Package com.lightstreamer.jmx

Interface ResourceMBean

public interface ResourceMBean
One ResourceMBean instance exists in the system, to provide information on the activity of the Server. It is created at startup by Lightstreamer Server and lasts until the shutdown of the Server.

ResourceMBean name:
"com.lightstreamer:type=Resource"

  • Method Details

    • getTotalSubscribedItems

      java.lang.Long getTotalSubscribedItems()
      Returns:
      The total number of currently subscribed Items, covering all the Data Adapters from all the Adapter Sets plugged in the Server. The count includes subscriptions needed to accomplish the Push Notification service.

    • getUsernames

      java.lang.Integer getUsernames()
      Returns:
      The number of unique user names of users currently connected to the Server.

    • getUsernameListProtected

      java.util.List<java.lang.String> getUsernameListProtected​(java.lang.Integer max)
      Parameters:
      max - The maximum number of elements to be returned, or null if no limit is requested.
      Returns:
      The list of unique user names of users currently connected to the Server. Expressed as an ArrayList of Strings, where each String contains a user name. Note that null is a possible user name.
      A maximum number of elements to be returned can be set, to protect the client or to get a sample. When the limit is set, the criteria for the determination of the returned elements are left unspecified.

    • getUsernameList

      java.util.List<java.lang.String> getUsernameList()
      Returns:
      The list of unique user names of users currently connected to the Server. Expressed as an ArrayList of Strings, where each String contains a user name. Note that null is a possible user name.
      The property is subject to the <disable_long_list_properties> configuration flag. If leveraged, the returned list will just contain a reminder text.
      See Also:
      getUsernameListProtected(java.lang.Integer)

    • getSessionListForUsername

      java.util.List<java.lang.String> getSessionListForUsername​(java.lang.String username)
      Parameters:
      username - a User name, possibly null.
      Returns:
      The list of current Sessions owned by the specified User. Expressed as an ArrayList of Strings, where each String contains the sessionID of the Session. The list includes "prestarted" sessions.
      See Also:
      getCurrentSessions()

    • getCurrentSessions

      java.lang.Integer getCurrentSessions()
      Returns:
      The number of currently active Sessions. Prestarted Sessions are not considered for this statistics. By prestarted Session we mean a session for which no related requests have been received yet. Binding a session with a new connection also brings it out of the prestarted state.

    • getCurrentPrestartedSessions

      java.lang.Integer getCurrentPrestartedSessions()
      Returns:
      The current number of prestarted Sessions. By prestarted Session we mean a session for which no related requests have been received yet. Binding a session with a new connection also brings it out of the prestarted state.

    • getCurrentPrestartedAverageWaitMillis

      java.lang.Long getCurrentPrestartedAverageWaitMillis()
      Returns:
      The average time the Sessions currently prestarted are in this state. A long average time may signal that many clients are stuck while trying to create sessions.
      See Also:
      getCurrentPrestartedSessions()

    • getCurrentSessionListProtected

      java.util.List<java.lang.String> getCurrentSessionListProtected​(java.lang.Integer max)
      Parameters:
      max - The maximum number of elements to be returned, or null if no limit is requested.
      Returns:
      The list of current Sessions. Expressed as an ArrayList of Strings, where each String contains the sessionID of the Session. The list includes "prestarted" sessions.
      A maximum number of elements to be returned can be set, to protect the client or to get a sample. When the limit is set, the criteria for the determination of the returned elements are left unspecified.
      See Also:
      getCurrentSessions()

    • getCurrentSessionList

      java.util.List<java.lang.String> getCurrentSessionList()
      Returns:
      The list of current Sessions. Expressed as an ArrayList of Strings, where each String contains the sessionID of the Session. The list includes "prestarted" sessions.
      The property is subject to the <disable_long_list_properties> configuration flag. If leveraged, the returned list will just contain a reminder text.
      See Also:
      getCurrentSessionListProtected(java.lang.Integer), getCurrentSessions()

    • getMaxSessions

      java.lang.Integer getMaxSessions()
      Returns:
      The maximum number of concurrent Sessions reached in the life of the Server. "Prestarted" Sessions are not considered.
      See Also:
      getCurrentSessions()

