LoadMBean (Lightstreamer JMX MBeans 5.8.1)

```
public interface LoadMBean
```
One LoadMBean instance exists in the system, to provide information related to the Server load. It is created at startup by Lightstreamer Server and lasts until the shutdown of the Server.

The main services provided by this MBean are:
- A getThreadPools() method that lists all the thread pools in use; these pools are used to perform most of the internal work.
- Aggregated information on the current usage state of the threads in the various pools (like getTotalPooledThreads() and getActivePooledThreads()).
- Aggregated information on the tasks pending on the various thread pools (like getTotalPoolQueue() and getAveragePoolQueueWait()).
- Report of the number of tasks pending on the various thread pools (like getQueueStageHTTPAccept() and getQueueStagePump()).
  Note that these properties cover all pools, although some optional subpools are also reported by other specialized MBeans.
- Information on the NIO selectors in use and on the writing tasks currently blocked on selectors (like getTotalNIOSelectors() and getCurrentNIOWriteQueueWait()).
- Some internal statistics on delays experienced by internal operations (like getExtraSleepMillis()).
- Some utility operations to configure JVM flags that governs JVM's own thread statistics (like enableThreadInspection()).
LoadMBean name:
"com.lightstreamer:type=Load"

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`disableThreadInspection()` Resets the JVM flags which enable the JVM's computation of usage statistics on the threads.
`void`	`enableThreadInspection()` Tries to set the JVM flags which enable the JVM's computation of usage statistics on the threads.
`java.lang.Integer`	`getActiveNIOWriteSelectors()`
`java.lang.Integer`	`getActivePooledThreads()`
`java.lang.Integer`	`getAveragePoolQueueWait()`
`java.lang.Integer`	`getCurrentNIOWriteQueue()`
`java.lang.Long`	`getCurrentNIOWriteQueueWait()`
`java.lang.Integer`	`getDelayMillis()`
`java.lang.Integer`	`getExtraSleepMillis()`
`java.lang.Integer`	`getExtraWaitMillis()`
`java.lang.Integer`	`getQueueStageEvents()`
`java.lang.Integer`	`getQueueStageHandshake()`
`java.lang.Integer`	`getQueueStageHTTPAccept()`
`java.lang.Integer`	`getQueueStageMPNExecutor()`
`java.lang.Integer`	`getQueueStageMPNNotifier()`
`java.lang.Integer`	`getQueueStagePump()`
`java.lang.Integer`	`getQueueStageSnapshot()`
`java.util.List<java.lang.String>`	`getThreadPools()`
`java.lang.Integer`	`getTotalJVMThreads()`
`java.lang.Integer`	`getTotalNIOSelectors()`
`java.lang.Integer`	`getTotalPooledThreads()`
`java.lang.Integer`	`getTotalPoolQueue()`
`java.lang.Integer`	`getWaitingPooledThreads()`

- Method Detail
  - getTotalJVMThreads
```
java.lang.Integer getTotalJVMThreads()
```
    Returns:
    
    The total number of threads in the Java virtual machine.
  - getTotalPooledThreads
```
java.lang.Integer getTotalPooledThreads()
```
    Returns:
    
    The global number of threads belonging to one of the thread pools used by Lightstreamer Server to manage the various processing stages. This value is the sum of getActivePooledThreads and getWaitingPooledThreads, but for possible further threads currently in a transition phase.
  - getActivePooledThreads
```
java.lang.Integer getActivePooledThreads()
```
    Returns:
    
    The total number of threads belonging to one of the thread pools used by Lightstreamer Server which are currently executing a task.
  - getWaitingPooledThreads
```
java.lang.Integer getWaitingPooledThreads()
```
    Returns:
    
    The total number of threads belonging to one of the thread pools used by Lightstreamer Server which are currently unused and waiting for a new task to be enqueued.
  - getQueueStageSnapshot
```
java.lang.Integer getQueueStageSnapshot()
```
    Returns:
    
