Changes between Version 14 and Version 15 of RRDtool13


Ignore:
Timestamp:
Jun 14, 2007, 10:55:03 PM (15 years ago)
Author:
oetiker
Comment:

Added Info about IO performance.

Legend:

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  • RRDtool13

    v14 v15  
    11= Features for RRDtool 1.3 =
     2
     3== Updates ==
     4
     5|| 2007-06-14 || Performance impact of MMAP IO and madvise quantified. ||
     6||            || Added TEXTALIGN command                               ||
     7
    28
    39== Completed ==
     
    612
    713The whole IO subsystem has been redone by Bernhard Fisher. It can now uses
    8 MMAPed IO for all rrd file access.
     14MMAPed IO for all RRD file access and uses madvise extensively to help the kernel with cache handling.
    915
    10 (Performance testing not done yet, but the load on the Kernel IO should be much lighter)
     16The net effect is that in-memory updates are about twice as fast as before.
     17My coreduo thnkpad was able todo 12k updates per second (in memory) with the
     181.2 code base while it is able to do 22k updates per second (in memory).
    1119
    12 === Cairo/Pango ===
     20Obviously RRD data has to go to disk eventually, there has not been all that much change,
     21since the OS still has to write the blocks. My 5400 RPM Thinkpad HD continues to get about250 Updates
     22to disk per second.
     23
     24The interesting thing here is that we are telling the kernel that we will not read the whole RRDfile
     25but just some blocks of it (random access). This helps optimize cache access and reduces disk IO.
     26The main advantage of this is that the cache usage gets optimized. The number of RRDfiles
     27that can be kept in cache at any one time is 3 to 5 times as large in 1.3 as in 1.2.
     28
     29=== Graphing with Cairo/Pango ===
    1330
    1431No more libart, no more strange error messages about stability.
    1532The switch to Cairo makes for a number of neat new features:
    1633
    17  * --graph-render-mode=mono brings back the rrdtool 1.0.x look and feel[[BR]][[Image(minmax.mono.png)]][[BR]]. The antialiasing can be configured for
     34 * --graph-render-mode=mono brings back the rrdtool 1.0.x look and feel[[BR]][[Image(minmax.mono.png)]][[BR]]. The anti aliasing can be configured for
    1835   graph and fonts separately.
    1936 * full grid-fitting of all drawing operations makes for crisper looking graph output
     
    3148   font properties inside any rrdtool graph text field.
    3249
     50=== Other Enhancements ===
     51
     52 TEXTALIGN::
     53 The TEXTALIGN command lets you specify how the legend of the graph should be aligned by
     54 default.
     55{{{
     56 TEXTALIGN:left
     57}}}
    3358== Planned ==
    3459
     
    3661 1. Architecture independent data format with xdr (tobi with help from Matt Massie)
    3762 1. command line parsing with popt (or some other thread-safe thing) (tobi)
    38  1. ALIGN:left|right|both function to alter the way rrdtool acts on encountering a full line.
    39     At the moment it justifies the line which may not look good in all cases
    4063 
    4164== Maybe ==

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