Revert "Merge pull request #15581 from vespa-engine/revert-15578-bratseth/apply-on-restart-take-10"

This reverts commit 4cf13bc7db215e77f7688e429f700880c115fe76, reversing
changes made to e21f385bd4f21326608f3a69325df4e96d4a65e5.

7 files changed, 63 insertions, 18 deletions

diff --git a/config/src/main/java/com/yahoo/config/subscription/ConfigSubscriber.java b/config/src/main/java/com/yahoo/config/subscription/ConfigSubscriber.java
index 6bfaa992eb1..ad131f8e0dd 100644
--- a/config/src/main/java/com/yahoo/config/subscription/ConfigSubscriber.java
+++ b/config/src/main/java/com/yahoo/config/subscription/ConfigSubscriber.java
@@ -33,6 +33,7 @@ import static java.util.stream.Collectors.toList;
 public class ConfigSubscriber implements AutoCloseable {
 
     private static final Logger log = Logger.getLogger(ConfigSubscriber.class.getName());
+
     private State state = State.OPEN;
     protected final List<ConfigHandle<? extends ConfigInstance>> subscriptionHandles = new CopyOnWriteArrayList<>();
     private final ConfigSource source;
@@ -46,6 +47,13 @@ public class ConfigSubscriber implements AutoCloseable {
     private boolean internalRedeploy = false;
 
     /**
+     * Whether the last generation should only be applied on restart, not immediately.
+     * Once this is set it will not be unset, as no future generation should be applied
+     * once there is a generation which require restart.
+     */
+    private boolean applyOnRestart = false;
+
+    /**
      * Reuse requesters for equal source sets, limit number if many subscriptions.
      */
     protected Map<ConfigSourceSet, JRTConfigRequester> requesters = new HashMap<>();
@@ -235,12 +243,15 @@ public class ConfigSubscriber implements AutoCloseable {
      * @param timeoutInMillis timeout to wait in milliseconds
      * @param requireChange if set, at least one config have to change
      * @return true, if a new config generation has been found for all configs (additionally requires
-     *         that at lest one of them has changed if <code>requireChange</code> is true), false otherwise
+     *         that at lest one of them has changed if <code>requireChange</code> is true), and
+     *         the config should be applied at this time, false otherwise
      */
     private boolean acquireSnapshot(long timeoutInMillis, boolean requireChange) {
+        boolean applyOnRestartOnly;
         synchronized (monitor) {
             if (state == State.CLOSED) return false;
             state = State.FROZEN;
+            applyOnRestartOnly = applyOnRestart;
         }
         long started = System.currentTimeMillis();
         long timeLeftMillis = timeoutInMillis;
@@ -269,9 +280,18 @@ public class ConfigSubscriber implements AutoCloseable {
                 allGenerationsChanged &= config.isGenerationChanged();
                 anyConfigChanged      |= config.isConfigChanged();
                 internalRedeployOnly  &= config.isInternalRedeploy();
+                applyOnRestartOnly    |= requireChange && config.applyOnRestart(); // only if this is reconfig
                 timeLeftMillis = timeoutInMillis + started - System.currentTimeMillis();
             }
-            reconfigDue = (anyConfigChanged || !requireChange) && allGenerationsChanged && allGenerationsTheSame;
+            reconfigDue = ((anyConfigChanged && !applyOnRestartOnly) || !requireChange)
+                          && allGenerationsChanged && allGenerationsTheSame;
+
+            if (requireChange && applyOnRestartOnly) { // if this is a reconfig, disable future reconfigs until restart
+                synchronized (monitor) {
+                    applyOnRestart = applyOnRestartOnly;
+                }
+            }
+
             if (!reconfigDue && timeLeftMillis > 0) {
                 sleep(timeLeftMillis);
             }
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java
index 3bf6093e872..15f6395c417 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java
@@ -40,21 +40,28 @@ public abstract class ConfigSubscription<T extends ConfigInstance> {
         private final T config;
         private final Long generation;
         private final boolean internalRedeploy;
-
-        private ConfigState(boolean generationChanged, Long generation, boolean internalRedeploy, boolean configChanged, T config) {
+        private final boolean applyOnRestart;
+
+        private ConfigState(boolean generationChanged,
+                            Long generation,
+                            boolean internalRedeploy,
+                            boolean applyOnRestart,
+                            boolean configChanged,
+                            T config) {
             this.generationChanged = generationChanged;
             this.generation = generation;
             this.internalRedeploy = internalRedeploy;
+            this.applyOnRestart = applyOnRestart;
             this.configChanged = configChanged;
             this.config = config;
         }
 
