Library Spring

Health

Health Manager

The HealthManager is responsible for gathering and managing the health data of the system, including information about the system's uptime, memory usage, processor status, and platform details. It continuously monitors the system’s health and provides this data when requested.

The HealthManager can be configured using specific properties defined in your application's configuration file (such as application.properties, application.yml or environment varaibles). These properties modify the behavior of the health manager and affect the health check response. Here are the key properties:

Application Name

application.name

Defines the name of the application or system. This value is used to generate the build information in the health check response. If not provided, it defaults to an empty string.

Application Version

application.version

Specifies the version of the application or system. This value is included in the build information in the health check response. If not specified, it defaults to an empty string.

Memory Threshold for Health Check

application.health.threshold.memory

Defines the memory usage threshold (in percentage). If the system's memory usage exceeds this threshold, the health check response will indicate a "low memory" state. The default value is 90, meaning the health check will trigger a low memory warning if memory usage exceeds 90%.

Add in your application

To integrate the health management functionality into your application, you can import the HealthManager class directly or use component scanning to automatically detect and register all classes in the net.dashio.spring.health package.

Import with class

@Import({HealthController.class, HealthManager.class})

Import with package

@ComponentScan("net.dashio.spring.health")

REST-GET/health

Health Controller

The HealthController is a Spring MVC controller that exposes an endpoint (typically /health) for external services to query the system’s health status. It uses the HealthManager to retrieve the current health information and returns this data in a standardized format (usually as a JSON response) with an HTTP 200 OK status if the system is healthy. This allows for easy monitoring of the system's operational state, often used in health checks for application uptime and performance monitoring tools.

Value Description

Name
status
Type
integer
Description
HTTP status code representing the health check response.
Name
startTime
Type
long
Description
Timestamp when the system started, in milliseconds since epoch.
Name
currentTime
Type
long
Description
Current system time in milliseconds since epoch.
Name
uptime
Type
long
Description
Duration the system has been up, in milliseconds.
Name
threshold.memory
Type
double
Description
Configured memory usage threshold percentage.
Name
threshold.lowMemory
Type
boolean
Description
Indicates if current memory usage exceeds the configured threshold.
Name
build.name
Type
string
Description
Application or system name (empty by default).
Name
build.version
Type
string
Description
Application or system version (empty by default).
Name
platform.platform
Type
string
Description
Operating system name.
Name
platform.platformVersion
Type
string
Description
Operating system version.
Name
platform.platformArchitecture
Type
string
Description
System architecture, e.g., "amd64."
Name
platform.javaVersion
Type
string
Description
Java runtime version.
Name
processor.name
Type
string
Description
Processor name and model.
Name
processor.count
Type
integer
Description
Number of physical processor cores.
Name
processor.logicalCount
Type
integer
Description
Number of logical processors (threads).
Name
processor.clock
Type
long
Description
Processor clock speed in MHz.
Name
processor.averageLoad
Type
array
Description
Array representing the system load average over 1, 5, and 15 minutes.
Name
memory.total
Type
long
Description
Total system memory in MB.
Name
memory.available
Type
long
Description
Available system memory in MB.
Name
memory.used
Type
long
Description
Used system memory in MB.
Name
memory.memoryUsage
Type
double
Description
Percentage of memory usage.
Name
memory.swap.total
Type
long
Description
Total swap memory in MB.
Name
memory.swap.available
Type
long
Description
Available swap memory in MB.
Name
memory.swap.used
Type
long
Description
Used swap memory in MB.
Name
memory.swap.memoryUsage
Type
double
Description
Percentage of swap memory usage.

Health Response

{
    "status": 200,
    "startTime": 1731522165615,
    "currentTime": 1731525559457,
    "uptime": 3393842,
    "threshold": {
        "memory": 90.0,
        "lowMemory": false
    },
    "build": {
        "name": "",
        "version": ""
    },
    "platform": {
        "platform": "Windows 10",
        "platformVersion": "10.0",
        "platformArchitecture": "amd64",
        "javaVersion": "21.0.3"
    },
    "processor": {
        "name": "Intel(R) Core(TM) i5-9300H CPU @ 2.40GHz",
        "count": 4,
        "logicalCount": 8,
        "clock": 2400,
        "averageLoad": [-1.0, -1.0, -1.0]
    },
    "memory": {
        "total": 32616,
        "available": 16554,
        "used": 16062,
        "memoryUsage": 49.246031950390886,
        "swap": {
            "total": 9216,
            "available": 8940,
            "used": 275,
            "memoryUsage": 2.984195285373264
        }
    }
}