X-Git-Url: https://git.tokkee.org/?p=pkg-rrdtool.git;a=blobdiff_plain;f=doc%2Frrdtool.txt;h=f6115a798adbd7a4d9a5c37ebfbec89c1dc8983e;hp=113857ef4b10f51d817969067f5796c51a911bbe;hb=645054bac6187b0e83fd4125fd59e4feda216b64;hpb=ffa00ac697dccce18dca8880ca7a14066521ac5c diff --git a/doc/rrdtool.txt b/doc/rrdtool.txt index 113857e..f6115a7 100644 --- a/doc/rrdtool.txt +++ b/doc/rrdtool.txt @@ -9,17 +9,16 @@ SSYYNNOOPPSSIISS rrrrddttooooll -- [workdir]| _f_u_n_c_t_i_o_n DDEESSCCRRIIPPTTIIOONN - OOVVEERRVVIIEEWW - + OOVVEERRVVIIEEWW It is pretty easy to gather status information from all sorts of things, ranging from the temperature in your office to the number of octets which have passed through the FDDI interface of your router. But it is not so trivial to store this data in an efficient and systematic - manner. This is where RRRRDDttooooll comes in handy. It lets you _l_o_g _a_n_d _a_n_a_- - _l_y_z_e the data you gather from all kinds of data-sources (DDSS). The data - analysis part of RRDtool is based on the ability to quickly generate - graphical representations of the data values collected over a definable - time period. + manner. This is where RRRRDDttooooll comes in handy. It lets you _l_o_g _a_n_d + _a_n_a_l_y_z_e the data you gather from all kinds of data-sources (DDSS). The + data analysis part of RRDtool is based on the ability to quickly + generate graphical representations of the data values collected over a + definable time period. In this man page you will find general information on the design and functionality of the Round Robin Database Tool (RRDtool). For a more @@ -29,8 +28,7 @@ DDEESSCCRRIIPPTTIIOONN For an introduction to the usage of RRDtool make sure you consult the rrdtutorial. - FFUUNNCCTTIIOONNSS - + FFUUNNCCTTIIOONNSS While the man pages talk of command line switches you have to set in order to make RRRRDDttooooll work it is important to note that RRRRDDttooooll can be remotely controlled through a set of pipes. This saves a considerable @@ -56,9 +54,9 @@ DDEESSCCRRIIPPTTIIOONN rreessttoorree Restore an RRD in XML format to a binary RRD. Check rrdrestore - ffeettcchh Get data for a certain time period from a RRD. The graph func- - tion uses fetch to retrieve its data from an RRD. Check rrd- - fetch. + ffeettcchh Get data for a certain time period from a RRD. The graph + function uses fetch to retrieve its data from an RRD. Check + rrdfetch. ttuunnee Alter setup of an RRD. Check rrdtune. @@ -79,9 +77,7 @@ DDEESSCCRRIIPPTTIIOONN rrrrddccggii This is a standalone tool for producing RRD graphs on the fly. Check rrdcgi. - HHOOWW DDOOEESS RRRRDDTTOOOOLL WWOORRKK?? - - + HHOOWW DDOOEESS RRRRDDTTOOOOLL WWOORRKK?? Data Acquisition When monitoring the state of a system, it is convenient to have the data available at a constant time interval. Unfortunately, @@ -97,17 +93,18 @@ DDEESSCCRRIIPPTTIIOONN You may log data at a 1 minute interval, but you might also be interested to know the development of the data over the last year. You could do this by simply storing the data in 1 minute - intervals for the whole year. While this would take consider- - able disk space it would also take a lot of time to analyze the - data when you wanted to create a graph covering the whole year. - RRRRDDttooooll offers a solution to this problem through its data con- - solidation feature. When setting up an Round Robin Database - (RRRRDD), you can define at which interval this consolidation - should occur, and what consolidation function (CCFF) (average, - minimum, maximum, total, last) should be used to build the con- - solidated values (see rrdcreate). You can define any number of - different consolidation setups within one RRRRDD. They will all be - maintained on the fly when new data is loaded into the RRRRDD. + intervals for the whole year. While this would take + considerable disk space it would also take a lot of time to + analyze the data when you wanted to create a graph covering the + whole year. RRRRDDttooooll offers a solution to this problem through + its data consolidation feature. When setting up an Round Robin + Database (RRRRDD), you can define at which interval this + consolidation should occur, and what consolidation function + (CCFF) (average, minimum, maximum, total, last) should be used to + build the consolidated values (see rrdcreate). You can define + any number of different consolidation setups within one RRRRDD. + They will all be maintained