(十三)— redis-benchmark性能测试

最后更新于:2022-04-01 20:20:40

     今天讲的这个是用来给redis数据库做性能测试的,说到性能测试,感觉这必然是高大上的操作了,redis性能测试,测的到底是哪方面的性能,如何测试,通过什么指标反映此次测试的性能好坏呢,下面我通过源码给大家做一一解答。    redis做的性能测试时对立面的基本操作做的检测,比如Client客户端执行set,get,lpush等数据操作的性能,可以从他的测试程序可以看出: ~~~ if (test_is_selected("get")) { len = redisFormatCommand(&cmd,"GET key:__rand_int__"); benchmark("GET",cmd,len); free(cmd); } if (test_is_selected("incr")) { len = redisFormatCommand(&cmd,"INCR counter:__rand_int__"); benchmark("INCR",cmd,len); free(cmd); } if (test_is_selected("lpush")) { len = redisFormatCommand(&cmd,"LPUSH mylist %s",data); benchmark("LPUSH",cmd,len); free(cmd); } if (test_is_selected("lpop")) { len = redisFormatCommand(&cmd,"LPOP mylist"); benchmark("LPOP",cmd,len); free(cmd); } ~~~ 那么通过什么指标反映测试性能的好坏之分呢,在这里我们使用的就是延时性来判断,最简单的想法,就是在测试到额最开始,记录一个时间,中间执行测试操作,在操作结束在记录一个时间,中间的时间差就是执行的时间,时间越短说明性能越好。这也正是redis性能测试的做法。 ~~~ /* 对指定的CMD命令做性能测试 */ static void benchmark(char *title, char *cmd, int len) { client c; config.title = title; config.requests_issued = 0; config.requests_finished = 0; c = createClient(cmd,len,NULL); createMissingClients(c); config.start = mstime(); aeMain(config.el); //最后通过计算总延时,显示延时报告,体现性能测试的结果 config.totlatency = mstime()-config.start; showLatencyReport(); freeAllClients(); } ~~~ 因为这样的操作要求时间精度比较高,用秒做单位肯定不行了,所以这里用的是ms毫秒,在这里添加个知识点,在这里用到了时间相关的结构体,在Linux里也存在: ~~~ /* 介绍一下struct timeval结构体 struct timeval结构体在time.h中的定义为: struct timeval { __time_t tv_sec; // Seconds. __suseconds_t tv_usec; // Microseconds. (微秒) }; */ ~~~ 那么下面是最关键的问题了,如何测,测试肯定要通过一个模拟客户端,按照配置文件中的设置去测试,所以必须存在一个配置信息,然后我们通过我们想要的配置再去逐步测试,亮出config,配置信息: ~~~ /* config配置信息结构体,static静态变量,使得全局只有一个 */ static struct config { //消息事件 aeEventLoop *el; const char *hostip; int hostport; //据此判断是否是本地测试 const char *hostsocket; //Client总数量 int numclients; int liveclients; //请求的总数 int requests; int requests_issued; //请求完成的总数 int requests_finished; int keysize; int datasize; int randomkeys; int randomkeys_keyspacelen; int keepalive; int pipeline; long long start; long long totlatency; long long *latency; const char *title; //Client列表,这个在下面会经常提起 list *clients; int quiet; int csv; //判断是否loop循环处理 int loop; int idlemode; int dbnum; sds dbnumstr; char *tests; char *auth; } config; typedef struct _client { //redis上下文 redisContext *context; //此缓冲区将用于后面的读写handler sds obuf; //rand指针数组 char **randptr; /* Pointers to :rand: strings inside the command buf */ //randptr中指针个数 size_t randlen; /* Number of pointers in client->randptr */ //randptr中没有被使用的指针个数 size_t randfree; /* Number of unused pointers in client->randptr */ unsigned int written; /* Bytes of 'obuf' already written */ //请求的发起时间 long long start; /* Start time of a request */ //请求的延时 long long latency; /* Request latency */ //请求的等待个数 int pending; /* Number of pending requests (replies to consume) */ int selectlen; /* If non-zero, a SELECT of 'selectlen' bytes is currently used as a prefix of the pipline of commands. This gets discarded the first time it's sent. */ } *client; ~~~ 上面还附带了client的一些信息,这里的Client和之前的RedisClient还不是一个东西,也就是说,这里的Client会根据config结构体中的配置做相应的操作。client根据获得到命令无非2种操作,read和Write,所以在后面的事件处理中也是针对这2种事件的处理,这里给出read的方法: ~~~ /* 读事件的处理方法 */ static void readHandler(aeEventLoop *el, int fd, void *privdata, int mask) { client c = privdata; void *reply = NULL; REDIS_NOTUSED(el); REDIS_NOTUSED(fd); REDIS_NOTUSED(mask); /* Calculate latency only for the first read event. This means that the * server already sent the reply and we need to parse it. Parsing overhead * is not part of the latency, so calculate it only once, here. */ //计算延时,然后比较延时,取得第一个read 的event事件 if (c->latency < 0) c->latency = ustime()-(c->start); if (redisBufferRead(c->context) != REDIS_OK) { //首先判断能否读 fprintf(stderr,"Error: %s\n",c->context->errstr); exit(1); } else { while(c->pending) { if (redisGetReply(c->context,&reply) != REDIS_OK) { fprintf(stderr,"Error: %s\n",c->context->errstr); exit(1); } if (reply != NULL) { //获取reply回复,如果这里出错,也会直接退出 if (reply == (void*)REDIS_REPLY_ERROR) { fprintf(stderr,"Unexpected error reply, exiting...