通過(guò) Arthas Trace 命令將接口性能優(yōu)化十倍

    
    

     往期熱門文章：
    
    

    
    

     
     

    
    

    
    

     1、公司用了 3 年多的多賬號(hào)統(tǒng)一登錄方案，萬(wàn)能通用，穩(wěn)的一批！
    
    
    
    

     2、用了這些IDEA插件以后，我寫代碼快了10倍！
    
    
    
    

     3、字節(jié)一面：post 為什么會(huì)發(fā)送兩次請(qǐng)求？被問(wèn)懵了…
    
    
    
    

     4、編寫 if 時(shí)盡量不要帶 else
    
    
    
    

     5、為什么 MyBatis 源碼中，沒(méi)有我那種 if···else
    
    

來(lái)源：juejin.cn/post/7259320326898876477

背景

Helios 系統(tǒng)要處理的數(shù)據(jù)量比較大，尤其是查詢所有服務(wù)一天的評(píng)分?jǐn)?shù)據(jù)時(shí)要返回每日 1440 分鐘的所有應(yīng)用的評(píng)分，總計(jì)有幾十萬(wàn)個(gè)數(shù)據(jù)點(diǎn)，接口有時(shí)延遲會(huì)達(dá)到數(shù)秒。本文記錄如何利用 Arthas ，將接口從幾百幾千 ms，優(yōu)化到幾十 ms。

從鏈路上看，線上獲取一整天的數(shù)據(jù)時(shí)大概 300 多 ms，而查詢數(shù)據(jù)庫(kù)只有 11ms，說(shuō)明大部分時(shí)間都是程序組裝數(shù)據(jù)時(shí)消耗的，于是動(dòng)起了優(yōu)化代碼的念頭。

優(yōu)化過(guò)程

代碼業(yè)務(wù)可以不用去理解，最主要的是看利用trace優(yōu)化的過(guò)程

初始未優(yōu)化版本

代碼

   
   

    private HeliosGetScoreResponse queryScores(HeliosGetScoreRequest request) {
    
    
    HeliosGetScoreResponse response = new HeliosGetScoreResponse();
    
    

    
    
    List<HeliosScore> heliosScores = heliosService.queryScoresTimeBetween(request.getStartTime(), request.getEndTime(), request.getFilterByAppId());
    
    
    if (CollectionUtils.isEmpty(heliosScores)) {
    
    
        return response;
    
    
    }
    
    

    
    
    Set<String> dateSet = new HashSet<>();
    
    

    
    
    Map<String, List<HeliosScore>> groupByAppIdHeliosScores = heliosScores.stream().collect(Collectors.groupingBy(HeliosScore::getAppId));
    
    
    for (List<HeliosScore> value : groupByAppIdHeliosScores.values()) {
    
    
        value.sort(Comparator.comparing(HeliosScore::getTimeFrom));
    
    
        HeliosGetScoreResponse.Score score = new HeliosGetScoreResponse.Score();
    
    
        score.setNamespace(value.get(0).getNamespace());
    
    
        score.setAppId(value.get(0).getAppId());
    
    
        for (HeliosScore heliosScore : value) {
    
    
            List<HeliosScore> splitHeliosScores = heliosScore.split();
    
    
            for (HeliosScore splitHeliosScore : splitHeliosScores) {
    
    
                if (splitHeliosScore.getTimeFrom().compareTo(request.getStartTime()) < 0) {
    
    
                    continue;
    
    
                }
    
    
                if (splitHeliosScore.getTimeFrom().compareTo(request.getEndTime()) > 0) {
    
    
                    break;
    
    
                }
    
    
                dateSet.add(DateUtils.yyyyMMddHHmm.formatDate(splitHeliosScore.getTimeFrom()));
    
    
                if (splitHeliosScore.getScores() == null) {
    
    
                    splitHeliosScore.setScores("100");
    
    
                    log.error("查詢時(shí)發(fā)現(xiàn)數(shù)據(jù)缺失: {}", heliosScore);
    
    
                }
    
    
                score.add(Math.max(0, Integer.parseInt(splitHeliosScore.getScores())), null);
    
    
            }
    
    
        }
    
    
        response.getValues().add(score);
    
    
    }
    
    

    
    
    response.setDates(new ArrayList<>(dateSet).stream().sorted().collect(Collectors.toList()));
    
    
    return response;
    
    
}
    
    

   
   

Arthas Trace

   
   

    
    `---ts=2021-08-17 16:28:00;thread_name=http-nio-8080-exec-10;id=81;is_daemon=true;priority=5;TCCL=org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader@20864cd1
    
    
    `---[4046.398447ms] xxxService.controller.HeliosController:queryScores()
    
    
        +---[0.022259ms] xxxService.model.helios.HeliosGetScoreResponse:<init>() #147
    
    
        +---[0.007132ms] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #149
    
    
        +---[0.006985ms] xxxService.model.helios.HeliosGetScoreRequest:getEndTime() #149
    
    
        +---[0.008704ms] xxxService.model.helios.HeliosGetScoreRequest:getFilterByAppId() #149
    
    
        +---[19.284658ms] xxxService.service.HeliosService:queryScoresTimeBetween() #149
    
    
        +---[0.017468ms] org.apache.commons.collections.CollectionUtils:isEmpty() #150
    
    
        +---[0.008054ms] java.util.HashSet:<init>() #154
    
    
        +---[0.027591ms] java.util.List:stream() #156
    
    
        +---[0.044229ms] java.util.stream.Collectors:groupingBy() #156
    
    
        +---[0.155582ms] java.util.stream.Stream:collect() #156
    
    
        +---[0.018318ms] java.util.Map:values() #157
    
    
        +---[0.019199ms] java.util.Collection:iterator() #157
    
    
        +---[min=3.51E-4ms,max=0.014266ms,total=0.125003ms,count=123] java.util.Iterator:hasNext() #157
    
    
        +---[min=5.11E-4ms,max=0.010188ms,total=0.145693ms,count=122] java.util.Iterator:next() #157
    
    
        +---[min=4.89E-4ms,max=0.045356ms,total=0.321978ms,count=122] java.util.Comparator:comparing() #158
    
    
        +---[min=0.003637ms,max=0.033049ms,total=0.928795ms,count=122] java.util.List:sort() #158
    
    
        +---[min=5.94E-4ms,max=0.010442ms,total=0.1485ms,count=122] xxxService.model.helios.HeliosGetScoreResponse$Score:<init>() #159
    
    
        +---[min=4.5E-4ms,max=0.010857ms,total=0.12773ms,count=122] java.util.List:get() #160
    