         private ConfigState(Long generation, T config) {
-            this(false, generation, false, false, config);
+            this(false, generation, false, false, false, config);
         }
 
         private ConfigState() {
-            this(false, 0L, false, false, null);
+            this(false, 0L, false, false, false, null);
         }
 
         private ConfigState<T> createUnchanged() { return new ConfigState<>(generation, config); }
@@ -68,6 +75,8 @@ public abstract class ConfigSubscription<T extends ConfigInstance> {
          */
         public boolean isInternalRedeploy() { return internalRedeploy; }
 
+        public boolean applyOnRestart() { return applyOnRestart; }
+
         public T getConfig() { return config; }
 
     }
@@ -181,29 +190,34 @@ public abstract class ConfigSubscription<T extends ConfigInstance> {
         return !prev.getGeneration().equals(requiredGen) || prev.isConfigChanged();
     }
 
-    void setConfig(Long generation, boolean internalRedeploy, T config) {
-        this.config.set(new ConfigState<>(true, generation, internalRedeploy, true, config));
+    void setConfig(Long generation, boolean internalRedeploy, boolean applyOnRestart, T config) {
+        this.config.set(new ConfigState<>(true, generation, internalRedeploy, applyOnRestart, true, config));
     }
 
     /** Used by {@link FileConfigSubscription} and {@link ConfigSetSubscription} */
     protected void setConfigIncGen(T config) {
         ConfigState<T> prev = this.config.get();
-        this.config.set(new ConfigState<>(true, prev.getGeneration() + 1, prev.isInternalRedeploy(), true, config));
+        this.config.set(new ConfigState<>(true, prev.getGeneration() + 1, prev.isInternalRedeploy(), prev.applyOnRestart(), true, config));
     }
 
     protected void setConfigIfChanged(T config) {
         ConfigState<T> prev = this.config.get();
-        this.config.set(new ConfigState<>(true, prev.getGeneration(), prev.isInternalRedeploy(), !config.equals(prev.getConfig()), config));
+        this.config.set(new ConfigState<>(true, prev.getGeneration(), prev.isInternalRedeploy(), prev.applyOnRestart(), !config.equals(prev.getConfig()), config));
     }
 
     void setGeneration(Long generation) {
         ConfigState<T> prev = config.get();
-        this.config.set(new ConfigState<>(true, generation, prev.isInternalRedeploy(), prev.isConfigChanged(), prev.getConfig()));
+        this.config.set(new ConfigState<>(true, generation, prev.isInternalRedeploy(), prev.applyOnRestart(), prev.isConfigChanged(), prev.getConfig()));
     }
 
     void setInternalRedeploy(boolean internalRedeploy) {
         ConfigState<T> prev = config.get();
-        this.config.set(new ConfigState<>(prev.isGenerationChanged(), prev.getGeneration(), internalRedeploy, prev.isConfigChanged(), prev.getConfig()));
+        this.config.set(new ConfigState<>(prev.isGenerationChanged(), prev.getGeneration(), internalRedeploy, prev.applyOnRestart(), prev.isConfigChanged(), prev.getConfig()));
+    }
+
+    void setApplyOnRestart(boolean applyOnRestart) {
+        ConfigState<T> prev = config.get();
+        this.config.set(new ConfigState<>(prev.isGenerationChanged(), prev.getGeneration(), prev.isInternalRedeploy(), applyOnRestart, prev.isConfigChanged(), prev.getConfig()));
     }
 
     /**
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/GenericJRTConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/GenericJRTConfigSubscription.java
index eec18b93e71..ba8fc8a5e19 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/GenericJRTConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/GenericJRTConfigSubscription.java
@@ -18,7 +18,6 @@ import static java.util.logging.Level.FINE;
  * Used by config proxy.
  *
  * @author Vegard Havdal
- *
  */
 public class GenericJRTConfigSubscription extends JRTConfigSubscription<RawConfig> {
 
@@ -33,7 +32,7 @@ public class GenericJRTConfigSubscription extends JRTConfigSubscription<RawConfi
 
