# &adminguide;

## Overview

This module helps developers to benchmark their module functions. By adding this module's functions via the configuration file or through its API, &kamailio; can log profiling information for every function.

The duration between calls to bm_start_timer() and bm_log_timer() is stored and logged via &kamailio;'s logging facility. Please note that all durations are given as microseconds (do not confuse with milliseconds). Support for nanosecond precission can be enabled by compiling with librt (see the Makefile of the module).

Note: the measurement can be done only in the context of the same application process. It does not work to measure the duration of execution between actions before suspending the transaction in one process and after resuming the processing in another process (e.g., functions from async or http_async_client modules).

## Dependencies

### &kamailio; Modules

The following modules must be loaded before this module:

- No dependencies on other &kamailio; modules.

### External Libraries or Applications

The following libraries or applications must be installed before running &kamailio; with this module loaded:

- None.

## Parameters

### `enable` (int)

Even when the module is loaded, benchmarking is not enabled per default. This variable may have three different values:

- -1 - Globally disable benchmarking

- 0 - Enable per-timer enabling. Single timers are inactive by default and can be activated through the RPC interface as soon as that feature is implemented.

- 1 - Globally enable benchmarking

Default value is 0.

#### Set `enable` parameter

    ...
    modparam("benchmark", "enable", 1)
    ...

### `granularity` (int)

Logging normally is not done for every reference to the log_timer() function, but only every n'th call. n is defined through this variable. A sensible granularity seems to be 100.

Default value is 1.

#### Set `granularity` parameter

    ...
    modparam("benchmark", "granularity", 500)
    ...

### `loglevel` (int)

Set the log level for the benchmark logs. These levels should be used:

- -5 - L_ALERT

- -4 - L_BUG

- -3 - L_CRIT

- -2 - L_CRIT (no prefix)

- -1 - L_ERR

- 0 - L_WARN

- 1 - L_NOTICE

- 2 - L_INFO

- 3 - L_DBG

Default value is 3 (L_INFO).

#### Set `loglevel` parameter

    ...
    modparam("benchmark", "loglevel", 4)
    ...

This will set the logging level to L_DBG.

### `register` (str)

Register a timer id at startup. Required when using the start/log functions via Kemi framework. This parameter can be set many times to register several timer ids.

Default value is NONE.

#### Set `register` parameter

    ...
    modparam("benchmark", "register", "test")
    modparam("benchmark", "register", "auth")
    ...

## Functions

### `bm_start_timer(name)`

Start timer name. A later call to bm_log_timer() logs this timer..

#### `bm_start_timer` usage

    ...
    bm_start_timer("test");
    ...

### `bm_log_timer(name)`

This function logs the timer with the given ID. The following data are logged:

- Last msgs is the number of calls in the last logging interval. This equals the granularity variable.

- Last sum is the accumulated duration in the current logging interval (i.e. for the last granularity calls).

- Last min is the minimum duration between start/log_timer calls during the last interval.

- Last max - maximum duration.

- Last average is the average duration between bm_start_timer() and bm_log_timer() since the last logging.

- Global msgs number of calls to log_timer.

- Global sum total duration in microseconds.

- Global min... You get the point. :)

- Global max also obvious.

- Global avg possibly the most interesting value.

#### `bm_log_timer` usage

    ...
    bm_log_timer("test");
    ...

## Exported Variables

Exported pseudo-variables are listed in the next sections.

### $BM_time_diff

$BM_time_diff - the time difference elapsed between calls of bm_start_timer(name) and bm_log_timer(name). The value is 0 if no bm_log_timer() was called.

## RPC Commands

### `benchmark.enable_global`

Enables/disables the module. Parameter may be -1, 0 or 1. See description of "enable" parameter.

### `benchmark.enable_timer`

Enable or disable a single timer. The following example enables timer "test" (the second parameter must be 0 to disable):

#### Enabling a timer

    ...
    &kamctl; rpc benchmark.enable_timer test 1
    ...

### `benchmark.granularity`

Modifies the benchmarking granularity. See "granularity" variable.

### `benchmark.loglevel`

Modifies the module log level. See "loglevel" variable.

### `benchmark.timer_list`

List data for all timers (Last complete period and global data) Displays info close to the one output in the log by using a RPC structure. period_sum, period_min and period_media show data for last granularity period already completed.

#### List all timers

    ...
    &kamctl; rpc benchmark.timer_list
    {
    	name: test
    	state: enabled
    	id: 0
    	granularity: 2
    	period_sum: 69
    	period_min: 22
    	period_max: 47
    	period_media: 34.500000
    	calls: 4
    	sum: 217
    	global_min: 22
    	global_max: 88
    	global_media: 54.250000
    }
    {
    	name: test2
    	state: enabled
    	id: 1
    	granularity: 2
    	period_sum: 122
    	period_min: 25
    	period_max: 97
    	period_media: 61.000000
    	calls: 4
    	sum: 349
    	global_min: 25
    	global_max: 151
    	global_media: 87.250000
    }
    ...

### `benchmark.timer_name_list`

List data for one timer based on its name (Last complete period and global data) It displays info close to the one output in the log by using a RPC structure. period_sum, period_min and period_media show data for last granularity period already completed.

#### List one timer

    ...
    &kamctl; rpc benchmark.timer_name_list test
    {
    	name: test
    	state: enabled
    	id: 0
    	granularity: 2
    	period_sum: 69
    	period_min: 22
    	period_max: 47
    	period_media: 34.500000
    	calls: 4
    	sum: 217
    	global_min: 22
    	global_max: 88
    	global_media: 54.250000
    }
    ...

## Example of usage

Measure the duration of user location lookup.

### benchmark usage

    ...
    bm_start_timer("usrloc-lookup");
    lookup("location");
    bm_log_timer("usrloc-lookup");
    ...