    
        +---[min=5.01E-4ms,max=0.007849ms,total=0.123696ms,count=122] xxxService.helios.entity.HeliosScore:getNamespace() #160
    
    
        +---[min=6.5E-4ms,max=0.007324ms,total=0.135906ms,count=122] xxxService.model.helios.HeliosGetScoreResponse$Score:setNamespace() #160
    
    
        +---[min=3.72E-4ms,max=0.010288ms,total=0.086703ms,count=122] java.util.List:get() #161
    
    
        +---[min=5.1E-4ms,max=0.00627ms,total=0.103871ms,count=122] xxxService.helios.entity.HeliosScore:getAppId() #161
    
    
        +---[min=5.97E-4ms,max=0.006531ms,total=0.126184ms,count=122] xxxService.model.helios.HeliosGetScoreResponse$Score:setAppId() #161
    
    
        +---[min=4.45E-4ms,max=0.020198ms,total=0.138299ms,count=122] java.util.List:iterator() #162
    
    
        +---[min=3.42E-4ms,max=0.014615ms,total=0.256056ms,count=366] java.util.Iterator:hasNext() #162
    
    
        +---[min=3.59E-4ms,max=0.014974ms,total=0.174396ms,count=244] java.util.Iterator:next() #162
    
    
        +---[min=0.071035ms,max=0.148132ms,total=19.444179ms,count=244] xxxService.helios.entity.HeliosScore:split() #163
    
    
        +---[min=4.06E-4ms,max=0.022364ms,total=0.210152ms,count=244] java.util.List:iterator() #164
    
    
        +---[min=3.07E-4ms,max=0.199649ms,total=143.267893ms,count=351604] java.util.Iterator:hasNext() #164
    
    
        +---[min=3.25E-4ms,max=24.863976ms,total=177.15363ms,count=351360] java.util.Iterator:next() #164
    
    
        +---[min=3.93E-4ms,max=0.096771ms,total=176.843018ms,count=351360] xxxService.helios.entity.HeliosScore:getTimeFrom() #165
    
    
        +---[min=4.07E-4ms,max=18.772715ms,total=205.632183ms,count=351360] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #165
    
    
        +---[min=3.33E-4ms,max=0.045589ms,total=149.24486ms,count=351360] java.util.Date:compareTo() #165
    
    
        +---[min=3.93E-4ms,max=0.032972ms,total=86.466793ms,count=175680] xxxService.helios.entity.HeliosScore:getTimeFrom() #168
    
    
        +---[min=4.12E-4ms,max=0.061003ms,total=94.294061ms,count=175680] xxxService.model.helios.HeliosGetScoreRequest:getEndTime() #168
    
    
        +---[min=3.37E-4ms,max=0.038792ms,total=74.505056ms,count=175680] java.util.Date:compareTo() #168
    
    
        +---[min=3.97E-4ms,max=0.036548ms,total=87.693935ms,count=175680] xxxService.helios.entity.HeliosScore:getTimeFrom() #171
    
    
     1  +---[min=0.001952ms,max=0.068413ms,total=391.739063ms,count=175680] xxxService.utils.DateUtils$yyyyMMddHHmm:formatDate() #171
    
    
        +---[min=4.07E-4ms,max=0.037904ms,total=108.107714ms,count=175680] java.util.Set:add() #171
    
    
        +---[min=3.95E-4ms,max=0.031555ms,total=88.173857ms,count=175680] xxxService.helios.entity.HeliosScore:getScores() #172
    
    
        +---[min=3.88E-4ms,max=0.033584ms,total=84.689466ms,count=175680] xxxService.helios.entity.HeliosScore:getScores() #176
    
    
        +---[min=3.11E-4ms,max=0.038121ms,total=69.708752ms,count=175680] java.lang.Math:max() #176
    
    
        +---[min=4.66E-4ms,max=0.03391ms,total=104.476576ms,count=175680] xxxService.model.helios.HeliosGetScoreResponse$Score:add() #176
    
    
        +---[min=6.17E-4ms,max=0.01503ms,total=0.159826ms,count=122] xxxService.model.helios.HeliosGetScoreResponse:getValues() #179
    
    
        +---[min=6.44E-4ms,max=0.03742ms,total=0.21068ms,count=122] java.util.List:add() #179
    
    
        +---[0.108961ms] java.util.ArrayList:<init>() #182
    
    
        +---[0.017455ms] java.util.ArrayList:stream() #182
    
    
        +---[0.011099ms] java.util.stream.Stream:sorted() #182
    
    
        +---[0.013699ms] java.util.stream.Collectors:toList() #182
    
    
        +---[0.38178ms] java.util.stream.Stream:collect() #182
    
    
        `---[0.004627ms] xxxService.model.helios.HeliosGetScoreResponse:setDates() #182
    
    

   
   

分析

Arthas 顯示總共花了 4 秒，但實(shí)際上在鏈路上看大概是 350~450ms 左右。其他多出來(lái)的時(shí)間是 Arthas 每一次執(zhí)行統(tǒng)計(jì)的消耗，因?yàn)榉椒ɡ锏难h(huán)比較多。這也告訴我們，不要用 trace 去看循環(huán)很多的方法。會(huì)對(duì)性能有非常嚴(yán)重的影響。

可以看出整個(gè)函數(shù)有 3 個(gè)循環(huán)，第一層循環(huán)的數(shù)量為 appId 的數(shù)量約為 140，第二層是查出來(lái)的數(shù)據(jù)條數(shù)，一天的數(shù)據(jù)已經(jīng)歸并了所以這里應(yīng)該是 1，第三層是時(shí)間區(qū)間的分鐘數(shù)，一天的話就是 1440 個(gè)。

Trace 中可以看到消耗最多的是封裝的一個(gè) SimpleDateFormat.formatDate()。

第一次優(yōu)化

優(yōu)化方向

1. 遍歷每個(gè)時(shí)間點(diǎn)的思路改變，把合并過(guò)的大對(duì)象拆分成一個(gè)個(gè)小對(duì)象直接遍歷，改成先合并起來(lái)，通過(guò)時(shí)間點(diǎn)邏輯上遍歷。這樣會(huì)減少創(chuàng)建幾十萬(wàn)個(gè)對(duì)象。
2. 將時(shí)間點(diǎn)集合 Set<String> dateSet 改為 Set<Date>，這樣減少反復(fù) formatDate() 的開銷。
3. 優(yōu)化字符串轉(zhuǎn)數(shù)字的過(guò)程，減少 Integer.parseInt方法調(diào)用，改為用 Map<String, Integer> 提前創(chuàng)建出 0~100 的字符串?dāng)?shù)字字典。（后來(lái)經(jīng)過(guò) JMH 測(cè)試，還是 Integer.parseInt 最快）

