X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=doc%2Frrdgraph_data.txt;h=2563b31021508905ca5410526e20efdf5b35b4c3;hb=23a63bef251017be5fd4f09db2be10575e3df59e;hp=23fd3160d541110acf19c4b81aa7653eba8265dd;hpb=ecfac614b914cef110a81ac665997a9b186da500;p=pkg-rrdtool.git diff --git a/doc/rrdgraph_data.txt b/doc/rrdgraph_data.txt index 23fd316..2563b31 100644 --- a/doc/rrdgraph_data.txt +++ b/doc/rrdgraph_data.txt @@ -6,8 +6,7 @@ NNAAMMEE rrdgraph_data - preparing data for graphing in rrdtool graph SSYYNNOOPPSSIISS - DDEEFF::_<_v_n_a_m_e_>=_<_r_r_d_f_i_l_e_>:_<_d_s_- - _n_a_m_e_>:_<_C_F_>[:step=_<_s_t_e_p_>][:start=_<_t_i_m_e_>][:end=_<_t_i_m_e_>][:reduce=_<_CC_FF_>] + DDEEFF::_<_v_n_a_m_e_>=_<_r_r_d_f_i_l_e_>:_<_d_s_-_n_a_m_e_>:_<_C_F_>[:step=_<_s_t_e_p_>][:start=_<_t_i_m_e_>][:end=_<_t_i_m_e_>][:reduce=_<_CC_FF_>] VVDDEEFF:_v_n_a_m_e=_R_P_N _e_x_p_r_e_s_s_i_o_n @@ -15,32 +14,31 @@ SSYYNNOOPPSSIISS DDEESSCCRRIIPPTTIIOONN These three instructions extract data values out of the RRRRDD files, - optionally altering them (think, for example, of a bytes to bits con- - version). If so desired, you can also define variables containing use- - ful information such as maximum, minimum etcetera. Two of the instruc- - tions use a language called RRPPNN which is described in its own manual - page. + optionally altering them (think, for example, of a bytes to bits + conversion). If so desired, you can also define variables containing + useful information such as maximum, minimum etcetera. Two of the + instructions use a language called RRPPNN which is described in its own + manual page. - Variable names (_v_n_a_m_e) must be made up strings of the following charac- - ters "A-Z, a-z, 0-9, -,_" and a maximum length of 255 characters. + Variable names (_v_n_a_m_e) must be made up strings of the following + characters "A-Z, a-z, 0-9, -,_" and a maximum length of 255 characters. When picking variable names, make sure you do not choose a name that is - already taken by an RPN operator. A save bet it to use lowercase or - mixedcase names for variables since operators will always be in upper- - case. + already taken by an RPN operator. A safe bet it to use lowercase or + mixed case names for variables since operators will always be in + uppercase. DDEEFF - DDEEFF::_<_v_n_a_m_e_>=_<_r_r_d_f_i_l_e_>:_<_d_s_- - _n_a_m_e_>:_<_C_F_>[:step=_<_s_t_e_p_>][:start=_<_t_i_m_e_>][:end=_<_t_i_m_e_>][:reduce=_<_CC_FF_>] + DDEEFF::_<_v_n_a_m_e_>=_<_r_r_d_f_i_l_e_>:_<_d_s_-_n_a_m_e_>:_<_C_F_>[:step=_<_s_t_e_p_>][:start=_<_t_i_m_e_>][:end=_<_t_i_m_e_>][:reduce=_<_CC_FF_>] This command fetches data from an RRRRDD file. The virtual name _v_n_a_m_e can then be used throughout the rest of the script. By default, an RRRRAA - which contains the correct consolidated data at an appropriate resolu- - tion will be chosen. The resolution can be overridden with the --step - option. The resolution can again be overridden by specifying the sstteepp - ssiizzee. The time span of this data is the same as for the graph by - default, you can override this by specifying ssttaarrtt aanndd eenndd. Remember - to escape colons in the time specification! + which contains the correct consolidated data at an appropriate + resolution will be chosen. The resolution can be overridden with the + --step option. The resolution can again be overridden by specifying + the sstteepp ssiizzee. The time span of this data is the same as for the graph + by default, you can override this by specifying ssttaarrtt aanndd eenndd. + Remember to escape colons in the time specification! If the resolution of the data is higher than the resolution of the graph, the data will be further consolidated. This may result in a @@ -52,8 +50,8 @@ DDEEFF end-8days8hours"). If consolidation needs to be done, the CCFF of the RRRRAA specified in the - DDEEFF itself