一、StatisticSlot 流程
1、StatisticSlot
StatisticSlot主要用于统计线程数量、请求数量、响应时间、阻塞数量、异常数量。
@SpiOrder(-7000)
public class StatisticSlot extends AbstractLinkedProcessorSlot<DefaultNode> {
@Override
public void entry(Context context, ResourceWrapper resourceWrapper, DefaultNode node, int count,
boolean prioritized, Object... args) throws Throwable {
try {
// Do some checking.
//先校验其他规则，再进行数据统计
fireEntry(context, resourceWrapper, node, count, prioritized, args);
// Request passed, add thread count and pass count.
//node 和 clusterNode 中访问线程数都加1
node.increaseThreadNum();
//node 和 clusterNode 中访问通过数都加1
//包括 分钟级时间窗口：rollingCounterInMinute, 秒级时间窗口：rollingCounterInSecond
node.addPassRequest(count);
//前置资源节点不为空时，增加访问线程数和访问通过数，用于填充上层链路节点的数据
if (context.getCurEntry().getOriginNode() != null) {
// Add count for origin node.
context.getCurEntry().getOriginNode().increaseThreadNum();
context.getCurEntry().getOriginNode().addPassRequest(count);
}
//入栈流量，全局访问线程数、访问通过数都加1
if (resourceWrapper.getEntryType() == EntryType.IN) {
// Add count for global inbound entry node for global statistics.
Constants.ENTRY_NODE.increaseThreadNum();
Constants.ENTRY_NODE.addPassRequest(count);
}
// Handle pass event with registered entry callback handlers.
// ProcessorSlotEntryCallback 回调
for (ProcessorSlotEntryCallback<DefaultNode> handler : StatisticSlotCallbackRegistry.getEntryCallbacks()) {
handler.onPass(context, resourceWrapper, node, count, args);
}
} catch (PriorityWaitException ex) {
//优先级等待异常，记录统计数据，记录了通过线程数，然后直接放行请求
node.increaseThreadNum();
if (context.getCurEntry().getOriginNode() != null) {
// Add count for origin node.
context.getCurEntry().getOriginNode().increaseThreadNum();
}
if (resourceWrapper.getEntryType() == EntryType.IN) {
// Add count for global inbound entry node for global statistics.
Constants.ENTRY_NODE.increaseThreadNum();
}
// Handle pass event with registered entry callback handlers.
for (ProcessorSlotEntryCallback<DefaultNode> handler : StatisticSlotCallbackRegistry.getEntryCallbacks()) {
handler.onPass(context, resourceWrapper, node, count, args);
}
} catch (BlockException e) {
//校验不通过异常
// Blocked, set block exception to current entry.
//设置异常信息
context.getCurEntry().setBlockError(e);
// Add block count.
//阻塞请求数增加1
node.increaseBlockQps(count);
if (context.getCurEntry().getOriginNode() != null) {
context.getCurEntry().getOriginNode().increaseBlockQps(count);
}
if (resourceWrapper.getEntryType() == EntryType.IN) {
// Add count for global inbound entry node for global statistics.
Constants.ENTRY_NODE.increaseBlockQps(count);
}
// Handle block event with registered entry callback handlers.
for (ProcessorSlotEntryCallback<DefaultNode> handler : StatisticSlotCallbackRegistry.getEntryCallbacks()) {
handler.onBlocked(e, context, resourceWrapper, node, count, args);
}
//继续抛出异常
throw e;
} catch (Throwable e) {
// Unexpected internal error, set error to current entry.
//其他异常，设置异常信息
context.getCurEntry().setError