9、Sentinel 控制台源码解析之流控规则添加查询

在之前使用Nacos持久化规则的文档中,最后发现只能使用Nacos推送配置到控制台,那么怎么实现控制台和Nacos的双向同步呢?

这里不直接提供解决方案,我们还是先分析下控制台的源码。

下面我们分析下添加、查询流控规则的源码及流程。

核心类

首先分析下用到的相关类

RuleEntity

RuleEntity接口,其实现类就是这些规则对应的实体类了。

 

重点看下FlowRuleEntity源码:

public class FlowRuleEntity implements RuleEntity {
   
     

    // 主键ID
    private Long id;
    // 后台应用名(客户端)
    private String app;
    // 后台应用IP
    private String ip;
    // 后台和控制台通信的端口 8719
    private Integer port;
    // 针对来源
    private String limitApp;
    // 资源名
    private String resource;
    /**
     * 阈值类型
     * 0为线程数;1为qps
     */
    private Integer grade;
    // 单机阈值
    private Double count;
    /**
     * 流控模式
     * 0为直接限流;1为关联限流;2为链路限流
     */
    private Integer strategy;
    // 关联限流时的关联资源
    private String refResource;
    /**
     * 流控效果 快速失败    Warm Up    排队等待
     * 0. default, 1. warm up, 2. rate limiter
     */
    private Integer controlBehavior;
    // warm up模式 预热时长
    private Integer warmUpPeriodSec;
    /**
     * 速率限制器行为中的最大排队时间
     */
    private Integer maxQueueingTimeMs;
    // 是否集群
    private boolean clusterMode;
    /**
     * 集群模式的流规则配置
     */
    private ClusterFlowConfig clusterConfig;
    // 创建时间
    private Date gmtCreate;
    // 修改时间
    private Date gmtModified;

    /**
     * FlowRule=>FlowRuleEntity
     */
    public static FlowRuleEntity fromFlowRule(String app, String ip, Integer port, FlowRule rule) {
   
     
 	 // 省略.....
    }

    /**
     * 实体类转为FlowRule
     */
    @Override
    public FlowRule toRule() {
   
     
		// 省略.....
    }
}

可以看到FlowRuleEntity就对应了界面中新增流控规则界面了。。

 

RuleRepository

RuleRepository是存储和查询规则的顶级接口,添加了增加、删除、查询规则的一系列方法。

public interface RuleRepository<T, ID> {
   
     
    T save(T entity);
    List<T> saveAll(List<T> rules);
    T delete(ID id);
    T findById(ID id);
    List<T> findAllByMachine(MachineInfo machineInfo);
    List<T> findAllByApp(String appName);
}

规则存储针对每种规则,都有对应的实现类,其抽象类InMemoryRuleRepositoryAdapter表示将规则存储在内存中,也是框架提供了唯一一个存储方式。

 

我们重点看下规则保存接口,这里会将所有规则保存到ConcurrentHashMap中。

@Override
public T save(T entity) {

 
    // 1. 设置ID
    if (entity.getId() == null) {

 
        entity.setId(nextId());
    }
    // 2. 调用子类处理实体类
    T processedEntity = preProcess(entity);
    if (processedEntity != null) {

 
        // 3. 将规则添加到ConcurrentHashMap,ID为KEY,规则为Value
        allRules.put(processedEntity.getId(), processedEntity);
        // 4. 将规则添加到ConcurrentHashMap,MachineInfo为KEY,所有的规则为Value
        machineRules.computeIfAbsent(MachineInfo.of(processedEntity.getApp(), processedEntity.getIp(),
            processedEntity.getPort()), e -> new ConcurrentHashMap<>(32))
            .put(processedEntity.getId(), processedEntity);
        // 5. 将规则添加到ConcurrentHashMap,后台应用名为KEY,所有的规则为Value
        appRules.computeIfAbsent(processedEntity.getApp(), v -> new ConcurrentHashMap<>(32))
            .put(processedEntity.getId(), processedEntity);
    }

    return processedEntity;
}

SentinelApiClient

SentinelApiClient类主要负责与 Sentinel 客户端通信,会发送HTTP调用客户端的API接口进行数据交互。

定义了很多常量,大部分都是API路径。

private static final String RESOURCE_URL_PATH = "jsonTree";
private static final String CLUSTER_NODE_PATH = "clusterNode";
private static final String GET_RULES_PATH = "getRules";
private static final String SET_RULES_PATH = "setRules";
private static final String GET_PARAM_RULE_PATH = "getParamFlowRules";
private static final String SET_PARAM_RULE_PATH = "setParamFlowRules";