\n"); exit(1); } freeReplyObject(reply); if (c->selectlen) { size_t j; /* This is the OK from SELECT. Just discard the SELECT * from the buffer. */ //执行到这里,请求已经执行成功,等待的请求数减1 c->pending--; sdsrange(c->obuf,c->selectlen,-1); /* We also need to fix the pointers to the strings * we need to randomize. */ for (j = 0; j < c->randlen; j++) c->randptr[j] -= c->selectlen; c->selectlen = 0; continue; } if (config.requests_finished < config.requests) config.latency[config.requests_finished++] = c->latency; c->pending--; if (c->pending == 0) { //调用客户端done完成后的方法 clientDone(c); break; } } else { break; } } } } ~~~ 这个方法其实是一个回调方法,会作为参数传入另一个函数中,redis的函数式编程的思想又再次体现了,在这些操作都执行好了之后,会有个延时报告,针对各种操作的延时统计,这时我们就能知道,性能之间的比较了: ~~~ /* 输出请求延时 */ static void showLatencyReport(void) { int i, curlat = 0; float perc, reqpersec; reqpersec = (float)config.requests_finished/((float)config.totlatency/1000); if (!config.quiet && !config.csv) { printf("====== %s ======\n", config.title); printf(" %d requests completed in %.2f seconds\n", config.requests_finished, (float)config.totlatency/1000); printf(" %d parallel clients\n", config.numclients); printf(" %d bytes payload\n", config.datasize); printf(" keep alive: %d\n", config.keepalive); printf("\n"); //将请求按延时排序 qsort(config.latency,config.requests,sizeof(long long),compareLatency); for (i = 0; i < config.requests; i++) { if (config.latency[i]/1000 != curlat || i == (config.requests-1)) { curlat = config.latency[i]/1000; perc = ((float)(i+1)*100)/config.requests; printf("%.2f%% <= %d milliseconds\n", perc, curlat); } } printf("%.2f requests per second\n\n", reqpersec); } else if (config.csv) { printf("\"%s\",\"%.2f\"\n", config.title, reqpersec); } else { printf("%s: %.2f requests per second\n", config.title, reqpersec); } } ~~~ 当然你能更改配置文件,做你想做的性能测试,不过这里我想吐槽一点,这么多个if判断语句不是很好吧,换成switch也比这简洁啊: ~~~ /* Returns number of consumed options. */ /* 根据读入的参数,设置config配置文件 */ int parseOptions(int argc, const char **argv) { int i; int lastarg; int exit_status = 1; for (i = 1; i < argc; i++) { lastarg = (i == (argc-1)); //通过多重if判断,但个人感觉不够优美,稳定性略差 if (!strcmp(argv[i],"-c")) { if (lastarg) goto invalid; config.numclients = atoi(argv[++i]); } else if (!strcmp(argv[i],"-n")) { if (lastarg) goto invalid; config.requests = atoi(argv[++i]); } else if (!strcmp(argv[i],"-k")) { if (lastarg) goto invalid; config.keepalive = atoi(argv[++i]); } else if (!strcmp(argv[i],"-h")) { if (lastarg) goto invalid; config.hostip = strdup(argv[++i]); } else if (!strcmp(argv[i],"-p")) { if (lastarg) goto invalid; config.hostport = atoi(argv[++i]); } else if (!strcmp(argv[i],"-s")) { if (lastarg) goto invalid; config.hostsocket = strdup(argv[++i]); } else if (!strcmp(argv[i],"-a") ) { if (lastarg) goto invalid; config.auth = strdup(argv[++i]); } else if (!strcmp(argv[i],"-d")) { if (lastarg) goto invalid; config.datasize = atoi(argv[++i]); if (config.datasize < 1) config.datasize=1; if (config.datasize > 1024*1024*1024) config.datasize = 1024*1024*1024; } else if (!strcmp(argv[i],"-P")) { if (lastarg) goto invalid; config.pipeline = atoi(argv[++i]); //......省略 ~~~ redis的性能测试还能支持本地测试和指定Ip,端口测试,挺方便的。下面列出全部的API: ~~~ /* Prototypes */ /* 方法原型 */ static void createMissingClients(client c); /* 创建没有Command命令要求的clint */ static long long ustime(void) /* 返回当期时间的单位为微秒的格式 */ static long long mstime(void) /* 返回当期时间的单位为毫秒的格式 */ static void freeClient(client c) /* 释放Client */ static void freeAllClients(void) /* 释放所有的Client */ static void resetClient(client c) /* 重置Client */ static void randomizeClientKey(client c) /* 随机填充client里的randptr中的key值 */ static void clientDone(client c) /* Client完成后的调用方法 */ static void readHandler(aeEventLoop *el, int fd, void *privdata, int mask) /* 读事件的处理方法 */ static void writeHandler(aeEventLoop *el, int fd, void *privdata, int mask) /* 写事件方法处理 */ static client createClient(char *cmd, size_t len, client from) /* 创建一个基准的Client */ static int compareLatency(const void *a, const void *b) /* 比较延时 */ static void showLatencyReport(void) /* 输出请求延时 */ static void benchmark(char *title, char *cmd, int len) /* 对指定的CMD命令做性能测试 */ int parseOptions(int argc, const char **argv) /* 根据读入的参数,设置config配置文件 */ int showThroughput(struct aeEventLoop *eventLoop, long long id, void *clientData) /* 显示Request执行的速度,简称RPS */ int test_is_selected(char *name) /* 检测config中的命令是否被选中 */ ~~~
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