infrastructure

commit 3cc676cc3c5b4a0735dd0988040ba2d14726052e
parent c02cce60cba446954a11de3e48038fd0d27939e7
Author: Silas Brack <silasbrack@gmail.com>
Date:   Sat,  4 Jul 2026 14:03:17 +0200

fix: add swap to helios, reduce ClickHouse memory to 500MB

Helios only has 2GB RAM and no swap — ClickHouse was getting
OOM-killed under load. Add 2GB swapfile and cap ClickHouse at
500MB to coexist with other services.

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

Diffstat:
M
hosts/helios.nix
 | 
5
+++++
M
modules/clickhouse-logs.nix
 | 
2
+-

2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/hosts/helios.nix b/hosts/helios.nix
@@ -48,6 +48,11 @@
     device = "/dev/sdb";
     fsType = "ext4";
   };
+  swapDevices = [{
+    device = "/var/lib/swapfile";
+    size = 2048;
+  }];
+
   nix.gc = {
     automatic = true;
     dates = "weekly";
diff --git a/modules/clickhouse-logs.nix b/modules/clickhouse-logs.nix
@@ -74,7 +74,7 @@ in
           <listen_host>${cfg.vpnAddress}</listen_host>
           <http_port>8123</http_port>
           <tcp_port>9000</tcp_port>
-          <max_server_memory_usage>1000000000</max_server_memory_usage>
+          <max_server_memory_usage>500000000</max_server_memory_usage>
         </clickhouse>
       '';
     };