brettwooldridge/HikariCP

HikariCP is a high-performance JDBC connection pool library for Java. It manages database connections and provides extensive monitoring capabilities through integrations with Dropwizard, Micrometer, and Prometheus. The system also supports Hibernate integration and dynamic credential management.

10 changes.

This period was dominated by the HikariCP 5.0 release, which introduced a redesigned configuration API, a new metrics tracking system, and a comprehensive refactoring of the core pool implementation. The work also included adding mock JDBC classes and OSGi integration tests to improve test coverage and reliability.

7 changes.

This period focused on expanding HikariCP's observability by adding support for Dropwizard 5 and Prometheus metrics systems. The work included implementing new metrics trackers and health checks, alongside comprehensive unit testing to verify the correct behavior of pool states, utility classes, and monitoring integrations.

5 changes.

This period focused on modernizing the project's build and runtime environment by adding Java 11+ module descriptor support and configuring Eclipse IDE settings. It also expanded observability by integrating Micrometer metrics and adding comprehensive tests for configuration sealing and secure logging.

Hikari now provides a new metrics tracker and health check implementation for Dropwizard 5 (io.dropwizard.metrics5). The new CodaHaleMetricsTracker, CodahaleHealthChecker, and associated factory classes register pool metrics (such as connection wait times, usage, creation, and timeouts) and expose health checks for connectivity and 99th-percentile wait times, enabling users to integrate Hikari with modern Dropwizard-based monitoring stacks.

src/main/java/com/zaxxer/hikari/metrics/dropwizard · high confidence

Users can now configure HikariCP via Hibernate properties using the new HikariConfigurationUtil and HikariConnectionProvider classes. The provider automatically maps standard Hibernate settings (such as driver, URL, username, and password) to HikariCP configuration, while also supporting any property prefixed with 'hibernate.hikari.' for fine-grained control. A deprecation warning is logged for Hibernate versions 4.3.6 and newer, indicating that the built-in HikariCP provider should be used instead.

src/main/java/com/zaxxer/hikari/hibernate · high confidence

HikariCP now provides a built-in Micrometer metrics tracker, enabling users to export connection pool statistics (such as active, idle, and pending connections, as well as acquisition and usage timings) directly to a Micrometer MeterRegistry. This new \MicrometerMetricsTracker\ and its factory allow for standard, configurable metrics collection without requiring external instrumentation libraries.

src/main/java/com/zaxxer/hikari/metrics/micrometer · high confidence

HikariCP now includes built-in support for exporting metrics to Prometheus. This change introduces a new \prometheus\ package containing two metrics tracking implementations: \PrometheusMetricsTracker\ (using Prometheus Summaries) and \PrometheusHistogramMetricsTracker\ (using Histograms for better performance). Both implementations support multiple connection pools by labeling metrics with the pool name and allow registration to a custom \CollectorRegistry\ via their respective factories (\PrometheusMetricsTrackerFactory\ and \PrometheusHistogramMetricsTrackerFactory\).

src/main/java/com/zaxxer/hikari/metrics/prometheus · high confidence

The release introduces a fix for the ConcurrentBag to avoid virtual-thread yield spin, addressing issue \#2402. The CHANGES file also documents previous fixes including setSchema behavior, metric registry NoSuchMethodException, and connection interruption handling. The README is updated to reflect the new version and configuration details.

(repo-wide) · high confidence

Added a new \com.zaxxer.hikari.metrics\ package containing the \IMetricsTracker\ interface, a default-implementation \MetricsTracker\ class, a \MetricsTrackerFactory\ interface, and a \PoolStats\ abstract class. This change provides the foundational classes for tracking connection pool metrics such as creation time, acquisition time, usage duration, and timeouts, enabling users to integrate with external monitoring systems.

src/main/java/com/zaxxer/hikari/metrics · high confidence

The utility package now includes new classes: ClockSource for resolution-independent time calculations, ConcurrentBag for high-performance connection management, Credentials for immutable username/password pairs, DriverDataSource for JDBC driver-based connections, FastList for optimized list operations, IsolationLevel for transaction isolation levels, JavassistProxyFactory for dynamic proxy generation, PropertyElf for reflective property setting, SuspendResumeLock for pool suspension, and UtilityElf for helper methods. These changes introduce new capabilities and refactor existing functionality to improve performance, maintainability, and feature support.

src/main/java/com/zaxxer/hikari/util · high confidence

The core pool implementation classes, including HikariPool, PoolBase, PoolEntry, and the proxy classes for JDBC interfaces (ProxyConnection, ProxyStatement, etc.), have been reorganized into the com.zaxxer.hikari.pool package. This refactoring isolates the internal pool logic and proxy implementations, moving them out of the root com.zaxxer.hikari package to better separate public API from internal implementation details.

src/main/java/com/zaxxer/hikari/pool · high confidence

New Eclipse project settings have been added to the repository, including .settings/org.eclipse.core.resources.prefs, .settings/org.eclipse.jdt.core.prefs, .settings/org.eclipse.jdt.apt.core.prefs, .settings/org.eclipse.m2e.core.prefs, and .settings/org.eclipse.pde.core.prefs. These files configure the Java compiler to target Java 11, set UTF-8 encoding for source and resource directories, and define workspace-specific preferences for the Eclipse IDE and M2E plugin.

