Use Hikari Connection Pool for handling Clickhouse connections

sink-connector/pom.xml

@@ -331,6 +331,11 @@
             <artifactId>maven-artifact</artifactId>
             <version>3.9.1</version>
         </dependency>
+        <dependency>
+            <groupId>com.zaxxer</groupId>
+            <artifactId>HikariCP</artifactId>
+            <version>6.0.0</version>
+        </dependency>
         <dependency>
             <groupId>com.clickhouse</groupId>
             <!-- or clickhouse-grpc-client if you prefer gRPC -->

sink-connector/src/main/java/com/altinity/clickhouse/sink/connector/db/BaseDbWriter.java

@@ -5,6 +5,7 @@
 import com.clickhouse.jdbc.ClickHouseConnection;
 import com.clickhouse.jdbc.ClickHouseDataSource;
 
+
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.time.ZoneId;
@@ -106,8 +107,16 @@ public static ClickHouseConnection createConnection(String url, String clientNam
                 Properties userProps = splitJdbcProperties(jdbcParams);
                 properties.putAll(userProps);
             }
+            // Add username/password to the url.
+            url = url + "?user=" + userName + "&password=" + password;
             ClickHouseDataSource dataSource = new ClickHouseDataSource(url, properties);
-            conn = dataSource.getConnection(userName, password);
+            // Get connection from the pool.
+            HikariDbSource hikariDbSource = HikariDbSource.getInstance(dataSource);
+            // Create a new ClickHouseConnection object with the connection from the pool.
+            // Convert Connection to ClickHouseConnection.
+
+            conn = (ClickHouseConnection) hikariDbSource.getConnection();
+            //conn = dataSource.getConnection(userName, password);
         } catch (Exception e) {
             log.error("Error creating ClickHouse connection" + e);
         }

sink-connector/src/main/java/com/altinity/clickhouse/sink/connector/db/HikariDbSource.java

@@ -0,0 +1,32 @@
+package com.altinity.clickhouse.sink.connector.db;
+
+import com.clickhouse.jdbc.ClickHouseDataSource;
+import com.zaxxer.hikari.HikariConfig;
+import com.zaxxer.hikari.HikariDataSource;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+
+// Singleton class to manage the Hikari connection pool
+public class HikariDbSource {
+
+    private HikariDataSource dataSource;
+
+
+    public HikariDbSource(HikariDataSource dataSource, String jdbcUrl, String username, String password) {
+
+        this.dataSource = dataSource;
+
+        HikariConfig poolConfig = new HikariConfig();
+        poolConfig.setConnectionTimeout(5000L);
+        poolConfig.setMaximumPoolSize(20);
+        poolConfig.setMaxLifetime(300_000L);
+        poolConfig.setDataSource(new ClickHouseDataSource(dataSource.getJdbcUrl(), dataSource.getUsername(), dataSource.getPassword()));
+
+        HikariDataSource ds = new HikariDataSource(poolConfig);
+    }
+
+    public Connection getConnection() throws SQLException {
+        return this.dataSource.getConnection();
+    }
+}