背景

由于导入及导出服务的使用，可能过多占用业务系统的请求。

为此在db层次做了切分（资源隔离）使用不同的db连接池。

同时针对导入导出服务增加请求频率限制，避免占用过多资源

解决方案

db连接资源分离

比较简单的利用spring做dataSource路由

/**     * Created by qixiaobo on 2016/12/2.     */    public class DataSourceRouter extends AbstractRoutingDataSource {        @Override        protected Object determineCurrentLookupKey() {            return WxbStatic.getDataSourceRouting();        }    }    import com.air.tqb.annoate.DataSource;    import com.air.tqb.annoate.DataSourceType;    import com.air.tqb.utils.WxbStatic;    import org.apache.commons.logging.Log;    import org.apache.commons.logging.LogFactory;    import org.aspectj.lang.ProceedingJoinPoint;    import org.aspectj.lang.annotation.Around;    import org.aspectj.lang.annotation.Aspect;    import org.springframework.core.Ordered;    import org.springframework.core.annotation.Order;    import org.springframework.stereotype.Component;         /**     * Created by qixiaobo on 2016/12/2.     */    @Aspect    @Component    @Order(Ordered.HIGHEST_PRECEDENCE + 2)    public class DataSourceRoutingAspect {             private static final Log logger = LogFactory.getLog(DataSourceRoutingAspect.class);                  @Around("execution(public * com.air.tqb.service..*.*(..)) && @annotation(com.air.tqb.annoate.DataSource) && @annotation(dataSource)")        public Object setDataSource(ProceedingJoinPoint joinPoint, DataSource dataSource) throws Throwable {            DataSourceType dataSourceType = dataSource.value();            try {                WxbStatic.setDataSourceRouting(dataSourceType.getValue());                if (logger.isDebugEnabled()) {                    logger.debug("DataSourceType[" + dataSourceType.getValue() + "] set.");                }                return joinPoint.proceed();            } finally {                WxbStatic.clearDataSourceRouting();                if (logger.isDebugEnabled()) {                    logger.debug("DataSourceType[" + dataSourceType.getValue() + "] remove.");                }            }             }                  @Around("execution(public * com.air.tqb.service.report..*.*(..))")        public Object setDataSource(ProceedingJoinPoint joinPoint) throws Throwable {            DataSourceType dataSourceType = DataSourceType.SLOW;            try {                WxbStatic.setDataSourceRouting(dataSourceType.getValue());                if (logger.isDebugEnabled()) {                    logger.debug("report DataSourceType[" + dataSourceType.getValue() + "] set.");                }                return joinPoint.proceed();            } finally {                WxbStatic.clearDataSourceRouting();                if (logger.isDebugEnabled()) {                    logger.debug("report DataSourceType[" + dataSourceType.getValue() + "] remove.");                }            }             }    }复制代码

这样我们可以吧report和正常请求区分开来。使用不同的db连接

/**     * Created by qixiaobo on 2016/12/2.     */    @Target({ElementType.METHOD})    @Retention(RetentionPolicy.RUNTIME)    @Inherited    public @interface DataSource {        DataSourceType value() default DataSourceType.NORMAL;    }    package com.air.tqb.annoate;         public enum DataSourceType {             NORMAL("normal"), SLOW("slow"), REPORT("report");             DataSourceType(String value) {            this.value = value;        }             private String value;             public String getValue() {            return value;        }    }复制代码

在不同的方法上加上指定的db标签可以完成db的选择。从而完成资源隔离。

方法调用限制

对于指定的占用资源方法采用开发按照key做配置，对于指定次数的限制

@Target({ElementType.METHOD})    @Retention(RetentionPolicy.RUNTIME)    @Inherited    public @interface OperationLimit {        int  value() default 5;        String key() default "import";    }复制代码

package com.air.tqb.aop;        import com.air.tqb.Exception.LimitOperationException;    import com.air.tqb.annoate.OperationLimit;    import com.google.common.base.Throwables;    import org.aspectj.lang.ProceedingJoinPoint;    import org.aspectj.lang.annotation.Around;    import org.aspectj.lang.annotation.Aspect;    import org.springframework.beans.factory.annotation.Autowired;    import org.springframework.beans.factory.annotation.Qualifier;    import org.springframework.core.Ordered;    import org.springframework.core.annotation.Order;    import org.springframework.data.redis.core.StringRedisTemplate;    import org.springframework.data.redis.core.ValueOperations;    import org.springframework.stereotype.Component;        import java.util.concurrent.TimeUnit;        @Aspect    @Component    @Order(Ordered.HIGHEST_PRECEDENCE + 4)    public class OperationLimitAspect {        @Autowired        @Qualifier(value = "stringRedisTemplate")        private StringRedisTemplate template;            private final static String LIMIT_KEY_PREFIX = "limit:";            @Around("@annotation(com.air.tqb.annoate.OperationLimit) && @annotation(operationLimit)")        public Object operationLimit(ProceedingJoinPoint joinPoint, OperationLimit operationLimit) {            ValueOperations
    
      stringStringValueOperations = template.opsForValue();            final String key = getLimitKey(operationLimit);            Long incremented = stringStringValueOperations.increment(key, 1);            //暂时不考虑事务了，简单策略过期即可            stringStringValueOperations.getOperations().expire(key, 180, TimeUnit.SECONDS);            boolean limitReached = checkLimit(incremented, operationLimit);            if (limitReached) {                stringStringValueOperations.increment(key, -1);                throw new LimitOperationException("当前操作" + operationLimit.key() + "已经超过最大操作数" + operationLimit.value() + "限制，请稍后再试！");            } else {                try {                    return joinPoint.proceed();                } catch (Throwable throwable) {                    return Throwables.propagate(throwable);                } finally {                    stringStringValueOperations.increment(key, -1);                }            }            }            private boolean checkLimit(Long incremented, OperationLimit operationLimit) {            if (operationLimit.value() < 0 || incremented <= operationLimit.value()) {                return false;            }            return true;        }            private String getLimitKey(OperationLimit operationLimit) {            return LIMIT_KEY_PREFIX + operationLimit.key();        }        }复制代码

这个数据是更新了的

对于返回为空可以参考

public Long incrBy(byte[] key, long value) {    		try {    			if (isPipelined()) {    				pipeline(new JedisResult(pipeline.incrBy(key, value)));    				return null;    			}    			if (isQueueing()) {    				transaction(new JedisResult(transaction.incrBy(key, value)));    				return null;    			}    			return jedis.incrBy(key, value);    		} catch (Exception ex) {    			throw convertJedisAccessException(ex);    		}    	}复制代码