Remove support for ancient legacy node state protocol versions

Protocol versions 0 and 1 haven't been in use for years. No point
in maintaining complexity to support automatic downgrades to these.

3 files changed, 17 insertions, 83 deletions

diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeInfo.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeInfo.java
index 55331e4bbed..54cf2dad00a 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeInfo.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeInfo.java
@@ -70,8 +70,10 @@ abstract public class NodeInfo implements Comparable<NodeInfo> {
     private long timeOfFirstFailingConnectionAttempt;
     /**
      * Sets the version of the state transaction that this node accepts.
-     * Version 0 is the original one, with getnodestate command.
-     * Version 1 is the new one, with getnodestate2 command too.
+     * Version 0 is the original one, with getnodestate command (legacy, not supported).
+     * Version 1 is for the getnodestate2 command ((legacy, not supported).
+     * Version 2 is for the getnodestate3 command
+     * Version 3 adds support for setdistributionstates
      */
     private int version;
 
@@ -374,15 +376,7 @@ abstract public class NodeInfo implements Comparable<NodeInfo> {
 
     /** @return True if we demoted communication version so this can be valid error. */
     public boolean notifyNoSuchMethodError(String methodName, Timer timer) {
-        if (methodName.equals("getnodestate3")) {
-            if (version > 1) {
-                downgradeToRpcVersion(1, methodName, timer);
-                return true;
-            } else if (timer.getCurrentTimeInMillis() - 2000 < adjustedVersionTime) {
-                log.log(LogLevel.DEBUG, "Node " + toString() + " does not support " + methodName + " call. Version already at 1 and was recently adjusted, so ignoring it.");
-                return true;
-            }
-        } else if (methodName.equals(RPCCommunicator.SET_DISTRIBUTION_STATES_RPC_METHOD_NAME)) {
+        if (methodName.equals(RPCCommunicator.SET_DISTRIBUTION_STATES_RPC_METHOD_NAME)) {
             if (version == RPCCommunicator.SET_DISTRIBUTION_STATES_RPC_VERSION) {
                 downgradeToRpcVersion(RPCCommunicator.LEGACY_SET_SYSTEM_STATE2_RPC_VERSION, methodName, timer);
                 return true;
@@ -390,14 +384,6 @@ abstract public class NodeInfo implements Comparable<NodeInfo> {
                 log.log(LogLevel.DEBUG, () -> "Node " + toString() + " does not support " + methodName + " call. Version already downgraded, so ignoring it.");
                 return true;
             }
-        } else if (methodName.equals("getnodestate2") || methodName.equals(RPCCommunicator.LEGACY_SET_SYSTEM_STATE2_RPC_METHOD_NAME)) {
-            if (version > 0) {
-                downgradeToRpcVersion(0, methodName, timer);
-                return true;
-            } else if (timer.getCurrentTimeInMillis() - 2000 < adjustedVersionTime) {
-                log.log(LogLevel.DEBUG, "Node " + toString() + " does not support " + methodName + " call. Version already at 0 and was recently adjusted, so ignoring it.");
-                return true;
-            }
         }
         log.log(LogLevel.WARNING, "Node " + toString() + " does not support " + methodName + " which it should.");
         return false;
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/RPCCommunicator.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/RPCCommunicator.java
index 8941b2e32ec..bad32f87a8c 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/RPCCommunicator.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/RPCCommunicator.java
@@ -79,43 +79,6 @@ public class RPCCommunicator implements Communicator {
         return t;
     }
 
