X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=doc%2Frrdcreate.1;fp=doc%2Frrdcreate.1;h=8809ca0cb9b8a642d52f2e2c8a7753510a259265;hb=3a03e55068747637db4480d4f3a8ab8ef26c50b1;hp=53fc8d98c073cdbf48cd0d603e26bdf77ab3ed10;hpb=8892808f3a79ec485e273390213ef3f16792eb54;p=pkg-rrdtool.git diff --git a/doc/rrdcreate.1 b/doc/rrdcreate.1 index 53fc8d9..8809ca0 100644 --- a/doc/rrdcreate.1 +++ b/doc/rrdcreate.1 @@ -129,7 +129,7 @@ .\" ======================================================================== .\" .IX Title "RRDCREATE 1" -.TH RRDCREATE 1 "2008-05-12" "1.3rc9" "rrdtool" +.TH RRDCREATE 1 "2008-06-11" "1.3.0" "rrdtool" .SH "NAME" rrdcreate \- Set up a new Round Robin Database .SH "SYNOPSIS" @@ -144,48 +144,47 @@ rrdcreate \- Set up a new Round Robin Database The create function of RRDtool lets you set up new Round Robin Database (\fB\s-1RRD\s0\fR) files. The file is created at its final, full size and filled with \fI*UNKNOWN*\fR data. -.IP "\fIfilename\fR" 8 -.IX Item "filename" +.Sh "\fIfilename\fP" +.IX Subsection "filename" The name of the \fB\s-1RRD\s0\fR you want to create. \fB\s-1RRD\s0\fR files should end with the extension \fI.rrd\fR. However, \fBRRDtool\fR will accept any filename. -.IP "\fB\-\-start\fR|\fB\-b\fR \fIstart time\fR (default: now \- 10s)" 8 -.IX Item "--start|-b start time (default: now - 10s)" +.Sh "\fB\-\-start\fP|\fB\-b\fP \fIstart time\fP (default: now \- 10s)" +.IX Subsection "--start|-b start time (default: now - 10s)" Specifies the time in seconds since 1970\-01\-01 \s-1UTC\s0 when the first value should be added to the \fB\s-1RRD\s0\fR. \fBRRDtool\fR will not accept any data timed before or at the time specified. -.Sp +.PP See also AT-STYLE \s-1TIME\s0 \s-1SPECIFICATION\s0 section in the \&\fIrrdfetch\fR documentation for other ways to specify time. -.IP "\fB\-\-step\fR|\fB\-s\fR \fIstep\fR (default: 300 seconds)" 8 -.IX Item "--step|-s step (default: 300 seconds)" +.Sh "\fB\-\-step\fP|\fB\-s\fP \fIstep\fP (default: 300 seconds)" +.IX Subsection "--step|-s step (default: 300 seconds)" Specifies the base interval in seconds with which data will be fed into the \fB\s-1RRD\s0\fR. -.IP "\fB\s-1DS:\s0\fR\fIds-name\fR\fB:\fR\fI\s-1DST\s0\fR\fB:\fR\fIdst arguments\fR" 8 -.IX Item "DS:ds-name:DST:dst arguments" +.Sh "\fB\s-1DS:\s0\fP\fIds-name\fP\fB:\fP\fI\s-1DST\s0\fP\fB:\fP\fIdst arguments\fP" +.IX Subsection "DS:ds-name:DST:dst arguments" A single \fB\s-1RRD\s0\fR can accept input from several data sources (\fB\s-1DS\s0\fR), for example incoming and outgoing traffic on a specific communication line. With the \fB\s-1DS\s0\fR configuration option you must define some basic properties of each data source you want to store in the \fB\s-1RRD\s0\fR. -.Sp +.PP \&\fIds-name\fR is the name you will use to reference this particular data source from an \fB\s-1RRD\s0\fR. A \fIds-name\fR must be 1 to 19 characters long in the characters [a\-zA\-Z0\-9_]. -.Sp +.PP \&\fI\s-1DST\s0\fR defines the Data Source Type. The remaining arguments of a data source entry depend on the data source type. For \s-1GAUGE\s0, \s-1COUNTER\s0, \&\s-1DERIVE\s0, and \s-1ABSOLUTE\s0 the format for a data source entry is: -.Sp +.PP \&\fB\s-1DS:\s0\fR\fIds-name\fR\fB:\fR\fI\s-1GAUGE\s0 | \s-1COUNTER\s0 | \s-1DERIVE\s0 | \s-1ABSOLUTE\s0\fR\fB:\fR\fIheartbeat\fR\fB:\fR\fImin\fR\fB:\fR\fImax\fR -.Sp +.PP For \s-1COMPUTE\s0 data sources, the format is: -.Sp +.PP \&\fB\s-1DS:\s0\fR\fIds-name\fR\fB:\fR\fI\s-1COMPUTE\s0\fR\fB:\fR\fIrpn-expression\fR -.Sp +.PP In order to decide which data source type to use, review the definitions that follow. Also consult the section on \*(L"\s-1HOW\s0 \s-1TO\s0 \s-1MEASURE\s0\*(R" for further insight. -.RS 8 .IP "\fB\s-1GAUGE\s0\fR" 4 .IX Item "GAUGE" is for things like temperatures or number of people in a room or the @@ -207,9 +206,9 @@ example, to measure the rate of people entering or leaving a room. Internally, derive works exactly like \s-1COUNTER\s0 but without overflow checks. So if your counter does not reset at 32 or 64 bit you might want to use \s-1DERIVE\s0 and combine it with a \s-1MIN\s0 value of 0. -.RS 4 -.IP "\s-1NOTE\s0 on \s-1COUNTER\s0 vs \s-1DERIVE\s0" 4 -.IX Item "NOTE on COUNTER vs DERIVE" +.Sp +\&\fB\s-1NOTE\s0 on \s-1COUNTER\s0 vs \s-1DERIVE\s0\fR +.Sp by Don Baarda .Sp If you cannot tolerate ever mistaking the occasional counter reset for a @@ -226,9 +225,6 @@ for high bandwidth interfaces and a 32bit counter, \s-1DERIVE\s0 with min=0 is probably preferable. If you are using