     @Override
     protected void setNewConfig(JRTClientConfigRequest jrtReq) {
-        setConfig(jrtReq.getNewGeneration(), jrtReq.responseIsInternalRedeploy(), RawConfig.createFromResponseParameters(jrtReq) );
+        setConfig(jrtReq.getNewGeneration(), jrtReq.responseIsInternalRedeploy(), jrtReq.responseIsApplyOnRestart(), RawConfig.createFromResponseParameters(jrtReq) );
         log.log(FINE, () -> "in setNewConfig, config=" + this.getConfigState().getConfig());
     }
 
@@ -60,6 +59,17 @@ public class GenericJRTConfigSubscription extends JRTConfigSubscription<RawConfi
         }
     }
 
+    // Override to propagate internal redeploy into the config value in addition to the config state
+    @Override
+    void setApplyOnRestart(boolean applyOnRestart) {
+        super.setApplyOnRestart(applyOnRestart);
+        ConfigState<RawConfig> configState = getConfigState();
+
+        if (configState.getConfig() != null) {
+            configState.getConfig().setApplyOnRestart(applyOnRestart);
+        }
+    }
+
     public RawConfig getRawConfig() {
         return getConfigState().getConfig();
     }
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigSubscription.java
index 44f6d65ee65..e9d5d317995 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigSubscription.java
@@ -94,6 +94,7 @@ public class JRTConfigSubscription<T extends ConfigInstance> extends ConfigSubsc
         log.log(FINE, () -> "Polled queue and found config " + jrtReq);
         if (jrtReq.hasUpdatedGeneration()) {
             setInternalRedeploy(jrtReq.responseIsInternalRedeploy());
+            setApplyOnRestart(jrtReq.responseIsApplyOnRestart());
             if (jrtReq.hasUpdatedConfig()) {
                 setNewConfig(jrtReq);
             } else {
@@ -111,7 +112,7 @@ public class JRTConfigSubscription<T extends ConfigInstance> extends ConfigSubsc
         } catch (IllegalArgumentException e) {
             badConfigE = e;
         }
-        setConfig(jrtReq.getNewGeneration(), jrtReq.responseIsInternalRedeploy(), configInstance);
+        setConfig(jrtReq.getNewGeneration(), jrtReq.responseIsInternalRedeploy(), jrtReq.responseIsApplyOnRestart(), configInstance);
         if (badConfigE != null) {
             throw new IllegalArgumentException("Bad config from jrt", badConfigE);
         }
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/JarConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/JarConfigSubscription.java
index 05da9a72837..9fc5d9d3300 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/JarConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/JarConfigSubscription.java
@@ -63,7 +63,7 @@ public class JarConfigSubscription<T extends ConfigInstance> extends ConfigSubsc
             } catch (IOException e) {
                 throw new ConfigurationRuntimeException(e);
             }
-            setConfig(0L, false, config);
+            setConfig(0L, false, false, config);
             try {
                 jarFile.close();
             } catch (IOException e) {
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 58eed7f9e78..3a284489109 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
@@ -115,7 +115,7 @@ public class MockConnection implements ConnectionPool, com.yahoo.vespa.config.Co
             JRTServerConfigRequestV3 jrtReq = JRTServerConfigRequestV3.createFromRequest(request);
             Payload payload = Payload.from(ConfigPayload.empty());
             long generation = 1;
-            jrtReq.addOkResponse(payload, generation, false, ConfigUtils.getMd5(payload.getData()));
+            jrtReq.addOkResponse(payload, generation, false, false, ConfigUtils.getMd5(payload.getData()));
         }
 
     }
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/RawConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/RawConfigSubscription.java
index 68ff6bb0135..1ff0a058a93 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/RawConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/RawConfigSubscription.java
@@ -35,7 +35,7 @@ public class RawConfigSubscription<T extends ConfigInstance> extends ConfigSubsc
         if (payload == null) {
             payload = inputPayload;
             ConfigPayload configPayload = new CfgConfigPayloadBuilder().deserialize(Arrays.asList(payload.split("\n")));
-            setConfig(0L, false, configPayload.toInstance(configClass, key.getConfigId()));
+            setConfig(0L, false, false, configPayload.toInstance(configClass, key.getConfigId()));
             return true;
         }
         try {