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IPA_CONV(8)            DragonFly System Manager's Manual           IPA_CONV(8)

NAME

ipa_conv -- IPA accounting/database module for converting statistics

DESCRIPTION

ipa_conv is an IPA accounting/database module with the following features: - The module is designed for converting statistics; - Statistics is converted according to custom plans, several plans can be used at the same time; - Each plan can have converting rules for months, days, week days and time ranges; - Statistics of one static rule can be converted and sent to another static rule. The name of the accounting system and the name of the database is conv.

DESIGN OVERVIEW

ipa_conv consists of one accounting module and one database module, but these two modules are implemented in one object file. This file must be loaded two times in the ipa.conf(5) configuration file, one time using the ac_mod parameter and second time using the db_mod parameter. Actually only a single copy of an object file is brought into the address space of ipa(8) and the module checks this at the time of initialization. An arbitrary static rule can use this module as a database (in this case this rule is called ``source rule'') and/or as an accounting system (in this case this rule is called ``destination rule''). Each source rule is the source of statistics for some one destination rule. Each source rule has a converting plan for converting statistics for corresponding destination rule. One destination rule can receive converted statistics from several source rules. When the database part of the module gets statistics for the source rule it converts this statistics according to the converting plan and sends converted statistics to the destination rule. The destination rule receives converted statistics from the accounting part of the module. In other words, the module works like a pipe between two rules, it converts statistics from one rule and sends converted statistics to another rule. A converting plan consists of time intervals with information how to convert original statistics. This information contains two numbers, the first number X is the amount of original statistics and the second number Y is the amount of corresponding converted statistics: full X units of the original statistics are converted to Y units (X > 0 and Y >= 0). By default the module scales X and Y values to the minimum possible values, but this feature can be disabled. There are several formats of time intervals (given below). The database part of the module always chooses the most specific time interval. The most specific time interval is chosen when the database part of the module gets updated statistics for some source rule. If the value of statistics was s1 at t1 time and the value of statistics is s2 at t2 time for some source rule and there were not database updates between t1 and t2 of this rule, then the time interval is chosen for t2 time and the difference (s2 - s1) is converted and sent to the destination rule (this difference can be negative). Too long time intervals between database updates can cause inaccurate converting of statistics. Usually a source rule should be written above the corresponding destination rule in the configuration file and it is better to tell ipa(8) to not change internally their order (use the keep_rules_order parameter). If a source rule is processed first and the corresponding destination rule is processed second at the same time, then the destination rule will receive converted statistics from a source rule immediately. Otherwise it will receive converted statistics during next database update time. This module works with increasing statistics and decreasing statistics. But since a database module receives only non-negative statistics, then this module cannot handle correctly situation when statistics of some rule became negative (in this case the module's database part receives zero statistics from ipa(8)). If this statistics becomes positive again, then the module will work as expected.

CONFIGURATION FILE FORMAT

One part of the configuration for the module is integrated into ipa.conf(5), other parts of the configuration are kept in files with converting plans. The configuration prefix of this module is ``conv''. The conv:scale parameter specifies whether the module should scale values in all loaded converting plans: conv:scale = <boolean>; This parameter should not be placed in any section and should be used before conv:load parameters. The default value of this parameter is ``yes'' and the module scales values in all plans. The conv:load parameter loads a file with converting plan and gives a local name to loaded plan: conv:load = <plan-name> "/path/file"; This parameter should not be placed in any section and it should be used before conv:plan parameters. The given file is loaded and parsed when the module parses this parameter. The conv:dest parameter specifies the destination rule name, the conv:plan parameter specifies the converting plan for this rule: conv:dest = <rule-name>; conv:plan = <plan-name>; These two parameters can be placed in the rule section. The module checks whether the given destination rule exists at the end of configuration file parsing. If a destination rule is inactive, then it does not received converted statistics. The conv:quiet parameter allows to make the module less or more verbose: conv:quiet = <value>; This parameter should not be placed in any section. The default value of this parameter is 3. If its value has 0x1 bit off, then the module sends a warning message when ipa(8) deinitializes some destination rule and this rule still have some converted statistics. If its value has 0x2 bit off, then the module sends a warning message when ipa(8) deinitializes some source rule and this rule still have some not converted original statistics. The conv:debug parameter helps to debug the module: conv:debug = <level>; This parameter should not be placed in any section. Only two values are allowed for the debug level: 0 and 1. The default value of this parameter is 0 and debugging is disabled.

CONVERTING PLAN FORMAT

A file with converting plan consists of lines. Each line should have not more than 255 characters. Each line can have a shell-like comment that starts with the '#' character. Empty lines or lines with only comments are ignored. A converting plan for one time interval should be written in one line containing three fields. The first field is a time interval, the second field is the amount of original statistics and the third field is the amount of corresponding converted statistics. These fields are separated by space or tab characters. A time interval can be given in different formats, but time intervals of one format should not overlap. Here is the list of time interval formats (time intervals types are checked exactly in the same order when the most specific time interval is being searched): o year.mon.day/h1:m1-h2:m2 specifies time interval for year, month and day. o year.mon.day specifies year, month and day. o mon.day/h1:m1-h2:m2 specifies time interval for month and day. o mon.day specifies month and day. o mon specifies a month. o X/h1:m1-h2:m2 specifies time interval for a week day. Valid values for X are: `S' Sunday, `M' Monday, `T' Tuesday, `W' Wednesday, `H' Thursday, `F' Friday, `A' Saturday. o X specifies a week day o h1:m1-h2:m2 specifies time interval. o `*' specifies the default settings and must exist in any plan. A month can be given as the first three characters of English language month name. A day starts at 00:00 and ends at 24:00. Example: There is one rule r1 that gets statistics from some accounting system. It is necessary to get only 50% of that statistics at night from 00:00 till 07:00 and statistics should not be changed at other time. Let's create a file with converting plan /etc/ipa/plan/night: # Interval Original Converted * 1 1 # 100% 00:00-07:00 2 1 # 50% (night) Let's create ipa.conf, rule r2 will get converted statistics from rule r1: /* ... */ ac_mod "ipa_conv.so"; db_mod "ipa_conv.so"; conv:load = night "/etc/ipa/plan/night"; rule r1 { /* ... */ db_list = conv; conv:dest = r2; conv:plan = night; } rule r2 { /* ... */ ac_list = conv; } Rule r1 can use several databases, rule r2 can use databases and another accounting systems. The accounting system used by rule r1 is not shown in this example.

AUTHOR

Andrey Simonenko <simon@comsys.ntu-kpi.kiev.ua>

BUGS

If you find any, please send email me. July 22, 2009 IPA_CONV(8)

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