Simplify code

Add equals and hashcode to JRTConnection
Just switch to a new one if current connection is failing
Removes need for last sucess, error etc. and healthy status

7 files changed, 17 insertions, 64 deletions

diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigRequester.java b/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigRequester.java
index f846231ac98..efb93c6aed2 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigRequester.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigRequester.java
@@ -234,7 +234,6 @@ public class JRTConfigRequester implements RequestWaiter {
         fatalFailures = 0;
         transientFailures = 0;
         noApplicationWarningLogged = Instant.MIN;
-        connection.setSuccess();
         sub.setLastCallBackOKTS(Instant.now());
         log.log(FINE, () -> "OK response received in handleOkRequest: " + jrtReq);
         if (jrtReq.hasUpdatedGeneration()) {
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/MockConnection.java b/config/src/main/java/com/yahoo/config/subscription/impl/MockConnection.java
index c234fdda32c..bed7a0fa3c4 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/MockConnection.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/MockConnection.java
@@ -22,11 +22,6 @@ public class MockConnection implements ConnectionPool, Connection {
     private final ResponseHandler responseHandler;
     private int numberOfRequests = 0;
 
-    public int getNumberOfFailovers() {
-        return numberOfFailovers;
-    }
-
-    private int numberOfFailovers = 0;
     private final int numSpecs;
 
     public MockConnection() {
@@ -59,16 +54,6 @@ public class MockConnection implements ConnectionPool, Connection {
     }
 
     @Override
-    public void setError(int errorCode) {
-        numberOfFailovers++;
-    }
-
-    @Override
-    public void setSuccess() {
-        numberOfFailovers = 0;
-    }
-
-    @Override
     public String getAddress() {
         return null;
     }
@@ -77,9 +62,7 @@ public class MockConnection implements ConnectionPool, Connection {
     public void close() {}
 
     @Override
-    public void setError(Connection connection, int errorCode) {
-        connection.setError(errorCode);
-    }
+    public void setError(Connection connection, int errorCode) { }
 
     @Override
     public Connection getCurrent() {
diff --git a/config/src/main/java/com/yahoo/vespa/config/Connection.java b/config/src/main/java/com/yahoo/vespa/config/Connection.java
index e39175a3a78..f10fbc487bd 100644
--- a/config/src/main/java/com/yahoo/vespa/config/Connection.java
+++ b/config/src/main/java/com/yahoo/vespa/config/Connection.java
@@ -1,4 +1,4 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config;
 
 import com.yahoo.jrt.Request;
@@ -13,9 +13,6 @@ public interface Connection {
 
     void invokeSync(Request request, double jrtTimeout);
 
-    void setError(int errorCode);
-
-    void setSuccess();
-
     String getAddress();
+
 }
diff --git a/config/src/main/java/com/yahoo/vespa/config/JRTConnection.java b/config/src/main/java/com/yahoo/vespa/config/JRTConnection.java
index 0d5f483ad2c..f6352204d4b 100644
--- a/config/src/main/java/com/yahoo/vespa/config/JRTConnection.java
+++ b/config/src/main/java/com/yahoo/vespa/config/JRTConnection.java
@@ -7,8 +7,7 @@ import com.yahoo.jrt.Spec;
 import com.yahoo.jrt.Supervisor;
 import com.yahoo.jrt.Target;
 
-import java.time.Duration;
-import java.time.Instant;
+import java.util.Objects;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -25,10 +24,6 @@ public class JRTConnection implements Connection {
     private final Supervisor supervisor;
     private Target target;
 
-    private Instant lastConnected = Instant.EPOCH.plus(Duration.ofSeconds(1)); // to be healthy initially, see isHealthy()
-    private Instant lastSuccess = Instant.EPOCH;
-    private Instant lastFailure = Instant.EPOCH;
-
     public JRTConnection(String address, Supervisor supervisor) {
         this.address = address;
         this.supervisor = supervisor;
@@ -58,38 +53,26 @@ public class JRTConnection implements Connection {
         if (target == null || !target.isValid()) {
             logger.log(Level.INFO, "Connecting to " + address);
             target = supervisor.connect(new Spec(address));
-            lastConnected = Instant.now();
         }
         return target;
     }
 
     @Override
-    public synchronized void setError(int errorCode) {
-        lastFailure = Instant.now();
+    public String toString() {
+        return address;
     }
 
     @Override
-    public synchronized void setSuccess() {
-        lastSuccess = Instant.now();
-    }
-
-    public synchronized boolean isHealthy() {
-        return lastSuccess.isAfter(lastFailure) || lastConnected.isAfter(lastFailure);
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        JRTConnection that = (JRTConnection) o;
+        return address.equals(that.address);
     }
 
