sysbench的框架实现介绍

sysbench是一个很是经典的综合性能测试工具，它支持CPU，IO，内存，尤为是数据库的性能测试。那它是怎么作到通用性的呢，总结一句话是大量运用了重载的方法。

sysbench整体架构
/* 某个测试用例的总体结构 */
typedef struct sb_test
{
  const char        *sname;
  const char        *lname;
  /* 下面有具体说明 */
  sb_operations_t   ops;
  sb_builtin_cmds_t builtin_cmds;
  sb_arg_t          *args;

  sb_list_item_t    listitem;
} sb_test_t;
/* 某个测试用例的具体操做实现结构 */
typedef struct
{
  sb_op_init            *init;            /* initialization function */
  sb_op_prepare         *prepare;         /* called after timers start,  but
                                             before thread execution */
  sb_op_thread_init     *thread_init;     /* thread initialization
                                             (called when each thread starts) */
  sb_op_print_mode      *print_mode;      /* print mode function */
  sb_op_next_event      *next_event;      /* event generation function */
  sb_op_execute_event   *execute_event;   /* event execution function */
  sb_op_report          *report_intermediate; /* intermediate reports handler */
  sb_op_report          *report_cumulative;   /* cumulative reports handler */
  sb_op_thread_run      *thread_run;      /* main thread loop */
  sb_op_thread_done     *thread_done;     /* thread finalize function */
  sb_op_cleanup         *cleanup;         /* called after exit from thread,
                                             but before timers stop */ 
  sb_op_done            *done;            /* finalize function */
} sb_operations_t;
/* 某个测试用例的三阶段实现结构 */
typedef struct
{
  sb_builtin_cmd_func_t *help;  /* print help */
  sb_builtin_cmd_func_t *prepare; /* prepare for the test */
  sb_builtin_cmd_func_t *run;   /* run the test */
  sb_builtin_cmd_func_t *cleanup; /* cleanup the test database, files, etc. */
} sb_builtin_cmds_t;
static sb_test_t cpu_test =
{
  .sname = "cpu", /*case简称*/
  .lname = "CPU performance test",/*case全称*/
  .ops = {
    .init = cpu_init, /* 初始化case */
    .print_mode = cpu_print_mode, /* case启动前，作说明 */
    .next_event = cpu_next_event, /* 拿到下一个event的数据 */
    .execute_event = cpu_execute_event, /* 具体执行这个event */
    .report_cumulative = cpu_report_cumulative,  /* 阶段性报告输出 */
    .done = cpu_done /* case结束后，处理干净 */
  },
  .args = cpu_args /*子case须要的参数说明*/
};复制代码

那sysbench的完整流程是怎样呢？黄色部分是测试用例须要实现的。

上面struct里面有个event概念，不一样的测试event的定义都不同：好比CPU的测试case，一个event是完成求得小于某数（默认10000）的全部质数。好比fileio的测试case，一次read或者一次write操做就是一个event。
sysbench的线程介绍

1. worker_thread具体实现是怎样呢：欣赏下sysbench.c里面某子线程是如何执行的，代码很是清晰易懂：

static int thread_run(sb_test_t *test, int thread_id)
{
  sb_event_t        event;
  int               rc = 0;

  while (sb_more_events(thread_id) && rc == 0)
  {
    event = test->ops.next_event(thread_id);
    if (event.type == SB_REQ_TYPE_NULL)
      break;

    sb_event_start(thread_id);

    rc = test->ops.execute_event(&event, thread_id);

    sb_event_stop(thread_id);
  }

  return rc;
}复制代码

1. intermediate_report线程：周期性输出性能数据，参数项为：--report-interval=N,对CPU的测试用例举例：sysbench cpu --report-interval=1,截取部分输出结果以下：

Threads started!

[ 1s ] thds: 1 eps: 922.10 lat (ms,95%): 1.08
[ 2s ] thds: 1 eps: 925.19 lat (ms,95%): 1.08
[ 3s ] thds: 1 eps: 926.00 lat (ms,95%): 1.08
[ 4s ] thds: 1 eps: 926.00 lat (ms,95%): 1.08
[ 5s ] thds: 1 eps: 926.00 lat (ms,95%): 1.08
[ 6s ] thds: 1 eps: 926.00 lat (ms,95%): 1.08
[ 7s ] thds: 1 eps: 925.00 lat (ms,95%): 1.08
[ 8s ] thds: 1 eps: 926.02 lat (ms,95%): 1.08
[ 9s ] thds: 1 eps: 925.99 lat (ms,95%): 1.08
[ 10s ] thds: 1 eps: 924.98 lat (ms,95%): 1.08复制代码

1. checkpoints_report线程：若是嫌周期性输出不够多，那么能够在某几个时间点总体输出，参数项为: --report-checkpoints=[LIST,...]

1. 仍是对CPU测试用例举例：sysbench cpu --report-checkpoints=3,8 run,截取部分输出结果以下：

Threads started!

[ 3s ] Checkpoint report:
CPU speed:
    events per second:   923.01

General statistics:
    total time:                          3.0001s
    total number of events:              2771

Latency (ms):
         min:                                  1.08
         avg:                                  1.08
         max:                                  1.22
         95th percentile:                      1.08
         sum:                               3000.88

Threads fairness:
    events (avg/stddev):           2773.0000/0.00
    execution time (avg/stddev):   3.0009/0.00

[ 8s ] Checkpoint report:
CPU speed:
    events per second:   924.47

General statistics:
    total time:                          8.0001s
    total number of events:              4622

Latency (ms):
         min:                                  1.08
         avg:                                  1.08
         max:                                  1.16
         95th percentile:                      1.08
         sum:                               4998.04

Threads fairness:
    events (avg/stddev):           4621.0000/0.00
    execution time (avg/stddev):   4.9980/0.00复制代码

1. tx_rate_controll线程，控制每秒输出量的一个线程：参数项为: --rate=N,默认是不作控制的。

1. 仍是拿CPU测试用例举例，控制每秒跑10个event：sysbench cpu run --rate=10,截取部分输出结果以下：

Running the test with following options:
Number of threads: 1
Target transaction rate: 10/sec
Initializing random number generator from current time

Prime numbers limit: 10000

Initializing worker threads...

Threads started!

CPU speed:
    events per second:     8.87 #没那么精准哈复制代码

1. 判断是否超时，默认是10秒

1. 判断是否到达最大event数，若是设置了的话

1. 就是速率控制。

sysbench是一个整体框架，它用来操做各个测性能的计算，那各个部门只须要作的一件事情是声明须要的实现。只要理解了这三个struct就能够了：

拿最简单的CPU性能计算举例，它须要实现的是：
看到这个后，把一个case须要作的事情描述很清楚了，从须要什么参数，到初始化，逐个event执行，函数定义很清晰。sysbench的其余case也都这样须要一个完整的结构说明，如io操做，则须要多一个case的prepare和cleandown声明。
至此，能够清晰地看到sysbench的框架仍是很是好理解。
每一秒输出一个结果，eps是每一秒的event数，lat单位是毫秒，95分位延迟数据是1.08
输出速率控制在哪里呢？眼尖的人立刻能够看到是在sb_more_events函数。那sb_more_events函数主要是作什么呢：

综上，大概介绍了sysbench框架的整体实现，关于数据库性能测试容下篇再介绍。