Hi all,
Here we use a tool which reports some extra statistics through gmetric
(job information).
I have always assumed the following for the maximum of a gmetric
message, which I found in the ChangeLog:
2002-08-30 22:17 sacerdoti
* lib/ganglia.h (1.2): Maximum multicast message length is 1500
bytes, the size of an ethernet frame.
2002-08-23 22:37 sacerdoti
* gmetric/: cmdline.c (1.3), cmdline.h (1.3), gmetric.c (1.7): Now
you can send gmetrics with up to 1400 characters in the value
field.
However, that does not seem correct, a gmetric's value can't be 1400
characters.
I have a gmetric here with total string size (including the XML tags and
stuff) of 1030 characters, which gets wrapped:
>>> bla_str
'<METRIC NAME="TOGA-JOB-6718" VAL="name=ADDA_bs queue=q_parallel
owner=myurkin requested_time=13:00:00 ppn=2 status=R
start_timestamp=1141299521 report ed=1141307950 poll_interval=10
domain=irc.sara.nl
nodes=gb-r28n16;gb-r28n16;gb-r28n15;gb-r28n15;gb-r28n14;gb-r28n14;gb-r28n13;gb-r28n13;gb-r28n12;gb-r28n12
;gb-r28n11;gb-r28n11;gb-r28n10;gb-r28n10;gb-r28n9;gb-r28n9;gb-r28n8;gb-r28n8;gb-r28n7;gb-r28n7;gb-r28n6;gb-r28n6;gb-r28n5;gb-r28n5;gb-r28n4;gb-r28n4;gb-r28
n3;gb-r28n3;gb-r28n2;gb-r28n2;gb-r28n1;gb-r28n1;gb-r27n20;gb-r27n20;gb-r27n19;gb-r27n19;gb-r27n18;gb-r27n18;gb-r27n17;gb-r27n17;gb-r27n16;gb-r27n16;gb-r27n15;gb-r27n15;gb-r27n14;gb-r27n14;gb-r27n13;gb-r27n13;gb-r27n12;gb-r27n12;gb-r27n11;gb-r27n11;gb-r27n10;gb-r27n10;gb-r27n9;gb-r27n9;gb-r27n8;gb-r27n8;gb-r27
n7;gb-r27n7;gb-r27n6;gb-r27n6;gb-r27n5;gb-r27n5;gb-r27n4;gb-r27n4;gb-r27n3;gb-r27n3;gb-r27n2;gb-r27n2;gb-r27n1;gb-r27n1;gb-r26n20;gb-r26n20;gb-r26n19;gb-r2
6n19;gb-r26n18;gb-r26n18;gb-r26n17;gb-r26n17;gb-r26n16;gb-r26n16;gb-r26n15;gb-r26n15;gb-r26n14;gb-\n'
>>> len( bla_str )
1030
>>>
So I was checking from my tool for a length of 1400 characters, but I
actually should be checking for a value length of around 900 characters
I think.
I probably shouldn't have assumed a old ChangeLog entry from 2002 was
still accurate and it probably changed when APR was introduced (you know
what they say about assumptions ;)), but I'd still like to know
nevertheless.
So now is my question, what is the real maximum length for a gmetric
(value)?
And perhaps we should incorporate better length/error checking in
gmetric, because this wrapped/broken gmetric from above breaks my entire
XML stream for the cluster:
Mar 2 16:45:17 ganglia /usr/sbin/gmetad[29108]: Process XML (LISA
Cluster): XML_ParseBuffer() error at line 15191: unclosed token
If I have the time I will try to write a patch myself, but it seems
buried deep down in the code somewhere and someone else might be able to
spot/fix it faster than me.
Kind regards,
- Ramon.
--
ing. R. Bastiaans HPC - Systems Programmer
SARA - Computing and Networking Services
Kruislaan 415 PO Box 194613
1098 SJ Amsterdam 1090 GP Amsterdam
Tel. +31 (0) 20 592 3000 Fax. +31 (0) 20 668 3167
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and those who say, "What happened?"
