Xymon Mailing List Archive search

hobbitgraph.cgi: Attempting to reuse 'mysqlht'

6 messages in this thread

list Arie Skliarouk · Wed, 24 Nov 2010 16:12:07 +0200 · 
Hi,

Initially I filed my problem as a bug over here:
https://sourceforge.net/tracker/?func=detail&aid=3116811&group_id=128058&atid=710488

but now I am not sure it is a bug, so posting it here for more lively
discussion:

I created a custom mysql parameters check that shows graphs on one server,
but not on the other. hobbitgraph.sh (hobbitgraph.cgi?) kept sending
following error instead of the actual image:
<html><head><title>Invalid request</title></head>
<body>Attempting to reuse 'mysqlht'</body></html>

If I request the same image for different server, same service - I get the
image. If I copy the mysql.rrd file from the
/var/lib/hobbit/rrd/atl-db01/mysql.rrd into the /var/lib/hobbit/rrd/pa04,
then the image for pa04 shows graph for the atl-db01.

Could be that dash in name of that particular server was affecting the
hobbitgraph.cgi somehow? I can attach the hobbitgraph.d/mysql.cfg and
hobbitserver.d/mysql.cfg if that would help.

--
Arie
list Arie Skliarouk · Thu, 25 Nov 2010 13:14:35 +0200 · 
Reposting the message as I received weird undelivery report:

This is an automatically generated Delivery Status Notification.

Delivery to the following recipients failed.

      user-d567979316a8@xymon.invalid

--
Arie
▸ quoted from Arie Skliarouk


On Wed, Nov 24, 2010 at 16:12, Arie Skliarouk <user-38cea896515c@xymon.invalid> wrote:

Hi,

Initially I filed my problem as a bug over here:

https://sourceforge.net/tracker/?func=detail&aid=3116811&group_id=128058&atid=710488

but now I am not sure it is a bug, so posting it here for more lively
discussion:

I created a custom mysql parameters check that shows graphs on one server,
but not on the other. hobbitgraph.sh (hobbitgraph.cgi?) kept sending
following error instead of the actual image:
<html><head><title>Invalid request</title></head>
<body>Attempting to reuse 'mysqlht'</body></html>

If I request the same image for different server, same service - I get the
image. If I copy the mysql.rrd file from the
/var/lib/hobbit/rrd/atl-db01/mysql.rrd into the /var/lib/hobbit/rrd/pa04,
then the image for pa04 shows graph for the atl-db01.

Could be that dash in name of that particular server was affecting the
hobbitgraph.cgi somehow? I can attach the hobbitgraph.d/mysql.cfg and
hobbitserver.d/mysql.cfg if that would help.

--
Arie
list Henrik Størner · Thu, 25 Nov 2010 15:59:40 +0000 (UTC) ·
▸ quoted from Arie Skliarouk
On Wed, 24 Nov 2010 16:12:07 +0200, Arie Skliarouk wrote:

I created a custom mysql parameters check that shows graphs on one
server, but not on the other. hobbitgraph.sh (hobbitgraph.cgi?) kept
sending following error instead of the actual image:
<html><head><title>Invalid request</title></head> <body>Attempting to
reuse 'mysqlht'</body></html>
This is an error from the rrdtool library. So I would suspect something 
dodgy with the graph-definition in hobbit-graphs.cfg, or the RRD file 
data is not as you would expect.

Could you show us the graph definition you use ? And the layout of the 
RRD-file - a command like

	rrdtool info mysql.rrd |grep "type ="

should give us the necessary info about the datasets and their type.
▸ quoted from Arie Skliarouk
If I request the same image for different server, same service - I get
the image. If I copy the mysql.rrd file from the
/var/lib/hobbit/rrd/atl-db01/mysql.rrd into the
/var/lib/hobbit/rrd/pa04, then the image for pa04 shows graph for the
atl-db01.

Could be that dash in name of that particular server was affecting the
hobbitgraph.cgi somehow? I can attach the hobbitgraph.d/mysql.cfg and
hobbitserver.d/mysql.cfg if that would help.
It shouldn't, and I know I have hostnames with dash'es in them. Haven't 
noticed any problems with graphs there, but I'll have a look.


Regards,
Henrik
list Arie Skliarouk · Sun, 28 Nov 2010 16:30:39 +0200 ·
▸ quoted from Henrik Størner
On Thu, Nov 25, 2010 at 17:59, Henrik Størner <user-ce4a2c883f75@xymon.invalid> wrote:

On Wed, 24 Nov 2010 16:12:07 +0200, Arie Skliarouk wrote:

I created a custom mysql parameters check that shows graphs on one
server, but not on the other. hobbitgraph.sh (hobbitgraph.cgi?) kept
sending following error instead of the actual image:
<html><head><title>Invalid request</title></head> <body>Attempting to
reuse 'mysqlht'</body></html>
This is an error from the rrdtool library. So I would suspect something
dodgy with the graph-definition in hobbit-graphs.cfg, or the RRD file
data is not as you would expect.