on the fly when new data is loaded + into the RRRRDD. Round Robin Archives Data values of the same consolidation setup are stored into @@ -118,14 +115,14 @@ DDEESSCCRRIIPPTTIIOONN It works like this: If you want to store 1'000 values in 5 minute interval, RRRRDDttooooll will allocate space for 1'000 data values and a header area. In the header it will store a pointer - telling which slots (value) in the storage area was last writ- - ten to. New values are written to the Round Robin Archive in, - you guessed it, a round robin manner. This automatically limits - the history to the last 1'000 values (in our example). Because - you can define several RRRRAAs within a single RRRRDD, you can setup - another one, for storing 750 data values at a 2 hour interval, - for example, and thus keep a log for the last two months at a - lower resolution. + telling which slots (value) in the storage area was last + written to. New values are written to the Round Robin Archive + in, you guessed it, a round robin manner. This automatically + limits the history to the last 1'000 values (in our example). + Because you can define several RRRRAAs within a single RRRRDD, you + can setup another one, for storing 750 data values at a 2 hour + interval, for example, and thus keep a log for the last two + months at a lower resolution. The use of RRRRAAs guarantees that the RRRRDD does not grow over time and that old data is automatically eliminated. By using the @@ -140,11 +137,11 @@ DDEESSCCRRIIPPTTIIOONN time, etc. Unknown Data - As mentioned earlier, the RRRRDD stores data at a constant inter- - val. Sometimes it may happen that no new data is available when - a value has to be written to the RRRRDD. Data acquisition may not - be possible for one reason or other. With RRRRDDttooooll you can han- - dle these situations by storing an _*_U_N_K_N_O_W_N_* value into the + As mentioned earlier, the RRRRDD stores data at a constant + interval. Sometimes it may happen that no new data is available + when a value has to be written to the RRRRDD. Data acquisition may + not be possible for one reason or other. With RRRRDDttooooll you can + handle these situations by storing an _*_U_N_K_N_O_W_N_* value into the database. The value '_*_U_N_K_N_O_W_N_*' is supported through all the functions of the tool. When consolidating a data set, the amount of _*_U_N_K_N_O_W_N_* data values is accounted for and when a new @@ -155,27 +152,27 @@ DDEESSCCRRIIPPTTIIOONN to the RRRRAA. Graphing - RRRRDDttooooll allows you to generate reports in numerical and graphi- - cal form based on the data stored in one or several RRRRDDs. The - graphing feature is fully configurable. Size, color and con- - tents of the graph can be defined freely. Check rrdgraph for + RRRRDDttooooll allows you to generate reports in numerical and + graphical form based on the data stored in one or several RRRRDDs. + The graphing feature is fully configurable. Size, color and + contents of the graph can be defined freely. Check rrdgraph for more information on this. Aberrant Behavior Detection by Jake Brutlag - RRRRDDttooooll provides the building blocks for near real-time aber- - rant behavior detection. These components include: + RRRRDDttooooll provides the building blocks for near real-time + aberrant behavior detection. These components include: - * An algorithm for predicting the value of a time series one + · An algorithm for predicting the value of a time series one time step into the future. - * A measure of deviation between predicted and observed val- - ues. + · A measure of deviation between predicted and observed + values. - * A mechanism to decide if and when an observed value or - sequence of observed values is _t_o_o _d_e_v_i_a_n_t from the pre- - dicted value(s). + · A mechanism to decide if and when an observed value or + sequence of observed values is _t_o_o _d_e_v_i_a_n_t from the + predicted value(s). Here is a brief explanation of these components: @@ -188,22 +185,22 @@ DDEESSCCRRIIPPTTIIOONN time point in the period (cycle). After a value is observed, each of these components is updated via exponential smoothing. This means that the algorithm "learns" from past values and - uses them to predict the future. The rate of adaptation is gov- - erned by 3 parameters, alpha (intercept), beta (slope), and + uses them to predict the future. The rate of adaptation is + governed by 3 parameters, alpha (intercept), beta (slope), and