jetstream
+fi
+mkdir -p /var/lib/nats/jetstream
+chown nats:nats /var/lib/nats/jetstream
+systemctl start nats-server
+'
+  done
+}
+
+wait_cluster() {
+  local n=0
+  until sudo pct exec 511 -- curl -fsS --max-time 2 http://127.0.0.1:8222/varz >/dev/null 2>&1; do
+    n=$((n + 1))
+    [[ $n -lt 30 ]] || { echo "nats-a varz not up" >&2; return 1; }
+    sleep 1
+  done
+  sleep 2
+}
+
+restore_durable() {
+  echo "restoring ZFS JetStream (product streams)"
+  unmount_tmpfs
+  wait_cluster
+  bash "$ROOT/scripts/ensure-streams.sh" || true
+}
+
+apply_resources
+patch_max_mem
+mount_tmpfs
+wait_cluster
+trap restore_durable EXIT
+
+export JS_EXTRA_MEMORY=1
+export COMPARE_DIR="${COMPARE_DIR:-$ROOT/results/20260912T051237Z}"
+# recorded in host-before by appending after dump starts — study script reads pct config live
+bash "$ROOT/scripts/study-on-ns1.sh"
+
+echo "maximize study finished; trap will restore ZFS jetstream"