Schedule node balancing acts

1 files changed, 45 insertions, 0 deletions

diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeSkewTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeSkewTest.java
new file mode 100644
index 00000000000..85ff4fe4264
--- /dev/null
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeSkewTest.java
@@ -0,0 +1,45 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.hosted.provision;
+
+import com.yahoo.config.provision.NodeResources;
+import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author bratseth
+ */
+public class NodeSkewTest {
+
+    private static final double d = 0.0001;
+
+    @Test
+    public void testNodeSkewComputation() {
+        // No skew
+        assertEquals(0, Node.skew(r(6, 4, 2), r(6, 4, 2)), d);
+        assertEquals(0, Node.skew(r(6, 4, 2), r(0, 0, 0)), d);
+        assertEquals(0, Node.skew(r(6, 4, 2), r(3, 2, 1)), d);
+
+        // Extremely skewed
+        assertEquals(0.2222, Node.skew(r(6, 4, 2), r(0, 4, 0)), d);
+        // A little less
+        assertEquals(0.1666, Node.skew(r(6, 4, 2), r(3, 4, 0)), d);
+        // A little less
+        assertEquals(0.0555, Node.skew(r(6, 4, 2), r(3, 4, 1)), d);
+        // The same, since being at half and full is equally skewed here
+        assertEquals(0.0555, Node.skew(r(6, 4, 2), r(3, 4, 2)), d);
+        // Almost not skewed
+        assertEquals(0.0062, Node.skew(r(6, 4, 2), r(5, 4, 2)), d);
+
+        // Skew is scale free
+        assertEquals(0.0201, Node.skew(r( 6, 4, 2), r(1, 1, 1)), d);
+        // - all dimensions twice as large
+        assertEquals(0.0201, Node.skew(r(12, 8, 4), r(2, 2, 2)), d);
+        // - just one dimension twice as large
+        assertEquals(0.0201, Node.skew(r(12, 4, 2), r(2, 1, 1)), d);
+    }
+
+    private NodeResources r(double vcpu, double memGb, double diskGb) {
+        return new NodeResources(vcpu, memGb, diskGb, 1);
+    }
+
+}