[rrd-users] rrd graph not flushing cached data

[Eduardo Bragatto]

Hello,

I started using rrdcached last week and I'm very pleased with it's  
performance, however I'm having problems to produce updated graphs.

I'm starting rrdcached with:

/usr/local/rrd143/bin/rrdcached -F -t 16 -s nobody -m 0666 -l unix:/ 
tmp/rrdcached.sock -w 900 -l 127.0.0.1:12345

All my "rrd graph" calls, have "--daemon unix:/tmp/rrdcached.sock" on  
them -- and I'm sure there's no permission errors (you can see I set  
it to 0666 to make sure that would not be a problem).

Checking it via telnet, here's what I see:

STATS
9 Statistics follow
QueueLength: 0
UpdatesReceived: 24854
FlushesReceived: 94
UpdatesWritten: 1621
DataSetsWritten: 1621
TreeNodesNumber: 11538
TreeDepth: 16
JournalBytes: 0
JournalRotate: 0

After viewing a lot of graphs (all sending flush command), I see  
rrdcached receives the flush, but does not flush to disk (comparing  
UpdatesWritten):

STATS
9 Statistics follow
QueueLength: 0
UpdatesReceived: 24865
FlushesReceived: 140
UpdatesWritten: 1621
DataSetsWritten: 1621
TreeNodesNumber: 11538
TreeDepth: 16
JournalBytes: 0
JournalRotate: 0

However, if I run the flush command on the telnet, it does write to  
disk:

FLUSH /my/file.rrd
0 Successfully flushed /my/file.rrd.
STATS
9 Statistics follow
QueueLength: 0
UpdatesReceived: 36230
FlushesReceived: 141
UpdatesWritten: 1622
DataSetsWritten: 1624
TreeNodesNumber: 11538
TreeDepth: 16
JournalBytes: 0
JournalRotate: 0
QUIT

Here, UpdatesWritten increased by one as expected, but it does not  
write to disk when "rrd graph" sends the flush command.

According to the docs, rrdcached has a parameter -b and I thought that  
could be the problem:

"The daemon will change into a specific directory at startup. All  
files passed to the daemon, that are specified by a relative path,  
will be interpreted to be relative to this directory. If not given the  
default, /tmp, will be used."

Since I'm not using -b in my rrdcached call, I understand it's set to / 
tmp, but *all* my rrd graph calls are using an absolute path, so that  
should not be a problem and the flush command should have worked.

Have anyone faced similar issues with rrdcached?

Thanks in advance,
Eduardo Bragatto.
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