On 09/04/2010, at 17:15, Ryan Rawson <ryano...@gmail.com> wrote:
In the HMaster, there is this:
private void startServiceThreads() {
// Do after main thread name has been set
this.metrics = new MasterMetrics();
which calls the MBeanUtil registration (a hadoop utility) which
registers the MasterMetrics which contains all those metrics you are
interested in. The HMaster constructor will block until the ZK master
node is available.
does this help?
Thanks for replying. I'm not sure I get it though (it's Friday and
I've had a beer), for a Master I can block and wait for that to
complete but then if the current process is a regionserver it would
wait forever. How can I differentiate a Master from a RegionServer
process?
One way would be to change the JMX namespace for the RPC bean in the
master so it doesn't look like it's an RS? Be nice if my requirement
didn't require HBase code changes though.
This sniffing works ok for straight Hadoop nodes because the NN, JT,
TT and DN all have distinct JMX names to sniff for.
On Thu, Apr 8, 2010 at 11:48 PM, Paul Smith <psm...@aconex.com> wrote:
Hi gents, related to the Parfait/PCP discussion recently, I'm
hitting a problem that I need your help.
Right now a MetricContext implementation is initialised fairly
early within the Hbase/Hadoop lifecycle, and is given a chance to
initialise which is good. However what I've noticed is that other
parts of the JMX namespace do not appear for, say, the HMaster
process until quite late; well after the MetricContext impl is
initialized.
My PCPContext implementation I'm working on is going to want to
'sniff' and identify what type of process it is, mainly so as to be
able to route metrics to a locally named file identifying it as
metrics from that service. There is no way that I can spot at the
moment where a MetricContext can be told that the process own
initialization is complete. I'd like to have this so that a proper
exploration of the JMX namespace can happen to export things like
JVM metrics etc.
Can someone point me in the right direction here? For example,
once the HMaster is started up, there exists a JMX bean with the
name pattern 'hadoop:service=Master' namespace. Unfortunately the
RegionServer process has a pattern that is 'hadoop:service=HBase',
but that ALSO appears in the Master process (and early) so right
now my naive topology sniffing is seeing this and thinking the
Master is a RegionServer.
If I can delay my PCPContext initialization (even by just waiting
until I can detect something has occurred) until the rest of the
HBase process is properly up and running, then I think I'm off and
racing.
Any hooks or ideas on this would be appreciated.
Paul
