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UsingTheJdbcDriver.md

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Using the AWS Advanced JDBC Driver

The AWS Advanced JDBC Driver leverages community JDBC drivers and enables support of AWS and Aurora functionalities. Currently, only the PostgreSQL JDBC Driver is supported. The JDBC Wrapper also supports connection pooling.

Wrapper Protocol

The AWS JDBC Driver uses the protocol prefix jdbc:aws-wrapper:. Internally, the JDBC Wrapper will replace this protocol prefix with jdbc:, making the final protocol jdbc:aws-wrapper:{suffix} where suffix is specific to the desired underlying protocol. For example, to connect to a PostgreSQL database, you would use the protocol jdbc:aws-wrapper:postgresql:, and inside the AWS JDBC Driver, the final protocol that will be used to connect to a database will be jdbc:postgresql:.

Getting a Connection

To get a connection from the AWS JDBC Driver, the user application can either connect with a DriverManager or with a DataSource.

The process of getting a connection with a DriverManager will remain the same as with other JDBC Drivers; this example demonstrates establishing a connection with the PostgreSQL JDBC driver.

Establishing a connection with a DataSource may require some additional steps. For detailed information and examples, review the Datasource documentation.

Connections with Different Query Lengths

It is recommended that user applications use different settings for connections or connection pools that execute queries of varying lengths. Long and short running queries have different preferred settings. For example, if the network timeout is set to 1 minute, given an application that executes both short running (~5 seconds) and long running (~1 minute) queries, the user would be waiting a large amount of time for the short running queries to time out. Alternatively, if the timeout is set to 5 seconds, the user would experience large numbers of false negatives in which the long queries are consistently failing due to the timeout.
Note: User applications with queries of varying lengths should also take into consideration any plugin configuration parameters that could be utilized to facilitate the needs of the application.

Integration with 3rd Party Frameworks

The JDBC Wrapper can be used with different frameworks and tools. More details for some frameworks can be found here.

Logging

The AWS JDBC Driver uses the Java Util Logger built-in library functionality to log information. To enable logging and see information logged by the AWS JDBC Driver:

  1. Create a .properties file and configure the logging level.
  2. Specify the .properties file with the java.util.logging.config.file option; for example, -Djava.util.logging.config.file=absolute\path\to\logging.properties.

An example .properties file is as follows:

# Possible values for log level (from most detailed to less detailed): FINEST, FINER, FINE, CONFIG, INFO, WARNING, SEVERE
.level=INFO
handlers=java.util.logging.ConsoleHandler
java.util.logging.ConsoleHandler.level=ALL
software.amazon.jdbc.Driver.level=FINER
software.amazon.jdbc.plugin.level=FINER

The AWS JDBC Driver also has a parameter, wrapperLoggerLevel, to configure the logging level.

AWS Advanced JDBC Driver Parameters

These parameters are applicable to any instance of the AWS JDBC Driver.

Parameter Value Required Description Default Value
wrapperLogUnclosedConnections Boolean No Allows the AWS JDBC Driver to track a point in the code where connection has been opened but not closed. false
wrapperLoggerLevel String No Logger level of the AWS JDBC Driver.

If it is used, it must be one of the following values: OFF, SEVERE, WARNING, INFO, CONFIG, FINE, FINER, FINEST, ALL.		 null
database String No Database name. null
user String No Database username. null
password String No Database password. null

Plugins

The AWS JDBC Driver uses plugins to execute JDBC methods. You can think of a plugin as an extensible code module that adds extra logic around any JDBC method calls. The AWS JDBC Driver has a number of built-in plugins available for use.

Plugins are loaded and managed through the Connection Plugin Manager and may be identified by a String name in the form of plugin code.

Connection Plugin Manager Parameters

Parameter Value Required Description Default Value
wrapperPlugins String No Comma separated list of connection plugin codes.

Example: failover,efm		 null
wrapperProfileName String No Driver configuration profile name. Instead of listing plugin codes with wrapperPlugins, the driver profile can be set with this parameter.