private static final String FETCH_CLUSTER_MODE_PATH = "getClusterMode";
private static final String MODIFY_CLUSTER_MODE_PATH = "setClusterMode";
private static final String FETCH_CLUSTER_CLIENT_CONFIG_PATH = "cluster/client/fetchConfig";
private static final String MODIFY_CLUSTER_CLIENT_CONFIG_PATH = "cluster/client/modifyConfig";

private static final String FETCH_CLUSTER_SERVER_BASIC_INFO_PATH = "cluster/server/info";

private static final String MODIFY_CLUSTER_SERVER_TRANSPORT_CONFIG_PATH = "cluster/server/modifyTransportConfig";
private static final String MODIFY_CLUSTER_SERVER_FLOW_CONFIG_PATH = "cluster/server/modifyFlowConfig";
private static final String MODIFY_CLUSTER_SERVER_NAMESPACE_SET_PATH = "cluster/server/modifyNamespaceSet";

private static final String FETCH_GATEWAY_API_PATH = "gateway/getApiDefinitions";
private static final String MODIFY_GATEWAY_API_PATH = "gateway/updateApiDefinitions";

private static final String FETCH_GATEWAY_FLOW_RULE_PATH = "gateway/getRules";
private static final String MODIFY_GATEWAY_FLOW_RULE_PATH = "gateway/updateRules";

private static final String FLOW_RULE_TYPE = "flow";
private static final String DEGRADE_RULE_TYPE = "degrade";
private static final String SYSTEM_RULE_TYPE = "system";
private static final String AUTHORITY_TYPE = "authority";

接下来看下SentinelApiClient中的setRulesAsync方法,它的作用主要是异步请求客户端设置规则。

/**
 *  异步请求客户端设置规则
 * @param app 应用名
 * @param ip 应用IP
 * @param port 通信端口
 * @param type 规则类型
 * @param entities 规则
 * @return
 */
private CompletableFuture<Void> setRulesAsync(String app, String ip, int port, String type, List<? extends RuleEntity> entities) {

 
    try {

 
        // 1. 检查参数
        AssertUtil.notNull(entities, "rules cannot be null");
        AssertUtil.notEmpty(app, "Bad app name");
        AssertUtil.notEmpty(ip, "Bad machine IP");
        AssertUtil.isTrue(port > 0, "Bad machine port");
        // 2. 规则集合转为Json
        String data = JSON.toJSONString(
            entities.stream().map(r -> r.toRule()).collect(Collectors.toList()));
        Map<String, String> params = new HashMap<>(2);
        // 3. 设置请求参数 
        params.put("type", type);
        params.put("data", data);
        // 4. 发送请求
        return executeCommand(app, ip, port, SET_RULES_PATH, params, true)
            .thenCompose(r -> {

 
                if ("success".equalsIgnoreCase(r.trim())) {

 
                    return CompletableFuture.completedFuture(null);
                }
                return AsyncUtils.newFailedFuture(new CommandFailedException(r));
            });
    } catch (Exception e) {

 
        logger.error("setRulesAsync API failed, type={}", type, e);
        return AsyncUtils.newFailedFuture(e);
    }
}

接下来看下SentinelApiClient中的executeCommand方法,它的作用就是执行请求了。

private CompletableFuture<String> executeCommand(String app, String ip, int port, String api, Map<String, String> params, boolean useHttpPost) {

 
   // 1. 拼接请求URL http://192.168.1.20:8721/setRules
    CompletableFuture<String> future = new CompletableFuture<>();
    if (StringUtil.isBlank(ip) || StringUtil.isBlank(api)) {

 
        future.completeExceptionally(new IllegalArgumentException("Bad URL or command name"));
        return future;
    }
    StringBuilder urlBuilder = new StringBuilder();
    urlBuilder.append("http://");
    urlBuilder.append(ip).append(':').append(port).append('/').append(api);
    if (params == null) {

 
        params = Collections.emptyMap();
    }
    // 2. 执行GET请求,参数拼在URL后面
    if (!useHttpPost || !isSupportPost(app, ip, port)) {

 
        // Using GET in older versions, append parameters after url
        if (!params.isEmpty()) {

 
            if (urlBuilder.indexOf("?") == -1) {

 
                urlBuilder.append('?');
            } else {

 
                urlBuilder.append('&');
            }
            urlBuilder.append(queryString(params));
        }
        return executeCommand(new HttpGet(urlBuilder.toString()));
    } else {