    • getMaxPrestartedSessions

      java.lang.Integer getMaxPrestartedSessions()
      Returns:
      The maximum number of concurrent prestarted Sessions reached in the life of the Server.
      See Also:
      getCurrentPrestartedSessions()

    • getCumulStartedSessions

      java.lang.Long getCumulStartedSessions()
      Returns:
      The total (cumulative) number of Sessions started in the life of the Server. Sessions still in "prestarted" state and sessions closed while still in "prestarted" state are not considered.
      See Also:
      getCurrentSessions()

    • getCumulTerminatedSessions

      java.lang.Long getCumulTerminatedSessions()
      Returns:
      The total (cumulative) number of Sessions terminated in the life of the Server. Sessions closed while still in "prestarted" state are not considered.
      See Also:
      getCurrentSessions(), getCumulSessionCloseCauses(String)

    • getCumulSessionCloseCauses

      java.util.Map<java.lang.String,​java.lang.Long> getCumulSessionCloseCauses​(java.lang.String placeholder)
      Parameters:
      placeholder - Dummy argument that turns the property into an operation and prevents JMX clients from computing the result in a non-interacting way. It can be left null.
      Returns:
      A Map which associates all different causes of session termination to the number of occurrences of such terminations in the life of the Server. The possible causes are freely determined internally and are represented by a textual description. Causes with no occurrences are not reported.

    • getNewStartedSessions

      java.lang.Integer getNewStartedSessions()
      Returns:
      The number of Sessions started in the last sampling period. Sessions still in "prestarted" state and sessions closed while still in "prestarted" state are not considered.
      See Also:
      getCurrentSessions()

    • getNewTerminatedSessions

      java.lang.Integer getNewTerminatedSessions()
      Returns:
      The number of Sessions terminated in the last sampling period. Sessions closed while still in "prestarted" state are not considered.
      See Also:
      getCurrentSessions(), getNewSessionCloseCauses(String)

    • getNewSessionCloseCauses

      java.util.Map<java.lang.String,​java.lang.Long> getNewSessionCloseCauses​(java.lang.String placeholder)
      Parameters:
      placeholder - Dummy argument that turns the property into an operation and prevents JMX clients from computing the result in a non-interacting way. It can be left null.
      Returns:
      A Map which associates all different causes of session termination to the number of occurrences of such terminations in the last sampling period. The possible causes are freely determined internally and are represented by a textual description. Causes with no occurrences are not reported.

    • destroySession

      java.lang.Boolean destroySession​(java.lang.String sessionId)
      Destroys a Session for a specified ID, if currently active.
      Parameters:
      sessionId - a session ID.
      Returns:
      True if operation succeeded. False if operation failed.

    • getCurrentWSSessions

      java.lang.Integer getCurrentWSSessions()
      Returns:
      The number of current Sessions that are working through a WebSocket connection. Note that a Session can switch between HTTP and WebSocket during its life. "Prestarted" Sessions are not considered.

    • getMaxWSSessions

      java.lang.Integer getMaxWSSessions()
      Returns:
      The maximum number of concurrent Sessions working through a WebSocket connection reached in the life of the Server. "Prestarted" Sessions are not considered.

    • getCurrentHTTPSessions

      java.lang.Integer getCurrentHTTPSessions()
      Returns:
      The number of current Sessions that are working through HTTP streaming or polling. Note that a Session can switch between HTTP and WebSocket during its life. "Prestarted" Sessions are not considered.

    • getMaxHTTPSessions

      java.lang.Integer getMaxHTTPSessions()
      Returns:
      The maximum number of concurrent Sessions working through HTTP streaming or polling reached in the life of the Server. "Prestarted" Sessions are not considered.

    • getCurrentStreamingSessions

      java.lang.Integer getCurrentStreamingSessions()
      Returns:
      The number of current Sessions that are working in Streaming. "Prestarted" Sessions are not considered.

    • getMaxStreamingSessions

      java.lang.Integer getMaxStreamingSessions()
      Returns:
      The maximum number of concurrent Sessions working in Streaming reached in the life of the Server. "Prestarted" Sessions are not considered.