Example: See below.		 null

To use a built-in plugin, specify its relevant plugin code for the wrapperPlugins. The default value for wrapperPlugins is auroraConnectionTracker,failover,efm. These 3 plugins are enabled by default. To read more about these plugins, see the List of Available Plugins section. To override the default plugins, simply provide a new value for wrapperPlugins. For instance, to use the IAM Authentication Connection Plugin and the Failover Connection Plugin:

properties.setProperty("wrapperPlugins", "iam,failover");

❗NOTE: The plugins will be initialized and executed in the order they have been specified.

Provide an empty string to disable all plugins:

properties.setProperty("wrapperPlugins", "");

The Wrapper behaves like the target driver when no plugins are used.

Configuration Profiles

An alternative way of loading plugins is to use a configuration profile. You can create custom configuration profiles that specify which plugins the AWS JDBC Driver should load. After creating the profile, set the wrapperProfileName parameter to the name of the created profile. Although you can use this method of loading plugins, this method will most often be used by those who require custom plugins that cannot be loaded with the wrapperPlugins parameter. The following example creates and sets a configuration profile:

properties.setProperty("wrapperProfileName", "testProfile");
DriverConfigurationProfiles.addOrReplaceProfile(
    "testProfile",
    Arrays.asList(
        FailoverConnectionPluginFactory.class, 
        HostMonitoringConnectionPluginFactory.class,
        CustomConnectionPluginFactory.class));

List of Available Plugins

The AWS JDBC Driver has several built-in plugins that are available to use. Please visit the individual plugin page for more details.

Plugin name Plugin Code Description
Failover Connection Plugin failover Enables the failover functionality supported by Amazon Aurora clusters. Prevents opening a wrong connection to an old writer node dues to stale DNS after failover event.
Host Monitoring Connection Plugin efm Enables enhanced host connection failure monitoring, allowing faster failure detection rates.
Aurora Host List Connection Plugin auroraHostList Retrieves Amazon Aurora clusters information.

⚠️Note: this plugin does not need to be explicitly loaded if the failover connection plugin is loaded.
Data Cache Connection Plugin dataCache Caches results from SQL queries matching the regular expression specified in the dataCacheTriggerCondition configuration parameter.
Execution Time Connection Plugin executionTime Logs the time taken to execute any JDBC method.
Log Query Connection Plugin logQuery Tracks and logs the SQL statements to be executed. Sometimes SQL statements are not passed directly to the JDBC method as a parameter, such as executeBatch(). Users can set enhancedLogQueryEnabled to true, allowing the JDBC Wrapper to obtain SQL statements via Java Reflection.

⚠️Note: Enabling Java Reflection may cause a performance degradation.
IAM Authentication Connection Plugin iam Enables users to connect to their Amazon Aurora clusters using AWS Identity and Access Management (IAM).
AWS Secrets Manager Connection Plugin awsSecretsManager Enables fetching database credentials from the AWS Secrets Manager service.
Aurora Stale DNS Plugin auroraStaleDns Prevents incorrectly opening a new connection to an old writer node when DNS records have not yet updated after a recent failover event.

⚠️Note: Contrary to failover plugin, auroraStaleDns plugin doesn't implement failover support itself. It helps to eliminate opening wrong connections to an old writer node after cluster failover is completed.

⚠️Note: This logic is already included in failover plugin so you can omit using both plugins at the same time.

❗NOTE: To see information logged by plugins such as DataCacheConnectionPlugin and LogQueryConnectionPlugin,

see the Logging section.

In addition to the built-in plugins, you can also create custom plugins more suitable for your needs. For more information, see Custom Plugins.

Using a Snapshot of the Driver

If there is an unreleased feature you would like to try, it may be available in a snapshot build of the driver. Snapshot builds can be found here. To use a snapshot, find the desired .jar file, which will be named aws-advanced-jdbc-wrapper-<version>-<date>-<time>-<snapshot-number>.jar, and add it to your project as a dependency.

As a Maven dependency

<dependencies>
  <dependency>
    <groupId>software.amazon.jdbc</groupId>
    <artifactId>aws-advanced-jdbc-wrapper</artifactId>
    <version>1.0.1-SNAPSHOT</version>
    <scope>system</scope>
    <systemPath>path-to-snapshot-jar</systemPath>
  </dependency>
</dependencies>

As a Gradle dependency

dependencies {
    implementation(files("path-to-snapshot-jar"))
}