-    public String toString() {
-        StringBuilder sb = new StringBuilder();
-        sb.append(address);
-        sb.append(", ").append(isHealthy() ? "healthy" : "unhealthy");
-        if (lastSuccess.isAfter(Instant.EPOCH)) {
-            sb.append(", last success: ");
-            sb.append(lastSuccess);
-        }
-        if (lastFailure.isAfter(Instant.EPOCH)) {
-            sb.append(", last failure: ");
-            sb.append(lastFailure);
-        }
-        return sb.toString();
+    @Override
+    public int hashCode() {
+        return Objects.hash(address);
     }
 
 }
diff --git a/config/src/main/java/com/yahoo/vespa/config/JRTConnectionPool.java b/config/src/main/java/com/yahoo/vespa/config/JRTConnectionPool.java
index cc005a54054..26eafb67c1b 100644
--- a/config/src/main/java/com/yahoo/vespa/config/JRTConnectionPool.java
+++ b/config/src/main/java/com/yahoo/vespa/config/JRTConnectionPool.java
@@ -12,7 +12,6 @@ import java.util.Map;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import java.util.stream.Collectors;
 
 /**
  * A pool of JRT connections to a config source (either a config server or a config proxy).
@@ -83,13 +82,8 @@ public class JRTConnectionPool implements ConnectionPool {
     synchronized JRTConnection switchConnection() {
         if (getSources().size() <= 1) throw new IllegalStateException("Cannot switch connection, not enough sources");
 
-        List<JRTConnection> sourceCandidates = getSources().stream()
-                                                           .filter(JRTConnection::isHealthy)
-                                                           .collect(Collectors.toList());
-        if (sourceCandidates.size() == 0) {
-            sourceCandidates = getSources();
-            sourceCandidates.remove(currentConnection);
-        }
+        List<JRTConnection> sourceCandidates = getSources();
+        sourceCandidates.remove(currentConnection);
         JRTConnection newConnection = pickNewConnectionRandomly(sourceCandidates);
         log.log(Level.INFO, () -> "Switching from " + currentConnection + " to " + newConnection);
         return currentConnection = newConnection;
@@ -117,7 +111,6 @@ public class JRTConnectionPool implements ConnectionPool {
 
     @Override
     public void setError(Connection connection, int errorCode) {
-        connection.setError(errorCode);
         switchConnection(connection);
     }
 
diff --git a/config/src/test/java/com/yahoo/config/subscription/impl/JRTConfigRequesterTest.java b/config/src/test/java/com/yahoo/config/subscription/impl/JRTConfigRequesterTest.java
index 4211345dff7..1b56e9290b2 100644
--- a/config/src/test/java/com/yahoo/config/subscription/impl/JRTConfigRequesterTest.java
+++ b/config/src/test/java/com/yahoo/config/subscription/impl/JRTConfigRequesterTest.java
@@ -277,7 +277,6 @@ public class JRTConfigRequesterTest {
         } catch (InterruptedException e) {
             e.printStackTrace();
         }
-        assertTrue(connection.getNumberOfFailovers() >= 1);
     }
 
     private JRTConfigSubscription<SimpletypesConfig> createSubscription(ConfigSubscriber subscriber, TimingValues timingValues) {
diff --git a/config/src/test/java/com/yahoo/vespa/config/JRTConnectionPoolTest.java b/config/src/test/java/com/yahoo/vespa/config/JRTConnectionPoolTest.java
index 8bd88d8958f..bfe132c9660 100644
--- a/config/src/test/java/com/yahoo/vespa/config/JRTConnectionPoolTest.java
+++ b/config/src/test/java/com/yahoo/vespa/config/JRTConnectionPoolTest.java
@@ -139,14 +139,13 @@ public class JRTConnectionPoolTest {
         JRTConnection secondConnection = failAndGetNewConnection(connectionPool, firstConnection);
         assertNotEquals(firstConnection, secondConnection);
 
-        // Should change connection, , not getting first or seconds connection as new
+        // Should change connection, not getting second connection as new
         JRTConnection thirdConnection = failAndGetNewConnection(connectionPool, secondConnection);
         // Fail a few more times with old connection, as will happen when there are multiple subscribers
         // Connection should not change
         assertEquals(thirdConnection, failAndGetNewConnection(connectionPool, secondConnection));
         assertEquals(thirdConnection, failAndGetNewConnection(connectionPool, secondConnection));
         assertEquals(thirdConnection, failAndGetNewConnection(connectionPool, secondConnection));
-        assertNotEquals(firstConnection, thirdConnection);
         assertNotEquals(secondConnection, thirdConnection);
 
         // Should change connection, not getting third connection as new