RRD is the Acronym for Round Robin Database. RRD is a system to store and
display time-series data (i.e. network bandwidth, machine-room temperature,
server load average). It stores the data in a very compact way that will not
expand over time, and it presents useful graphs by processing the data to
enforce a certain data density. It can be used either via simple wrapper
scripts (from shell or Perl) or via frontends that poll network devices and
put a friendly user interface on it.
bin_dec_hex Most people use the decimal numbering system. This system uses ten symbols to represent numbers. When those ten symbols are used up, they start all over again... cdeftutorial Intention of this document: to provide some examples of the commonly used parts of RRDtool's CDEF language. If you think some important feature is not explained... rpntutorial This tutorial should help you get to grips with RRDtool RPN expressions as seen in CDEF arguments of RRDtool graph. rrd-beginners This manual is an attempt to assist beginners in understanding the concepts of RRDtool. It sheds a light on differences between RRDtool and other databases... rrdbuild If you downloaded the source of RRDtool you have to compile it. This document will give some information on how this is done. RRDtool relies on services of... rrdcached rrdcached is a daemon that receives updates to existing RRD files, accumulates them and, if enough have been received or a defined time has passed, writes the... rrdcgi rrdcgi is a sort of very limited script interpreter. Its purpose is to run as a cgi-program and parse a web page template containing special <RRD:: tags. rrdcgi... rrdcreate The create function of RRDtool lets you set up new Round Robin Database (RRD) files. The file is created at its final, full size and filled with *UNKNOWN* data... rrddump The dump function writes the contents of an RRD in human readable (?) XML format to a file or to stdout. This format can be read by rrdrestore. Together they... rrdfetch The fetch function is normally used internally by the graph function to get data from RRDs. fetch will analyze the RRD and try to retrieve the data in the... rrdfirst The first function returns the UNIX timestamp of the first data sample entered into the specified RRA of the RRD file. rrdflushcached The flushcached function connects to rrdcached, the RRD caching daemon, and issues a "flush" command for the given files. The daemon will put the files to the... rrdgraph The graph function of RRDtool is used to present the data from an RRD to a human viewer. Its main purpose is to create a nice graphical representation, but it... rrdgraph_data These three instructions extract data values out of the RRD files, optionally altering them (think, for example, of a bytes to bits conversion). If so desired... rrdgraph_examples For your convenience some of the commands are explained here by using detailed examples. They are not always cut-and-paste ready because comments are intermixed... rrdgraph_graph These instructions allow you to generate your image or report. If you don't use any graph elements, no graph is generated. Similarly, no report is generated if... rrdgraph_rpn If you have ever used a traditional HP calculator you already know RPN (Reverse Polish Notation). The idea behind RPN is that you have a stack and push your... rrdinfo The info function prints the header information from an RRD in a parsing friendly format. Check rrdcreate if you are uncertain about the meaning of the... rrdlast The last function returns the UNIX timestamp of the most recent update of the RRD. rrdlastupdate The lastupdate function returns the UNIX timestamp and the value stored for each datum in the most recent update of an RRD. rrdlua Calling Sequence This module accesses RRDtool functionality directly from within Lua. The arguments to the functions listed in the Synopsis are explained in the... rrdresize The resize function is used to modify the number of rows in an RRA. rrdrestore The restore function reads the XML representation of an RRD and converts it to the native RRD format. rrdthreads Provisions for linking the RRD library to use in multi-threaded programs rrdtool Overview 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... rrdtune The tune option allows you to alter some of the basic configuration values stored in the header area of a Round Robin Database (RRD). One application of the... rrdtutorial RRDtool is written by Tobias Oetiker <email@example.com> with contributions from many people all around the world. This document is written by Alex van den... rrdupdate The update function feeds new data values into an RRD. The data is time aligned (interpolated) according to the properties of the RRD to which the data is... rrdxport The xport function's main purpose is to write an XML formatted representation of the data stored in one or several RRDs. It can also extract numerical reports...