JDBC Drivers YSQL

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YugabyteDB JDBC smart driver is a JDBC driver for YSQL built on the PostgreSQL JDBC driver, with additional connection load balancing features.

For more information on the YugabyteDB Java smart driver, see the following:

Download the driver dependency

YugabyteDB JDBC Driver is available as maven dependency. Download the driver by adding the following dependency entries in the java project.

Maven dependency

To get the driver and HikariPool from Maven, add the following dependencies to the Maven project:

<dependency>
  <groupId>com.yugabyte</groupId>
  <artifactId>jdbc-yugabytedb</artifactId>
  <version>42.3.5-yb-8</version>
</dependency>

<!-- https://mvnrepository.com/artifact/com.zaxxer/HikariCP -->
<dependency>
  <groupId>com.zaxxer</groupId>
  <artifactId>HikariCP</artifactId>
  <version>4.0.3</version>
</dependency>

Gradle dependency

To get the driver and HikariPool, add the following dependencies to the Gradle project:

// https://mvnrepository.com/artifact/org.postgresql/postgresql
implementation 'com.yugabyte:jdbc-yugabytedb:42.3.5-yb-8'
implementation 'com.zaxxer:HikariCP:4.0.3'

Note that v4 of HikariCP is required because the YugabyteDB JDBC Driver requires Java 8.

Fundamentals

Learn how to perform common tasks required for Java application development using the YugabyteDB JDBC driver.

Note

The driver requires YugabyteDB version 2.7.2.0 or higher, and Java 8 or above.

Load balancing connection properties

The following connection properties need to be added to enable load balancing:

  • load-balance - enable cluster-aware load balancing by setting this property to one of the allowed values other than false; disabled by default.
  • topology-keys - provide comma-separated geo-location values to enable topology-aware load balancing. Geo-locations can be provided as cloud.region.zone. Specify all zones in a region as cloud.region.*. To designate fallback locations for when the primary location is unreachable, specify a priority in the form :n, where n is the order of precedence. For example, cloud1.datacenter1.rack1:1,cloud1.datacenter1.rack2:2.

By default, the driver refreshes the list of nodes every 300 seconds (5 minutes ). You can change this value by including the yb-servers-refresh-interval parameter.

For more information, see Cluster-aware load balancing.

Use the driver

The YugabyteDB JDBC driver's driver class is com.yugabyte.Driver. The driver package includes a YBClusterAwareDataSource class that uses one initial contact point for the YugabyteDB cluster as a means of discovering all the nodes and, if required, refreshing the list of live endpoints with every new connection attempt. The refresh is triggered if stale information (by default, older than 5 minutes) is discovered.

To use the driver, do the following:

  • Pass new connection properties for load balancing in the connection URL or properties pool.

    To enable uniform load balancing across all servers, you set the load-balance property to true in the URL, as per the following example:

    String yburl = "jdbc:yugabytedb://127.0.0.1:5433/yugabyte?user=yugabyte&password=yugabyte&load-balance=true";
    DriverManager.getConnection(yburl);
    

    To provide alternate hosts during the initial connection in case the first address fails, specify multiple hosts in the connection string, as follows:

    String yburl = "jdbc:yugabytedb://127.0.0.1:5433,127.0.0.2:5433,127.0.0.3:5433/yugabyte?user=yugabyte&password=yugabyte&load-balance=true";
    DriverManager.getConnection(yburl);
    

    After the driver establishes the initial connection, it fetches the list of available servers from the universe, and performs load balancing of subsequent connection requests across these servers.

    To specify topology keys, you set the topology-keys property to comma separated values, as per the following example:

    String yburl = "jdbc:yugabytedb://127.0.0.1:5433/yugabyte?user=yugabyte&password=yugabyte&load-balance=true&topology-keys=cloud1.region1.zone1,cloud1.region1.zone2";
    DriverManager.getConnection(yburl);
    
  • Configure YBClusterAwareDataSource for uniform load balancing and then use it to create a connection, as per the following example:

    String jdbcUrl = "jdbc:yugabytedb://127.0.0.1:5433/yugabyte";
    YBClusterAwareDataSource ds = new YBClusterAwareDataSource();
    ds.setUrl(jdbcUrl);
    // Set topology keys to enable topology-aware distribution
    ds.setTopologyKeys("cloud1.region1.zone1,cloud1.region2.zone2");
    // Provide more end points to prevent first connection failure
    // if an initial contact point is not available
    ds.setAdditionalEndpoints("127.0.0.2:5433,127.0.0.3:5433");
    
    Connection conn = ds.getConnection();
    
  • Configure YBClusterAwareDataSource with a pooling solution such as Hikari and then use it to create a connection, as per the following example:

    Properties poolProperties = new Properties();
    poolProperties.setProperty("dataSourceClassName", "com.yugabyte.ysql.YBClusterAwareDataSource");
    poolProperties.setProperty("maximumPoolSize", 10);
    poolProperties.setProperty("dataSource.serverName", "127.0.0.1");
    poolProperties.setProperty("dataSource.portNumber", "5433");
    poolProperties.setProperty("dataSource.databaseName", "yugabyte");
    poolProperties.setProperty("dataSource.user", "yugabyte");
    poolProperties.setProperty("dataSource.password", "yugabyte");
    // If you want to provide additional end points
    String additionalEndpoints = "127.0.0.2:5433,127.0.0.3:5433,127.0.0.4:5433,127.0.0.5:5433";
    poolProperties.setProperty("dataSource.additionalEndpoints", additionalEndpoints);
    // If you want to load balance between specific geo locations using topology keys
    String geoLocations = "cloud1.region1.zone1,cloud1.region2.zone2";
    poolProperties.setProperty("dataSource.topologyKeys", geoLocations);
    
    poolProperties.setProperty("poolName", name);
    
    HikariConfig config = new HikariConfig(poolProperties);
    config.validate();
    HikariDataSource ds = new HikariDataSource(config);
    
    Connection conn = ds.getConnection();
    

Try it out

This tutorial shows how to use the YugabyteDB JDBC Driver with YugabyteDB. It starts by creating a three-node cluster with a replication factor of 3. This tutorial uses the yugabyted utility.