 
        // Using POST
        // 3. 执行POST请求
        return executeCommand(
                postRequest(urlBuilder.toString(), params, isSupportEnhancedContentType(app, ip, port)));
    }
}

最终请求会使用apache提供了httpClient执行请求,获取返回结果。

 

添加流控规则源码解析

1. 访问接口

首先在页面中添加一个流控规则,并F12打开开发者模式,对/app/get进行限流。

 

点击新增按钮,发送请求,我们看到是访问的/v1/flow/rule,然后注意下请求参数。

 

2. 控制台后台接口

上面的访问路径,对应的就是FlowControllerV1中的apiAddFlowRule控制器了,这是一个Spring MVC 接口。

这个接口主要是保存了规则在控制台的内存中,然后又调用了客户端的API,将规则发送给了客户端应用,具体怎么执行了,之前的核心类源码SentinelApiClient已经分析过了。

@PostMapping("/rule")
@AuthAction(PrivilegeType.WRITE_RULE)
public Result<FlowRuleEntity> apiAddFlowRule(@RequestBody FlowRuleEntity entity) {

 
    // 1. 参数校验
    Result<FlowRuleEntity> checkResult = checkEntityInternal(entity);
    if (checkResult != null) {

 
        return checkResult;
    }
    // 2. 设置附加参数
    entity.setId(null);
    Date date = new Date();
    entity.setGmtCreate(date);
    entity.setGmtModified(date);
    entity.setLimitApp(entity.getLimitApp().trim());
    entity.setResource(entity.getResource().trim());
    try {

 
        // 3. 保存流控规则,默认在内存,InMemoryRuleRepositoryAdapter
        entity = repository.save(entity);
        // http://192.168.1.20:8721/setRules
        // 4. 调用客户端的API重新设置规则 SentinelApiClient
        publishRules(entity.getApp(), entity.getIp(), entity.getPort()).get(5000, TimeUnit.MILLISECONDS);
        return Result.ofSuccess(entity);
    } catch (Throwable t) {

 
        Throwable e = t instanceof ExecutionException ? t.getCause() : t;
        logger.error("Failed to add new flow rule, app={}, ip={}", entity.getApp(), entity.getIp(), e);
        return Result.ofFail(-1, e.getMessage());
    }
}

3. 客户端后台接口

第二步中控制台调用了客户端的setRules接口,接下来我们看下客户端这个接口都做了什么。

setRules接口进入的是ModifyRulesCommandHandler处理器进行处理,其handle方法,主要是接受请求,然后根据不同的规则类型的管理器进行处理。

    public CommandResponse<String> handle(CommandRequest request) {
   
     
        // 1. XXX from 1.7.2, 当 fastjson 早于 1.2.12 时强制失败
        if (VersionUtil.fromVersionString(JSON.VERSION) < FASTJSON_MINIMAL_VER) {
   
     
            // fastjson版本太低
            return CommandResponse.ofFailure(new RuntimeException("The \"fastjson-" + JSON.VERSION
                    + "\" introduced in application is too old, you need fastjson-1.2.12 at least."));
        }
        // 2. 获取请求参数
        String type = request.getParam("type");
        String data = request.getParam("data");
        if (StringUtil.isNotEmpty(data)) {
   
     
            try {
   
     
                data = URLDecoder.decode(data, "utf-8");
            } catch (Exception e) {
   
     
                RecordLog.info("Decode rule data error", e);
                return CommandResponse.ofFailure(e, "decode rule data error");
            }
        }

        RecordLog.info("Receiving rule change (type: {}): {}", type, data);

        String result = "success";
        // 3. 判断规则类型
        if (FLOW_RULE_TYPE.equalsIgnoreCase(type)) {
   
     
            // 流控规则  解析参数为流控规则对象集合
            List<FlowRule> flowRules = JSONArray.parseArray(data, FlowRule.class);
            // 调用流量规则管理器加载规则 返回结果
            FlowRuleManager.loadRules(flowRules);
            if (!writeToDataSource(getFlowDataSource(), flowRules)) {
   
     
                result = WRITE_DS_FAILURE_MSG;
            }
            return CommandResponse.ofSuccess(result);
        } else if (AUTHORITY_RULE_TYPE.equalsIgnoreCase(type)) {
   
