GEODE-9552: Change how Radish server shutdown/disconnect is handled (#6871)

- Close client connection on CancelException
 - Fix handling of RedisCommandParserException
 - Remove unused constants

Authored-by: Donal Evans <doevans@vmware.com>

Author: Donal Evans

geode-apis-compatible-with-redis/src/main/java/org/apache/geode/redis/internal/RedisConstants.java

@@ -24,14 +24,11 @@ public class RedisConstants {
       "The command received by GeodeRedisServer was improperly formatted";
   public static final String SERVER_ERROR_MESSAGE =
       "The server had an internal error please try again";
-  public static final String SERVER_ERROR_SHUTDOWN = "The server is shutting down";
   public static final String ERROR_SELECT = "Only DB 0 supported";
   public static final String ERROR_CURSOR = "invalid cursor";
   public static final String ERROR_UNKNOWN_COMMAND =
       "unknown command `%s`, with args beginning with: %s";
   public static final String ERROR_OUT_OF_RANGE = "The number provided is out of range";
-  public static final String ERROR_NO_PASS = "Client sent AUTH, but no password is set";
-  public static final String ERROR_INVALID_PWD = "invalid password";
   public static final String ERROR_NOT_AUTH = "NOAUTH Authentication required.";
   public static final String ERROR_WRONG_TYPE =
       "Operation against a key holding the wrong kind of value";

geode-apis-compatible-with-redis/src/main/java/org/apache/geode/redis/internal/netty/ExecutionHandlerContext.java

@@ -24,11 +24,10 @@
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
-import io.netty.handler.codec.DecoderException;
 import org.apache.logging.log4j.Logger;
 import org.apache.shiro.subject.Subject;
 
-import org.apache.geode.cache.CacheClosedException;
+import org.apache.geode.CancelException;
 import org.apache.geode.cache.LowMemoryException;
 import org.apache.geode.distributed.DistributedMember;
 import org.apache.geode.internal.security.SecurityService;
@@ -163,13 +162,15 @@ private RedisResponse getExceptionResponse(ChannelHandlerContext ctx, Throwable
       return RedisResponse.error(rootCause.getMessage());
     } else if (rootCause instanceof LowMemoryException) {
       return RedisResponse.oom(RedisConstants.ERROR_OOM_COMMAND_NOT_ALLOWED);
-    } else if (rootCause instanceof DecoderException
-        && rootCause.getCause() instanceof RedisCommandParserException) {
+    } else if (rootCause instanceof RedisCommandParserException) {
       return RedisResponse
           .error(RedisConstants.PARSING_EXCEPTION_MESSAGE + ": " + rootCause.getMessage());
-    } else if (rootCause instanceof InterruptedException
-        || rootCause instanceof CacheClosedException) {
-      return RedisResponse.error(RedisConstants.SERVER_ERROR_SHUTDOWN);
+    } else if (rootCause instanceof InterruptedException || rootCause instanceof CancelException) {
+      logger
+          .warn("Closing Redis client connection because the server doing this operation departed: "
+              + rootCause.getMessage());
+      channelInactive(ctx);
+      return null;
     } else {
       if (logger.isErrorEnabled()) {
         logger.error("GeodeRedisServer-Unexpected error handler for {}", ctx.channel(), rootCause);