Next, you use yb-sample-apps to demonstrate the driver's load balancing features and create a Maven project to learn how to use the driver in an application.

Note

The driver requires YugabyteDB version 2.7.2.0 or higher, and Java 8 or above.

Install YugabyteDB and create a local cluster

Create a universe with a 3-node RF-3 cluster with some fictitious geo-locations assigned. The placement values used are just tokens and have nothing to do with actual AWS cloud regions and zones.

$ cd <path-to-yugabytedb-installation>

To create a multi-zone cluster, do the following:

  1. Start the first node by running the yugabyted start command, passing in the --cloud_location and --fault_tolerance flags to set the node location details, as follows:

    ./bin/yugabyted start --advertise_address=127.0.0.1 \
        --base_dir=$HOME/yugabyte-2.23.0.0/node1 \
        --cloud_location=aws.us-east-1.us-east-1a \
        --fault_tolerance=zone
    
  2. Start the second and the third node on two separate VMs using the --join flag, as follows:

    ./bin/yugabyted start --advertise_address=127.0.0.2 \
        --join=127.0.0.1 \
        --base_dir=$HOME/yugabyte-2.23.0.0/node2 \
        --cloud_location=aws.us-east-1.us-east-1a \
        --fault_tolerance=zone
    
    ./bin/yugabyted start --advertise_address=127.0.0.3 \
        --join=127.0.0.1 \
        --base_dir=$HOME/yugabyte-2.23.0.0/node3 \
        --cloud_location=aws.us-east-1.us-east-1b \
        --fault_tolerance=zone
    

Check uniform load balancing using yb-sample-apps

Download the yb-sample-apps JAR file.

wget https://github.com/yugabyte/yb-sample-apps/releases/download/v1.4.0/yb-sample-apps.jar

Run the SqlInserts workload application, which creates multiple threads that perform read and write operations on a sample table created by the app. Uniform load balancing is enabled by default in all Sql* workloads of the yb-sample-apps, including SqlInserts.

java -jar yb-sample-apps.jar  \
      --workload SqlInserts \
      --num_threads_read 15 --num_threads_write 15 \
      --nodes 127.0.0.1:5433,127.0.0.2:5433,127.0.0.3:5433

The application creates 30 connections, 1 for each reader and writer threads. To verify the behavior, wait for the app to create connections and then visit http://<host>:13000/rpcz from your browser for each node to see that the connections are equally distributed among the nodes.

This URL presents a list of connections where each element of the list has some information about the connection as shown in the following screenshot. You can count the number of connections from that list, or search for the occurrence count of the host keyword on that webpage. Each node should have 10 connections.

Load balancing with host connections

Check topology-aware load balancing using yb-sample-apps

For topology-aware load balancing, run the SqlInserts workload application with the topology-keys1 property set to aws.us-east-1.us-east-1a; only two nodes are used in this case.

java -jar yb-sample-apps.jar \
      --workload SqlInserts \
      --nodes 127.0.0.1:5433,127.0.0.2:5433,127.0.0.3:5433 \
      --num_threads_read 15 --num_threads_write 15 \
      --topology_keys aws.us-east-1.us-east-1a

To verify the behavior, wait for the app to create connections and then navigate to http://<host>:13000/rpcz. The first two nodes should have 15 connections each, and the third node should have zero connections.

Clean up

When you're done experimenting, run the following command to destroy the local cluster:

./bin/yugabyted destroy --base_dir=$HOME/yugabyte-2.23.0.0/node1
./bin/yugabyted destroy --base_dir=$HOME/yugabyte-2.23.0.0/node2
./bin/yugabyted destroy --base_dir=$HOME/yugabyte-2.23.0.0/node3

Other examples

To access sample applications that use the YugabyteDB JDBC driver, visit YugabyteDB JDBC driver.

To use the samples, complete the following steps:

  • Install YugabyteDB by following the instructions in Quick start.

  • Build the examples by running mvn package.

  • Run the run.sh script, as per the following guideline:

    ./run.sh [-v] [-i] -D -<path_to_yugabyte_installation>
    

    In the preceding command, replace:

    • [-v] [-i] with -v if you want to run the script in VERBOSE mode.

    • [-v] [-i] with -i if you want to run the script in INTERACTIVE mode.

    • [-v] [-i] with -v -i if you want to run the script in both VERBOSE and INTERACTIVE mode at the same time.

    • <path_to_yugabyte_installation> with the path to the directory where you installed YugabyteDB.

    The following is an example of a shell command that runs the script:

    ./run.sh -v -i -D ~/yugabyte-2.7.2.0/
    

    Note

    The driver requires YugabyteDB version 2.7.2.0 or higher.

    The run script starts a YugabyteDB cluster, demonstrates load balancing through Java applications, and then destroys the cluster.

    When started, the script displays a menu with two options: UniformLoadBalance and TopologyAwareLoadBalance. Choose one of these options to run the corresponding script with its Java application in the background.