gamma (seasonal). The prediction can also be viewed as a smoothed value for the time series. - The measure of deviation is a seasonal weighted absolute devia- - tion. The term _s_e_a_s_o_n_a_l means deviation is measured separately - for each time point in the seasonal cycle. As with Holt-Winters - forecasting, deviation is predicted using the measure computed - from past values (but only at that point in the seasonal - cycle). After the value is observed, the algorithm learns from - the observed value via exponential smoothing. Confidence bands - for the observed time series are generated by scaling the - sequence of predicted deviation values (we usually think of the - sequence as a continuous line rather than a set of discrete - points). + The measure of deviation is a seasonal weighted absolute + deviation. The term _s_e_a_s_o_n_a_l means deviation is measured + separately for each time point in the seasonal cycle. As with + Holt-Winters forecasting, deviation is predicted using the + measure computed from past values (but only at that point in + the seasonal cycle). After the value is observed, the algorithm + learns from the observed value via exponential smoothing. + Confidence bands for the observed time series are generated by + scaling the sequence of predicted deviation values (we usually + think of the sequence as a continuous line rather than a set of + discrete points). Aberrant behavior (a potential failure) is reported whenever the number of times the observed value violates the confidence @@ -216,17 +213,16 @@ DDEESSCCRRIIPPTTIIOONN data you could, for example, use a front-end application to RRRRDDttooooll to initiate real-time alerts. - For a detailed description on how to set this up, see rrdcre- - ate. - - RREEMMOOTTEE CCOONNTTRROOLL + For a detailed description on how to set this up, see + rrdcreate. + RREEMMOOTTEE CCOONNTTRROOLL When you start RRRRDDttooooll with the command line option '--' it waits for input via standard input (STDIN). With this feature you can improve - performance by attaching RRRRDDttooooll to another process (MRTG is one exam- - ple) through a set of pipes. Over these pipes RRRRDDttooooll accepts the same - arguments as on the command line and some special commands like qquuiitt,, - ccdd,, mmkkddiirr and llss. For detailed help on the server commands type: + performance by attaching RRRRDDttooooll to another process (MRTG is one + example) through a set of pipes. Over these pipes RRRRDDttooooll accepts the + same arguments as on the command line and some special commands like + qquuiitt,, ccdd,, mmkkddiirr and llss. For detailed help on the server commands type: rrdtool help cd|mkdir|pwd|ls|quit @@ -234,13 +230,12 @@ DDEESSCCRRIIPPTTIIOONN followed by timing information of the form uu::_u_s_e_r_t_i_m_e ss::_s_y_s_t_e_m_t_i_m_e. Both values are the running totals of seconds since RRDtool was started. If an error occurs, a line of the form '"ERROR:" _D_e_s_c_r_i_p_t_i_o_n - _o_f _e_r_r_o_r' will be printed instead. RRRRDDttooooll will not abort, unless some- - thing really serious happens. If a wwoorrkkddiirr is specified and the UID is - 0, RRDtool will do a chroot to that workdir. If the UID is not 0, RRD- - tool only changes the current directory to wwoorrkkddiirr. - - RRRRDD SSeerrvveerr + _o_f _e_r_r_o_r' will be printed instead. RRRRDDttooooll will not abort, unless + something really serious happens. If a wwoorrkkddiirr is specified and the UID + is 0, RRDtool will do a chroot to that workdir. If the UID is not 0, + RRDtool only changes the current directory to wwoorrkkddiirr. + RRRRDD SSeerrvveerr If you want to create a RRD-Server, you must choose a TCP/IP Service number and add them to _/_e_t_c_/_s_e_r_v_i_c_e_s like this: @@ -258,9 +253,9 @@ DDEESSCCRRIIPPTTIIOONN Don't forget to create the database directory /var/rrd and reinitialize your inetd. - If all was setup correctly, you can access the server with Perl sock- - ets, tools like netcat, or in a quick interactive test by using 'telnet - localhost rrdsrv'. + If all was setup correctly, you can access the server with Perl + sockets, tools like netcat, or in a quick interactive test by using + 'telnet localhost rrdsrv'. NNOOTTEE:: that there is no authentication with this feature! Do not setup such a port unless you are sure what you are doing. @@ -283,4 +278,4 @@ AAUUTTHHOORR -1.3.99909060808 2009-05-26 RRDTOOL(1) +1.3.999 2009-06-09 RRDTOOL(1)