本文主要研究一下dubbo的StatusChecker
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 } }
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(); }
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 < 0 ? Status.Level.UNKNOWN : (load < cpu ? Status.Level.OK : Status.Level.WARN), (load < 0 ? "" : "load:" + load + ",") + "cpu:" + cpu); } }
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 < 2M 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); } }
maxMemory - (totalMemory - freeMemory) > 2048
返回OK,否则返回WARN maxMemory - (totalMemory - freeMemory) > 2048