代碼

private HeliosGetScoreResponse queryScores(HeliosGetScoreRequest request) { HeliosGetScoreResponse response = new HeliosGetScoreResponse();

   
   

    
    List<HeliosScore> heliosScoresRecord = heliosService.queryScoresTimeBetween(request.getStartTime(), request.getEndTime(), request.getFilterByAppId());
    
    
if (CollectionUtils.isEmpty(heliosScoresRecord)) {
    
    
    return response;
    
    
}
    
    

    
    
Set<Date> dateSet = new HashSet<>();
    
    

    
    
List<HeliosScore> heliosScores = HeliosDataMergeJob.mergeData(heliosScoresRecord);
    
    

    
    
Map<String, List<HeliosScore>> groupByAppIdHeliosScores = heliosScores.stream().collect(Collectors.groupingBy(HeliosScore::getAppId));
    
    

    
    
for (List<HeliosScore> scores : groupByAppIdHeliosScores.values()) {
    
    
    HeliosScore heliosScore = scores.get(0);
    
    
    HeliosGetScoreResponse.Score score = new HeliosGetScoreResponse.Score();
    
    
    score.setNamespace(heliosScore.getNamespace());
    
    
    score.setAppId(heliosScore.getAppId());
    
    
    score.setScores(new ArrayList<>());
    
    
    response.getValues().add(score);
    
    

    
    
    List<Integer> scoreIntList = HeliosHelper.splitScores(heliosScore);
    
    

    
    
    // 以 requestTime 為準(zhǔn)
    
    
    Calendar indexDate = DateUtils.roundDownMinute(request.getStartTime().getTime());
    
    
    int index = 0;
    
    
    // 如果 timeFrom < requestTime，則增加 timeFrom 到 requestTime
    
    
    while (indexDate.getTime().compareTo(heliosScore.getTimeFrom()) > 0) {
    
    
        heliosScore.getTimeFrom().setTime(heliosScore.getTimeFrom().getTime() + 60_000);
    
    
        index++;
    
    
    }
    
    

    
    
    while (indexDate.getTime().compareTo(request.getEndTime()) <= 0 && indexDate.getTime().compareTo(heliosScore.getTimeTo()) <= 0  && index < scoreIntList.size()) {
    
    
        Integer scoreInt = scoreIntList.get(index++);
    
    
        score.getScores().add(scoreInt);
    
    
        dateSet.add(indexDate.getTime());
    
    
        indexDate.add(Calendar.MINUTE, 1);
    
    
    }
    
    
}
    
    

    
    
    response.setDates(new ArrayList<>(dateSet).stream().sorted().map(DateUtils.yyyyMMddHHmm::formatDate).collect(Collectors.toList()));
    
    
    return response;
    
    
}
    
    

   
   

Arthas Trace

   
   

    
    ---ts=2021-08-17 14:44:11;thread_name=http-nio-8080-exec-10;id=ab;is_daemon=true;priority=5;TCCL=org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader@16ea0f22
    
    
    `---[6997.005629ms] xxxService.controller.HeliosController:queryScores()
    
    
        +---[0.020032ms] xxxService.model.helios.HeliosGetScoreResponse:<init>() #149
    
    
        +---[0.007451ms] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #151
    
    
        +---[min=0.001054ms,max=7.458198ms,total=213.19538ms,count=170754] xxxService.model.helios.HeliosGetScoreRequest:getEndTime() #57
    
    
        +---[0.007267ms] xxxService.model.helios.HeliosGetScoreRequest:getFilterByAppId() #57
    
    
        +---[15.255919ms] xxxService.service.HeliosService:queryScoresTimeBetween() #57
    
    
        +---[0.020045ms] org.apache.commons.collections.CollectionUtils:isEmpty() #152
    
    
        +---[0.015161ms] java.util.HashSet:<init>() #156
    
    
        +---[20.06713ms] xxxService.helios.jobs.HeliosDataMergeJob:mergeData() #158
    
    
        +---[0.043042ms] java.util.List:stream() #160
    
    
        +---[0.028232ms] java.util.stream.Collectors:groupingBy() #57
    
    
        +---[min=0.087087ms,max=1.931641ms,total=2.018728ms,count=2] java.util.stream.Stream:collect() #57
    
    
        +---[0.0151ms] java.util.Map:values() #162
    
    
        +---[0.019611ms] java.util.Collection:iterator() #57
    
    
        +---[min=7.55E-4ms,max=0.015165ms,total=0.201221ms,count=121] java.util.Iterator:hasNext() #57
    
    
        +---[min=0.001178ms,max=0.02477ms,total=0.220931ms,count=120] java.util.Iterator:next() #57
    
    
        +---[min=8.14E-4ms,max=0.01101ms,total=0.155044ms,count=120] java.util.List:get() #163
    
    
        +---[min=0.001049ms,max=0.009425ms,total=0.231297ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:<init>() #164
    
    
        +---[min=0.001167ms,max=0.009721ms,total=0.194502ms,count=120] xxxService.helios.entity.HeliosScore:getNamespace() #165
    
    
        +---[min=0.001222ms,max=0.020409ms,total=0.264791ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setNamespace() #57
    
    
        +---[min=0.001097ms,max=0.006475ms,total=0.169987ms,count=120] xxxService.helios.entity.HeliosScore:getAppId() #166
    
    
        +---[min=0.00121ms,max=0.007106ms,total=0.207877ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setAppId() #57
    
    
        +---[min=8.63E-4ms,max=0.008981ms,total=0.176195ms,count=120] java.util.ArrayList:<init>() #167
    
    
        +---[min=0.001225ms,max=0.021948ms,total=0.340375ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setScores() #57
    
    
        +---[min=0.00112ms,max=0.008984ms,total=0.196212ms,count=120] xxxService.model.helios.HeliosGetScoreResponse:getValues() #168
    
    
        +---[min=7.64E-4ms,max=0.027237ms,total=154.660479ms,count=170753] java.util.List:add() #57
    
    
        +---[min=0.028779ms,max=0.237608ms,total=20.049731ms,count=120] xxxService.helios.HeliosHelper:splitScores() #170
    
    
        +---[min=0.001178ms,max=0.008102ms,total=0.199087ms,count=120] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #173
    
    
        +---[min=6.89E-4ms,max=0.048069ms,total=140.74298ms,count=170040] java.util.Date:getTime() #57
    
    
        +---[min=0.004686ms,max=0.03805ms,total=0.775394ms,count=120] xxxService.utils.DateUtils:roundDownMinute() #57
    
    
        +---[min=7.84E-4ms,max=7.562581ms,total=162.855553ms,count=170040] java.util.Calendar:getTime() #176
    
