JMX Monitoring

Java Management Extensions (JMX) is a technology that lets you implement management interfaces for Java applications. JConsole is a JMX-compliant monitoring tool, which comes with the Java Development Kit (JDK) 1.5 or later versions. Therefore, when you use a WSO2 product, JMX is enabled by default, which allows you to monitor the product using JConsole.

Go to the WSO2 Administration Guide for detailed instructions on how to configure JMX for a WSO2 product and how to use JConsole for monitoring a product.

MBeans for WSO2 EI

When JMX is enabled, WSO2 EI exposes a number of management resources as JMX Management Beans (MBeans) that can be used for managing and monitoring the running server. When you start JConsole, you can monitor these MBeans from the MBeans tab. While some of these MBeans (ServerAdmin and DataSource) are common to all WSO2 products, some MBeans are specific to WSO2 EI.

The common MBeans are explained in detail in the WSO2 Administration Guide. Listed below are the MBeans that are specific to WSO2 EI.

For details on using JMX based mediation flow statistics in your EI server and detailed explanation of the relevant MBeans, see Monitoring JMX Based Statistics.

This section summarizes the attributes and operations available for the following WSO2 EI specific MBeans:

Connection MBeans

These MBeans provide connection statistics for the HTTP and HTTPS transports.

You can view the following Connection MBeans:

org.apache.synapse/PassThroughConnections/http-listener
org.apache.synapse/PassThroughConnections/http-sender
org.apache.synapse/PassThroughConnections/https-listener
org.apache.synapse/PassThroughConnections/https-sender

Attributes

Attribute Name	Description
`ActiveConnections`	Number of currently active connections.
`ActiveConnectionsPerHosts`	A map of the number of connections against hosts.
`LastXxxConnections`	The number of connections created during last Xxx time period.
`RequestSizesMap`	A map of the number of requests against their sizes.
`ResponseSizesMap`	A map of the number of responses against their sizes.
`LastResetTime`	The time when the connection-statistic recordings were last reset.

Operations

Operation Name	Description
`reset()`	Clear recorded connection statistics and restart recording.

Latency MBeans

This view provides statistics of the latencies from all backend services connected through the HTTP and HTTPS transports. These statistics are provided as an aggregate value.

You can view the following Latency MBeans:

org.apache.synapse/PassthroughLatencyView/nio-http-http
org.apache.synapse/PassthroughLatencyView/nio-https-https

Attributes

Attribute Name	Description
`AllTimeAvgLatency`	Average latency since the latency recording was last reset.
`LastxxxAvgLatency`	Average latency for last xxx time period. For example, LastHourAvgLatency returns the average latency for the last hour.
`LastResetTime`	The time when the latency-statistic recordings were last reset.

Operations

Operation Name	Description
`reset()`	Clear recorded latency statistics and restart recording.

Threading MBeans

These MBeans are only available in the NHTTP transport and not in the default Pass-Through transport.

You can view the following Threading MBeans:

org.apache.synapse/Threading/HttpClientWorker
org.apache.synapse/Threading/HttpServerWorker

Attributes

Attribute Name	Description
`TotalWorkerCount`	Total worker threads related to this server/client.
`AvgUnblockedWorkerPercentage`	Time-averaged unblocked worker thread percentage.
`AvgBlockedWorkerPercentage`	Time-averaged blocked worker thread percentage.
`LastXxxBlockedWorkerPercentage`	Blocked worker thread percentage averaged for last Xxx time period.
`DeadLockedWorkers`	Number of deadlocked worker threads since last statistics reset.
`LastResetTime`	The time the thread statistic recordings were last reset.

Operations

Operation Name	Description
`reset()`	Clear recorded thread statistic and restart recording.

Transport MBeans

For each transport listener and sender enabled in WSO2 EI, there will be an MBean under the org.apache.axis2/Transport domain. For example, when the JMS transport is enabled, the following MBean will be exposed:

org.apache.axis2/Transport/jms-sender-n

You can also view the following Transport MBeans:

org.apache.synapse/Transport/passthru-http-receiver
org.apache.synapse/Transport/passthru-http-sender
org.apache.synapse/Transport/passthru-https-receiver
org.apache.synapse/Transport/passthru-https-sender

