Revert "Add support for connection throttling in JDisc"

This reverts commit 36221bb67238256d46cb0fe69ca682172d2bec65.

4 files changed, 0 insertions, 167 deletions

diff --git a/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectionThrottler.java b/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectionThrottler.java
deleted file mode 100644
index 370ac0aa788..00000000000
--- a/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectionThrottler.java
+++ /dev/null
@@ -1,128 +0,0 @@
-// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.jdisc.http.server.jetty;
-
-import com.yahoo.jdisc.http.ConnectorConfig;
-import org.eclipse.jetty.server.AcceptRateLimit;
-import org.eclipse.jetty.server.ConnectionLimit;
-import org.eclipse.jetty.server.Connector;
-import org.eclipse.jetty.server.LowResourceMonitor;
-import org.eclipse.jetty.util.component.LifeCycle;
-
-import java.time.Duration;
-import java.util.ArrayDeque;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.TimeUnit;
-
-import static java.util.Collections.singleton;
-
-/**
- * Throttles new connections using {@link LowResourceMonitor}, {@link AcceptRateLimit} and {@link ConnectionLimit}.
- *
- * @author bjorncs
- */
-class ConnectionThrottler {
-
-    private final Object monitor = new Object();
-    private final Queue<Runnable> throttleResetters = new ArrayDeque<>();
-    private final Collection<LifeCycle> beans = new ArrayList<>();
-    private final Connector connector;
-    private int throttlersCount;
-
-    ConnectionThrottler(Connector connector, ConnectorConfig.Throttling config) {
-        this.connector = connector;
-        Duration idleTimeout = fromSeconds(config.idleTimeout());
-        if (config.maxAcceptRate() != -1) {
-            beans.add(new CoordinatedAcceptRateLimit(config.maxAcceptRate(), fromSeconds(config.maxAcceptRatePeriod())));
-        }
-        if (config.maxConnections() != -1) {
-            beans.add(new CoordinatedConnectionLimit(config.maxConnections(), idleTimeout));
-        }
-        if (config.maxMemoryUsage() != -1) {
-            beans.add(new CoordinatedLowResourcesLimit(config.maxMemoryUsage(), idleTimeout));
-        }
-    }
-
-    void registerBeans() {
-        beans.forEach(bean -> connector.getServer().addBean(connector));
-    }
-
-    private static Duration fromSeconds(double seconds) {
-        return Duration.ofMillis((long) (seconds * 1000));
-    }
-
-    private void onThrottle(Runnable throttleResetter) {
-        synchronized (monitor) {
-            ++throttlersCount;
-            throttleResetters.offer(throttleResetter);
-        }
-    }
-
-    private void onReset() {
-        List<Runnable> resetters = new ArrayList<>();
-        synchronized (monitor) {
-            if (--throttlersCount == 0) {
-                resetters.addAll(throttleResetters);
-                throttleResetters.clear();
-            }
-        }
-        resetters.forEach(Runnable::run);
-    }
-
-    private class CoordinatedLowResourcesLimit extends LowResourceMonitor {
-        CoordinatedLowResourcesLimit(int maxMemoryUsageMegaBytes, Duration idleTimeout) {
-            super(connector.getServer());
-            super.setMonitoredConnectors(singleton(connector));
-            super.setMaxMemory(maxMemoryUsageMegaBytes * 1024 * 1024L);
-            super.setLowResourcesIdleTimeout((int)idleTimeout.toMillis());
-        }
-
-        @Override
-        protected void setLowResources() {
-            super.setLowResources();
-            ConnectionThrottler.this.onThrottle(() -> super.clearLowResources());
-        }
-
-        @Override
-        protected void clearLowResources() {
-            ConnectionThrottler.this.onReset();
-        }
-    }
-
-    private class CoordinatedConnectionLimit extends ConnectionLimit {
-        CoordinatedConnectionLimit(int maxConnections, Duration idleTimeout) {
-            super(maxConnections, connector);
-            super.setIdleTimeout(idleTimeout.toMillis());
-        }
-
-        @Override
-        protected void limit() {
-            super.limit();
-            ConnectionThrottler.this.onThrottle(() -> super.unlimit());
-        }
-
-        @Override
-        protected void unlimit() {
-            ConnectionThrottler.this.onReset();
-        }
-    }
-
-    private class CoordinatedAcceptRateLimit extends AcceptRateLimit {
-        CoordinatedAcceptRateLimit(int limit, Duration period) {
-            super(limit, period.toMillis(), TimeUnit.MILLISECONDS, connector);
-        }
-
-        @Override
-        protected void limit() {
-            super.limit();
-            ConnectionThrottler.this.onThrottle(() -> super.unlimit());
-        }
-
-        @Override
-        protected void unlimit() {
-            ConnectionThrottler.this.onReset();
-        }
-    }
-}
diff --git a/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/JDiscServerConnector.java b/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/JDiscServerConnector.java
index a80e694ed30..f7d6e1717af 100644
--- a/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/JDiscServerConnector.java
+++ b/jdisc_http_service/src/main/java/com/yahoo/jdisc/http/server/jetty/JDiscServerConnector.java
@@ -50,10 +50,6 @@ class JDiscServerConnector extends ServerConnector {
 
