Author: jbellis
Date: Wed Aug 3 18:58:21 2011
New Revision: 1153610
URL: http://svn.apache.org/viewvc?rev=1153610&view=rev
Log:
add scheduler JMX metrics
patch by stuhood; reviewed by Nirmal Ranganathan for CASSANDRA-2962
Modified:
cassandra/trunk/CHANGES.txt
cassandra/trunk/src/java/org/apache/cassandra/scheduler/RoundRobinScheduler.java
Modified: cassandra/trunk/CHANGES.txt
URL:
http://svn.apache.org/viewvc/cassandra/trunk/CHANGES.txt?rev=1153610&r1=1153609&r2=1153610&view=diff
==============================================================================
--- cassandra/trunk/CHANGES.txt (original)
+++ cassandra/trunk/CHANGES.txt Wed Aug 3 18:58:21 2011
@@ -25,6 +25,7 @@
* add paging to get_count (CASSANDRA-2894)
* fix "short reads" in [multi]get (CASSANDRA-2643)
* add optional compression for sstables (CASSANDRA-47)
+ * add scheduler JMX metrics (CASSANDRA-2962)
0.8.3
Modified:
cassandra/trunk/src/java/org/apache/cassandra/scheduler/RoundRobinScheduler.java
URL:
http://svn.apache.org/viewvc/cassandra/trunk/src/java/org/apache/cassandra/scheduler/RoundRobinScheduler.java?rev=1153610&r1=1153609&r2=1153610&view=diff
==============================================================================
---
cassandra/trunk/src/java/org/apache/cassandra/scheduler/RoundRobinScheduler.java
(original)
+++
cassandra/trunk/src/java/org/apache/cassandra/scheduler/RoundRobinScheduler.java
Wed Aug 3 18:58:21 2011
@@ -23,13 +23,11 @@ package org.apache.cassandra.scheduler;
import java.util.Map;
import java.util.concurrent.Semaphore;
-import java.util.concurrent.SynchronousQueue;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.config.RequestSchedulerOptions;
-import org.apache.cassandra.utils.Pair;
import org.cliffc.high_scale_lib.NonBlockingHashMap;
/**
@@ -42,16 +40,17 @@ public class RoundRobinScheduler impleme
{
private static final Logger logger =
LoggerFactory.getLogger(RoundRobinScheduler.class);
- //The Pair is the weighted queue - the left is the weight and the right is
the queue
- private final NonBlockingHashMap<String, Pair<Integer,
SynchronousQueue<Thread>>> queues;
+ //Map of queue id to weighted queue
+ private final NonBlockingHashMap<String, WeightedQueue> queues;
private static boolean started = false;
private final Semaphore taskCount;
+ // Tracks the count of threads available in all queues
// Used by the the scheduler thread so we don't need to busy-wait until
there is a request to process
private final Semaphore queueSize = new Semaphore(0, false);
- private Integer defaultWeight;
+ private int defaultWeight;
private Map<String, Integer> weights;
public RoundRobinScheduler(RequestSchedulerOptions options)
@@ -62,7 +61,7 @@ public class RoundRobinScheduler impleme
weights = options.weights;
taskCount = new Semaphore(options.throttle_limit);
- queues = new NonBlockingHashMap<String, Pair<Integer,
SynchronousQueue<Thread>>>();
+ queues = new NonBlockingHashMap<String, WeightedQueue>();
Runnable runnable = new Runnable()
{
public void run()
@@ -75,18 +74,18 @@ public class RoundRobinScheduler impleme
};
Thread scheduler = new Thread(runnable, "REQUEST-SCHEDULER");
scheduler.start();
- logger.info("Started the RoundRobin Request Scheduler");
started = true;
+ logger.info("Started the RoundRobin Request Scheduler");
}
public void queue(Thread t, String id)
{
- Pair<Integer, SynchronousQueue<Thread>> weightedQueue =
getWeightedQueue(id);
+ WeightedQueue weightedQueue = getWeightedQueue(id);
try
{
queueSize.release();
- weightedQueue.right.put(t);
+ weightedQueue.put(t);
}
catch (InterruptedException e)
{
@@ -101,19 +100,14 @@ public class RoundRobinScheduler impleme
private void schedule()
{
- int weight;
- SynchronousQueue<Thread> queue;
- Thread t;
-
queueSize.acquireUninterruptibly();
- for (Map.Entry<String,Pair<Integer, SynchronousQueue<Thread>>> request
: queues.entrySet())
+ for (Map.Entry<String,WeightedQueue> request : queues.entrySet())
{
- weight = request.getValue().left;
- queue = request.getValue().right;
+ WeightedQueue queue = request.getValue();
//Using the weight, process that many requests at a time (for that
scheduler id)
- for (int i=0; i<weight; i++)
+ for (int i=0; i<queue.weight; i++)
{
- t = queue.poll();
+ Thread t = queue.poll();
if (t == null)
break;
else
@@ -130,18 +124,21 @@ public class RoundRobinScheduler impleme
* Get the Queue for the respective id, if one is not available
* create a new queue for that corresponding id and return it
*/
- private Pair<Integer, SynchronousQueue<Thread>> getWeightedQueue(String id)
+ private WeightedQueue getWeightedQueue(String id)
{
- Pair<Integer, SynchronousQueue<Thread>> weightedQueue = queues.get(id);
+ WeightedQueue weightedQueue = queues.get(id);
if (weightedQueue != null)
// queue existed
return weightedQueue;
- Pair<Integer, SynchronousQueue<Thread>> maybenew = new
Pair(getWeight(id), new SynchronousQueue<Thread>(true));
+ WeightedQueue maybenew = new WeightedQueue(id, getWeight(id));
weightedQueue = queues.putIfAbsent(id, maybenew);
if (weightedQueue == null)
- // created new queue
+ {
+ // created new queue: register for monitoring
+ maybenew.register();
return maybenew;
+ }
// another thread created the queue
return weightedQueue;