Could you show us the graph definition you use ?

See attached. Also attached all files you might require to recreate the
mysql sensor.

Note that the graph works for one machine, but not for the other.
▸ quoted from Henrik Størner


And the layout of the
RRD-file - a command like

       rrdtool info mysql.rrd |grep "type ="

Both files yield identical output:
ds[mysqlht].type = "GAUGE"
ds[mysqlhq].type = "GAUGE"
ds[mysqlhs].type = "GAUGE"

--
Arie
▸ quoted from Henrik Størner
should give us the necessary info about the datasets and their type.

If I request the same image for different server, same service - I get
the image. If I copy the mysql.rrd file from the
/var/lib/hobbit/rrd/atl-db01/mysql.rrd into the
/var/lib/hobbit/rrd/pa04, then the image for pa04 shows graph for the
atl-db01.

Could be that dash in name of that particular server was affecting the
hobbitgraph.cgi somehow? I can attach the hobbitgraph.d/mysql.cfg and
hobbitserver.d/mysql.cfg if that would help.
It shouldn't, and I know I have hostnames with dash'es in them. Haven't
noticed any problems with graphs there, but I'll have a look.


Regards,
Henrik
Attachments (4)
list Henrik Størner · Mon, 29 Nov 2010 21:54:47 +0000 (UTC) ·
▸ quoted from Arie Skliarouk
On Sun, 28 Nov 2010 16:30:39 +0200, Arie Skliarouk wrote:

On Thu, Nov 25, 2010 at 17:59, Henrik Størner <user-ce4a2c883f75@xymon.invalid> wrote:

On Wed, 24 Nov 2010 16:12:07 +0200, Arie Skliarouk wrote:

I created a custom mysql parameters check that shows graphs on one
server, but not on the other. hobbitgraph.sh (hobbitgraph.cgi?) kept
sending following error instead of the actual image:
<html><head><title>Invalid request</title></head> <body>Attempting to
reuse 'mysqlht'</body></html>
This is an error from the rrdtool library. So I would suspect something
dodgy with the graph-definition in hobbit-graphs.cfg, or the RRD file
data is not as you would expect.

Could you show us the graph definition you use ?

See attached.
OK, the interesting part of your graph definition looks like this:

[mysql]
    FNPATTERN mysql.rrd
    TITLE MySQL
    YAXIS Number
    DEF:mysqlht=@RRDFN@:mysqlht:AVERAGE
    DEF:mysqlhs=@RRDFN@:mysqlhs:AVERAGE
    DEF:mysqlhq=@RRDFN@:mysqlhq:AVERAGE
    LINE2:mysqlht#00CCCC:MySQL threads
    LINE2:mysqlhs#ff0000:Slow queries
    LINE2:mysqlhq#ff00ff:Queries per sec

The problem occurs because you're using an FNPATTERN definition, but you
only expect one file to match. I'll bet that the problem host has another
RRD file present which matches "mysql.rrd" - there is no anchor in the
pattern, so a file "blablamysql.rrd" will also match this pattern. Or
even "mysql.rrd.old".

When you have multiple files that match FNPATTERN, the rest of the 
definition is repeated for each file when Xymon tells RRDtool how to 
generate the graph. So you'll end up with two DEF lines that define a 
"mysqlht" variable - one for each file that matches FNPATTERN. That
is not allowed, and causes RRDtool to complain with the error you see.

If you only want to use one specific RRD file, don't use FNPATTERN.
Instead, put the filename where you have "@RRDFN@" now:

[mysql]
    TITLE MySQL
    YAXIS Number
    DEF:mysqlht=mysql.rrd:mysqlht:AVERAGE
    DEF:mysqlhs=mysql.rrd:mysqlhs:AVERAGE
    DEF:mysqlhq=mysql.rrd:mysqlhq:AVERAGE
    LINE2:mysqlht#00CCCC:MySQL threads
    LINE2:mysqlhs#ff0000:Slow queries
    LINE2:mysqlhq#ff00ff:Queries per sec

Just for the record, if you DO want to match multiple files, then you 
must include the index-number in the DEF and GPRINT definition. E.g.

