Fix slowness in performance mode and failover not working when protocol is unsupported

Author: zhicwu

clickhouse-cli-client/README.md

@@ -6,11 +6,11 @@ This is a thin wrapper of ClickHouse native command-line client. It provides an
 - native CLI client instead of pure Java implementation
 - an example of implementing SPI defined in `clickhouse-client` module
 
-Either [clickhouse-client](https://clickhouse.com/docs/en/interfaces/cli/) or [docker](https://docs.docker.com/get-docker/) must be installed prior to use. And it's important to understand that this module uses sub-process(in addition to threads) and file-based streaming, meaning 1) it's not as fast as native CLI client or pure Java implementation, although it's close in the case of dumping and loading data; and 2) it's not suitable for scenarios like dealing with many queries in short period of time.
+Either [clickhouse](https://clickhouse.com/docs/en/interfaces/cli/) or [docker](https://docs.docker.com/get-docker/) must be installed prior to use. And it's important to understand that this module uses sub-process(in addition to threads) and file-based streaming, meaning 1) it's not as fast as native CLI client or pure Java implementation, although it's close in the case of dumping and loading data; and 2) it's not suitable for scenarios like dealing with many queries in short period of time.
 
 ## Limitations and Known Issues
 
-- Only `max_result_rows` and `result_overflow_mode` two settings are currently supported
+- Only `max_result_rows`, `result_overflow_mode` and `readonly` 3 settings are currently supported
 - ClickHouseResponseSummary is always empty - see ClickHouse/ClickHouse#37241
 - Session is not supported - see ClickHouse/ClickHouse#37308
 
