Reduce number of janitor threads

Scale janitor threadpool with number of cores.
It is currently only used for closing completion handlers (to avoid deadlock scenarios).
Its size can therefore be greatly reduced.

1 files changed, 2 insertions, 1 deletions

diff --git a/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/JettyHttpServer.java b/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/JettyHttpServer.java
index 03f29aa7bf3..e72f8bceb1f 100644
--- a/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/JettyHttpServer.java
+++ b/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/JettyHttpServer.java
@@ -206,8 +206,9 @@ public class JettyHttpServer extends AbstractServerProvider {
         return ports.stream().map(Object::toString).collect(Collectors.joining(":"));
     }
 
+    // Separate threadpool for tasks that cannot be executed on the jdisc default threadpool due to risk of deadlock
     private static ExecutorService newJanitor() {
-        int threadPoolSize = Runtime.getRuntime().availableProcessors();
+        int threadPoolSize = Math.max(1, Runtime.getRuntime().availableProcessors()/8);
         log.info("Creating janitor executor with " + threadPoolSize + " threads");
         return Executors.newFixedThreadPool(
                 threadPoolSize,