X-Git-Url: https://git.octo.it/?p=rrdtool.git;a=blobdiff_plain;f=doc%2Frrdtool.pod;h=0d701ca4a420818fd431cb47c57d1b40e222ea9a;hp=281b331b80004fadac4ef599e7b9758ddd697fdf;hb=7cd3bc3512c11bb861490bb65553cea5cc0c98b4;hpb=4b7345f9345915c8061e4b37b26ce8887828c973 diff --git a/doc/rrdtool.pod b/doc/rrdtool.pod index 281b331..0d701ca 100644 --- a/doc/rrdtool.pod +++ b/doc/rrdtool.pod @@ -34,10 +34,10 @@ While the man pages talk of command line switches you have to set in order to make B work it is important to note that B can be remotely controlled through a set of pipes. This saves a considerable amount of startup time when you plan to make -B do a lot of things quickly. Check the section on L<"Remote -Control"> further down. There is also a number of language bindings -for RRDtool which allow you to use it directly from perl, python, tcl, -php, etc. +B do a lot of things quickly. Check the section on L +further down. There is also a number of language bindings +for RRDtool which allow you to use it directly from Perl, python, Tcl, +PHP, etc. =over 8 @@ -91,7 +91,11 @@ Change the size of individual RRAs. This is dangerous! Check L. =item B -Export data retrieved from one or several RRDs. Check L +Export data retrieved from one or several RRDs. Check L. + +=item B + +Flush the values for a specific RRD file from memory. Check L. =item B @@ -109,9 +113,9 @@ L. When monitoring the state of a system, it is convenient to have the data available at a constant time interval. Unfortunately, you may not always be able to fetch data at exactly the time you want -to. Therefore B lets you update the logfile at any time you +to. Therefore B lets you update the log file at any time you want. It will automatically interpolate the value of the data-source -(B) at the latest official time-slot (intervall) and write this +(B) at the latest official time-slot (interval) and write this interpolated value to the log. The original value you have supplied is stored as well and is also taken into account when interpolating the next log entry. @@ -154,7 +158,7 @@ The use of Bs guarantees that the B does not grow over time and that old data is automatically eliminated. By using the consolidation feature, you can still keep data for a very long time, while gradually reducing the resolution of the data along the time -axis. +axis. Using different consolidation functions (B) allows you to store exactly the type of information that actually interests you: the maximum @@ -186,12 +190,12 @@ for more information on this. =item Aberrant Behavior Detection -by Jake Brutlag Ejakeb@corp.webtv.netE +by Jake Brutlag B provides the building blocks for near real-time aberrant behavior detection. These components include: -=over 12 +=over =item * @@ -260,21 +264,21 @@ accepts the same arguments as on the command line and some special commands like B and B. For detailed help on the server commands type: - rrdtool help cd|mkdir|ls|quit + rrdtool help cd|mkdir|pwd|ls|quit -When a command is completed, RRDtool will print the string 'C', -followed by timing information of the form BI -BI. Both values are the running totals of seconds -since RRDtool was started. If an error occurs, a line of the -form 'C I' will be printed. B -will not abort, if possible, but follow the ERROR line with an OK line. -If a B 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 B. +When a command is completed, RRDtool will print the string 'C', +followed by timing information of the form BI +BI. Both values are the running totals of seconds since +RRDtool was started. If an error occurs, a line of the form 'C +I' will be printed instead. B will not abort, +unless something really serious happens. If +a B 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 +B. =head2 RRD Server -If you want to create a RRD-Server, you must choose a TCP/IP Service +If you want to create a RRD-Server, you must choose a TCP/IP Service number and add them to I like this: rrdsrv 13900/tcp # RRD server @@ -285,20 +289,30 @@ server and the client system must use the same port, of course. With this configuration you can add RRDtool as meta-server to I. For example: - + rrdsrv stream tcp nowait root /opt/rrd/bin/rrdtool rrdtool - /var/rrd 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 +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'. +B that there is no authentication with this feature! Do not setup +such a port unless you are sure what you are doing. + +=head1 RRDCACHED, THE CACHING DAEMON + +For very big setups, updating thousands of RRD files often becomes a serious IO +problem. If you run into such problems, you might want to take a look at +L, a caching daemon for RRDtool which may help you lessen the +stress on your disks. =head1 SEE ALSO -rrdcreate, rrdupdate, rrdgraph, rrddump, rrdfetch, rrdtune, rrdlast, rrdxport +rrdcreate, rrdupdate, rrdgraph, rrddump, rrdfetch, rrdtune, rrdlast, rrdxport, +rrdflushcached, rrdcached =head1 BUGS @@ -306,5 +320,5 @@ Bugs? Features! =head1 AUTHOR -Tobias Oetiker +Tobias Oetiker