@@ -28,10 +28,10 @@ Either [clickhouse-client](https://clickhouse.com/docs/en/interfaces/cli/) or [d
 ## Examples
 
 ```java
-// make sure 'clickhouse-client' or 'docker' is in PATH before you start the program
+// make sure 'clickhouse' or 'docker' is in PATH before you start the program
 // alternatively, configure CLI path in either Java system property or environment variable, for examples:
-// CHC_CLICKHOUSE_CLI_PATH=/path/to/clickhouse-client CHC_DOCKER_CLI_PATH=/path/to/docker java MyProgram
-// java -Dchc_clickhouse_cli_path=/path/to/clickhouse-client -Dchc_docker_cli_path=/path/to/docker MyProgram
+// CHC_CLICKHOUSE_CLI_PATH=/path/to/clickhouse CHC_DOCKER_CLI_PATH=/path/to/docker java MyProgram
+// java -Dchc_clickhouse_cli_path=/path/to/clickhouse -Dchc_docker_cli_path=/path/to/docker MyProgram
 
 // clickhouse-cli-client uses TCP protocol
 ClickHouseProtocol preferredProtocol = ClickHouseProtocol.TCP;

clickhouse-cli-client/src/main/java/com/clickhouse/client/cli/ClickHouseCommandLine.java

@@ -8,6 +8,7 @@
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.UncheckedIOException;
+import java.net.ConnectException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -93,7 +94,7 @@ static void dockerCommand(ClickHouseConfig config, String hostDir, String contai
             cli = DEFAULT_DOCKER_CLI_PATH;
         }
         if (!check(timeout, cli, DEFAULT_CLI_ARG_VERSION)) {
-            throw new IllegalStateException("Docker command-line is not available: " + cli);
+            throw new UncheckedIOException(new ConnectException("Docker command-line is not available: " + cli));
         } else {
             commands.add(cli);
         }
@@ -111,7 +112,7 @@ static void dockerCommand(ClickHouseConfig config, String hostDir, String contai
                             DEFAULT_CLI_ARG_VERSION)
                             && !check(timeout, cli, "run", "--rm", "--name", str, "-v", hostDir + ':' + containerDir,
                                     "-d", img, "tail", "-f", "/dev/null")) {
-                        throw new IllegalStateException("Failed to start new container: " + str);
+                        throw new UncheckedIOException(new ConnectException("Failed to start new container: " + str));
                     }
                 }
             }
@@ -122,7 +123,7 @@ static void dockerCommand(ClickHouseConfig config, String hostDir, String contai
         } else { // create new container for each query
             if (!check(timeout, cli, "run", "--rm", img, DEFAULT_CLICKHOUSE_CLI_PATH, DEFAULT_CLIENT_OPTION,
                     DEFAULT_CLI_ARG_VERSION)) {
-                throw new IllegalStateException("Invalid ClickHouse docker image: " + img);
+                throw new UncheckedIOException(new ConnectException("Invalid ClickHouse docker image: " + img));
             }
             commands.add("run");
             commands.add("--rm");
@@ -235,6 +236,10 @@ static Process startProcess(ClickHouseNode server, ClickHouseRequest<?> request)
         if (value != null) {
             commands.add("--result_overflow_mode=".concat(value.toString()));
         }
+        value = settings.get("readonly");
+        if (value != null) {
+            commands.add("--readonly=".concat(value.toString()));
+        }
         if ((boolean) config.getOption(ClickHouseCommandLineOption.USE_PROFILE_EVENTS)) {
             commands.add("--print-profile-events");
             commands.add("--profile-events-delay-ms=-1");

clickhouse-cli-client/src/main/java/com/clickhouse/client/cli/config/ClickHouseCommandLineOption.java

@@ -8,10 +8,10 @@
 public enum ClickHouseCommandLineOption implements ClickHouseOption {
     /**
      * ClickHouse native command-line client path. Empty value is treated as
-     * 'clickhouse-client'.
+     * 'clickhouse'.
      */
     CLICKHOUSE_CLI_PATH("clickhouse_cli_path", "",
-            "ClickHouse native command-line client path, empty value is treated as 'clickhouse-client'"),
+            "ClickHouse native command-line client path, empty value is treated as 'clickhouse'"),
     /**
      * ClickHouse docker image. Empty value is treated as
      * 'clickhouse/clickhouse-server'.

clickhouse-client/src/main/java/com/clickhouse/client/ClickHouseClient.java

@@ -151,7 +151,7 @@ static ClickHouseInputStream getResponseInputStream(ClickHouseConfig config, Inp
 
     /**
      * Gets piped input stream for reading data from response asynchronously. When
-     * {@code config} is null or {@code config.isAsync()} is faluse, this method is
+     * {@code config} is null or {@code config.isAsync()} is false, this method is
      * same as
      * {@link #getResponseInputStream(ClickHouseConfig, InputStream, Runnable)}.
      *

clickhouse-client/src/main/java/com/clickhouse/client/ClickHouseClientBuilder.java

@@ -1,6 +1,8 @@
 package com.clickhouse.client;
 
 import java.io.Serializable;
+import java.io.UncheckedIOException;
+import java.net.ConnectException;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
@@ -27,7 +29,7 @@
  */
 public class ClickHouseClientBuilder {
     /**
-     * Dummy client which is only used {@link Agent}.
+     * Dummy client which is only used by {@link Agent}.
      */
     static class DummyClient implements ClickHouseClient {
         static final ClickHouseConfig CONFIG = new ClickHouseConfig();
@@ -40,7 +42,10 @@ public boolean accept(ClickHouseProtocol protocol) {
 
         @Override
         public CompletableFuture<ClickHouseResponse> execute(ClickHouseRequest<?> request) {
-            return CompletableFuture.completedFuture(ClickHouseResponse.EMPTY);
+            CompletableFuture<ClickHouseResponse> future = new CompletableFuture<>();
+            future.completeExceptionally(
+                    new ConnectException("No client available for connecting to: " + request.getServer()));
+            return future;
         }
 
         @Override
@@ -55,7 +60,7 @@ public void close() {
 
         @Override
         public boolean ping(ClickHouseNode server, int timeout) {
-            return true;
+            return false;
         }
     }
 
@@ -166,6 +171,11 @@ ClickHouseResponse retry(ClickHouseRequest<?> sealedRequest, Throwable cause, in
         }
 
         ClickHouseResponse handle(ClickHouseRequest<?> sealedRequest, Throwable cause) {
+            // in case there's any recoverable exception wrapped by UncheckedIOException
+            if (cause instanceof UncheckedIOException && cause.getCause() != null) {