    
      2 +---[min=9.94E-4ms,max=0.029962ms,total=385.371864ms,count=339960] xxxService.helios.entity.HeliosScore:getTimeFrom() #57
    
    
      1 +---[min=7.76E-4ms,max=7.936578ms,total=483.361269ms,count=511428] java.util.Date:compareTo() #57
    
    
        +---[min=9.95E-4ms,max=0.077109ms,total=192.749805ms,count=169920] xxxService.helios.entity.HeliosScore:getTimeFrom() #177
    
    
        +---[min=6.94E-4ms,max=7.358942ms,total=151.184751ms,count=169920] java.util.Date:setTime() #57
    
    
        +---[min=7.67E-4ms,max=0.029244ms,total=152.500401ms,count=170753] java.util.Calendar:getTime() #181
    
    
        +---[min=7.65E-4ms,max=0.016336ms,total=151.879643ms,count=170635] java.util.Calendar:getTime() #182
    
    
        +---[min=0.001011ms,max=0.028133ms,total=196.192946ms,count=170635] xxxService.helios.entity.HeliosScore:getTimeTo() #57
    
    
        +---[min=6.93E-4ms,max=0.836104ms,total=141.443001ms,count=170635] java.util.List:size() #57
    
    
        +---[min=7.63E-4ms,max=7.940119ms,total=162.285955ms,count=170633] java.util.List:get() #183
    
    
      3 +---[min=0.001068ms,max=0.973964ms,total=209.721ms,count=170633] xxxService.model.helios.HeliosGetScoreResponse$Score:getScores() #184
    
    
        +---[min=7.71E-4ms,max=0.028856ms,total=154.918574ms,count=170633] java.util.Calendar:getTime() #185
    
    
        +---[min=8.07E-4ms,max=8.030316ms,total=186.971072ms,count=170633] java.util.Set:add() #57
    
    
        +---[min=7.82E-4ms,max=0.034732ms,total=156.2645ms,count=170633] java.util.Calendar:add() #186
    
    
        +---[0.050615ms] java.util.ArrayList:<init>() #190
    
    
        +---[0.019114ms] java.util.ArrayList:stream() #57
    
    
        +---[0.029096ms] java.util.stream.Stream:sorted() #57
    
    
        +---[0.018823ms] java.util.stream.Stream:map() #57
    
    
        +---[0.009092ms] java.util.stream.Collectors:toList() #57
    
    
        `---[0.006768ms] xxxService.model.helios.HeliosGetScoreResponse:setDates() #57
    
    

   
   

分析

這一步實(shí)際上執(zhí)行時(shí)間優(yōu)化了 50ms 左右。

從 Trace 中看耗時(shí)時(shí)間最長(zhǎng)的是 Date 的 compareTo，也就是代碼中的 if (splitHeliosScore.getTimeFrom().compareTo(request.getStartTime()) < 0)

而比較意外的是從對(duì)象中 get 屬性居然也是有開銷的。

第二次優(yōu)化

優(yōu)化方向

結(jié)合上一次 Arthas Trace 的結(jié)果，在以下幾個(gè)方向進(jìn)行優(yōu)化：

1. 將 Date 對(duì)象的換成 long 型時(shí)間戳進(jìn)行比較
2. 將 Date 對(duì)象反復(fù) getTime、setTime，改為 long 型時(shí)間戳 += 60_000 實(shí)現(xiàn)，得到結(jié)果后只 setTime 一次。
3. 每次填充數(shù)據(jù)都往 Set<String> dateSet 放入數(shù)據(jù)，改為通過(guò)標(biāo)識(shí)判斷只放入一次。
4. 存放分?jǐn)?shù)的 ArrayList 在第一次循環(huán)之后，可以確認(rèn)大小，之后循環(huán)創(chuàng)建 ArrayList 時(shí)直接填入固定的大小，減少內(nèi)存創(chuàng)建。

代碼

   
   

    private HeliosGetScoreResponse queryScores(HeliosGetScoreRequest request) {
    
    
    HeliosGetScoreResponse response = new HeliosGetScoreResponse();
    
    

    
    
    List<HeliosScore> heliosScoresRecord = heliosService.queryScoresTimeBetween(request.getStartTime(), request.getEndTime(), request.getFilterByAppId());
    
    
    if (CollectionUtils.isEmpty(heliosScoresRecord)) {
    
    
        return response;
    
    
    }
    
    

    
    
    Set<Date> dateSet = new HashSet<>();
    
    
    boolean isDateSetInitial = false;
    
    
    int scoreSize = 16;
    
    

    
    
    List<HeliosScore> heliosScores = HeliosDataMergeJob.mergeData(heliosScoresRecord);
    
    

    
    
    Map<String, List<HeliosScore>> groupByAppIdHeliosScores = heliosScores.stream().collect(Collectors.groupingBy(HeliosScore::getAppId));
    
    

    
    
    for (List<HeliosScore> scores : groupByAppIdHeliosScores.values()) {
    
    
        HeliosScore heliosScore = scores.get(0);
    
    
        HeliosGetScoreResponse.Score score = new HeliosGetScoreResponse.Score();
    
    
        score.setNamespace(heliosScore.getNamespace());
    
    
        score.setAppId(heliosScore.getAppId());
    
    
        score.setScores(new ArrayList<>(scoreSize));
    
    
        response.getValues().add(score);
    
    

    
    
        List<Integer> scoreIntList = HeliosHelper.splitScores(heliosScore);
    
    

    
    
        // 以 requestTime 為準(zhǔn)
    
    
        long indexDateMills = request.getStartTime().getTime();
    
    
        int index = 0;
    
    
        // 如果 timeFrom < requestTime，則增加 timeFrom 到 requestTime
    
    
        long heliosScoreTimeFromMills = heliosScore.getTimeFrom().getTime();
    
    
        while (indexDateMills > heliosScoreTimeFromMills) {
    
    
            heliosScoreTimeFromMills += 60_000;
    
    
            index++;
    
    
        }
    
    
        heliosScore.getTimeFrom().setTime(heliosScoreTimeFromMills);
    
    

    
    
        long requestEndTimeMills = request.getEndTime().getTime();
    
    
        long heliosScoreTimeToMills = heliosScore.getTimeTo().getTime();
    
    
        // 循環(huán)條件為 (當(dāng)前時(shí)間 <= 請(qǐng)求最大時(shí)間) && (當(dāng)前時(shí)間 <= 數(shù)據(jù)最大時(shí)間) && (index < 數(shù)據(jù)條數(shù))
    
    
        while (indexDateMills <= requestEndTimeMills && indexDateMills <= heliosScoreTimeToMills && index < scoreIntList.size()) {
    
    
            score.getScores().add(scoreIntList.get(index++));
    
    
            if (!isDateSetInitial) {
    
    
                dateSet.add(new Date(indexDateMills));
    