[mysql]
    FNPATTERN mysql.rrd
    TITLE MySQL
    YAXIS Number
    DEF:mysqlht at RRDIDX@=@RRDFN@:mysqlht:AVERAGE
    DEF:mysqlhs at RRDIDX@=@RRDFN@:mysqlhs:AVERAGE
    DEF:mysqlhq at RRDIDX@=@RRDFN@:mysqlhq:AVERAGE
    LINE2:mysqlht at RRDIDX@#@COLOR@:@RRDPARAM@ MySQL threads

See e.g. the [la] and [disk] definitions in the standard graphs.cfg / 
hobbitgraph.cfg file.


Regards,
Henrik
list Arie Skliarouk · Tue, 30 Nov 2010 11:34:34 +0200 · 
Thank you for helpful explanation, after I removed FNPATTERN and replaced
@RRDFN@ with mysql.rrd - the graph appeared for the second machine too.

And no, I neither have other mysql*.rrd file in the
/var/lib/hobbit/rrd/HOSTNAME/ directory, nor any of the existing ones had
keys starting with "mysql" string.

--
Arie
▸ quoted from Henrik Størner


On Mon, Nov 29, 2010 at 23:54, Henrik Størner <user-ce4a2c883f75@xymon.invalid> wrote:

On Sun, 28 Nov 2010 16:30:39 +0200, Arie Skliarouk wrote:

On Thu, Nov 25, 2010 at 17:59, Henrik Størner <user-ce4a2c883f75@xymon.invalid> wrote:

On Wed, 24 Nov 2010 16:12:07 +0200, Arie Skliarouk wrote:

I created a custom mysql parameters check that shows graphs on one
server, but not on the other. hobbitgraph.sh (hobbitgraph.cgi?) kept
sending following error instead of the actual image:
<html><head><title>Invalid request</title></head> <body>Attempting to
reuse 'mysqlht'</body></html>
This is an error from the rrdtool library. So I would suspect something
dodgy with the graph-definition in hobbit-graphs.cfg, or the RRD file
data is not as you would expect.

Could you show us the graph definition you use ?

See attached.
OK, the interesting part of your graph definition looks like this:

[mysql]
   FNPATTERN mysql.rrd
   TITLE MySQL
   YAXIS Number
   DEF:mysqlht=@RRDFN@:mysqlht:AVERAGE
   DEF:mysqlhs=@RRDFN@:mysqlhs:AVERAGE
   DEF:mysqlhq=@RRDFN@:mysqlhq:AVERAGE
   LINE2:mysqlht#00CCCC:MySQL threads
   LINE2:mysqlhs#ff0000:Slow queries
   LINE2:mysqlhq#ff00ff:Queries per sec

The problem occurs because you're using an FNPATTERN definition, but you
only expect one file to match. I'll bet that the problem host has another
RRD file present which matches "mysql.rrd" - there is no anchor in the
pattern, so a file "blablamysql.rrd" will also match this pattern. Or
even "mysql.rrd.old".

When you have multiple files that match FNPATTERN, the rest of the
definition is repeated for each file when Xymon tells RRDtool how to
generate the graph. So you'll end up with two DEF lines that define a
"mysqlht" variable - one for each file that matches FNPATTERN. That
is not allowed, and causes RRDtool to complain with the error you see.

If you only want to use one specific RRD file, don't use FNPATTERN.
Instead, put the filename where you have "@RRDFN@" now:

[mysql]
   TITLE MySQL
   YAXIS Number
   DEF:mysqlht=mysql.rrd:mysqlht:AVERAGE
   DEF:mysqlhs=mysql.rrd:mysqlhs:AVERAGE
   DEF:mysqlhq=mysql.rrd:mysqlhq:AVERAGE
   LINE2:mysqlht#00CCCC:MySQL threads
   LINE2:mysqlhs#ff0000:Slow queries
   LINE2:mysqlhq#ff00ff:Queries per sec

Just for the record, if you DO want to match multiple files, then you
must include the index-number in the DEF and GPRINT definition. E.g.

[mysql]
   FNPATTERN mysql.rrd
   TITLE MySQL
   YAXIS Number
   DEF:mysqlht at RRDIDX@=@RRDFN@:mysqlht:AVERAGE
   DEF:mysqlhs at RRDIDX@=@RRDFN@:mysqlhs:AVERAGE
   DEF:mysqlhq at RRDIDX@=@RRDFN@:mysqlhq:AVERAGE
   LINE2:mysqlht at RRDIDX@#@COLOR@:@RRDPARAM@ MySQL threads

See e.g. the [la] and [disk] definitions in the standard graphs.cfg /
hobbitgraph.cfg file.


Regards,
Henrik