Talk about sentinel ModifyRulesCommandHandler

sequence

In this paper, we study the sentinel ModifyRulesCommandHandler

ModifyRulesCommandHandler

Sentinel – transport – common – while – sources. The jar! /com/alibaba/csp/sentinel/command/handler/ModifyRulesCommandHandler.java

@CommandMapping(name = "setRules") public class ModifyRulesCommandHandler implements CommandHandler<String> { static DataSource<? , List<FlowRule>> flowDataSource = null; static DataSource<? , List<AuthorityRule>> authorityDataSource = null; static DataSource<? , List<DegradeRule>> degradeDataSource = null; static DataSource<? , List<SystemRule>> systemSource = null; public static synchronized void registerFlowDataSource(DataSource<? , List<FlowRule>> datasource) { flowDataSource = datasource; } public static synchronized void registerAuthorityDataSource(DataSource<? , List<AuthorityRule>> dataSource) { authorityDataSource = dataSource; } public static synchronized void registerDegradeDataSource(DataSource<? , List<DegradeRule>> dataSource) { degradeDataSource = dataSource; } public static synchronized void registerSystemDataSource(DataSource<? , List<SystemRule>> dataSource) { systemSource = dataSource; } @Override public CommandResponse<String> handle(CommandRequest request) { Stringtype = request.getParam("type");
        // rule data in get parameter
        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("receive rule change:" + type);
        RecordLog.info(data);

        String result = "success";

        if ("flow".equalsIgnoreCase(type)) {
            List<FlowRule> flowRules = JSONArray.parseArray(data, FlowRule.class);
            FlowRuleManager.loadRules(flowRules);
            if(flowDataSource ! = null) { try { flowDataSource.writeDataSource(flowRules); } catch (Exception e) { result ="partial success"; RecordLog.info(e.getMessage(), e); }}return CommandResponse.ofSuccess(result);
        } else if ("authority".equalsIgnoreCase(type)) {
            List<AuthorityRule> rules = JSONArray.parseArray(data, AuthorityRule.class);
            AuthorityRuleManager.loadRules(rules);
            if(authorityDataSource ! = null) { try { authorityDataSource.writeDataSource(rules); } catch (Exception e) { result ="partial success"; RecordLog.info(e.getMessage(), e); }}return CommandResponse.ofSuccess(result);
        } else if ("degrade".equalsIgnoreCase(type)) {
            List<DegradeRule> rules = JSONArray.parseArray(data, DegradeRule.class);
            DegradeRuleManager.loadRules(rules);
            if(degradeDataSource ! = null) { try { degradeDataSource.writeDataSource(rules); } catch (Exception e) { result ="partial success"; RecordLog.info(e.getMessage(), e); }}return CommandResponse.ofSuccess(result);
        } else if ("system".equalsIgnoreCase(type)) {
            List<SystemRule> rules = JSONArray.parseArray(data, SystemRule.class);
            SystemRuleManager.loadRules(rules);
            if(systemSource ! = null) { try { systemSource.writeDataSource(rules); } catch (Exception e) { result ="partial success"; RecordLog.info(e.getMessage(), e); }}return CommandResponse.ofSuccess(result);
        }
        return CommandResponse.ofFailure(new IllegalArgumentException("invalid type")); }}Copy the code

• If the type is a flow of words, call the FlowRuleManager loadRules (flowRules); update

FlowRuleManager

Sentinel – core – while – sources jar! /com/alibaba/csp/sentinel/slots/block/flow/FlowRuleManager.java

/** * Load {@link FlowRule}s, former rules will be replaced. * * @param rules new rules to load. */ public static void loadRules(List<FlowRule> rules)  { currentProperty.updateValue(rules); }Copy the code

• DynamicSentinelProperty’s updateValue is called

DynamicSentinelProperty

Sentinel – core – while – sources jar! /com/alibaba/csp/sentinel/property/DynamicSentinelProperty.java

    public void updateValue(T newValue) {
        if (isEqual(value, newValue)) {
            return;
        }
        RecordLog.info("SentinelProperty, config is real updated to: " + newValue);

        value = newValue;
        for(PropertyListener<T> listener : listeners) { listener.configUpdate(newValue); }}Copy the code

• The configUpdate is delegated to listeners

FlowPropertyListener

Sentinel – core – while – sources jar! /com/alibaba/csp/sentinel/slots/block/flow/FlowRuleManager.java

    private static final class FlowPropertyListener implements PropertyListener<List<FlowRule>> {

        @Override
        public void configUpdate(List<FlowRule> value) {
            Map<String, List<FlowRule>> rules = loadFlowConf(value);
            if(rules ! = null) { flowRules.clear(); flowRules.putAll(rules); } RecordLog.info("receive flow config: " + flowRules);
        }

        @Override
        public void configLoad(List<FlowRule> conf) {
            Map<String, List<FlowRule>> rules = loadFlowConf(conf);
            if(rules ! = null) { flowRules.clear(); flowRules.putAll(rules); } RecordLog.info("load flow config: "+ flowRules); }}Copy the code

• The configUpdate method here calls loadFlowConf to load

FlowRuleManager.loadFlowConf

Sentinel – core – while – sources jar! /com/alibaba/csp/sentinel/slots/block/flow/FlowRuleManager.java

    private static Map<String, List<FlowRule>> loadFlowConf(List<FlowRule> list) {
        Map<String, List<FlowRule>> newRuleMap = new ConcurrentHashMap<String, List<FlowRule>>();

        if (list == null) {
            return newRuleMap;
        }

        for (FlowRule rule : list) {
            if (StringUtil.isBlank(rule.getLimitApp())) {
                rule.setLimitApp(FlowRule.LIMIT_APP_DEFAULT);
            }

            Controller rater = new DefaultController(rule.getCount(), rule.getGrade());
            if(rule.getGrade() == RuleConstant.FLOW_GRADE_QPS && rule.getControlBehavior() == RuleConstant.CONTROL_BEHAVIOR_WARM_UP &&  rule.getWarmUpPeriodSec() > 0) { rater = new WarmUpController(rule.getCount(), rule.getWarmUpPeriodSec(), ColdFactorProperty.coldFactor); }else if (rule.getGrade() == RuleConstant.FLOW_GRADE_QPS
                && rule.getControlBehavior() == RuleConstant.CONTROL_BEHAVIOR_RATE_LIMITER
                && rule.getMaxQueueingTimeMs() > 0) {
                rater = new PaceController(rule.getMaxQueueingTimeMs(), rule.getCount());
            }
            rule.setRater(rater);

            String identity = rule.getResource();
            List<FlowRule> ruleM = newRuleMap.get(identity);

            if (ruleM == null) {
                ruleM = new ArrayList<FlowRule>();
                newRuleMap.put(identity, ruleM);
            }

            ruleM.add(rule);

        }
        return newRuleMap;
    }
Copy the code

• The rater is set here. There are two types of rater, WarmUpController and PaceController

summary

• Adding traffic limiting rules to a specific instance in the Sentinel dashboard will synchronously invoke the sentinel interface of the instance and send setRules instructions
• Application side receives the setRules instruction, using ModifyRulesCommandHandler to processing, specific is to cover the local rules

doc

• Main process of Sentinel work