    
            }
    
    
            indexDateMills += 60_000;
    
    
        }
    
    
        // 性能優(yōu)化，減少重復(fù)放入的次數(shù)
    
    
        isDateSetInitial = true;
    
    
        // 性能優(yōu)化，初始化足夠的 size 減少擴(kuò)容次數(shù)。 x1.1 為了萬(wàn)一數(shù)據(jù)數(shù)量不一致，留出一點(diǎn) buffer。
    
    
        scoreSize = (int) (score.getScores().size() * 1.1);
    
    
    }
    
    

    
    
    response.setDates(new ArrayList<>(dateSet).stream().sorted().map(DateUtils.yyyyMMddHHmm::formatDate).collect(Collectors.toList()));
    
    
    return response;
    
    
}
    
    

   
   

Arthas Trace

   
   

    
    `---ts=2021-08-17 15:20:41;thread_name=http-nio-8080-exec-7;id=aa;is_daemon=true;priority=5;TCCL=org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader@14be750c
    
    
    `---[1411.395123ms] xxxService.controller.HeliosController:queryScores()
    
    
        +---[0.016102ms] xxxService.model.helios.HeliosGetScoreResponse:<init>() #149
    
    
        +---[0.019084ms] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #151
    
    
        +---[0.007879ms] xxxService.model.helios.HeliosGetScoreRequest:getEndTime() #57
    
    
        +---[0.006808ms] xxxService.model.helios.HeliosGetScoreRequest:getFilterByAppId() #57
    
    
        +---[27.494178ms] xxxService.service.HeliosService:queryScoresTimeBetween() #57
    
    
        +---[0.02087ms] org.apache.commons.collections.CollectionUtils:isEmpty() #152
    
    
        +---[0.007694ms] java.util.HashSet:<init>() #156
    
    
        +---[19.990512ms] xxxService.helios.jobs.HeliosDataMergeJob:mergeData() #160
    
    
        +---[0.044161ms] java.util.List:stream() #162
    
    
        +---[0.025737ms] java.util.stream.Collectors:groupingBy() #57
    
    
        +---[min=0.079651ms,max=2.007048ms,total=2.086699ms,count=2] java.util.stream.Stream:collect() #57
    
    
        +---[0.018405ms] java.util.Map:values() #164
    
    
        +---[0.021408ms] java.util.Collection:iterator() #57
    
    
        +---[min=7.4E-4ms,max=0.015625ms,total=0.177657ms,count=121] java.util.Iterator:hasNext() #57
    
    
        +---[min=0.001193ms,max=0.026712ms,total=0.258491ms,count=120] java.util.Iterator:next() #57
    
    
        +---[min=7.69E-4ms,max=0.011855ms,total=0.158671ms,count=120] java.util.List:get() #165
    
    
        +---[min=0.001045ms,max=0.019788ms,total=0.232004ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:<init>() #166
    
    
        +---[min=0.001072ms,max=0.007958ms,total=0.193652ms,count=120] xxxService.helios.entity.HeliosScore:getNamespace() #167
    
    
        +---[min=0.001164ms,max=0.007796ms,total=0.201584ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setNamespace() #57
    
    
        +---[min=0.001048ms,max=0.007456ms,total=0.178323ms,count=120] xxxService.helios.entity.HeliosScore:getAppId() #168
    
    
        +---[min=0.001137ms,max=0.010225ms,total=0.201887ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setAppId() #57
    
    
        +---[min=0.001627ms,max=0.010431ms,total=0.291395ms,count=120] java.util.ArrayList:<init>() #169
    
    
        +---[min=0.00116ms,max=0.0088ms,total=0.20171ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setScores() #57
    
    
        +---[min=0.001076ms,max=0.010293ms,total=0.199407ms,count=120] xxxService.model.helios.HeliosGetScoreResponse:getValues() #170
    
    
        +---[min=7.54E-4ms,max=0.086952ms,total=150.86682ms,count=170753] java.util.List:add() #57
    
    
        +---[min=0.020428ms,max=0.269554ms,total=19.477128ms,count=120] xxxService.helios.HeliosHelper:splitScores() #172
    
    
        +---[min=0.001092ms,max=0.005258ms,total=0.202045ms,count=120] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #175
    
    
        +---[min=7.09E-4ms,max=0.021027ms,total=0.630747ms,count=480] java.util.Date:getTime() #57
    
    
        +---[min=0.00106ms,max=0.015055ms,total=0.188439ms,count=120] xxxService.helios.entity.HeliosScore:getTimeFrom() #178
    
    
        +---[min=0.001025ms,max=0.009712ms,total=0.171506ms,count=120] xxxService.helios.entity.HeliosScore:getTimeFrom() #183
    
    
        +---[min=7.4E-4ms,max=0.092253ms,total=0.251068ms,count=120] java.util.Date:setTime() #57
    
    
        +---[min=0.001086ms,max=0.006234ms,total=0.184256ms,count=120] xxxService.model.helios.HeliosGetScoreRequest:getEndTime() #185
    
    
        +---[min=0.001036ms,max=0.012332ms,total=0.176491ms,count=120] xxxService.helios.entity.HeliosScore:getTimeTo() #186
    
    
      3 +---[min=6.73E-4ms,max=0.066785ms,total=135.009239ms,count=170635] java.util.List:size() #188
    
    
      1 +---[min=0.001085ms,max=0.089243ms,total=208.003309ms,count=170633] xxxService.model.helios.HeliosGetScoreResponse$Score:getScores() #189
    
    
      2 +---[min=7.31E-4ms,max=0.070823ms,total=145.488732ms,count=170633] java.util.List:get() #57
    
    
        +---[min=0.001177ms,max=0.143546ms,total=2.319379ms,count=1440] java.util.Date:<init>() #191
    
    
        +---[min=0.001346ms,max=0.064411ms,total=2.839878ms,count=1440] java.util.Set:add() #57
    
    
        +---[min=0.001096ms,max=0.009059ms,total=0.190336ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:getScores() #198
    
    
        +---[min=6.92E-4ms,max=0.016223ms,total=0.141751ms,count=120] java.util.List:size() #57
    
    
        +---[0.069753ms] java.util.ArrayList:<init>() #201
    
    
        +---[0.021066ms] java.util.ArrayList:stream() #57
    
    
        +---[0.029498ms] java.util.stream.Stream:sorted() #57
    
    
        +---[0.014089ms] java.util.stream.Stream:map() #57
    
    
        +---[0.013053ms] java.util.stream.Collectors:toList() #57
    
    
        `---[0.009818ms] xxxService.model.helios.HeliosGetScoreResponse:setDates() #57
    
    