    • getCumulStreamingRequests

      java.lang.Long getCumulStreamingRequests()
      Returns:
      The total (cumulative) number of Requests for Streaming data received in the life of the Server. Note that multiple subsequent Requests for Streaming data are possible throughout the life of a single Session.

    • getCumulStreamingResponses

      java.lang.Long getCumulStreamingResponses()
      Returns:
      The total (cumulative) number of Requests for Streaming data fully accomplished in the life of the Server. Note that multiple subsequent Requests for Streaming data are possible throughout the life of a single Session.

    • getCumulRequestsFailed

      java.lang.Long getCumulRequestsFailed()
      Returns:
      The total (cumulative) number of Requests of any type that have failed in the life of the Server. It comprises Streaming, Polling, Control and Web Server requests. See getNewControlRequests() for details on how Control Requests are counted.
      Note that the concept of failed request is not a strict one; a few main considerations have to be taken into account:
      • If multiple subrequests of a single Control Request are counted and a severe error occurs in the processing which causes a single error message for the whole Request to be reported to the client, then all subrequests will be considered as failed, regardless of their real outcome.
      • Streaming and Polling requests are never counted as failed after the data collection phase has started.
      • Exceptions received from the Data Adapter in subscription and unsubscription operations are not reported to the clients and they are not considered as causing requests to fail.
      • In case of requests for asynchronous message submission, exceptions received from the Metadata Adapter upon submission are not considered as causing requests to fail.

    • getCumulRequestsRefused

      java.lang.Long getCumulRequestsRefused()
      Returns:
      The total (cumulative) number of Requests that have been refused in the life of the Server. Specifically, it applies to Requests for opening new Sessions that have been refused because of load limits, including thread pool queue limits.

    • getNewRequestsFailed

      java.lang.Integer getNewRequestsFailed()
      Returns:
      The number of Requests of any type that have failed in the last sampling period. It comprises Streaming, Polling, Control and Web Server requests. See getCumulRequestsFailed() for remarks on the identification of failed requests.

    • getNewRequestsRefused

      java.lang.Integer getNewRequestsRefused()
      Returns:
      The number of Requests that have been refused in the last sampling period. Specifically, it applies to Requests for opening new Sessions that have been refused because of load limits, including thread pool queue limits.

    • getNewStreamingRequests

      java.lang.Integer getNewStreamingRequests()
      Returns:
      The number of Requests for Streaming data opened in the last sampling period. Note that multiple subsequent Requests for Streaming data are possible throughout the life of a single Session.

    • getNewStreamingResponses

      java.lang.Integer getNewStreamingResponses()
      Returns:
      The number of Requests for Streaming data fully accomplished and completed in the last sampling period. Note that multiple subsequent Requests for Streaming data are possible throughout the life of a single Session.

    • getCurrentPollingSessions

      java.lang.Integer getCurrentPollingSessions()
      Returns:
      The number of current Sessions that are working in Polling. Note that Streaming Sessions may, in their initial phase, act as Polling Sessions; in that case, they may be temporarily included in this count. "Prestarted" Sessions are not considered.
      See Also:
      getCurrentSessions()

    • getMaxPollingSessions

      java.lang.Integer getMaxPollingSessions()
      Returns:
      The maximum number of concurrent Sessions working in Polling reached in the life of the Server. Note that Streaming Sessions may, in their initial phase, act as Polling Sessions; in that case, they may be temporarily included in this count. "Prestarted" Sessions are not considered.
      See Also:
      getCurrentSessions()

    • getCumulPollingRequests

      java.lang.Long getCumulPollingRequests()
      Returns:
      The total (cumulative) number of Requests for single polls received in the life of the Server.

    • getCumulPollingResponses

      java.lang.Long getCumulPollingResponses()
      Returns:
      The total (cumulative) number of Requests for single polls accomplished in the life of the Server.

    • getNewPollingRequests

      java.lang.Integer getNewPollingRequests()
      Returns:
      The number of Requests for single polls received in the last sampling period.

    • getNewPollingResponses

      java.lang.Integer getNewPollingResponses()
      Returns:
      The number of Requests for single polls accomplished and completed in the last sampling period.