+                cause = ((UncheckedIOException) cause).getCause();
+            }
+
             try {
                 int times = sealedRequest.getConfig().getFailover();
                 if (times > 0) {
@@ -352,7 +362,7 @@ public ClickHouseClient build() {
             }
         }
 
-        if (client == null) {
+        if (client == null && !agent) {
             throw new IllegalStateException(
                     ClickHouseUtils.format("No suitable ClickHouse client(out of %d) found in classpath for %s.",
                             counter, nodeSelector));

clickhouse-client/src/main/java/com/clickhouse/client/ClickHouseNodes.java

@@ -314,6 +314,10 @@ public static ClickHouseNodes of(String enpoints, Map<?, ?> options) {
      * Load balancing tags for filtering out nodes.
      */
     protected final ClickHouseNodeSelector selector;
+    /**
+     * Flag indicating whether it's single node or not.
+     */
+    protected final boolean singleNode;
     /**
      * Template node.
      */
@@ -358,8 +362,11 @@ protected ClickHouseNodes(Collection<ClickHouseNode> nodes, ClickHouseNode templ
             n.setManager(this);
         }
         if (autoDiscovery) {
+            this.singleNode = false;
             this.discoveryFuture.getAndUpdate(current -> policy.schedule(current, ClickHouseNodes.this::discover,
                     (int) template.config.getOption(ClickHouseClientOption.NODE_DISCOVERY_INTERVAL)));
+        } else {
+            this.singleNode = nodes.size() == 1;
         }
         this.healthCheckFuture.getAndUpdate(current -> policy.schedule(current, ClickHouseNodes.this::check,
                 (int) template.config.getOption(ClickHouseClientOption.HEALTH_CHECK_INTERVAL)));
@@ -472,6 +479,15 @@ protected ClickHouseNode get() {
         return apply(selector);
     }
 
+    /**
+     * Checks whether it's single node or not.
+     *
+     * @return true if it's single node; false otherwise
+     */
+    public boolean isSingleNode() {
+        return singleNode;
+    }
+
     @Override
     public ClickHouseNode apply(ClickHouseNodeSelector t) {
         lock.readLock().lock();

clickhouse-jdbc/src/main/java/com/clickhouse/jdbc/internal/ClickHouseConnectionImpl.java

@@ -27,11 +27,13 @@
 
 import com.clickhouse.client.ClickHouseChecker;
 import com.clickhouse.client.ClickHouseClient;
+import com.clickhouse.client.ClickHouseClientBuilder;
 import com.clickhouse.client.ClickHouseColumn;
 import com.clickhouse.client.ClickHouseConfig;
 import com.clickhouse.client.ClickHouseFormat;
 import com.clickhouse.client.ClickHouseNode;
 import com.clickhouse.client.ClickHouseNodeSelector;
+import com.clickhouse.client.ClickHouseNodes;
 import com.clickhouse.client.ClickHouseParameterizedQuery;
 import com.clickhouse.client.ClickHouseRecord;
 import com.clickhouse.client.ClickHouseRequest;
@@ -218,16 +220,33 @@ public ClickHouseConnectionImpl(ConnectionInfo connInfo) throws SQLException {
         jdbcConf = connInfo.getJdbcConfig();
 
         autoCommit = !jdbcConf.isJdbcCompliant() || jdbcConf.isAutoCommit();
-
-        ClickHouseNode node = connInfo.getServer();
-        log.debug("Connecting to: %s", node);
-
         jvmTimeZone = TimeZone.getDefault();
 
-        client = ClickHouseClient.builder().options(ClickHouseDriver.toClientOptions(connInfo.getProperties()))
-                .defaultCredentials(connInfo.getDefaultCredentials())
-                .nodeSelector(ClickHouseNodeSelector.of(node.getProtocol())).build();
-        clientRequest = client.connect(node);
+        ClickHouseClientBuilder clientBuilder = ClickHouseClient.builder()
+                .options(ClickHouseDriver.toClientOptions(connInfo.getProperties()))
+                .defaultCredentials(connInfo.getDefaultCredentials());
+        ClickHouseNodes nodes = connInfo.getNodes();
+        final ClickHouseNode node;
+        if (nodes.isSingleNode()) {
+            try {
+                node = nodes.apply(nodes.getNodeSelector());
+            } catch (Exception e) {
+                throw SqlExceptionUtils.clientError("Failed to get single-node", e);
+            }
+            client = clientBuilder.nodeSelector(ClickHouseNodeSelector.of(node.getProtocol())).build();
+            clientRequest = client.connect(node);
+        } else {
+            log.debug("Selecting node from: %s", nodes);
+            client = clientBuilder.nodeSelector(nodes.getNodeSelector()).build();
+            clientRequest = client.connect(nodes);
+            try {
+                node = clientRequest.getServer();
+            } catch (Exception e) {
+                throw SqlExceptionUtils.clientError("No healthy node available", e);
+            }
+        }
+
+        log.debug("Connecting to: %s", node);
         ClickHouseConfig config = clientRequest.getConfig();
         String currentUser = null;
         TimeZone timeZone = null;

clickhouse-jdbc/src/main/java/com/clickhouse/jdbc/internal/ClickHouseJdbcUrlParser.java

@@ -12,14 +12,10 @@
 import com.clickhouse.client.ClickHouseUtils;
 import com.clickhouse.client.config.ClickHouseClientOption;
 import com.clickhouse.client.config.ClickHouseDefaults;
-import com.clickhouse.client.logging.Logger;
-import com.clickhouse.client.logging.LoggerFactory;
 import com.clickhouse.jdbc.JdbcConfig;
 import com.clickhouse.jdbc.SqlExceptionUtils;
 
 public class ClickHouseJdbcUrlParser {
-    private static final Logger log = LoggerFactory.getLogger(ClickHouseJdbcUrlParser.class);
-
     public static class ConnectionInfo {
         private final ClickHouseCredentials credentials;
         private final ClickHouseNodes nodes;
@@ -46,6 +42,14 @@ public ClickHouseCredentials getDefaultCredentials() {
             return this.credentials;
         }
 
+        /**
+         * Gets selected server.
+         *
+         * @return non-null selected server
+         * @deprecated will be removed in v0.3.3, please use {@link #getNodes()}
+         *             instead
+         */
+        @Deprecated
         public ClickHouseNode getServer() {
             return nodes.apply(nodes.getNodeSelector());
         }
@@ -54,6 +58,15 @@ public JdbcConfig getJdbcConfig() {
             return jdbcConf;
         }
 
+        /**
+         * Gets nodes defined in connection string.
+         *
+         * @return non-null nodes
+         */
+        public ClickHouseNodes getNodes() {
+            return nodes;
+        }
+
         public Properties getProperties() {
             return props;
         }