Attributes

Attribute Name	Description
`ActiveThreadCount`	Threads active in this transport listener/sender.
`AvgSizeReceived`	The average size of received messages.
`AvgSizeSent`	The average size of sent messages.
`BytesReceived`	The number of bytes received through this transport.
`BytesSent`	The number of bytes sent through this transport.
`FaultsReceiving`	The number of faults encountered while receiving.
`FaultsSending`	The number of faults encountered while sending.
`LastResetTime`	The time when the last transport listener/sender statistic recording was reset.
`MaxSizeReceived`	Maximum message size of received messages.
`MaxSizeSent`	Maximum message size of sent messages.
`MetricsWindow`	Time difference between current time and last reset time in milliseconds.
`MinSizeReceived`	Minimum message size of received messages.
`MinSizeSent`	Minimum message size of sent messages.
`MessagesReceived`	The total number of messages received through this transport.
`MessagesSent`	The total number of messages sent through this transport.
`QueueSize`	The number of messages currently queued. Messages get queued if all the worker threads in this transport thread pool are busy.
`ResponseCodeTable`	The number of messages sent against their response codes.
`TimeoutsReceiving`	Message receiving timeout.
`TimeoutsSending`	Message sending timeout.

Operations

Operation Name	Description
`start()`	Start this transport listener/sender.
`stop()`	Stop this transport listener/sender.
`resume()`	Resume this transport listener/sender which is currently paused.
`resetStatistics()`	Clear recorded transport listener/sender statistics and restart recording.
`pause()`	Pause this transport listener/sender which has been started.
`maintenenceShutdown(long gracePeriod)`	Stop processing new messages, and wait the specified maximum time for in-flight requests to complete before a controlled shutdown for maintenence.

Broker-specific MBeans

You can also view the following MBeans that are specific to the Brokering profile of WSO2 EI:

org.wso2.andes/ClusterManagementInformation

Attribute Name	Description
`ClusteringEnabled`	If the clustering mode is enabled in the Brokering profile or not.
`AllClusterNodeAddresses`	Retrieve the addresses of the members in a cluster
`MyNodeID`	Retrieve the ID that is assigned to the node
`StoreHealth`	Retrieve the health status of the message store

org.wso2.andes/MessageStatusInformation

Operation Name Description
dumpMessageStatusInfo() Retrieve the lifecycle status of the messages in the store to a specified Excel sheet.

org.wso2.andes/QueueManageInformation Attributes

Attribute Name	Description
`NamesOfAllDurableQueues`	Retrieve the names of all durable queues.
`AllQueueCounts`	Retrieve the number of messages in all the queues of the message store
`AllQueueNames`	Retrieve the names of all the queues in the message store
`MessageCountOfQueuesAsCompositeData`	Retrieve the number of messages that are in the queues as Composite data

Operations

Operation Name	Description
`getMessageCount()`	Get the number of messages in the store
`restoreSelectedMessagesFromDeadLetterChannel()`	Restore the messages you select from the dead letter channel
`rerouteSelectedMessagesFromDeadLetterChannel()`	Reroute the messages you select from the dead letter channel
`deleteMessagesFromDeadLetterQueue()`	Delete the messages you specify, from the dead letter channel
`getNumberOfMessagesInDLCForQueue()`	Retrieve the message count in the dead letter channel of a queue
`getMessagesInDLCForQueue()`	Retrieve the messages in the dead letter channel of a queue
`browseQueue()`	Retrieve information of a queue by browsing it.
`getMessageMetadataInDeadLetterChannel()`	Retrieve metadata of messages in a dead letter channel
`rerouteAllMessagesInDeadLetterChannelForQueue()`	Reroute all the messages in a dead letter channel of a queue
`isQueueExists()`	Check if a queue exists by a given name
`deleteAllMessagesInQueue()`	Delete all the messages in a queue with the specified name
`getDLCQueueInformation()`	Retrieve information of the dead letter channel of a specified queue
`getSubscriptionCount()`	Retrieve the number of subscriptions of a specified queue

org.wso2.andes/Subscription/ManagementInformation

Operation Name	Description
`getMessageCount()`	Retrieve the number of messages of a specified subscription
`getSubscriptions()`	Retrieve all subscriptions
`getFilteredSubscriptions()`	Retrieve only a set of specified subscriptions
`getTotalSubscriptionCountForSearchResult()`	Retrieve the total number of subscriptions for a specified search
`getPendingMessageCount()`	Retrieve the pending number of messages in all subscriptions
`removeSubscription()`	Remove a specified subscription

Disabling the JMX thread view

Dumping JMX threads is an expensive operation that affects the CPU consumption when many threads are being processed at the same time.

WSO2 EI has enabled thread dumping by default. Therefore, to avoid dumping all the threads here, you can configure the property given below.

It is recommended not to dump the thread especially when you have enabled WSO2 EI analytics in a production environment.

Open the <EI_HOME>/synapse.properties file.
Add the following property to the file and save the file.
```
synapse.jmx.thread.view.enabled=false
```