-    public void doVersion0HandShake(Target connection, final NodeInfo node) {
-        log.log(LogLevel.DEBUG, "Sending version 0 handshake request as version has been set down to 0 for " + node);
-        Request req = new Request("vespa.storage.connect");
-        req.parameters().add(new StringValue("storage/cluster." + node.getCluster().getName() + (node.isDistributor() ? "/distributor/" : "/storage/") + node.getNodeIndex()));
-        connection.invokeAsync(req, 10.0, new RequestWaiter(){
-            public void handleRequestDone(Request req) {
-                if (req.isError()) {
-                    log.log(LogLevel.WARNING, "Failed to do version 0 handshake towards " + node + ", " + req.errorCode() + ": " + req.errorMessage());
-                } else if (!req.checkReturnTypes("i")) {
-                    log.log(LogLevel.WARNING, "Wrong arguments returned from version 0 handshake attempt towards " + node);
-                } else if (req.returnValues().get(0).asInt32() == 1) {
-                    log.log(LogLevel.DEBUG, "Session already opened when handshaking towards " + node + ".");
-                } else if (req.returnValues().get(0).asInt32() > 1) {
-                    log.log(LogLevel.WARNING, "Handshaking attempt towards " + node + " failed with code " + req.returnValues().get(0).asInt32());
-                }
-            }
-        });
-        node.setConnectionVersion(0);
-    }
-
-    public void clearOldStoredNodeState(Target connection, final NodeInfo node) {
-        log.log(LogLevel.DEBUG, "In case old node had stored a wanted state it is reporting, send a command to clear any unwanted stored state.");
-        Request req = new Request("setnodestate");
-        req.parameters().add(new StringValue(""));
-        connection.invokeAsync(req, 10.0, new RequestWaiter() {
-            public void handleRequestDone(Request req) {
-                if (req.isError()) {
-                    if (node.getReportedState().getState() != State.DOWN) {
-                        log.log(LogLevel.WARNING, "Failed to clear nodestate on old node " + node + ", " + req.errorCode() + ": " + req.errorMessage());
-                    }
-                } else if (!req.checkReturnTypes("is")) {
-                    log.log(LogLevel.WARNING, "Wrong arguments returned from version 0 setnodestate attempt to clear any unwanted state on " + node);
-                }
-            }
-        });
-    }
-
     @Override
     public void propagateOptions(final FleetControllerOptions options) {
         checkArgument(options.nodeStateRequestTimeoutMS > 0);
@@ -137,25 +100,13 @@ public class RPCCommunicator implements Communicator {
         if ( ! connection.isValid()) {
             log.log(LogLevel.DEBUG, "Connection to " + node.getRpcAddress() + " could not be created.");
         }
-        // TODO remove this deprecated legacy stuff
-        if (node.getVersion() == 0 && node.getConnectionVersion() > 0) {
-            doVersion0HandShake(connection, node);
-            clearOldStoredNodeState(connection, node);
-        }
         NodeState currentState = node.getReportedState();
-        Request req;
-        if (node.getVersion() == 0) {
-            req = new Request("getnodestate");
-        } else {
-            req = new Request(node.getVersion() == 1 ? "getnodestate2" : "getnodestate3");
-            req.parameters().add(new StringValue(
-                    currentState.getState().equals(State.DOWN) || node.getConnectionAttemptCount() > 0
-                       ? "unknown" : currentState.serialize()));
-            req.parameters().add(new Int32Value(generateNodeStateRequestTimeoutMs()));
-            if (node.getVersion() > 1) {
-                req.parameters().add(new Int32Value(fleetControllerIndex));
-            }
-        }
+        Request req = new Request("getnodestate3");
+        req.parameters().add(new StringValue(
+                currentState.getState().equals(State.DOWN) || node.getConnectionAttemptCount() > 0
+                   ? "unknown" : currentState.serialize()));
+        req.parameters().add(new Int32Value(generateNodeStateRequestTimeoutMs()));
+        req.parameters().add(new Int32Value(fleetControllerIndex));
 
         RPCGetNodeStateRequest stateRequest = new RPCGetNodeStateRequest(node, req);
         RPCGetNodeStateWaiter waiter = new RPCGetNodeStateWaiter(stateRequest, externalWaiter, timer);
@@ -179,16 +130,8 @@ public class RPCCommunicator implements Communicator {
             return;
         }
         final int nodeVersion = node.getVersion();
-        // TODO remove this deprecated legacy stuff
-        if (nodeVersion == 0 && node.getConnectionVersion() > 0) {
-            doVersion0HandShake(connection, node);
-            clearOldStoredNodeState(connection, node);
-        }
         Request req;
-        if (nodeVersion == 0) {
-            req = new Request("setsystemstate");
-            req.parameters().add(new StringValue(baselineState.toString(true)));
-        } else if (nodeVersion <= 2) {
+        if (nodeVersion <= 2) {
             req = new Request(LEGACY_SET_SYSTEM_STATE2_RPC_METHOD_NAME);
             req.parameters().add(new StringValue(baselineState.toString(false)));
         } else {
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/rpc/RPCCommunicatorTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/rpc/RPCCommunicatorTest.java
index 2665175c637..7602f0c83a2 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/rpc/RPCCommunicatorTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/rpc/RPCCommunicatorTest.java
@@ -3,6 +3,9 @@ package com.yahoo.vespa.clustercontroller.core.rpc;
 
 import com.yahoo.jrt.*;
 import com.yahoo.vdslib.state.Node;
+import com.yahoo.vdslib.state.NodeState;
+import com.yahoo.vdslib.state.NodeType;
+import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.*;
 import org.junit.Test;
 import org.mockito.Mockito;
@@ -87,6 +90,8 @@ public class RPCCommunicatorTest {
 
         when(target.isValid()).thenReturn(true);
         when(nodeInfo.getConnection()).thenReturn(target);
+        when(nodeInfo.getVersion()).thenReturn(3);
+        when(nodeInfo.getReportedState()).thenReturn(new NodeState(NodeType.DISTRIBUTOR, State.UP));
         communicator.getNodeState(nodeInfo, null);
         Mockito.verify(target).invokeAsync(
                 (Request)any(),