    • getCumulControlResponses

      java.lang.Long getCumulControlResponses()
      Returns:
      The total (cumulative) number of Control Requests accomplished in the life of the Server. See the text protocol documentation for a resume of the possible Control Requests. See getNewControlRequests() for details on how Control Requests are counted.

    • getNewControlRequests

      java.lang.Integer getNewControlRequests()
      Returns:
      The number of Control Requests received in the last sampling period. See the text protocol documentation for a resume of the possible Control Requests.
      Note that single Control Requests may contain multiple subrequests; in this case, each subrequest is counted separately, unless the processing fails before the full interpretation of the Request.

    • getNewControlResponses

      java.lang.Integer getNewControlResponses()
      Returns:
      The number of Control Requests accomplished and completed in the last sampling period. See the text protocol documentation for a resume of the possible Control Requests. See getNewControlRequests() for details on how Control Requests are counted.

    • getCumulPageResponses

      java.lang.Long getCumulPageResponses()
      Returns:
      The total (cumulative) number of Requests to be managed by the Internal Web Server accomplished in the life of the Server. The Internal Web Server should not be enabled in a production scenario; even in that case, some special requests related with the push activity are still accomplished by the Internal Web Server.

    • getNewPageRequests

      java.lang.Integer getNewPageRequests()
      Returns:
      The number of Requests to be managed by the Internal Web Server received in the last sampling period. The Internal Web Server should not be enabled in a production scenario; even in that case, some special requests related with the push activity are still accomplished by the Internal Web Server.

    • getNewPageResponses

      java.lang.Integer getNewPageResponses()
      Returns:
      The number of Requests to be managed by the Internal Web Server accomplished and completed in the last sampling period. The Internal Web Server should not be enabled in a production scenario; even in that case, some special requests related with the push activity are still accomplished by the Internal Web Server.

    • getCumulUnrecognizedRequests

      java.lang.Long getCumulUnrecognizedRequests()
      Returns:
      The total (cumulative) number of Requests that could not be understood managed in the life of the Server.

    • getNewUnrecognizedRequests

      java.lang.Integer getNewUnrecognizedRequests()
      Returns:
      The number of Requests that could not be understood managed in the last sampling period.

    • getCumulResponses

      java.lang.Long getCumulResponses()
      Returns:
      The total (cumulative) number of Requests accomplished in the life of the Server. It comprises Streaming, Polling, Control, Web Server and unrecognized requests. It also includes any client reverse heartbeats received. See getNewControlRequests() for details on how Control Requests are counted.

    • getNewRequests

      java.lang.Integer getNewRequests()
      Returns:
      The number of Requests received in the last sampling period. It comprises Streaming, Polling, Control, Web Server and unrecognized requests. It also includes any client reverse heartbeats received. See getNewControlRequests() for details on how Control Requests are counted.

    • getNewResponses

      java.lang.Integer getNewResponses()
      Returns:
      The number of Requests accomplished and completed in the last sampling period. It comprises Streaming, Polling, Control, Web Server and unrecognized requests. It also includes any client reverse heartbeats received. See getNewControlRequests() for details on how Control Requests are counted.

    • getCurrentSockets

      java.lang.Integer getCurrentSockets()
      Returns:
      The number of currently connected sockets, which may carry any kind of Request. Sockets currently idle or performing a TLS/SSL initial handshake are also included in this count (see getCurrentIdleSockets() and getCurrentHandshakingSockets()).

    • getCurrentHTTPSockets

      java.lang.Integer getCurrentHTTPSockets()
      Returns:
      The number of currently connected sockets, which may carry any kind of Request, used for normal HTTP interaction. Note that, when socket reuse is possible, multiple subsequent requests may be carried by a single socket connection; connections left in an idle state by the client, waiting for a possible reuse, are also included in this count. On the other hand, when the HTTP interaction is upgraded to the WebSocket protocol, the socket is no longer included in this count (see getCurrentWSSockets()).