   
   

分析

這一步將執(zhí)行時(shí)間又優(yōu)化了 80ms 左右?，F(xiàn)在還剩是 160ms 了。

從 Trace 中看耗時(shí)時(shí)間最長(zhǎng)的是三個(gè)方法：

• getScores。直接 get 了屬性啥也沒(méi)干，但是積少成多
• list.size()
• list.get(index)

也就是說(shuō)雖然這幾個(gè)函數(shù)里也沒(méi)干什么東西，但是函數(shù)調(diào)用、指針尋址本身也是有開銷的。

第三次優(yōu)化

優(yōu)化方向

1. 減少 list 屬性的調(diào)用
2. 一次次 list.add 方法改成 subList 一次性放入

也就是說(shuō)循環(huán)中不做任何耗時(shí)操作，不做任何指針/引用。

代碼

private HeliosGetScoreResponse queryScores(HeliosGetScoreRequest request) { HeliosGetScoreResponse response = new HeliosGetScoreResponse();

   
   

    
    List<HeliosScore> heliosScoresRecord = heliosService.queryScoresTimeBetween(request.getStartTime(), request.getEndTime(), request.getFilterByAppId());
    
    
if (CollectionUtils.isEmpty(heliosScoresRecord)) {
    
    
    return response;
    
    
}
    
    

    
    
Set<Date> dateSet = new HashSet<>();
    
    
boolean isDateSetInitial = false;
    
    
int scoreSize = 16;
    
    

    
    
List<HeliosScore> heliosScores = HeliosDataMergeJob.mergeData(heliosScoresRecord);
    
    

    
    
Map<String, List<HeliosScore>> groupByAppIdHeliosScores = heliosScores.stream().collect(Collectors.groupingBy(HeliosScore::getAppId));
    
    

    
    
for (List<HeliosScore> scores : groupByAppIdHeliosScores.values()) {
    
    
    HeliosScore heliosScore = scores.get(0);
    
    
    HeliosGetScoreResponse.Score score = new HeliosGetScoreResponse.Score();
    
    
    score.setNamespace(heliosScore.getNamespace());
    
    
    score.setAppId(heliosScore.getAppId());
    
    
    score.setScores(new ArrayList<>(scoreSize));
    
    
    response.getValues().add(score);
    
    

    
    
    List<Integer> scoreIntList = HeliosHelper.splitScores(heliosScore);
    
    

    
    
    // 以 requestTime 為準(zhǔn)
    
    
    long indexDateMills = request.getStartTime().getTime();
    
    
    int index = 0;
    
    
    // 如果 timeFrom < requestTime，則增加 timeFrom 到 requestTime
    
    
    long heliosScoreTimeFromMills = heliosScore.getTimeFrom().getTime();
    
    
    while (indexDateMills > heliosScoreTimeFromMills) {
    
    
        heliosScoreTimeFromMills += 60_000;
    
    
        index++;
    
    
    }
    
    
    heliosScore.getTimeFrom().setTime(heliosScoreTimeFromMills);
    
    

    
    
    long requestEndTimeMills = request.getEndTime().getTime();
    
    
    long heliosScoreTimeToMills = heliosScore.getTimeTo().getTime();
    
    

    
    
    // 循環(huán)條件為 (當(dāng)前時(shí)間 <= 請(qǐng)求最大時(shí)間) && (當(dāng)前時(shí)間 <= 數(shù)據(jù)最大時(shí)間) && (index < 數(shù)據(jù)條數(shù))
    
    
    int scoreIntListSize = scoreIntList.size();
    
    
    int indexStart = index;
    
    
    while (indexDateMills <= requestEndTimeMills && indexDateMills <= heliosScoreTimeToMills && index++ < scoreIntListSize) {
    
    
        if (!isDateSetInitial) {
    
    
            dateSet.add(new Date(indexDateMills));
    
    
        }
    
    
        indexDateMills += 60_000;
    
    
    }
    
    
    score.getScores().addAll(scoreIntList.subList(indexStart, index - 1));
    
    
    // 性能優(yōu)化，減少重復(fù)放入的次數(shù)
    
    
    isDateSetInitial = true;
    
    
    // 性能優(yōu)化，初始化足夠的 size 減少擴(kuò)容次數(shù)。 x1.1 為了萬(wàn)一數(shù)據(jù)數(shù)量不一致，留出一點(diǎn) buffer。
    
    
    scoreSize = (int) (score.getScores().size() * 1.1);
    
    
}
    
    

    
    
response.setDates(new ArrayList<>(dateSet).stream().sorted().map(DateUtils.yyyyMMddHHmm::formatDate).collect(Collectors.toList()));
    
    
return response;
    
    
}
    
    

   
   

Arthas Trace

   
   

    
    `---ts=2021-08-17 15:33:40;thread_name=http-nio-8080-exec-11;id=f1;is_daemon=true;priority=5;TCCL=org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader@d1c5cf2
    
    
    `---[138.624811ms] xxxService.controller.HeliosController:queryScores()
    
    
        +---[0.021852ms] xxxService.model.helios.HeliosGetScoreResponse:<init>() #149
    
    
        +---[0.00746ms] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #151
    
    
        +---[0.005838ms] xxxService.model.helios.HeliosGetScoreRequest:getEndTime() #57
    
    
        +---[0.006341ms] xxxService.model.helios.HeliosGetScoreRequest:getFilterByAppId() #57
    
    
    2   +---[15.227453ms] xxxService.service.HeliosService:queryScoresTimeBetween() #57
    
    
        +---[0.02168ms] org.apache.commons.collections.CollectionUtils:isEmpty() #152
    
    
        +---[0.008923ms] java.util.HashSet:<init>() #156
    
    
    1   +---[22.703926ms] xxxService.helios.jobs.HeliosDataMergeJob:mergeData() #160
    
    
        +---[0.047118ms] java.util.List:stream() #162
    
    
        +---[0.043183ms] java.util.stream.Collectors:groupingBy() #57
    
    
        +---[min=0.095654ms,max=2.183288ms,total=2.278942ms,count=2] java.util.stream.Stream:collect() #57
    
    
        +---[0.022906ms] java.util.Map:values() #164
    
    
        +---[0.025777ms] java.util.Collection:iterator() #57
    
    
        +---[min=9.28E-4ms,max=0.017187ms,total=0.261862ms,count=121] java.util.Iterator:hasNext() #57
    
    
        +---[min=9.88E-4ms,max=0.018901ms,total=0.280889ms,count=120] java.util.Iterator:next() #57
    