a 64bit counter, just about any max setting will eliminate the possibility of mistaking a reset for a counter wrap. -.RE -.RS 4 -.RE .IP "\fB\s-1ABSOLUTE\s0\fR" 4 .IX Item "ABSOLUTE" is for counters which get reset upon reading. This is used for fast counters @@ -246,24 +242,22 @@ formula. Consolidation functions are then applied normally to the PDPs of the \s-1COMPUTE\s0 data source (that is the rpn-expression is only applied to generate PDPs). In database software, such data sets are referred to as \*(L"virtual\*(R" or \*(L"computed\*(R" columns. -.RE -.RS 8 -.Sp +.PP \&\fIheartbeat\fR defines the maximum number of seconds that may pass between two updates of this data source before the value of the data source is assumed to be \fI*UNKNOWN*\fR. -.Sp +.PP \&\fImin\fR and \fImax\fR define the expected range values for data supplied by a data source. If \fImin\fR and/or \fImax\fR any value outside the defined range will be regarded as \fI*UNKNOWN*\fR. If you do not know or care about min and max, set them to U for unknown. Note that min and max always refer to the processed values of the \s-1DS\s0. For a traffic\-\fB\s-1COUNTER\s0\fR type \s-1DS\s0 this would be the maximum and minimum data-rate expected from the device. -.Sp +.PP \&\fIIf information on minimal/maximal expected values is available, always set the min and/or max properties. This will help RRDtool in doing a simple sanity check on the data supplied when running update.\fR -.Sp +.PP \&\fIrpn-expression\fR defines the formula used to compute the PDPs of a \&\s-1COMPUTE\s0 data source from other data sources in the same <\s-1RRD\s0>. It is similar to defining a \fB\s-1CDEF\s0\fR argument for the graph command. Please @@ -274,22 +268,20 @@ the \s-1RPN\s0 expression, the \s-1COMPUTE\s0 data source may only refer to the names of data source listed previously in the create command. This is similar to the restriction that \fB\s-1CDEF\s0\fRs must refer only to \fB\s-1DEF\s0\fRs and \fB\s-1CDEF\s0\fRs previously defined in the same graph command. -.RE -.IP "\fB\s-1RRA:\s0\fR\fI\s-1CF\s0\fR\fB:\fR\fIcf arguments\fR" 8 -.IX Item "RRA:CF:cf arguments" +.Sh "\fB\s-1RRA:\s0\fP\fI\s-1CF\s0\fP\fB:\fP\fIcf arguments\fP" +.IX Subsection "RRA:CF:cf arguments" The purpose of an \fB\s-1RRD\s0\fR is to store data in the round robin archives (\fB\s-1RRA\s0\fR). An archive consists of a number of data values or statistics for each of the defined data-sources (\fB\s-1DS\s0\fR) and is defined with an \fB\s-1RRA\s0\fR line. -.Sp +.PP When data is entered into an \fB\s-1RRD\s0\fR, it is first fit into time slots of the length defined with the \fB\-s\fR option, thus becoming a \fIprimary data point\fR. -.Sp +.PP The data is also processed with the consolidation function (\fI\s-1CF\s0\fR) of the archive. There are several consolidation functions that consolidate primary data points via an aggregate function: \fB\s-1AVERAGE\s0\fR, \&\fB\s-1MIN\s0\fR, \fB\s-1MAX\s0\fR, \fB\s-1LAST\s0\fR. -.RS 8 .IP "\s-1AVERAGE\s0" 4 .IX Item "AVERAGE" the average of the data points is stored. @@ -302,29 +294,27 @@ the largest of the data points is stored. .IP "\s-1LAST\s0" 4 .IX Item "LAST" the last data points is used. -.RE -.RS 8 -.Sp +.PP Note that data aggregation inevitably leads to loss of precision and information. The trick is to pick the aggregate function such that the \&\fIinteresting\fR properties of your data is kept across the aggregation process. -.Sp +.PP The format of \fB\s-1RRA\s0\fR line for these consolidation functions is: -.Sp +.PP \&\fB\s-1RRA:\s0\fR\fI\s-1AVERAGE\s0 | \s-1MIN\s0 | \s-1MAX\s0 | \s-1LAST\s0\fR\fB:\fR\fIxff\fR\fB:\fR\fIsteps\fR\fB:\fR\fIrows\fR -.Sp +.PP \&\fIxff\fR The xfiles factor defines what part of a consolidation interval may be made up from \fI*UNKNOWN*\fR data while the consolidated value is still regarded as known. It is given as the ratio of allowed \fI*UNKNOWN*\fR PDPs to the number of PDPs in the interval. Thus, it ranges from 0 to 1 (exclusive). -.Sp +.PP \&\fIsteps\fR defines how many of these \fIprimary data points\fR are used to build a \fIconsolidated data point\fR which then goes into the archive. -.Sp +.PP \&\fIrows\fR defines how many generations of data values are kept in an \fB\s-1RRA\s0\fR. -.RE +Obviously, this has to be greater than zero. .SH "Aberrant Behavior Detection with Holt-Winters Forecasting" .IX Header "Aberrant Behavior Detection with Holt-Winters Forecasting" In addition to the aggregate functions, there are a set of specialized