[alerter] 告警处理指标数据，告警表达式计算，内容模版关键字替换

alerter/src/main/java/com/usthe/alert/AlerterConfiguration.java

@@ -0,0 +1,22 @@
+package com.usthe.alert;
+
+import com.googlecode.aviator.AviatorEvaluator;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author tomsun28
+ * @date 2021/11/3 12:55
+ */
+@Configuration
+public class AlerterConfiguration {
+
+    private static final int AVIATOR_LRU_CACHE_SIZE = 1024;
+
+    @Bean
+    public void configAviatorEvaluator() {
+        // 配置AviatorEvaluator使用LRU缓存编译后的表达式
+        AviatorEvaluator.getInstance()
+                .useLRUExpressionCache(AVIATOR_LRU_CACHE_SIZE);
+    }
+}