         this.statistics = new ServerConnectionStatistics();
         addBean(statistics);
-        ConnectorConfig.Throttling throttlingConfig = config.throttling();
-        if (throttlingConfig.enabled()) {
-            new ConnectionThrottler(this, throttlingConfig).registerBeans();
-        }
     }
 
     @Override
diff --git a/jdisc_http_service/src/main/resources/configdefinitions/jdisc.http.connector.def b/jdisc_http_service/src/main/resources/configdefinitions/jdisc.http.connector.def
index ae4e66a236b..157ffabdd63 100644
--- a/jdisc_http_service/src/main/resources/configdefinitions/jdisc.http.connector.def
+++ b/jdisc_http_service/src/main/resources/configdefinitions/jdisc.http.connector.def
@@ -41,24 +41,6 @@ tcpKeepAliveEnabled                 bool     default=false
 # Enable/disable TCP_NODELAY (disable/enable Nagle's algorithm).
 tcpNoDelay                          bool     default=true
 
-# Whether to enable connection throttling. New connections will be dropped when a threshold is exceeded.
-throttling.enabled                  bool     default=false
-
-# Max number of connections.
-throttling.maxConnections           int      default=-1
-
-# Max memory usage in megabytes (totalMemory - freeMemory).
-throttling.maxMemoryUsage           int      default=-1
-
-# Max connection accept rate.
-throttling.maxAcceptRate            int      default=-1
-
-# Accept rate sample period in seconds. Used in conjunction with throttling.maxAcceptRate.
-throttling.maxAcceptRatePeriod      double   default=1.0
-
-# Idle timeout in seconds applied to endpoints when a threshold is exceeded (except accept rate threshold).
-throttling.idleTimeout              double   default=1.0
-
 # Whether to enable SSL for this connector.
 ssl.enabled                         bool     default=false
 
diff --git a/jdisc_http_service/src/test/java/com/yahoo/jdisc/http/server/jetty/HttpServerTest.java b/jdisc_http_service/src/test/java/com/yahoo/jdisc/http/server/jetty/HttpServerTest.java
index 479cf514e30..30d5f9e657a 100644
--- a/jdisc_http_service/src/test/java/com/yahoo/jdisc/http/server/jetty/HttpServerTest.java
+++ b/jdisc_http_service/src/test/java/com/yahoo/jdisc/http/server/jetty/HttpServerTest.java
@@ -16,7 +16,6 @@ import com.yahoo.jdisc.handler.RequestHandler;
 import com.yahoo.jdisc.handler.ResponseDispatch;
 import com.yahoo.jdisc.handler.ResponseHandler;
 import com.yahoo.jdisc.http.ConnectorConfig;
-import com.yahoo.jdisc.http.ConnectorConfig.Throttling;
 import com.yahoo.jdisc.http.Cookie;
 import com.yahoo.jdisc.http.HttpRequest;
 import com.yahoo.jdisc.http.HttpResponse;
@@ -481,22 +480,6 @@ public class HttpServerTest {
         assertThat(driver.close(), is(true));
     }
 
-    @Test
-    public void requireThatConnectionThrottleDoesNotBlockConnectionsBelowThreshold() throws Exception {
-        final TestDriver driver = TestDrivers.newConfiguredInstance(
-                new EchoRequestHandler(),
-                new ServerConfig.Builder(),
-                new ConnectorConfig.Builder()
-                        .throttling(new Throttling.Builder()
-                                            .enabled(true)
-                                            .maxAcceptRate(10)
-                                            .maxMemoryUsage(100*1024)
-                                            .maxConnections(10)));
-        driver.client().get("/status.html")
-                .expectStatusCode(is(OK));
-        assertThat(driver.close(), is(true));
-    }
-
     private static RequestHandler mockRequestHandler() {
         final RequestHandler mockRequestHandler = mock(RequestHandler.class);
         when(mockRequestHandler.refer()).thenReturn(References.NOOP_REFERENCE);