    The length of the queue of the tasks waiting to be processed by the "SNAPSHOT" thread pool. This pool manages the dispatching of snapshot related events to the sessions which issued a snapshot request.
  - getQueueStageEvents
```
java.lang.Integer getQueueStageEvents()
```
    Returns:
    
    The length of the queue of the tasks waiting to be processed by the "EVENTS" thread pool. This pool manages the dispatching of each new update event to all sessions in which the involved item was subscribed to.
  - getQueueStagePump
```
java.lang.Integer getQueueStagePump()
```
    Returns:
    
    The length of the queue of the tasks waiting to be processed by the "PUMP" thread pool. This pool manages the collection of all available updates for a session into a packet to be sent to the client.
  - getQueueStageHTTPAccept
```
java.lang.Integer getQueueStageHTTPAccept()
```
    Returns:
    
    The length of the queue of the tasks waiting to be processed by the "ACCEPT" and "SERVER" thread pools or any of the optional thread pools that can be defined to override the latter for specific subsets of tasks. These pools manage reading and processing incoming client requests (this includes all kinds of client requests).
  - getQueueStageHandshake
```
java.lang.Integer getQueueStageHandshake()
```
    Returns:
    
    The length of the queue of the tasks waiting to be processed by the "TLS-SSL HANDSHAKE" and "TLS-SSL AUTHENTICATION" thread pools. These pools manage the operations needed to accomplish all TLS/SSL handshakes, on connections to ports listening in https.
    
    Edition Note:
    
    TLS/SSL is an optional feature, available depending on Edition and License Type. To know what features are enabled by your license, please check out the com.lightstreamer.Edition bean.
  - getQueueStageMPNExecutor
```
java.lang.Integer getQueueStageMPNExecutor()
```
    Returns:
    
    The length of the queue of the tasks waiting to be processed by the "MPN EXECUTOR" and "MPN TAKEOVER AND ADOPTION" thread pools. These pools manages the external database that maintains the state of the Push Notification service.
    
    Edition Note:
    
    MPN is an optional feature, available depending on Edition and License Type. To know what features are enabled by your license, please check out the com.lightstreamer.Edition bean.
  - getQueueStageMPNNotifier
```
java.lang.Integer getQueueStageMPNNotifier()
```
    Returns:
    
    The length of the queue of the tasks waiting to be processed by the various "MPN XXX YYYYYYYYY" thread pools, where XXX represents any supported external Push Notifications service. These pools manage the submission of the Push Notifications to the external services.
    
    Edition Note:
    
    MPN is an optional feature, available depending on Edition and License Type. To know what features are enabled by your license, please check out the com.lightstreamer.Edition bean.
  - getTotalPoolQueue
```
java.lang.Integer getTotalPoolQueue()
```
    Returns:
    
    The total number of queued tasks, waiting to be processed by any of the thread pools used by Lightstreamer Server.
    Note that the AUTHENTICATION and MSG pools are always defined and are used to invoke callbacks that are expected to behave asynchronously. For this reason, the queue count reported for these pools includes the requests currently in asynchronous execution on the Metadata Adapter.
    
    See Also:
    
    ThreadPoolMBean.getQueue(), ThreadPoolMBean.getPendingAsyncTasks()
  - getAveragePoolQueueWait
```
java.lang.Integer getAveragePoolQueueWait()
```
    Returns:
    
    The average waiting time in milliseconds experienced by the tasks whose processing by any of the thread pools used by Lightstreamer Server started in the last sampling period. A large or constantly increasing value may signal that some thread pool has all the available threads blocked.
  - getThreadPools
```
java.util.List<java.lang.String> getThreadPools()
```
    Returns:
    
    A list with the internal names of all the thread pools currently used by the Server. The internal names are consistent with the pool names as expressed in the various configuration instructions. The names can be used to address the related ThreadPoolMBean's.
  - getCurrentNIOWriteQueue
```
java.lang.Integer getCurrentNIOWriteQueue()
```
    Returns:
    
