Revert "Merge pull request #31177 from vespa-engine/revert-31158-jonmv/start-lower-when-feeding"

This reverts commit dc1d2982e21098e0dee252f229762960259382ac, reversing
changes made to 1073327b4b38213311e992f2c2353a376d3404de.

6 files changed, 18 insertions, 17 deletions

diff --git a/client/go/internal/vespa/document/throttler.go b/client/go/internal/vespa/document/throttler.go
index 39900156563..0400ba1a150 100644
--- a/client/go/internal/vespa/document/throttler.go
+++ b/client/go/internal/vespa/document/throttler.go
@@ -37,8 +37,8 @@ type dynamicThrottler struct {
 
 func newThrottler(connections int, nowFunc func() time.Time) *dynamicThrottler {
 	var (
-		minInflight = 16 * int64(connections)
-		maxInflight = 256 * minInflight // 4096 max streams per connection on the server side
+		minInflight = 2 * int64(connections)
+		maxInflight = 256 * minInflight // 512 max streams per connection on the server side
 	)
 	t := &dynamicThrottler{
 		minInflight: minInflight,
@@ -49,7 +49,7 @@ func newThrottler(connections int, nowFunc func() time.Time) *dynamicThrottler {
 		start: nowFunc(),
 		now:   nowFunc,
 	}
-	t.targetInflight.Store(8 * minInflight)
+	t.targetInflight.Store(minInflight)
 	t.targetTimesTen.Store(10 * maxInflight)
 	return t
 }
@@ -57,7 +57,7 @@ func newThrottler(connections int, nowFunc func() time.Time) *dynamicThrottler {
 func NewThrottler(connections int) Throttler { return newThrottler(connections, time.Now) }
 
 func (t *dynamicThrottler) Sent() {
-	currentInflight := t.targetInflight.Load()
+	currentInflight := t.TargetInflight()
 	t.sent++
 	if t.sent*t.sent*t.sent < 100*currentInflight*currentInflight {
 		return
diff --git a/client/go/internal/vespa/document/throttler_test.go b/client/go/internal/vespa/document/throttler_test.go
index 03f0bc75bdc..410e518e596 100644
--- a/client/go/internal/vespa/document/throttler_test.go
+++ b/client/go/internal/vespa/document/throttler_test.go
@@ -9,14 +9,14 @@ import (
 func TestThrottler(t *testing.T) {
 	clock := &manualClock{tick: time.Second}
 	tr := newThrottler(8, clock.now)
-	for i := 0; i < 100; i++ {
-		tr.Sent()
-	}
-	if got, want := tr.TargetInflight(), int64(1024); got != want {
+	if got, want := tr.TargetInflight(), int64(16); got != want {
 		t.Errorf("got TargetInflight() = %d, but want %d", got, want)
 	}
-	tr.Throttled(5)
-	if got, want := tr.TargetInflight(), int64(128); got != want {
+	for tr.TargetInflight() < int64(18) {
+		tr.Sent()
+	}
+	tr.Throttled(34)
+	if got, want := tr.TargetInflight(), int64(17); got != want {
 		t.Errorf("got TargetInflight() = %d, but want %d", got, want)
 	}
 }
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/DynamicThrottlePolicy.java b/messagebus/src/main/java/com/yahoo/messagebus/DynamicThrottlePolicy.java
index 97f681404e9..1a42b688437 100644
--- a/messagebus/src/main/java/com/yahoo/messagebus/DynamicThrottlePolicy.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/DynamicThrottlePolicy.java
@@ -167,10 +167,10 @@ public class DynamicThrottlePolicy extends StaticThrottlePolicy {
     }
 