    • getCurrentHTTPSSockets

      java.lang.Integer getCurrentHTTPSSockets()
      Returns:
      The number of currently connected sockets, which may carry any kind of Request, used for HTTP over TLS/SSL interaction. Note that, when socket reuse is possible, multiple subsequent requests may be carried by a single socket connection; connections left in an idle state by the client, waiting for a possible reuse, are also included in this count. On the other hand, when the HTTP interaction is upgraded to the WebSocket protocol, the socket is no longer included in this count (see getCurrentWSSSockets()).
      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.

    • getCurrentWSSockets

      java.lang.Integer getCurrentWSSockets()
      Returns:
      The number of currently connected sockets managed through the normal WebSocket protocol. Note that WebSocket connections may be used by the clients to issue one or multiple requests concurrently, or may also be kept idle for some time; a WebSocket connection is included in this count regardless of the current state of activity.

    • getCurrentWSSSockets

      java.lang.Integer getCurrentWSSSockets()
      Returns:
      The number of currently connected sockets managed through the WebSocket protocol over TLS/SSL. Note that WebSocket connections may be used by the clients to issue one or multiple requests concurrently, or may also be kept idle for some time; a WebSocket connection is included in this count regardless of the current state of activity.
      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.

    • getCurrentIdleSockets

      java.lang.Integer getCurrentIdleSockets()
      Returns:
      The number of currently connected sockets that are being left in an idle state by the client, waiting for a possible reuse. The count includes WebSocket connections for which no request is currently in process.

    • getCurrentHandshakingSockets

      java.lang.Integer getCurrentHandshakingSockets()
      Returns:
      The number of currently connected sockets that are performing a TLS/SSL handshake, in order to initiate an HTTP over TLS/SSL interaction.
      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.

    • getMaxSockets

      java.lang.Integer getMaxSockets()
      Returns:
      The maximum number of concurrent connected sockets, which may have carried any kind of Request, reached in the life of the Server. See getCurrentSockets().

    • getMaxHTTPSockets

      java.lang.Integer getMaxHTTPSockets()
      Returns:
      The maximum number of concurrent connected sockets, which may have carried any kind of Request, used for normal HTTP interaction, reached in the life of the Server. See getCurrentHTTPSockets().

    • getMaxHTTPSSockets

      java.lang.Integer getMaxHTTPSSockets()
      Returns:
      The maximum number of concurrent connected sockets, which may have carried any kind of Request, used for HTTP over TLS/SSL interaction, reached in the life of the Server. See getCurrentHTTPSSockets().
      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.

    • getMaxWSSockets

      java.lang.Integer getMaxWSSockets()
      Returns:
      The maximum number of concurrent connected sockets, managed through the normal WebSocket protocol, reached in the life of the Server. See getCurrentWSSockets().

    • getMaxWSSSockets

      java.lang.Integer getMaxWSSSockets()
      Returns:
      The maximum number of concurrent connected sockets, managed through the WebSocket protocol over TLS/SSL, reached in the life of the Server. See getCurrentWSSSockets().
      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.

    • getMaxIdleSockets

      java.lang.Integer getMaxIdleSockets()
      Returns:
      The maximum number of concurrent connected sockets that have been left in an idle state by the client, waiting for a possible reuse. See getCurrentIdleSockets().

    • getMaxHandshakingSockets

      java.lang.Integer getMaxHandshakingSockets()
      Returns:
      The maximum number of concurrent connected sockets performing a TLS/SSL handshake. See getCurrentHandshakingSockets().
      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.

    • getCumulConnections

      java.lang.Long getCumulConnections()
      Returns:
      The total (cumulative) number of socket connections performed in the life of the Server.

    • getCumulHTTPConnections

      java.lang.Long getCumulHTTPConnections()
      Returns:
      The total (cumulative) number of socket connections performed in the life of the Server, used for normal HTTP interaction or for upgrade to the WebSocket protocol.

    • getCumulHTTPSConnections

      java.lang.Long getCumulHTTPSConnections()
      Returns:
      The total (cumulative) number of socket connections performed in the life of the Server, used for HTTP over TLS/SSL interaction or for upgrade to the WebSocket protocol over TLS/SSL.
      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.

    • getCumulWSUpgrades

      java.lang.Long getCumulWSUpgrades()
      Returns:
      The total (cumulative) number of socket connections upgraded from HTTP to the WebSocket protocol in the life of the Server.