    
        +---[min=9.65E-4ms,max=0.014741ms,total=0.262695ms,count=120] java.util.List:get() #165
    
    
        +---[min=0.001215ms,max=0.013928ms,total=0.347762ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:<init>() #166
    
    
        +---[min=0.001253ms,max=0.010855ms,total=0.328842ms,count=120] xxxService.helios.entity.HeliosScore:getNamespace() #167
    
    
        +---[min=0.001316ms,max=0.014714ms,total=0.372553ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setNamespace() #57
    
    
        +---[min=0.001211ms,max=0.010511ms,total=0.322723ms,count=120] xxxService.helios.entity.HeliosScore:getAppId() #168
    
    
        +---[min=0.00132ms,max=0.010201ms,total=0.334627ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setAppId() #57
    
    
        +---[min=0.00116ms,max=0.014504ms,total=0.386879ms,count=120] java.util.ArrayList:<init>() #169
    
    
        +---[min=0.00131ms,max=0.014072ms,total=0.344922ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setScores() #57
    
    
        +---[min=0.001261ms,max=0.017312ms,total=0.356444ms,count=120] xxxService.model.helios.HeliosGetScoreResponse:getValues() #170
    
    
        +---[min=9.73E-4ms,max=0.016531ms,total=0.275794ms,count=120] java.util.List:add() #57
    
    
     3  +---[min=0.023208ms,max=19.808819ms,total=47.196601ms,count=120] xxxService.helios.HeliosHelper:splitScores() #172
    
    
        +---[min=0.001289ms,max=0.009578ms,total=0.36878ms,count=120] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #175
    
    
        +---[min=8.85E-4ms,max=0.016405ms,total=0.994157ms,count=480] java.util.Date:getTime() #57
    
    
        +---[min=0.001238ms,max=0.016801ms,total=0.34399ms,count=120] xxxService.helios.entity.HeliosScore:getTimeFrom() #178
    
    
        +---[min=0.001217ms,max=0.008931ms,total=0.316197ms,count=120] xxxService.helios.entity.HeliosScore:getTimeFrom() #183
    
    
        +---[min=9.14E-4ms,max=0.015929ms,total=0.277078ms,count=120] java.util.Date:setTime() #57
    
    
        +---[min=0.001238ms,max=0.01061ms,total=0.3375ms,count=120] xxxService.model.helios.HeliosGetScoreRequest:getEndTime() #185
    
    
        +---[min=0.001225ms,max=0.018059ms,total=0.315198ms,count=120] xxxService.helios.entity.HeliosScore:getTimeTo() #186
    
    
        +---[min=8.79E-4ms,max=0.022669ms,total=0.272356ms,count=120] java.util.List:size() #189
    
    
        +---[min=0.002001ms,max=0.056977ms,total=4.32853ms,count=1440] java.util.Date:<init>() #193
    
    
        +---[min=0.002174ms,max=0.040594ms,total=4.594415ms,count=1440] java.util.Set:add() #57
    
    
        +---[min=0.001302ms,max=0.012925ms,total=0.353165ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:getScores() #197
    
    
        +---[min=0.001004ms,max=0.033424ms,total=0.338294ms,count=120] java.util.List:subList() #57
    
    
        +---[min=0.004871ms,max=0.051046ms,total=2.945263ms,count=120] java.util.List:addAll() #57
    
    
        +---[min=0.001291ms,max=0.009831ms,total=0.314292ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:getScores() #201
    
    
        +---[min=8.84E-4ms,max=0.018168ms,total=0.249321ms,count=120] java.util.List:size() #57
    
    
        +---[0.054305ms] java.util.ArrayList:<init>() #204
    
    
        +---[0.024481ms] java.util.ArrayList:stream() #57
    
    
        +---[0.028717ms] java.util.stream.Stream:sorted() #57
    
    
        +---[0.013725ms] java.util.stream.Stream:map() #57
    
    
        +---[0.0128ms] java.util.stream.Collectors:toList() #57
    
    
        `---[0.007166ms] xxxService.model.helios.HeliosGetScoreResponse:setDates() #57
    
    

   
   

分析

這一步又優(yōu)化了 100ms 左右，現(xiàn)在還剩 60ms。

現(xiàn)在從 trace 上看耗時(shí)操作只有三個(gè)了：

• 查數(shù)據(jù)庫(kù)
• 合并數(shù)據(jù)
• 拆分得分字符串 "100,100,100" 為 int 數(shù)組 [100,100,100]

第四次優(yōu)化

優(yōu)化方向

1. 查數(shù)據(jù)庫(kù)發(fā)現(xiàn)由于 SQL 判斷不準(zhǔn)確，每次會(huì)多查出來(lái)一條數(shù)據(jù)，在后邊循環(huán)的時(shí)候會(huì)多循環(huán)一倍
2. 合并數(shù)據(jù)時(shí)發(fā)現(xiàn)可以針對(duì)單條數(shù)據(jù)的情況直接過(guò)濾，減少開銷。

代碼

1. 改了 SQL 并驗(yàn)證，減少查詢出來(lái)的數(shù)據(jù)量
2. 單條數(shù)據(jù)時(shí)不再處理合并邏輯

Arthas Trace

   
   

    
    ---ts=2021-08-17 16:03:24;thread_name=http-nio-8080-exec-13;id=f1;is_daemon=true;priority=5;TCCL=org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader@69e2fe3b
    
    
    `---[38.171379ms] xxxService.controller.HeliosController:queryScores()
    
    
        +---[0.009463ms] xxxService.model.helios.HeliosGetScoreResponse:<init>() #149
    
    
        +---[0.00348ms] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #151
    
    
        +---[0.003233ms] xxxService.model.helios.HeliosGetScoreRequest:getEndTime() #57
    
    
        +---[0.003395ms] xxxService.model.helios.HeliosGetScoreRequest:getFilterByAppId() #57
    
    
     1  +---[10.157226ms] xxxService.service.HeliosService:queryScoresTimeBetween() #57
    
    
        +---[0.009989ms] org.apache.commons.collections.CollectionUtils:isEmpty() #152
    
    
        +---[0.003394ms] java.util.HashSet:<init>() #156
    
    
        +---[0.083535ms] xxxService.helios.jobs.HeliosDataMergeJob:mergeData() #160
    
    
        +---[0.017819ms] java.util.List:stream() #162
    
    
        +---[0.011787ms] java.util.stream.Collectors:groupingBy() #57
    
    
        +---[min=0.047561ms,max=2.02786ms,total=2.075421ms,count=2] java.util.stream.Stream:collect() #57
    