     
            List<AuthorityRule> rules = JSONArray.parseArray(data, AuthorityRule.class);
            AuthorityRuleManager.loadRules(rules);
            if (!writeToDataSource(getAuthorityDataSource(), rules)) {
   
     
                result = WRITE_DS_FAILURE_MSG;
            }
            return CommandResponse.ofSuccess(result);
        } else if (DEGRADE_RULE_TYPE.equalsIgnoreCase(type)) {
   
     
            List<DegradeRule> rules = JSONArray.parseArray(data, DegradeRule.class);
            DegradeRuleManager.loadRules(rules);
            if (!writeToDataSource(getDegradeDataSource(), rules)) {
   
     
                result = WRITE_DS_FAILURE_MSG;
            }
            return CommandResponse.ofSuccess(result);
        } else if (SYSTEM_RULE_TYPE.equalsIgnoreCase(type)) {
   
     
            List<SystemRule> rules = JSONArray.parseArray(data, SystemRule.class);
            SystemRuleManager.loadRules(rules);
            if (!writeToDataSource(getSystemSource(), rules)) {
   
     
                result = WRITE_DS_FAILURE_MSG;
            }
            return CommandResponse.ofSuccess(result);
        }
        return CommandResponse.ofFailure(new IllegalArgumentException("invalid type"));
    }

流控规则调用的是FlowRuleManager,其loadRules方法最终调用的就是DynamicSentinelProperty的updateValue方法。

可以看到DynamicSentinelProperty维护了之前流控规则,并接受了新的流控规则。

 

之后会调用管理器中的监听器并循环。

 

最终调用监听器的configUpdate方法,更新规则管理器中存放规则的ConcurrentHashMap,这样客户端的内存中流控规则也就更新了。

 

查询流控规则源码解析

1. 访问接口

F12可以看到访问的是/v1/flow/rules接口。

 

/v1/flow/rules接口的逻辑处理如下:

@GetMapping("/rules")
@AuthAction(PrivilegeType.READ_RULE)
public Result<List<FlowRuleEntity>> apiQueryMachineRules(@RequestParam String app,
                                                         @RequestParam String ip,
                                                         @RequestParam Integer port) {

 

    if (StringUtil.isEmpty(app)) {

 
        return Result.ofFail(-1, "app can't be null or empty");
    }
    if (StringUtil.isEmpty(ip)) {

 
        return Result.ofFail(-1, "ip can't be null or empty");
    }
    if (port == null) {

 
        return Result.ofFail(-1, "port can't be null");
    }
    try {

 
        // 1. 调用客户端API,查询规则 http://192.168.1.20:8721/getRules
        List<FlowRuleEntity> rules = sentinelApiClient.fetchFlowRuleOfMachine(app, ip, port);
        // 2. 将客户端查询到的规则 重新存放到控制台中,会事先清理控制台内存中的规则
        rules = repository.saveAll(rules);
        return Result.ofSuccess(rules);
    } catch (Throwable throwable) {

 
        logger.error("Error when querying flow rules", throwable);
        return Result.ofThrowable(-1, throwable);
    }
}

2.客户端查询规则

控制台发出getRules请求后,是交给FetchActiveRuleCommandHandler处理器来进行处理。

@Override
public CommandResponse<String> handle(CommandRequest request) {

 
    String type = request.getParam("type");
    if ("flow".equalsIgnoreCase(type)) {

 
        // 调用管理器获取规则
        return CommandResponse.ofSuccess(JSON.toJSONString(FlowRuleManager.getRules()));
    } else if ("degrade".equalsIgnoreCase(type)) {

 
        return CommandResponse.ofSuccess(JSON.toJSONString(DegradeRuleManager.getRules()));
    } else if ("authority".equalsIgnoreCase(type)) {

 
        return CommandResponse.ofSuccess(JSON.toJSONString(AuthorityRuleManager.getRules()));
    } else if ("system".equalsIgnoreCase(type)) {

 
        return CommandResponse.ofSuccess(JSON.toJSONString(SystemRuleManager.getRules()));
    } else {

 
        return CommandResponse.ofFailure(new IllegalArgumentException("invalid type"));
    }
}

在管理器中会将内存中的规则返回给控制台。

public static List<FlowRule> getRules() {

 
    List<FlowRule> rules = new ArrayList<FlowRule>();
    for (Map.Entry<String, List<FlowRule>> entry : flowRules.entrySet()) {

 
        rules.addAll(entry.getValue());
    }
    return rules;
}