    • getCumulWSSUpgrades

      java.lang.Long getCumulWSSUpgrades()
      Returns:
      The total (cumulative) number of socket connections upgraded from HTTP over TLS/SSL to the WebSocket protocol over TLS/SSL in the life of the Server.
      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.

    • getCumulDisconnections

      java.lang.Long getCumulDisconnections()
      Returns:
      The total (cumulative) number of socket connections completed in the life of the Server.
      See Also:
      getCumulConnecionCloseCauses(String)

    • getCumulConnecionCloseCauses

      java.util.Map<java.lang.String,​java.lang.Long> getCumulConnecionCloseCauses​(java.lang.String placeholder)
      Parameters:
      placeholder - Dummy argument that turns the property into an operation and prevents JMX clients from computing the result in a non-interacting way. It can be left null.
      Returns:
      A Map which associates all different causes of connection termination to the number of occurrences of such terminations in the life of the Server. The possible causes are freely determined internally and are represented by a textual description. Causes with no occurrences are not reported.

    • getCumulHandshakesFailed

      java.lang.Long getCumulHandshakesFailed()
      Returns:
      The total (cumulative) number of socket connections terminated because of an interrupted or failed TLS/SSL handshake.
      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.

    • getNewConnections

      java.lang.Integer getNewConnections()
      Returns:
      The number of socket connections opened in the last sampling period. They may be carrying any kind of Request, including wrong ones.

    • getNewDisconnections

      java.lang.Integer getNewDisconnections()
      Returns:
      The number of socket connections closed in the last sampling period. They may have carried any kind of Request, including wrong ones.
      See Also:
      getNewConnecionCloseCauses(String)

    • getNewConnecionCloseCauses

      java.util.Map<java.lang.String,​java.lang.Long> getNewConnecionCloseCauses​(java.lang.String placeholder)
      Parameters:
      placeholder - Dummy argument that turns the property into an operation and prevents JMX clients from computing the result in a non-interacting way. It can be left null.
      Returns:
      A Map which associates all different causes of connection termination to the number of occurrences of such terminations in the last sampling period. The possible causes are freely determined internally and are represented by a textual description. Causes with no occurrences are not reported.

    • getNewHandshakesFailed

      java.lang.Integer getNewHandshakesFailed()
      Returns:
      The number of socket connections terminated in the last sampling period because of an interrupted or failed TLS/SSL handshake.
      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.

    • getCurrentItemSubscriptions

      java.lang.Integer getCurrentItemSubscriptions()
      Returns:
      The current number of subscriptions currently active for some client. Different subscriptions to the same Item performed by different clients (or even the same client) are reported multiple times in the count. The count includes subscriptions needed to accomplish the Push Notification service.

    • getMaxItemSubscriptions

      java.lang.Integer getMaxItemSubscriptions()
      Returns:
      The maximum number of subscriptions concurrently active reached in the life of the Server. See getCurrentItemSubscriptions().

    • getNewItemSubscriptions

      java.lang.Integer getNewItemSubscriptions()
      Returns:
      The number of subscriptions performed by the clients in the last sampling period. See getCurrentItemSubscriptions().

    • getNewItemUnsubscriptions

      java.lang.Integer getNewItemUnsubscriptions()
      Returns:
      The number of unsubscriptions performed by some client in the last sampling period; this includes unsubscriptions due to session closure. See getCurrentItemSubscriptions().

    • getCurrClientVersions

      java.util.Map<java.lang.String,​java.lang.Long> getCurrClientVersions​(java.lang.String placeholder)
      Parameters:
      placeholder - Dummy argument that turns the property into an operation and prevents JMX clients from computing the result in a non-interacting way. It can be left null.
      Returns:
      A Map which associates all different types of clients involved in the currently active sessions to the number of occurrences of such types. The types of clients are determined by the type of client API and by the signature, including version and build number, of the client API. For some old clients, all or some of these pieces of information may not be available. Client types currently with no occurrences are not reported.
      See Also:
      SessionMBean.getClientType(), SessionMBean.getClientVersion()