    
        +---[0.015525ms] java.util.Map:values() #164
    
    
        +---[0.021965ms] java.util.Collection:iterator() #57
    
    
        +---[min=7.25E-4ms,max=0.009733ms,total=0.115783ms,count=121] java.util.Iterator:hasNext() #57
    
    
        +---[min=8.43E-4ms,max=0.011422ms,total=0.142771ms,count=120] java.util.Iterator:next() #57
    
    
        +---[min=7.81E-4ms,max=0.010883ms,total=0.128809ms,count=120] java.util.List:get() #165
    
    
        +---[min=0.001023ms,max=0.004301ms,total=0.150165ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:<init>() #166
    
    
        +---[min=0.001066ms,max=0.004648ms,total=0.154698ms,count=120] xxxService.helios.entity.HeliosScore:getNamespace() #167
    
    
        +---[min=0.001137ms,max=0.005607ms,total=0.170279ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setNamespace() #57
    
    
        +---[min=0.001023ms,max=0.004292ms,total=0.151767ms,count=120] xxxService.helios.entity.HeliosScore:getAppId() #168
    
    
        +---[min=0.001105ms,max=0.004701ms,total=0.164955ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setAppId() #57
    
    
        +---[min=0.001359ms,max=0.007931ms,total=0.233665ms,count=120] java.util.ArrayList:<init>() #169
    
    
        +---[min=0.001117ms,max=0.00785ms,total=0.168539ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:setScores() #57
    
    
        +---[min=0.001073ms,max=0.004488ms,total=0.156654ms,count=120] xxxService.model.helios.HeliosGetScoreResponse:getValues() #170
    
    
        +---[min=7.98E-4ms,max=0.00977ms,total=0.125818ms,count=120] java.util.List:add() #57
    
    
        +---[min=0.022304ms,max=0.12093ms,total=8.88628ms,count=120] xxxService.helios.HeliosHelper:splitScores() #172
    
    
        +---[min=0.001092ms,max=0.004967ms,total=0.161288ms,count=120] xxxService.model.helios.HeliosGetScoreRequest:getStartTime() #175
    
    
        +---[min=7.02E-4ms,max=0.012136ms,total=0.467786ms,count=480] java.util.Date:getTime() #57
    
    
        +---[min=0.001022ms,max=0.004944ms,total=0.151353ms,count=120] xxxService.helios.entity.HeliosScore:getTimeFrom() #178
    
    
        +---[min=0.001018ms,max=0.004731ms,total=0.148025ms,count=120] xxxService.helios.entity.HeliosScore:getTimeFrom() #183
    
    
        +---[min=7.3E-4ms,max=0.009359ms,total=0.120588ms,count=120] java.util.Date:setTime() #57
    
    
        +---[min=0.00107ms,max=0.008948ms,total=0.162848ms,count=120] xxxService.model.helios.HeliosGetScoreRequest:getEndTime() #185
    
    
        +---[min=0.001034ms,max=0.014003ms,total=0.158614ms,count=120] xxxService.helios.entity.HeliosScore:getTimeTo() #186
    
    
        +---[min=6.99E-4ms,max=0.009995ms,total=0.11179ms,count=120] java.util.List:size() #189
    
    
        +---[min=6.95E-4ms,max=0.005468ms,total=1.116308ms,count=1440] java.util.Date:<init>() #193
    
    
        +---[min=7.79E-4ms,max=0.029909ms,total=1.407528ms,count=1440] java.util.Set:add() #57
    
    
        +---[min=0.001097ms,max=0.008616ms,total=0.160597ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:getScores() #197
    
    
        +---[min=8.23E-4ms,max=0.0294ms,total=0.153353ms,count=120] java.util.List:subList() #57
    
    
        +---[min=0.005771ms,max=0.04465ms,total=1.992151ms,count=120] java.util.List:addAll() #57
    
    
        +---[min=0.001098ms,max=0.007013ms,total=0.169555ms,count=120] xxxService.model.helios.HeliosGetScoreResponse$Score:getScores() #201
    
    
        +---[min=7.04E-4ms,max=0.01315ms,total=0.120998ms,count=120] java.util.List:size() #57
    
    
        +---[0.197732ms] java.util.ArrayList:<init>() #204
    
    
        +---[0.018589ms] java.util.ArrayList:stream() #57
    
    
        +---[0.025192ms] java.util.stream.Stream:sorted() #57
    
    
        +---[0.012544ms] java.util.stream.Stream:map() #57
    
    
        +---[0.012188ms] java.util.stream.Collectors:toList() #57
    
    
        `---[0.0067ms] xxxService.model.helios.HeliosGetScoreResponse:setDates() #57
    
    

   
   

分析

可以看到現(xiàn)在最大耗時(shí)的地方終于是數(shù)據(jù)庫(kù)查詢了?，F(xiàn)在查詢一整天的數(shù)據(jù)，也只需要 25~40ms 左右。

結(jié)果

鏈路上看程序代碼還是要處理個(gè)十幾 ms，主要是字符串轉(zhuǎn) int[] 時(shí)的開銷，這一步可以再想辦法繼續(xù)優(yōu)化。

結(jié)論

從這次優(yōu)化我們可以得到一些結(jié)論：

1. 盡量少創(chuàng)建對(duì)象
2. SimpleDateFormat的開銷很大
3. Date.compare 的開銷不低
4. 哪怕最簡(jiǎn)單的操作如 list.size() list.add次數(shù)多了開銷也很可觀
5. 對(duì)于性能分析和優(yōu)化一定要有合適工具，才能得出有用的結(jié)論并針對(duì)性優(yōu)化。一開始我以為減少對(duì)象創(chuàng)建就萬(wàn)事大吉，但實(shí)際上性能消耗的大頭并不在這里。還是得借助 Arthas 的 Trace 才能真正針對(duì)性地優(yōu)化

   
   

    往期熱門文章：
   
   

    
    

     1、微軟全力擁抱 Java ！
    
    
    
    

     
     2、巧用 Redis，實(shí)現(xiàn)微博 Feed 流功能！
    
    

    
    

     3、知乎高贊：為什么別選計(jì)算機(jī)專業(yè)？
    
    
   
   

    4、Guava騷操作，10分鐘搞定日志脫敏需求！
   
   
   
   

    5、公司棄用 Nginx，選擇這款工具！
   
   
   
   

    6、項(xiàng)目自從用了接口請(qǐng)求合并，效率直接加倍！
   
   
   
   

    7、記一次CPU飆升問(wèn)題排查
   
   
   
   

    8、聊聊企業(yè)級(jí)消息推送的架構(gòu)設(shè)計(jì)
   
   
   
   

    9、new ArrayList 不當(dāng)導(dǎo)致 CPU 飆升。。
   
   
   
   

    10、假如Linus在中國(guó)···