com.tailf.dp

Class DpNotifStream

Object

Thread

com.tailf.dp.DpNotifStream

All Implemented Interfaces:

Runnable

public class DpNotifStream
extends Thread

The application can generate notifications that are sent via the northbound protocols. Currently NETCONF notification streams are supported. The application generates the content for each notification and sends it via a socket to ConfD/NCS, which in turn manages the stream subscriptions and distributes the notifications accordingly.

A stream always has a "live feed", which is the sequence of new notifications, sent in real time as they are generated. Subscribers may also request "replay" of older, logged notifications if the stream supports this, perhaps transition to the live feed when the end of the log is reached. There may be one or more replays active simultaneously with the live feed. ConfD/NCS forwards replay requests from subscribers to the application via callbacks if the stream supports replay.

Each notification has an associated time stamp, the "event time". This is the time when the event that generated the notification occurred, rather than the time the notification is logged or sent, in case these times differ. The application must pass the event time to ConfD/NCS when sending a notification, and it is also needed when replaying logged events.

This class implements the Notification streams. The purpose of this class to provide a mechanism for sending notifications.

Example: Consider the following yang model of a notification:

  module mynotif {
    namespace "http://tail-f.com/test/mynotif/1.0";
    prefix myn;

    import ietf-yang-types {
      prefix yang;
    }

    notification my_notif {
      leaf arg1 {
        type string;
      }
      leaf arg2 {
        type int64;
      }
    }
  }
 

For a netconf notification stream to be valid it must be defined in the ConfD/NCS config file. For NCS this example needs the following definitions in the config (there are small differences in the tagnames for ConfD)

   <notifications>
     <event-streams>
       <stream>
         <name>mystream</name>
         <description>my test stream</description>
         <replay-support>false</replay-support>
       </stream>
     </event-streams>
   </notifications>
 

If we want to sent a NETCONF notification based on the above model we can do the following:

  // create new control socket
  Socket ctrlSocket = new Socket("127.0.0.1", Conf.PORT);
  // This is the main Data Provider instance. "dp"
  Dp dp = new Dp("hosts_daemon", ctrlSocket);
  mynotif myn = new mynotif();
  // create Dp Notification stream (you may create many)
  DpNotifStream stream = dp.createNotifStream("mystream");
  // send a notification
  ConfXMLParam[] vals =
      new ConfXMLParam[] {
          new ConfXMLParamStart(myn.hash(), mynotif.myn_my_notif),
          new ConfXMLParamValue(myn.hash(), mynotif.myn_arg1,
                                new ConfBuf("Hello")),
          new ConfXMLParamValue(myn.hash(), mynotif.myn_arg2,
                                new ConfInt64(32)),
          new ConfXMLParamStop(myn.hash(), mynotif.myn_my_notif)
      };
  stream.send(ConfDatetime.getConfDatetime(), vals);
 

Nested Class Summary

Nested classes/interfaces inherited from class Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Method Summary

Methods

Modifier and Type	Method and Description
void	flush() Notifications are sent asynchronously, i.e.
Dp	getDp() The Data Provider main class.
int	getFD() file descriptor
int	getQRef() last qref
DpNotifReplayCallback	getReplayCb() The replay callback
Socket	getSocket() The worker socket which is connected to ConfD/NCS.
String	getStreamName()
int	getSubId() last subid.
void	send(ConfDatetime time, ConfXMLParam params) Send a notification on this notification stream to ConfD/NCS.
void	send(ConfDatetime time, ConfXMLParam[] params) Send a notification on this notification stream to ConfD/NCS.
void	setFD(int fd) file descriptor
void	setQRef(int qref) last qref
void	setSocket(Socket socket)
void	setSubId(int subid) last subid.

Methods inherited from class Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, run, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

flush

public void flush()
           throws IOException,
                  ConfException

Notifications are sent asynchronously, i.e. normally without blocking the caller of the send functions described above. This means that in some cases, the servers sending of the notifications on the northbound interfaces may lag behind the send calls. If we want to make sure that the notifications have actually been sent out, e.g. in some shutdown procedure, we can call DpNotifStream.flush(). This function will block until all notifications sent using the given notification stream have been fully processed by the server. It can be used both for notification streams and for SNMP notifications (however it will not wait for replies to SNMP inform-requests to arrive).

Throws:

IOException

ConfException

getDp

public Dp getDp()

The Data Provider main class. provided when registering with a Dp.

getFD

public int getFD()

file descriptor

getQRef

public int getQRef()

last qref

getReplayCb

public DpNotifReplayCallback getReplayCb()

The replay callback

getSocket

public Socket getSocket()

The worker socket which is connected to ConfD/NCS. This socket will be used for sending notifications to ConfD/NCS. Set when allocated by Dp.

getStreamName

public String getStreamName()

getSubId

public int getSubId()

last subid. subid>0 is a replay

send

public void send(ConfDatetime time,
        ConfXMLParam params)
          throws IOException,
                 ConfException

Send a notification on this notification stream to ConfD/NCS.

Parameters:

time - ConfDatetime time to begin replay

params - ConfXMLParam structure of data

Throws:

IOException

ConfException

send

public void send(ConfDatetime time,
        ConfXMLParam[] params)
          throws IOException,
                 ConfException

Send a notification on this notification stream to ConfD/NCS.

Parameters:

time - ConfDatetime time to begin replay

params - ConfXMLParam structure of data

Throws:

IOException

ConfException

setFD

public void setFD(int fd)

file descriptor

setQRef

public void setQRef(int qref)

last qref

setSocket

public void setSocket(Socket socket)

setSubId

public void setSubId(int subid)

last subid. subid>0 is a replay