.settings · high confidence

The project now includes a module-info.java file, enabling Java Platform Module System (JPMS) support for Java 11 and above. This change explicitly declares dependencies on several libraries, including io.dropwizard.metrics5 and simpleclient, indicating support for Dropwizard 5 metrics alongside existing metrics integrations like Micrometer and Prometheus.

src/main/java · high confidence

HikariCP has been refactored into a new major version (5.0), introducing a redesigned configuration API where HikariConfig implements the new HikariConfigMXBean interface, allowing runtime modification of pool properties via JMX. The library now uses a Credentials class for atomic username/password handling and provides a HikariCredentialsProvider interface for dynamic credential retrieval. Additionally, the pool management is exposed through a new HikariPoolMXBean interface, and the codebase has been updated to Java 11 with improved validation and logging.

src/main/java/com/zaxxer/hikari · high confidence

Added OSGi bundle integration tests; Added and updated tests for the HikariCP pool; Added mock JDBC classes for testing; Added test coverage for JDBC URL logging; Added test resource files for configuration and logging; Added tests for idle timeout behavior; Added unit tests for Dropwizard metrics trackers; Added unit tests for Prometheus metrics integration; Added unit tests for utility classes; Tests for sealed configuration and accessible methods.

The project's Maven build configuration (pom.xml) has been updated with newer versions of several dependencies, including Javassist (3.29.2-GA), Log4j (2.25.1), Micrometer (1.5.4), Mockito (3.7.7), and Testcontainers (2.0.5).

(dependencies) · high confidence

Written by watchdog.canine.dev from the codebase's own history, inside the signed delivery this page is composed from.

• CAI 54 → 63 (+8.3)
• Rubric changed (rubric-2026.08.19 → rubric-2026.09.15) — scores are not directly comparable.

• Code Health 90 → 93 (+3.5)
• Architecture 100 → 99 (-0.6)
• Maturity 54 → 54 (-0.0)
• Readiness 42 → 58 (+16.1)
• Security 62 → 70 (+8.7)

• Coverage not included — suite not readable by the collector
• Dependency hygiene not measured — dependency manifest found but not parsed for hygiene
• Duplicated block (7 lines × 2) (src/main/java/com/zaxxer/hikari/metrics/dropwizard/CodaHaleMetricsTracker.java)
• Duplicated block (9 lines × 2) (src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java)
• High: security finding (details withheld)
• High: security finding (details withheld)
• High: security finding (details withheld)
• No exposed public API
• Off-boarding risk: anonymized user #1
• Scanner failed to run — not a clean result
• Test reliability not included

• Change coupling: CodaHaleMetricsTracker.java ↔ HikariPool.java (src/main/java/com/zaxxer/hikari/metrics/dropwizard/CodaHaleMetricsTracker.java)
• ClassTooLong: HikariConfig (src/main/java/com/zaxxer/hikari/HikariConfig.java)
• ClassTooLong: HikariPool (src/main/java/com/zaxxer/hikari/pool/HikariPool.java)
• Dependency hygiene PARTLY measured — Maven/Gradle declarations read, no dependency graph resolved
• Documentation: no installation or build instructions (README.md)
• Documentation: no usage examples (README.md)
• Duplicated block (10 lines × 4) (src/main/java/com/zaxxer/hikari/pool/ProxyConnection.java)
• Duplicated block (11 lines × 2) (src/main/java/com/zaxxer/hikari/metrics/dropwizard/CodaHaleMetricsTracker.java)
• Duplicated block (18 lines × 2) (src/main/java/com/zaxxer/hikari/metrics/dropwizard/CodaHaleMetricsTracker.java)
• Duplicated block (5 lines × 2) (src/main/java/com/zaxxer/hikari/metrics/prometheus/PrometheusHistogramMetricsTrackerFactory.java)
• Duplicated block (8 lines × 2) (src/main/java/com/zaxxer/hikari/metrics/prometheus/PrometheusHistogramMetricsTracker.java)
• Duplicated block (9 lines × 2) (src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java)
• High: security finding (details withheld)
• High: security finding (details withheld)
• High: security finding (details withheld)
• Inconsistent naming convention for base implementation methods. The ClockSource abstract class uses currentTime for the public API but currentTime0 for the concrete implementation hook. Subclasses (MillisecondClockSource, NanosecondClockSource) expose currentTime0 directly. This suggests an internal implementation detail (0 suffix) leaking into the public type signatures, which is inconsistent with standard Java naming conventions for abstract vs concrete methods.
• Medium: security finding (details withheld)
• Medium: security finding (details withheld)
• Medium: security finding (details withheld)
• No assertions: connectionAcquisitionMetrics (src/test/java/com/zaxxer/hikari/metrics/prometheus/PrometheusHistogramMetricsTrackerTest.java)
• …and 45 more

Written by watchdog.canine.dev from the codebase's own history, inside the signed delivery this page is composed from.

brettwooldridge/HikariCP was measured the same way every project in this corpus was: the same rubric, at a pinned commit, with the result published in full. Point a surveyor at a repository you know and see whether you agree with it.