On Jul 20, 2009, at 9:16 AM, Edward Capriolo wrote:
On Mon, Jul 20, 2009 at 11:53 AM, Ryan McKinley<ryan...@gmail.com>
wrote:
On Jul 20, 2009, at 8:47 AM, Edward Capriolo wrote:
Hey all,
We have several deployments of Solr across our enterprise. Our
largest
one is a several GB and when enough documents are added an OOM
exception is occurring.
To debug this problem I have enable JMX. My goal is to write some
cacti templates similar to the ones I have done for hadoop.
http://www.jointhegrid.com/hadoop/. The only cacti template for
solr I
have found is old, broken and is using curl and PHP to try and read
the values off the web interface. I have a few general
questions/comments and also would like to know how others are
dealing
with this.
1) SNMP has counters/gauges. With JMX it is hard to know what a
variable is without watching it for a while. Some fields are
obvious,
(total_x) (cumulative_x) it is worth wild to add some notes in the
MBEAN info to say "works like counter" "works like gauge". This
way a
"network engineer" like me does not have to go code surfing to
figure
out how to graph them.
Has anyone written up a list of what the attributes are, types, and
what they mean?
2) The values that are not counter style I am assuming are sampled,
what is the sampling rate and is it adjustable?
Any tips are helpful. Thank you,
Check:
http://svn.apache.org/repos/asf/lucene/solr/trunk/src/java/org/apache/solr/handler/RequestHandlerBase.java
For cacti, you should probably ignore the two 'rate' based
calculations as
they are just derivatives:
lst.add("avgTimePerRequest", (float) totalTime / (float)
this.numRequests);
lst.add("avgRequestsPerSecond", (float) numRequests*1000 /
(float)(System.currentTimeMillis()-handlerStart));
Thanks Ryan,
Actually, I typically graph the derivatives directly. As graphing a
derivative is usually easier then writing cacti CDEF's which can be
fickle when exporting the templates between versions, but I see your
point.
However, do you see the point I was getting at? Without MBEAN info
stating that these values are derivatives I have to dig through source
code. It is not a complaint, just a note that their seems to be so
much work on JMX counters, but just a few word description in the
MBEAN info would eliminate the need to dig through the source tree
when it actually comes time to for someone to render these counters.
no doubt -- i am unfamiliar with how these get passed to JMX (or where
extra docs would be helpful) -- feel free to submit a patch that adds
this info, perhaps to the wiki? javadoc? this way it will be easier
for the next guy
Also one more question on my mind, how are the JMX objects effected by
a multi core deployment. Does each core have its own objects or are
they shared?
each core/handler gets its own object -- they are not shared across
cores.
Thank you,
Edward
