Merge pull request #480 from metamx/compute-cache-monitor

enable cache monitor on computes by default

docs/content/Broker-Config.md

@@ -81,7 +81,7 @@ druid.server.http.numThreads=50
 druid.request.logging.type=emitter
 druid.request.logging.feed=druid_requests
 
-druid.monitoring.monitors=["com.metamx.metrics.SysMonitor","com.metamx.metrics.JvmMonitor", "io.druid.client.cache.CacheMonitor"]
+druid.monitoring.monitors=["com.metamx.metrics.SysMonitor","com.metamx.metrics.JvmMonitor"]
 
 # Emit metrics over http
 druid.emitter=http
@@ -106,16 +106,16 @@ The broker module uses several of the default modules in [Configuration](Configu
 
 |Property|Description|Default|
 |--------|-----------|-------|
-|`druid.broker.cache.sizeInBytes`|Maximum size of the cache. If this is zero, cache is disabled.|10485760 (10MB)|
-|`druid.broker.cache.initialSize`|The initial size of the cache in bytes.|500000|
-|`druid.broker.cache.logEvictionCount`|If this is non-zero, there will be an eviction of entries.|0|
+|`druid.broker.cache.sizeInBytes`|Maximum cache size in bytes. Zero disables caching.|0|
+|`druid.broker.cache.initialSize`|Initial size of the hashtable backing the cache.|500000|
+|`druid.broker.cache.logEvictionCount`|If non-zero, log cache eviction every `logEvictionCount` items.|0|
 
 #### Memcache
 
 |Property|Description|Default|
 |--------|-----------|-------|
-|`druid.broker.cache.expiration`|Memcache [expiration time ](https://code.google.com/p/memcached/wiki/NewCommands#Standard_Protocol).|2592000 (30 days)|
-|`druid.broker.cache.timeout`|Maximum time in milliseconds to wait for a response from Memcache.|500|
-|`druid.broker.cache.hosts`|Memcache hosts.|none|
-|`druid.broker.cache.maxObjectSize`|Maximum object size in bytes for a Memcache object.|52428800 (50 MB)|
-|`druid.broker.cache.memcachedPrefix`|Key prefix for all keys in Memcache.|druid|
+|`druid.broker.cache.expiration`|Memcached [expiration time](https://code.google.com/p/memcached/wiki/NewCommands#Standard_Protocol).|2592000 (30 days)|
+|`druid.broker.cache.timeout`|Maximum time in milliseconds to wait for a response from Memcached.|500|
+|`druid.broker.cache.hosts`|Command separated list of Memcached hosts `<host:port>`.|none|
+|`druid.broker.cache.maxObjectSize`|Maximum object size in bytes for a Memcached object.|52428800 (50 MB)|
+|`druid.broker.cache.memcachedPrefix`|Key prefix for all keys in Memcached.|druid|

server/src/main/java/io/druid/client/cache/LocalCacheProvider.java

@@ -29,7 +29,7 @@ public class LocalCacheProvider implements CacheProvider
 {
   @JsonProperty
   @Min(0)
-  private long sizeInBytes = 10485760;
+  private long sizeInBytes = 0;
 
   @JsonProperty
   @Min(0)

services/src/main/java/io/druid/cli/CliHistorical.java

@@ -26,6 +26,7 @@ import com.metamx.common.logger.Logger;
 import io.airlift.command.Command;
 import io.druid.client.cache.Cache;
 import io.druid.client.cache.CacheConfig;
+import io.druid.client.cache.CacheMonitor;
 import io.druid.client.cache.CacheProvider;
 import io.druid.guice.Jerseys;
 import io.druid.guice.JsonConfigProvider;
@@ -38,6 +39,7 @@ import io.druid.server.QueryResource;
 import io.druid.server.coordination.ServerManager;
 import io.druid.server.coordination.ZkCoordinator;
 import io.druid.server.initialization.JettyServerInitializer;
+import io.druid.server.metrics.MetricsModule;
 import org.eclipse.jetty.server.Server;
 
 import java.util.List;
@@ -77,10 +79,11 @@ public class CliHistorical extends ServerRunnable
 
             LifecycleModule.register(binder, ZkCoordinator.class);
             LifecycleModule.register(binder, Server.class);
+
             binder.bind(Cache.class).toProvider(CacheProvider.class).in(ManageLifecycle.class);
             JsonConfigProvider.bind(binder, "druid.historical.cache", CacheProvider.class);
             JsonConfigProvider.bind(binder, "druid.historical.cache", CacheConfig.class);
-
+            MetricsModule.register(binder, CacheMonitor.class);
           }
         }
     );