    The number of socket write operations currently waiting to be selected by the NIO selector. A steadily nonzero value may signal that some clients are not dequeueing the updates properly, unless the average wait times are very small.
  - getCurrentNIOWriteQueueWait
```
java.lang.Long getCurrentNIOWriteQueueWait()
```
    Returns:
    
    The waiting time in milliseconds averaged over all the socket write operations currently waiting to be selected by the NIO selector. A large or constantly increasing value may signal that some clients are not dequeueing the updates properly.
  - getActiveNIOWriteSelectors
```
java.lang.Integer getActiveNIOWriteSelectors()
```
    Returns:
    
    The number of NIO selectors currently used to handle socket write operations. The minimum number is determined by the Server. Temporary selectors can be added if a maximum number of tasks per selector is configured. In this case, it is also possible that the overall count of threads associated to different write-related selectors is higher than the count of the currently active ones.
  - getTotalNIOSelectors
```
java.lang.Integer getTotalNIOSelectors()
```
    Returns:
    
    The number of NIO selectors currently used to handle all possible socket operations. The minimum number for each operation type is determined by the Server. Temporary selectors can be added if a maximum number of tasks per selector is configured.
  - getExtraSleepMillis
```
java.lang.Integer getExtraSleepMillis()
```
    Returns:
    
    The average extra-time experienced for sleep() system calls. It is expected that the difference between the expected time and the observed time increases when the available CPU decreases, though significant delays with plenty of CPU available have sometimes been observed.
  - getExtraWaitMillis
```
java.lang.Integer getExtraWaitMillis()
```
    Returns:
    
    The average time experienced between a notify() system call and the exit from the related wait() in a producer/consumer interaction. It is expected that this time difference increases when the available CPU decreases, though significant time differences with plenty of CPU available have sometimes been observed.
  - getDelayMillis
```
java.lang.Integer getDelayMillis()
```
    Returns:
    
    A very heuristic indicator of how thread context switches are slow, due to high load. It is based on an exponentially weighted moving average of the most recent internal delays observed. The same samples used for getExtraSleepMillis and getExtraWaitMillis are used.
  - enableThreadInspection
```
void enableThreadInspection()
```
    Tries to set the JVM flags which enable the JVM's computation of usage statistics on the threads. This is necessary to enable the collection of these statistics on the thread pools (see ThreadPoolMBean.getAvgBlocksCount(), ThreadPoolMBean.getAvgBlockedTime(), and ThreadPoolMBean.getAvgCPUTime()).
    Note that these are global JVM flags, that are used and managed by the JVM's ThreadMXBean (namely, via "setThreadContentionMonitoringEnabled" and "setThreadCpuTimeEnabled"), hence changing them also affects the overall JVM behavior and the ThreadMXBean in particular; likewise, changing them via the ThreadMXBean is equivalent to doing that here.
    Also note that the specific JVM may not support the computation of these statistics, hence the statistics on the thread pools may remain disabled.
  - disableThreadInspection
```
void disableThreadInspection()
```
    Resets the JVM flags which enable the JVM's computation of usage statistics on the threads. See enableThreadInspection().
    Note that, by the JVM default, these flags are initially disabled.

Interface LoadMBean

Method Summary

Method Detail

getTotalJVMThreads

getTotalPooledThreads

getActivePooledThreads

getWaitingPooledThreads

getQueueStageSnapshot

getQueueStageEvents

getQueueStagePump

getQueueStageHTTPAccept

getQueueStageHandshake

getQueueStageMPNExecutor

getQueueStageMPNNotifier

getTotalPoolQueue

getAveragePoolQueueWait

getThreadPools

getCurrentNIOWriteQueue

getCurrentNIOWriteQueueWait

getActiveNIOWriteSelectors

getTotalNIOSelectors

getExtraSleepMillis

getExtraWaitMillis

getDelayMillis

enableThreadInspection

disableThreadInspection