聊聊dubbo的StatusChecker
序
本文主要研究一下dubbo的StatusChecker
Status
dubbo-2.7.2/dubbo-common/src/main/java/org/apache/dubbo/common/status/Status.java
public class Status {
private final Level level;
private final String message;
private final String description;
public Status(Level level) {
this(level, null, null);
}
public Status(Level level, String message) {
this(level, message, null);
}
public Status(Level level, String message, String description) {
this.level = level;
this.message = message;
this.description = description;
}
public Level getLevel() {
return level;
}
public String getMessage() {
return message;
}
public String getDescription() {
return description;
}
/**
* Level
*/
public enum Level {
/**
* OK
*/
OK,
/**
* WARN
*/
WARN,
/**
* ERROR
*/
ERROR,
/**
* UNKNOWN
*/
UNKNOWN
}
}
Status定义了三个属性，分别是level、message、description；其中level有OK、WARN、ERROR、UNKNOWN四个级别StatusChecker
dubbo-2.7.2/dubbo-common/src/main/java/org/apache/dubbo/common/status/StatusChecker.java
@SPI
public interface StatusChecker {
/**
* check status
*
* @return status
*/
Status check();
}
StatusChecker定义了check界面，返回StatusLoadStatusChecker
dubbo-2.7.2/dubbo-common/src/main/java/org/apache/dubbo/common/status/support/LoadStatusChecker.java
@Activate
public class LoadStatusChecker implements StatusChecker {
@Override
public Status check() {
OperatingSystemMXBean operatingSystemMXBean = ManagementFactory.getOperatingSystemMXBean();
double load;
try {
Method method = OperatingSystemMXBean.class.getMethod("getSystemLoadAverage", new Class>[0]);
load = (Double) method.invoke(operatingSystemMXBean, new Object[0]);
if (load == -1) {
com.sun.management.OperatingSystemMXBean bean =
(com.sun.management.OperatingSystemMXBean) operatingSystemMXBean;
load = bean.getSystemCpuLoad();
}
} catch (Throwable e) {
load = -1;
}
int cpu = operatingSystemMXBean.getAvailableProcessors();
return new Status(load (load }
}
LoadStatusChecker实现了StatusChecker界面，其check方法从operatingSystemMXBean的getSystemLoadAverage方法读取load，然后根据cpu个数来计算loadMemoryStatusChecker
dubbo-2.7.2/dubbo-common/src/main/java/org/apache/dubbo/common/status/support/MemoryStatusChecker.java
@Activate
public class MemoryStatusChecker implements StatusChecker {
@Override
public Status check() {
Runtime runtime = Runtime.getRuntime();
long freeMemory = runtime.freeMemory();
long totalMemory = runtime.totalMemory();
long maxMemory = runtime.maxMemory();
boolean ok = (maxMemory - (totalMemory - freeMemory) > 2048); // Alarm when spare memory String msg = "max:" + (maxMemory / 1024 / 1024) + "M,total:"
+ (totalMemory / 1024 / 1024) + "M,used:" + ((totalMemory / 1024 / 1024) - (freeMemory / 1024 / 1024)) + "M,free:" + (freeMemory / 1024 / 1024) + "M";
return new Status(ok ? Status.Level.OK : Status.Level.WARN, msg);
}
}
MemoryStatusChecker实现了实现了StatusChecker界面，其check方法从Runtime获取freeMemory、totalMemory、maxMemory，当maxMemory - (totalMemory - freeMemory) > 2048返回OK，否则返回WARN小结
StatusChecker定义了check界面，返回Status；Status定义了三个属性，分别是level、message、description；其中level有OK、WARN、ERROR、UNKNOWN四个级别LoadStatusChecker实现了StatusChecker界面，其check方法从operatingSystemMXBean的getSystemLoadAverage方法读取load，然后根据cpu个数来计算loadMemoryStatusChecker实现了实现了StatusChecker界面，其check方法从Runtime获取freeMemory、totalMemory、maxMemory，当maxMemory - (totalMemory - freeMemory) > 2048返回OK，否则返回WARNdoc
StatusCheckerLoadStatusCheckerMemoryStatusChecker