will be used to reduce the data density. This behaviour can - be changed using ":reduce=". This optional parameter specifies the + DDEEFF itself will be used to reduce the data density. This behavior can + be changed using ":reduce=__". This optional parameter specifies the CCFF to use during the data reduction phase. Example: @@ -66,29 +64,54 @@ DDEEFF VVDDEEFF VVDDEEFF:_v_n_a_m_e=_R_P_N _e_x_p_r_e_s_s_i_o_n - This command returns a value and/or a time according to the RRPPNN state- - ments used. The resulting _v_n_a_m_e will, depending on the functions used, - have a value and a time component. When you use this _v_n_a_m_e in another - RRPPNN expression, you are effectively inserting its value just as if you - had put a number at that place. The variable can also be used in the - various graph and print elements. + This command returns a value and/or a time according to the RRPPNN + statements used. The resulting _v_n_a_m_e will, depending on the functions + used, have a value and a time component. When you use this _v_n_a_m_e in + another RRPPNN expression, you are effectively inserting its value just as + if you had put a number at that place. The variable can also be used + in the various graph and print elements. Example: "VDEF:avg=mydata,AVERAGE" - Note that currently only agregation functions work in VDEF rpn expres- - sions. Patches to change this are welcome. + Note that currently only aggregation functions work in VDEF rpn + expressions. Patches to change this are welcome. CCDDEEFF CCDDEEFF:_v_n_a_m_e=_R_P_N _e_x_p_r_e_s_s_i_o_n This command creates a new set of data points (in memory only, not in - the RRRRDD file) out of one or more other data series. The RRPPNN instruc- - tions are used to evaluate a mathematical function on each data point. - The resulting _v_n_a_m_e can then be used further on in the script, just as - if it were generated by a DDEEFF instruction. + the RRRRDD file) out of one or more other data series. The RRPPNN + instructions are used to evaluate a mathematical function on each data + point. The resulting _v_n_a_m_e can then be used further on in the script, + just as if it were generated by a DDEEFF instruction. Example: "CDEF:mydatabits=mydata,8,*" +AAbboouutt CCDDEEFF vveerrssuuss VVDDEEFF + At some point in processing, RRRRDDttooooll has gathered an array of rates + ready to display. + + CCDDEEFF works on such an array. For example, _C_D_E_F_:_n_e_w_=_d_s_0_,_8_,_* would + multiply each of the array members by eight (probably transforming + bytes into bits). The result is an array containing the new values. + + VVDDEEFF also works on such an array but in a different way. For example, + _V_D_E_F_:_m_a_x_=_d_s_0_,_M_A_X_I_M_U_M would scan each of the array members and store the + maximum value. + + WWhheenn ddoo yyoouu uussee VVDDEEFF vveerrssuuss CCDDEEFF?? + Use CCDDEEFF to transform your data prior to graphing. In the above + example, we'd use a CCDDEEFF to transform bytes to bits before graphing the + bits. + + You use a VVDDEEFF if you want _m_a_x_(_1_,_5_,_3_,_2_,_4_) to return five which would be + displayed in the graph's legend (to answer, what was the maximum value + during the graph period). + + If you want to apply 'complex' operations to the result of a VDEF you + have to use a CDEF again since VDEFs only look like RPN expressions, + they aren't really. + SSEEEE AALLSSOO rrdgraph gives an overview of how rrrrddttooooll ggrraapphh works. rrdgraph_data describes DDEEFF,CCDDEEFF and VVDDEEFF in detail. rrdgraph_rpn describes the RRPPNN @@ -100,8 +123,9 @@ SSEEEE AALLSSOO AAUUTTHHOORR Program by Tobias Oetiker - This manual page by Alex van den Bogaerdt + This manual page by Alex van den Bogaerdt with + corrections and/or additions by several people -1.2.26 2007-11-20 RRDGRAPH_DATA(1) +1.4.7 2009-10-14 RRDGRAPH_DATA(1)