Delete data from RRDTool

Question

I have several graphs created by RRDTool that have been collecting bad data over a couple of hours.

How can I delete data from RRD during this time period so that it no longer displays?

Answer 1

The best method I found for this ...

• Use RRDTool Dump to export RRD files to XML.
• Open the XML file, find and edit the bad data.
• Recover RRD file using RRDTool Restore .

Answer 2

xml , - ( , ), rrd , .

, python + rrdtool, :

• rrd
• rrd
• rrd .

Answer 3

, RRDtool, script ( - , , )

#!/usr/bin/env python2                                                                                                                                                                                 
"""                                                                                                                                                                                                    
Modify XML data generated by `rrdtool dump` such that the last update was at                                                                                                                           
the unixtime specified (decimal). Data newer than this is simply omitted.                                                                                                                              

Sample usage::                                                                                                                                                                                         

    rrdtool dump foo.rrd \
       | python remove_samples_newer_than.py 1414782122 \
       | rrdtool restore - foo_trimmed.rrd                                                                                          
"""                                                                                                                                                                                                    

import sys                                                                                                                                                                                             

assert sys.argv[1:], "Must specify maximum Unix timestamp in decimal"                                                                                                                                  

iMaxUpdate = sys.argv[1]                                                                                                                                                                               

for rLine in iter(sys.stdin.readline, ''):                                                                                                                                                             
    if "<lastupdate>" in rLine:                                                                                                                                                                        
        # <lastupdate>1414782122</lastupdate> <!-- 2014-10-31 19:02:02 GMT -->                                                                                                                         
        _, _, rData = rLine.partition("<lastupdate>")                                                                                                                                                  
        rData, _, _ = rData.partition("</lastupdate")                                                                                                                                                  
        iLastUpdate = int(rData)                                                                                                                                                                       
        assert iLastUpdate < iMaxUpdate, "Last update in RRD older than " \                                                                                                                            
                                    "the time you provided, nothing to do"                                                                                                                             
        print "<lastupdate>{0}</lastupdate>".format(iMaxUpdate)                                                                                                                                        
    elif "<row>" in rLine:                                                                                                                                                                             
        # <!-- 2014-10-17 20:04:00 BST / 1413572640 --> <row><v>9.8244774011e+01</v><v>8.5748587571e-01</v><v>4.2046610169e+00</v><v>9.3016101695e+01</v><v>5.0000000000e-02</v><v>1.6652542373e-01</  v><v>1.1757062147e+00</v><v>1.6901226735e+10</v><v>4.2023108608e+09</v><v>2.1457537707e+08</v><v>3.9597816832e+09</v><v>6.8812800000e+05</v><v>3.0433198080e+09</v><v>6.0198912250e+06</v><v>2.        0000000000e+00</v><v>0.0000000000e+00</v></row>                                                                                                                                                        
        rData, _, _ = rLine.partition("<row>")                                                                                                                                                         
        _, _, rData = rData.partition("/")                                                                                                                                                             
        rData, _, _ = rData.partition("--")                                                                                                                                                            
        rData = rData.strip()                                                                                                                                                                          
        iUpdate = int(rData)                                                                                                                                                                           
        if iUpdate < iMaxUpdate:                                                                                                                                                                       
            print rLine,                                                                                                                                                                               
    else:                                                                                                                                                                                              
        print rLine,                                                                                                                                                                                   

. , - .

Answer 4

, , , RobM. , rrdtool 1.4.7

AVERAGE, MAX MIN. DERIVE, GAUGE COMPUTED. : (70), (70), (25), (367). : ( : ).

RobM: , . . . . 70 NaN, ​​.

So, my working solution is that if I delete records for a certain period, I add the same number of NaN records to this period, starting with the correct time reduction. An exception is daily entries, they are deleted without adding. If it becomes empty after deletion, I fill it with NaN notes ending before my new end time (rounded to the border of the period).