     /**
-     * Determines where on each latency level the attractor sits. 2 is at the very end, and makes this to *boom*.
+     * Determines where on each latency level the attractor sits. 2 is at the very end, and makes this go *boom*.
      * 0.2 is at the very start, and makes the algorithm more conservative. Probably fine to stay away from this.
      */
-    // Original javadoc is non-sense, but kept for historical reasons.
+    // Original javadoc is nonsense, but kept for historical reasons.
     /*
      * Sets the lower efficiency threshold at which the algorithm should perform window size back off. Efficiency is
      * the correlation between throughput and window size. The algorithm will increase the window size until efficiency
diff --git a/vespa-feed-client/src/main/java/ai/vespa/feed/client/impl/DynamicThrottler.java b/vespa-feed-client/src/main/java/ai/vespa/feed/client/impl/DynamicThrottler.java
index 951a1776b6f..81e972fe45d 100644
--- a/vespa-feed-client/src/main/java/ai/vespa/feed/client/impl/DynamicThrottler.java
+++ b/vespa-feed-client/src/main/java/ai/vespa/feed/client/impl/DynamicThrottler.java
@@ -28,12 +28,12 @@ public class DynamicThrottler extends StaticThrottler {
 
     public DynamicThrottler(FeedClientBuilderImpl builder) {
         super(builder);
-        targetInflight = new AtomicLong(8 * minInflight);
+        targetInflight = new AtomicLong(minInflight);
     }
 
     @Override
     public void sent(long __, CompletableFuture<HttpResponse> ___) {
-        double currentInflight = targetInflight.get();
+        double currentInflight = targetInflight();
         if (++sent * sent * sent < 1e2 * currentInflight * currentInflight)
             return;
 
diff --git a/vespa-feed-client/src/main/java/ai/vespa/feed/client/impl/StaticThrottler.java b/vespa-feed-client/src/main/java/ai/vespa/feed/client/impl/StaticThrottler.java
index 9010b0a7ad8..f0ee434e87c 100644
--- a/vespa-feed-client/src/main/java/ai/vespa/feed/client/impl/StaticThrottler.java
+++ b/vespa-feed-client/src/main/java/ai/vespa/feed/client/impl/StaticThrottler.java
@@ -22,7 +22,7 @@ public class StaticThrottler implements Throttler {
 
     public StaticThrottler(FeedClientBuilderImpl builder) {
         minInflight = 2L * builder.connectionsPerEndpoint * builder.endpoints.size();
-        maxInflight = 256 * minInflight; // 4096 max streams per connection on the server side.
+        maxInflight = 256 * minInflight; // 512 max streams per connection on the server side.
         targetX10 = new AtomicLong(10 * maxInflight); // 10x the actual value to allow for smaller updates.
     }
 
diff --git a/vespa-feed-client/src/test/java/ai/vespa/feed/client/impl/HttpRequestStrategyTest.java b/vespa-feed-client/src/test/java/ai/vespa/feed/client/impl/HttpRequestStrategyTest.java
index 54fab9b859b..b1a04ac9ed4 100644
--- a/vespa-feed-client/src/test/java/ai/vespa/feed/client/impl/HttpRequestStrategyTest.java
+++ b/vespa-feed-client/src/test/java/ai/vespa/feed/client/impl/HttpRequestStrategyTest.java
@@ -33,6 +33,7 @@ import static ai.vespa.feed.client.FeedClient.CircuitBreaker.State.OPEN;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -105,7 +106,7 @@ class HttpRequestStrategyTest {
         cluster.expect((__, vessel) -> vessel.completeExceptionally(new RuntimeException("boom")));
         ExecutionException expected = assertThrows(ExecutionException.class,
                                                    () -> strategy.enqueue(id1, request).get());
-        assertTrue(expected.getCause() instanceof FeedException);
+        assertInstanceOf(FeedException.class, expected.getCause());
         assertEquals("java.lang.RuntimeException: boom", expected.getCause().getMessage());
         assertEquals(1, strategy.stats().requests());
 
@@ -200,7 +201,7 @@ class HttpRequestStrategyTest {
                                                                                     @Override public int retries() { return 1; }
                                                                                 })
                                                                                 .setCircuitBreaker(breaker)
-                                                                                .setConnectionsPerEndpoint(1),
+                                                                                .setConnectionsPerEndpoint(3), // Must be >= 0.5x text ops.
                                                                cluster);
 
         DocumentId id1 = DocumentId.of("ns", "type", "1");